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Review

TRPV1: A Common Denominator Mediating Antinociceptive and Antiemetic Effects of Cannabinoids

by
Kathleen Louis-Gray
1,
Srinivasan Tupal
2 and
Louis S. Premkumar
2,*
1
Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
2
Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL 62794, USA
*
Author to whom correspondence should be addressed.
Int. J. Mol. Sci. 2022, 23(17), 10016; https://doi.org/10.3390/ijms231710016
Submission received: 8 August 2022 / Revised: 26 August 2022 / Accepted: 29 August 2022 / Published: 2 September 2022
(This article belongs to the Special Issue TRP Channel)

Abstract

:
The most common medicinal claims for cannabis are relief from chronic pain, stimulation of appetite, and as an antiemetic. However, the mechanisms by which cannabis reduces pain and prevents nausea and vomiting are not fully understood. Among more than 450 constituents in cannabis, the most abundant cannabinoids are Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD). Cannabinoids either directly or indirectly modulate ion channel function. Transient receptor potential vanilloid 1 (TRPV1) is an ion channel responsible for mediating several modalities of pain, and it is expressed in both the peripheral and the central pain pathways. Activation of TRPV1 in sensory neurons mediates nociception in the ascending pain pathway, while activation of TRPV1 in the central descending pain pathway, which involves the rostral ventral medulla (RVM) and the periaqueductal gray (PAG), mediates antinociception. TRPV1 channels are thought to be implicated in neuropathic/spontaneous pain perception in the setting of impaired descending antinociceptive control. Activation of TRPV1 also can cause the release of calcitonin gene-related peptide (CGRP) and other neuropeptides/neurotransmitters from the peripheral and central nerve terminals, including the vagal nerve terminal innervating the gut that forms central synapses at the nucleus tractus solitarius (NTS). One of the adverse effects of chronic cannabis use is the paradoxical cannabis-induced hyperemesis syndrome (HES), which is becoming more common, perhaps due to the wider availability of cannabis-containing products and the chronic use of products containing higher levels of cannabinoids. Although, the mechanism of HES is unknown, the effective treatment options include hot-water hydrotherapy and the topical application of capsaicin, both activate TRPV1 channels and may involve the vagal-NTS and area postrema (AP) nausea and vomiting pathway. In this review, we will delineate the activation of TRPV1 by cannabinoids and their role in the antinociceptive/nociceptive and antiemetic/emetic effects involving the peripheral, spinal, and supraspinal structures.

1. Introduction

The effects of cannabis have been known since 2737 BC, when the Chinese emperor, Shen-Nung, used it to treat symptoms associated with gout. Since then, there have been many claims of the beneficial effects of cannabis, while at the same time, studies have raised skepticism regarding its usefulness as an antinociceptive and antiemetic agent [1,2]. In this review, we will focus on the transient receptor potential vanilloid 1 (TRPV1) ion channel and its interactions with cannabinoids.
Marijuana (cannabis) refers to both the whole marijuana plant as well as a raw, unprocessed preparation. Often, the term “medical marijuana” is used, but these preparations are not actually approved by the FDA as medicines. The identified phytochemicals are called cannabinoids. Although there are more than 450 phytochemicals in this plant, the major components are Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) in the Cannabis sativa species, and the hemp plant also has high concentrations of CBD [3,4].
Cannabis has been used for centuries for recreational purposes because of its psychoactive properties. It has been well-characterized that THC exerts its effects on specific receptors, which have been identified as cannabinoid receptor 1 (CBR1) and cannabinoid receptor 2 (CBR2). CBR1 is distributed in the peripheral and central nervous systems, and the central CBR1 mediates the psychoactive effects of THC. The effects of CBR1 are mediated by G-protein-coupled receptor pathways [5,6,7]. Meanwhile, CBR2 is primarily expressed in the immune system and the nervous system and it modulates responses via G-protein-coupled receptors as well [5,6,7].
CBD has no psychoactive properties and has been utilized in the treatment of certain childhood epilepsies [8,9]. Unlike THC, a specific receptor for CBD has not been identified, but there are studies showing that it interacts with TRPV1 to exert some of its effects [10,11,12]. The FDA has also approved a CBD-based liquid medication, Epidiolex (cannabidiol), which has been used for the treatment of two forms of severe childhood epilepsy, Dravet syndrome and Lennox-Gastaut syndrome [13]. This effect is specific to formulations containing higher amounts of CBD. It appears that CBD reduces both the frequency and the severity of the episodes. There is evidence that TRPV1 may be involved in febrile epilepsy [14].
TRPV1, a nonselective cation channel with a high Ca2+ permeability is expressed in the small-diameter sensory neurons and supraspinally in the central descending pain pathways that regulate nociception [15,16,17,18,19,20,21,22]. In fact, activation of TRPV1 in the ascending pain pathway mediates nociception, whereas activation of TRPV1 in the descending pain pathway mediates antinociception.
Several transient receptor potential (TRP) channels have been cloned and characterized. There are 6 families of TRP channels: TRP Vanilloid 1–4 (TRPV1–4), TRP Canonical (TRPC), TRP Melastatin (TRPM8), TRP Ankyrin (TRPA), TRP Polycystin (TRPP), and TRP Mucolipin (TRPML) [23,24,25]. TRPV1 channels are activated by phytochemicals, such as capsaicin, an ingredient in hot chili peppers (Capsicum annuum or frutescens), and by resiniferatoxin (RTX), which can activate TRPV1, which is obtained from a spurge (Euphorbia resinifera/poissonii) [15,16,26,27,28]. Interestingly, cannabinoids obtained from Cannabis sativa/indica/ruderalis have been shown to activate TRPV1; however, the major psychoactive cannabinoid Δ9-tetrahydrocannabinol (THC) does not activate TRPV1, whereas the other major cannabinoid, cannabidiol (CBD) is a potent activator of TRPV1 [9,10,11,12]. Other minor cannabinoids have also been shown to activate TRPV1 [10]. Cannabigerol (CBG) is reported to act as a ligand for TRPV1 [10]. THC has been shown to potently activate TRPV2 [10,29]. A widely used CBR1 agonist, WIN55, 212-2, has been shown to exert some of its effects through the activation of TRPV1 and TRPA1 [30,31,32]. Also, it should be considered that ajulemic acid is a metabolite of THC which shows anti-inflammatory and antifibrotic effects without exerting psychoactive properties [33]. Tetrahydrocannabivarin (THCV and THV) is a homologue of THC which acts as an antagonist of CBR1 [5]. Anandamide (AEA) is an endocannabinoid that activates both CBR1 and TRPV1 receptors [34,35,36].
There are complex effects resulting from interactions between the effects of THC and CBD. The actions of CBD on TRPV1 also have an impact on this interaction. Chronic inflammatory pain is mediated by the sensitization of TRPV1 by various mechanisms, including its phosphorylation [37,38,39]. Since CBR1 receptors are negatively coupled to cAMP via Gi, CBR1-mediated dephosphorylation of TRPV1 may indirectly affect the downstream effects of TRPV1 by CBD.
One example of the interplay between THC and CBD includes the way in which CBD reduces the psychosis-like effects of THC. There are studies suggesting that CBD may have its own antipsychotic effects [40,41,42,43,44]. In animal models, acute exposure to THC affects cognitive behavior; it induces dose-related effects on decision making, abstract-thinking abilities, and executive functions [45,46,47]. The most remarkable effects are on the short-term working memory, verbal skills, and attention deficits [45,46,47,48,49,50,51]. Interestingly, CBD is able to reduce THC-induced cognitive impairment [43]. As discussed earlier, most preparations contain unknown amounts of THC and CBD; therefore, the discrepancies found in studies as to the effects of CBD could be attributed to these interactions.
Cannabis is also used as an antiemetic agent in various conditions. One of the side effects of the chronic and improper use of cannabis is hyperemesis syndrome (HES), which is becoming more common with increased use as a result of the legalization of marijuana [52,53,54,55]. Nausea and vomiting result from complex interactions between afferent and efferent pathways of the gastrointestinal tract, central nervous system, and autonomic nervous system [52,53]. The role of TRPV1 has been demonstrated by experiments conducted with resiniferatoxin (RTX), a potent TRPV1 agonist. Lower concentrations of RTX act as an antiemetic, while higher concentrations induce emesis. The use of CBD alone, via the activation of TRPV1, is likely to induce antiemetic effects [10]. However, when TRPV1 is downregulated by the activation of CBR1-receptor-mediated dephosphorylation, this could result in HES [6,7]. As indicated above, the combination ratios of THC and CBD are critical. Specific formulations have been approved by the FDA, such as dronabinol (Marinol) and nabilone (Cesamet). These contain THC as the active ingredient, which can be useful in treating chemotherapy-induced nausea and as an appetite stimulant [56].
Given the outcomes of recent legislation, it is likely that marijuana will be legalized in many states in the U.S. and in other parts of the world in the future [54,55]. Therefore, rigorous scientific research must be conducted so as to identify the specific targets, pharmacological effects, and the pharmacokinetic and pharmacovigilance profiles for the effective use of cannabis, and that should be supported by evidence-based clinical trials. The purported uses of cannabinoids are for relief of pain and for prevention of nausea and vomiting. The mechanisms underlying these effects are not fully understood. In this review, we will delineate the role of TRPV1 in inducing these antinociceptive and antiemetic properties. We will also discuss the role of TRPV1 in the possible reduction of the antinociceptive effect and in avoiding hyperemesis syndrome (HES) following the use of cannabinoids.

2. Role of TRPV1 in Cannabinoid-Induced Antinociception

Pain is carried from the periphery by nociceptors Aδ and C-fibers, which are thinly myelinated and unmyelinated, respectively. These fibers are further subdivided by their sensitivities to physical stimuli: the C-fibers that are responsible for sensing mechanical and heat stimuli are classified as CMH fibers, and there is also a set of C-fibers which is mechano-insensitive, classified as CMi fibers [56,57]. These nociceptors are TRPV1-expressing peptidergic (CGRP and substance P (SP)-releasing) fibers. Neuropathic pain occurs as a result of the abnormal activity of Aδ and C nociceptors, which is associated with several conditions, such as peripheral nerve injuries [58], painful DPN [59,60], painful peripheral herpes neuropathy (PHN) [61,62], painful HIV-associated neuropathy (HIV-AN) [63], complex regional pain syndrome (CRPS) [64], small-fiber neuropathy in metabolic syndrome [65], neuropathic pain manifestations in Fabry disease [66], and chemotherapy-induced peripheral neuropathy [67,68]. Cannabis use has been claimed to be useful in relieving pain in these conditions [1,2,69]. In a small number of patients with HIV-AN, one study showed a 30% reduction in reported pain after a week of smoking medicinal cannabis [70].
The classic behavioral effects of cannabis in rodents are called a “tetrad”, which includes the reduction in body temperature, analgesia, reduced locomotion, and catalepsy [71]. Hypothermia could be explained by the activation of TRPV1, and analgesia could be explained by the desensitization/downregulation of peripheral TRPV1 or by the activation of central TRPV1 in the descending pain pathway [72,73]. The interactions of CBD and THC could occur through TRPV1 channels. CBD potentiated the suppression of locomotion and reduced hypothermia caused by THC when administered in a 1:1 (CBD:THC) ratio in mice [74], but it potentiated both the suppression of locomotion and hypothermia when administered in a 10:1 (CBD:THC) or a 50:1 (CBD:THC) ratio [75]. Administration of CBD in rats (20 mg/kg, i.p.) prolonged the duration of hyperthermia and hypolocomotion [76]. These studies suggest interactions between THC and CBD, as well as between TRPV1 and CBD.
TRPV1 channels are expressed in the peripheral nerve terminals of nociceptors (Aδ and C-fibers). Upon activation, it depolarizes the nerve terminals, generates action potentials, and propagates noxious information to the higher brain centers via the spinal cord [15,21,77,78,79]. Activation of TRPV1 can also cause the release of neuropeptides, such as CGRP and SP, from the peripheral and central nerve endings. CGRP is known to be a potent vasodilator [80,81]. Blood vessels are strongly stained for TRPV1 [82]. Cannabinoids have been shown to exert powerful hypotensive effects [83]. TRPV1 channels are also expressed in the central nerve terminals of sensory neurons, where peripheral afferents form synapses at the spinal dorsal horn, vagal nerve afferents at the NTS, and trigeminal nerve afferents at the caudal trigeminal nucleus [84,85,86,87,88,89,90]. TRPV1 channels are expressed in specific locations in the higher centers of the brain, such as the descending pain pathway involving the rostral ventral medulla (RVM) and the periaqueductal gray (PAG) [91,92,93,94,95,96]. However, there are controversies regarding the extent of TRPV1 expression in the central nervous system. Studies have shown that its expression is restricted to the peripheral nervous system [82]. TRPV1 channels expressed in the periphery mediate nociception, whereas TRPV1 channels expressed in the descending pain pathway mediate antinociception. The sustained activation of these channels at nerve terminals can cause the desensitization/depolarization block of the nerve terminals, preventing the generation and propagation of action potentials. RTX, an ultrapotent agonist of TRPV1, is very effective in inducing the depolarization block resulting in antinociception [26,27,28].
In order to account for the interaction, the effects of phosphorylation on TRPV1 must be taken into consideration. PKC- and PKA-mediated phosphorylation robustly potentiates TRPV1 functions by sensitizing the receptors, and thereby the nociceptors (C and Aδ fibers) [16,37,38,39]. This effect underlies the basis for inflammatory pain and the development of TRPV1 antagonists as analgesic and anti-inflammatory agents to treat certain modalities of pain. However, in clinical trials, it became apparent that the TRPV1 blockade increased the core body temperature, which led to the abandonment of developing TRPV1 antagonists as analgesics [97]. Also, it should be taken into consideration that the blockade of central TRPV1 in the descending pain pathway mediates antinociception [91,92,93,94,95,96]. In regard to cannabinoids, if CBR1 and TRPV1 are expressed in the same neuron, the CBR1-mediated reduction in cAMP levels could downregulate TRPV1 expression and function by reducing the phosphorylated state of the channel. Therefore, when a mixture of THC and CBD in a preparation is consumed or administered, depending upon the quantities of each of the active ingredients, the activation of TRPV1 by CBD and the downregulation of TRPV1 by the activation of CBR1 could mutually nullify the effects [98,99,100,101,102]. Some of the well-known formulations, such as nabiximols, have a combination of THC and CBD [103,104]. Another added complexity is that some of the minor cannabinoids, such as THCV, act as antagonists of CBR1 [10]. A careful analysis should be carried out using pure ingredients with known proportions in the mixtures to delineate the ultimate effects of cannabinoids [104]. The United Kingdom, Canada, and several European countries have approved nabiximols (Sativex), which is an equal ratio (1:1) mixture of THC (2.7 mg) and CBD (2.5 mg), formulated as a mouth spray to alleviate neuropathic pain, incontinence, spasticity, and multiple sclerosis, but it has not been approved by the FDA. It should be mentioned that CBD is freely available for online purchase from several companies in different concentrations accompanied by analytical data regarding possible contaminants, including pesticides [105].
Despite decades of research and clinical usage of cannabis in treating chronic pain conditions, incontrovertible evidence for its efficacy has yet to be established [106]. This may be due to the lack of a clear understanding of the mechanism of action and the use of unregulated combinations of cannabinoids in treatment regimens [10,103,104]. Changes in legislation are being promulgated in different countries; therefore, it is likely that use will increase worldwide. These products are most commonly used for chronic pain conditions—apart from their recreational use [107].
Chronic pain is considered to be the most significant cause of disability globally. Several preclinical and clinical studies have been undertaken, but the results are conflicting. Some studies show significant effects, and other show minimal effects. A review has been compiled recently using the outcomes specified in the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT), which quite controversially concludes that it is unlikely that cannabinoids are effective as medicine for treating chronic noncancer pain [106].
Capsaicin, a competitive TRPV1 agonist, when applied peripherally, induces intense burning pain. It has been shown that TRPV1 expression and function are increased and decreased in hyper- or hypoalgesia, respectively, in the periphery and at the first sensory synapse in the spinal dorsal horn [108]. The role of TRPV1 has been confirmed using a potent TRPV1 agonist, RTX, that induces a depolarization block by persistently activating TRPV1 expressed in the nerve terminals in the short-term, as well as nerve terminal desensitization/depletion in the long-term and reversed thermal hyperalgesia [26,27,108]. RTX is currently in clinical trials for the treatment of certain terminal-cancer pain conditions [109,110,111,112,113,114,115,116].
Pain involving the head and neck is carried by trigeminal neurons. Trigeminal neurons that synapse at the caudal trigeminal nucleus express TRPV1, and TRPV1-mediated CGRP, a potent vasodilator, release has been implicated in migraine-type headaches [117,118], and cannabis has been shown to be effective in the treatment of migraines. In a study, 11% of migraineurs reported complete resolution [119]. Given the knowledge we have gained regarding TRPV1 and pain, and also that regarding TRPV1 and CGRP levels in migraine, it is conceivable that cannabinoids could play a role in migraines. The activation of CBD might worsen the symptoms as a result of a further increase in TRPV1-mediated CGRP-release, causing the vasodilation of the meningeal vessels, while on the other hand, THC activation of CBR1 may downregulate TRPV1 function and decrease CGRP-release and aid in the relief of migraine pain. It has been suggested that cannabinoids may be useful in relieving craniofacial pain associated with dental problems, anxiety, trigeminal neuralgia, and temporomandibular joint dysfunction [120,121,122].
Our bodies also produce their own cannabinoid chemicals, called “endocannabinoids”. They play a role in regulating pleasure, memory, thinking, concentration, body movement, awareness of time, appetite, pain, and the senses (taste, touch, smell, hearing, and sight). Neuronal activity increases the production of endovanilloids/cannabinoids during chronic pain conditions and play a role in anxiety [123,124,125]. Endovanilloids, such as N-arachidonyl ethanolamine (anandamide, AEA) and 2-arachidonyl glycerol (2-AG), are synthesized and released on demand and metabolized by fatty acid amide hydroxylase (FAAH) and monoacylglyceride lipase (MAGL), respectively [126,127,128]. The activation of CBR1 and CBR2 receptors stimulates the production of oleoylethanolamide (OEA), which is known to activate peroxisome proliferator-activated receptor-α (PPAR-α) [129], which is involved in fat metabolism; therefore, it could be useful in treating obesity [130]. Interestingly, the activation of TRPV1 by OEA enhances metabolism in brown fat cells [131].
Liao et al., 2011 [132] have concluded from their experiments in the PAG that the activation of TRPV1 in the glutamatergic terminals releases glutamate, which in turn activates the metabotropic glutamate receptors (mGluR) in the postsynaptic cells. The activation of mGluRs is involved in the synthesis of 2-AG, which retrogradely activates CBR1 in the presynaptic terminal in ventrolateral PAG (vlPAG), causing reduced gamma aminobutyric acid (GABA) release and mediating antinociception in the descending pain pathway [133,134,135].
PAG is a midbrain structure whose role in the descending control of pain has been quite well-established. Glutamatergic neurons project from vlPAG to the adjacent RVM. Physiologically, this system tends to suppress pain signals [133,134]. Three kinds of neurons (ON-, OFF- and neutral cells) from the RVM project to the dorsal horn of the spinal cord. The OFF-cells in the RVM can be stimulated by the glutamatergic axonal projections from the vlPAG [135,136,137]. Any intervention that increases OFF-cell firing in the PAG or the RVM inhibits the transmission of pain signals from the periphery. On the contrary, ON-cell activity facilitates pain transmission [137,138,139]. One of the most studied central analgesic mechanisms of cannabinoids and opiates is the disinhibition of vlPAG glutamatergic-projecting neurons that results in the stimulation of RVM OFF-cells. The mechanism of disinhibition by these agents is the attenuation of GABA release from interneurons in the PAG [140,141].
Increased glutamatergic transmission in the projecting neurons in vlPAG induces antinociception. The administration of the TRPV1 agonist capsaicin into vlPAG increases glutamatergic neuronal firing and increases GABA release. However, CBR1-receptor activation by WIN55, 212-2 induces antinociception by decreasing GABA-release, leading to the disinhibition of the glutamatergic neurons. In painful diabetic peripheral neuropathy, the TRPV1-mediated antinociceptive effect is attenuated as a result of the reduction of the expression of the TRPV1 receptors. On the other hand, when CBR1-receptor expression is increased, that could lead to a reduction in GABA release, thereby further augmenting the disinhibition of the glutamatergic transmission [92].
Administration of intra-vlPAG palmitoylethanolamide (PEA), a PPAR-α agonist, induces antinociceptive effects, which are seen as a decrease in the RVM ON- and OFF-cell activities. PPAR-α responses are mediated by the activation of the CBR1 and TRPV1 receptors. The TRPV1 blocker, iodo-RTX, had no effect on the ON-cell activity or tail-flick latency, whereas it blocked the PEA-induced decrease in the ongoing activity of the OFF-cell [142]. The roles of CBR1 and TRPV1 receptors have been further confirmed by blocking the degradation of AEA (which activates both the CBR1 and TRPV1 receptors) by FAAH inhibitor, which revealed the modulation of synaptic transmission in the PAG [143,144]. It has been shown that, in cells expressing CBR1 and TRPV1 receptors, the activation of the CBR1 receptor either stimulates or inhibits, and the inhibition is dependent upon the activation of cAMP signaling [145]. dlPAG determines the core affective aspects of aversive memory formation controlled by the local TRPV1/CBR1 balance [146].
5-HT1A, an autoreceptor of serotonin expressed presynaptically, can modulate neurotransmitter release. If the coupling mechanism is similar to that of CBR1, TRPV1 receptors expressed in the vicinity could be downregulated. CBD administration into dlPAG has been shown to decrease anxiety, which is mediated by 5-HT1A receptors, but not by CBR1 because a CBR1-receptor antagonist (SR141716 or SR144528) had no effect [147]. The dorsal raphe nucleus (DRN) is involved in nociception [20,148,149,150,151]. There are reports that, following the induction of neuropathic pain, 5-HT neurons in DRN show a decrease in firing rate [152], but other studies have shown an increase in neuronal firing [153]. In animal models of neuropathic pain, CBD is able to reverse mechanical allodynia, but not the antianxiety effects mediated by the 5-HT1A receptors which could be reversed by TRPV1 antagonists [10,11,154].
The pain relief could be associated with psychoactive properties of cannabinoids [155,156]. Combinations of THC + CBD have been useful to reduce anxiety and could be useful in generalized social anxiety disorder. It has been reported that CBD alone could be useful in reducing anxiety and cognitive impairment [156]. Some of these effects could be related to the concentration of THC and CBD in a given preparation. The effects of CBD have been compared to a known antidepressant drug, imipramine [157]. This observation raises the question as to whether cannabinoids cause depression. In an elaborate study involving 6900 subjects, with an age ranging from adolescent to mature adult, there was no indication that cannabinoids cause depression [158,159,160].
Multiple sclerosis (MS) is a debilitating condition; it causes neuronal inflammation and muscle spasticity. MS patients benefit from use of cannabis [161]. Two patient surveys have revealed that, in spinal cord injuries, 50% of respondents reported that marijuana reduced muscle spasticity, and 97% of MS patients who used cannabis in conjunction with their therapy reported that cannabis improved spasticity, chronic pain, tremor, weight loss, and other symptoms [162].

3. Role of TRPV1 in Cannabinoid-Induced Antiemesis

One of the uses of cannabis is to prevent nausea and vomiting in various conditions. It is useful in improving appetite, probably acting as an antiemetic agent. There is widespread use of cannabinoids as antiemetic agents, especially during cancer chemotherapy [52,53]. Antiretroviral therapy for HIV/AIDS treatment results in a number of side effects, such as neuropathic pain, lack of appetite, anxiety, and depression. In this group of patients, cannabis has been shown to improve quality of life [163]. Although it has been shown that cannabis could be useful as an antiemetic, it can be also proemetic [52]. It is not recommended for use against pregnancy-induced nausea because the effects of cannabis on the unborn have not yet been established [164]. However, chronic use of higher levels of cannabinoids induces hyperemesis syndrome (HES). Antiemesis and HES caused by cannabinoids could be explained by their actions on TRPV1 channels in the emesis pathway [52,53].
The precise neurocircuitry involved in nausea and vomiting is not fully understood. It involves structures within the medullary reticular formation of the hindbrain, which includes the AP, NTS, and dorsal motor nucleus of the vagus (DMV) [160,165,166]. Although the effects are attributed to THC, there is increasing evidence that CBD may play a role in nausea and vomiting [167]. There is a clear link between TRPV1 and nausea and vomiting. Since CBD activates TRPV1, there could be an interaction. Given these findings, it is possible that chronic nausea caused by cannabinoids could be mediated via central TRPV1, similar to the antinociceptive effects of central TRPV1 in the descending pain pathway.
Therefore, it is necessary to understand the correlation between the activation of TRPV1 by CBD and its role in nausea and vomiting. Nausea and vomiting involve complex interactions between the afferent and efferent pathways of the gastrointestinal tract, the central nervous system, and the autonomic nervous system. Afferents from the vagus nerve, vestibular system, and chemoreceptor trigger- zone project to NTS, which in turn relays signals to initiate multiple downstream pathways mediating nausea and vomiting [165,168]. There appears to be a distinction between acute and chronic nausea; acute nausea originates from the GI tract in response to the consumption of toxic substances, whereas chronic nausea originates from the central neuronal circuits that can be equated to centrally mediated chronic neuropathic pain [169]. Several neuromodulators, including cannabinoids, have been shown to be efficacious in the treatment of nausea and vomiting. It is noteworthy that conventional antiemetic therapies used for the treatment of acute vomiting are not effective in treating chronic vomiting, suggesting disparate mechanisms [170].
However, long-duration, excessive use of cannabis can lead to HES, which is characterized by symptoms of cyclic abdominal pain, nausea, and vomiting. Hot-water hydrotherapy is a mainstay self-treatment for cannabinoid-induced HES, suggesting that the heat-induced activation of TRPV1 may play a role in the antiemetic effect [53,171,172,173]. Furthermore, topical capsaicin is a treatment option for HES, further suggesting the role of TRPV1. The downstream signaling pathway include the vagus nerve, NTS, and AP, acting via the SP/NK1 receptors [174].
Gut–brain signaling via the vagal nerve mediates motor functions and emesis, which could involve cannabinoid and TRPV1 receptors [175]. A similar mechanism that mediates nociception/antinociception via the activation of TRPV1 could also be involved in mediating the emetic/antiemetic effects of cannabinoids. The activation of TRPV1 by cannabinoids in the central emesis pathway may mediate antiemetic effects [176,177,178,179]. Similar to the effects in the central descending pain pathway, chronic use of higher concentrations of THC-containing mixtures of cannabinoids may downregulate TRPV1 via the activation of CBR1, resulting in an emetic response.
The role of TRPV1 has been confirmed by experiments conducted with RTX, a potent TRPV1 agonist. RTX is one of the most potent emetic substances described so far in animal models, mediated by TRPV1 located on neurons in the brainstem containing substance P [53,179,180]. However, RTX has also been shown to induce antiemetic effects. Very low concentrations of RTX irreversibly activate TRPV1, leading to depolarization block, but at higher concentrations, it leads to the desensitization/depletion of TRPV1-expressing nerve terminals, which may explain the concentration-dependent opposing effects of RTX [26,27,53]. Therefore, a dual effect could be expected with RTX; at lower concentrations, it is antiemetic, but at higher concentrations, it induces emesis. The downstream mechanism may involve the release of CGRP and SP and the activation of their respective receptors [80,81]. As discussed earlier, RTX is a unique compound, in that it can induce depolarization block by irreversibly activating TRPV1, resulting in the gradual inactivation of sodium channels, resulting in a failure to generate action potentials. Several TRPV1 agonists, such as arvanil, arachidonamide, AEA (which activates both CBR1 and TRPV1), and N-arachidonoyl-dopamine (NADA), all induce antiemetic effects [175]. Since CBD is known to activate TRPV1 [10], it is expected that it has antiemetic properties. However, constant, high-dose cannabis use results in HES. This is likely due to TRPV1 downregulation/desensitization via constant activation by CBD, as well as by CBR1 mediated by TRPV1 hypofunction. The area responsible for the action appears to be NTS, where vagus nerve terminals express TRPV1 and modulate synaptic transmission [179,180,181,182].
The involvement of substance P and its receptor, tachykinin (NK1), has been demonstrated by the direct application of SP to the dorsal brainstem in the AP, which induced emesis in ferrets [179]. This suggests that TRPV1-mediated CGRP and SP release from nerve terminals play a role in emesis [53]. NK1-receptor antagonists have been successfully used along with 5-HT3-receptor antagonists to treat chemotherapy-induced emesis [183,184]. Morphine and 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) act as antiemetics [185]. The role of TRPV1 in the descending pain pathway has been established; in fact, antinociception induced by TRPV1 activation in the descending pathway involves the release of encephalin and endorphin at the level of RVM and PAG [91,92,93,94,95,96]. A similar mechanism could exist at the brainstem area to cause endorphin/encephalin-release-mediating antiemetic effects.

4. Concluding Remarks and Future Directions

The activation of the central TRPV1 channels by cannabinoids (CBD, but not THC) in the descending pain pathway that involves RVM and PAG plays a key role in the antinociceptive effects of cannabinoids. However, when CBR1 is also activated, the TRPV1 receptor is downregulated via a Gi-coupled mechanism by inhibiting protein kinase A-mediated phosphorylation and impairs the antinociceptive effects. Similarly, the activation of TRPV1 channels by cannabinoids in the NTS and AP circuitry mediates the antiemetic effects, whereas the downregulation of TRPV1 in this circuitry could result in HES. Therefore, maintenance of the central TRPV1 function is critical for mediating the analgesic effect and mitigating the adverse effect of HES.

Author Contributions

K.L.-G. initiated the idea and aided in writing the article; S.T. organized the references and contributed to the content of the article; L.S.P. wrote the initial draft and finalized. All authors have read and agreed to the published version of the manuscript.

Funding

This study was supported by funding from the National Institutes of Health to LSP (DA028017, R43DK117674).

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Not applicable.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Hill, K.P. Medical Marijuana for Treatment of Chronic Pain and Other Medical and Psychiatric Problems: A Clinical Review. JAMA 2015, 313, 2474–2483. [Google Scholar] [CrossRef] [PubMed]
  2. Allan, G.M.; Finley, C.R.; Ton, J.; Perry, D.; Ramji, J.; Crawford, K.; Lindblad, A.J.; Korownyk, C.; Kolber, M.R. Systematic review of systematic reviews for medical cannabinoids: Pain, nausea and vomiting, spasticity, and harms. Can. Fam. Physician 2018, 64, e78–e94. [Google Scholar] [PubMed]
  3. ElSohly, M.A.; Radwan, M.M.; Gul, W.; Chandra, S.; Galal, A. Phytochemistry of Cannabis sativa L. Prog. Chem. Org. Nat. Prod. 2017, 103, 1–36. [Google Scholar]
  4. Pollio, A. A Short Guide for Nonbotanists. Cannabis Cannabinoid Res. 2016, 1, 234–238. [Google Scholar] [CrossRef] [PubMed]
  5. Pertwee, R.G. The diverse CB1 and CB2 receptor pharmacology of three plant cannabinoids: Delta9-tetrahydrocannabinol, cannabidiol and delta9-tetrahydrocannabivarin. Br. J. Pharmacol. 2008, 153, 199–215. [Google Scholar] [CrossRef]
  6. Howlett, A.C.; Abood, M.E. CB1 and CB2 Receptor Pharmacology. Adv. Pharmacol. 2017, 201, 169–206. [Google Scholar]
  7. Ibsen, M.S.; Connor, M.; Glass, M. Cannabinoid CB1 and CB2 Receptor Signaling and Bias. Cannabis Cannabinoid Res. 2017, 2, 48–60. [Google Scholar] [CrossRef]
  8. Zaheer, S.; Kumar, D.; Khan, M.T.; Giyanwani, P.R.; Kiran, F. Epilepsy and Cannabis: A Literature Review. Cureus 2018, 10, e3278. [Google Scholar] [CrossRef]
  9. Devinsky, O.; Cilio, M.R.; Cross, H.; Fernandez-Ruiz, J.; French, J.; Hill, C.; Katz, R.; Di Marzo, V.; Jutras-Aswad, D.; Notcutt, W.G.; et al. Cannabidiol: Pharmacology and potential therapeutic role in epilepsy and other neuropsychiatric disorders. Epilepsia 2014, 55, 791–802. [Google Scholar] [CrossRef]
  10. Iannotti, F.A.; Hill, C.L.; Leo, A.; Alhusaini, A.; Soubrane, C.; Mazzarella, E.; Russo, E.; Whalley, B.J.; Di Marzo, V.; Stephens, G.J. Nonpsychotropic plant cannabinoids, cannabidivarin (CBDV) and cannabidiol (CBD), activate and desensitize transient receptor potential vanilloid 1 (TRPV1) channels in vitro: Potential for the treatment of neuronal hyperexcitability. ACS Chem. Neurosci. 2014, 5, 1131–1141. [Google Scholar] [CrossRef]
  11. Muller, C.; Morales, P.; Reggio, P.H. Cannabinoid Ligands Targeting TRP Channels. Front. Mol. Neurosci. 2019, 11, 487. [Google Scholar] [CrossRef] [PubMed]
  12. De Petrocellis, L.; Ligresti, A.; Moriello, A.S.; Allarà, M.; Bisogno, T.; Petrosino, S.; Stott, C.G.; Di Marzo, V. Effects of cannabinoids and cannabinoid-enriched Cannabis extracts on TRP channels and endocannabinoid metabolic enzymes. Br. J. Pharmacol. 2011, 163, 1479–1494. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  13. Sekar, K.; Pack, A. Epidiolex as adjunct therapy for treatment of refractory epilepsy: A comprehensive review with a focus on adverse effects. F1000Research 2019, 8, 234. [Google Scholar] [CrossRef]
  14. Barrett, K.T.; Wilson, R.J.; Scantlebury, M.H. TRPV1 deletion exacerbates hyperthermic seizures in an age-dependent manner in mice. Epilepsy Res. 2016, 128, 27–34. [Google Scholar] [CrossRef]
  15. Caterina, M.J.; Schumacher, M.A.; Tominaga, M.; Rosen, T.A.; Levine, J.D.; Julius, D. The capsaicin receptor: A heat-activated ion channel in the pain pathway. Nature 1997, 389, 816–824. [Google Scholar] [CrossRef] [PubMed]
  16. Premkumar, L.S.; Ahern, G.P. Induction of vanilloid receptor channel activity by protein kinase C. Nature 2000, 408, 985–990. [Google Scholar] [CrossRef]
  17. Dinh, Q.T.; Groneberg, D.A.; Peiser, C.; Mingomataj, E.; Joachim, R.A.; Witt, C. Substance P expression in TRPV1 and trkA-positive dorsal root ganglion neurons innervating the mouse lung. Respir. Physiol. Neurobiol. 2004, 144, 15–24. [Google Scholar] [CrossRef]
  18. Suzuki, R.; Dickenson, A. Spinal and supraspinal contributions to central sensitization in peripheral neuropathy. Neurosignals 2005, 14, 175–181. [Google Scholar] [CrossRef]
  19. Premkumar, L.S.; Abooj, M. TRP channels and analgesia. Life Sci. 2013, 92, 415–424. [Google Scholar] [CrossRef]
  20. De Gregorio, D.; McLaughlin, R.J.; Posa, L.; Ochoa-Sanchez, R.; Enns, J.; Lopez-Canul, M.; Aboud, M.; Maione, S.; Comai, S.; Gobbi, G. Cannabidiol modulates serotonergic transmission and reverses both allodynia and anxiety-like behavior in a model of neuropathic pain. Pain 2019, 160, 136–150. [Google Scholar] [CrossRef]
  21. Julius, D. TRP channels and pain. Annu. Rev. Cell. Dev. Biol. 2013, 29, 355–384. [Google Scholar] [CrossRef]
  22. Palazzo, E.; Luongo, L.; de Novellis, V.; Rossi, F.; Marabese, I.; Maione, S. Transient receptor potential vanilloid type 1 and pain development. Curr. Opin. Pharmacol. 2012, 12, 9–17. [Google Scholar] [CrossRef]
  23. Patapoutian, A. TRP channels and thermosensation. Chem. Senses 2005, 30, 193–194. [Google Scholar] [CrossRef]
  24. Venkatachalam, K.; Montell, C. TRP channels. Annu. Rev. Biochem. 2007, 76, 387–417. [Google Scholar] [CrossRef]
  25. Pedersen, S.F.; Owsianik, G.; Nilius, B. TRP channels: An overview. Cell Calcium 2005, 38, 233–252. [Google Scholar] [CrossRef]
  26. Jeffry, J.A.; Yu, S.Q.; Sikand, P.; Parihar, A.; Evans, M.S.; Premkumar, L.S. Selective targeting of TRPV1 expressing sensory nerve terminals in the spinal cord for long lasting analgesia. PLoS ONE 2009, 9, e7021. [Google Scholar] [CrossRef]
  27. Raisinghani, M.; Pabbidi, R.M.; Premkumar, L.S. Activation of transient receptor potential vanilloid 1 (TRPV1) by resiniferatoxin. J. Physiol. 2005, 567, 771–786. [Google Scholar] [CrossRef]
  28. Premkumar, L.S.; Agarwal, S.; Steffen, D. Single-channel properties of native and cloned rat vanilloid receptors. J. Physiol. 2002, 545, 107–117. [Google Scholar] [CrossRef] [PubMed]
  29. Qin, N.; Neeper, M.P.; Liu, Y.; Hutchinson, T.L.; Lubin, M.L.; Flores, C.M. TRPV2 is activated by cannabidiol and mediates CGRP release in cultured rat dorsal root ganglion neurons. J. Neurosci. 2008, 28, 6231–6238. [Google Scholar] [CrossRef] [PubMed]
  30. Jeske, N.A.; Patwardhan, A.M.; Gamper, N.; Price, T.J.; Akopian, A.N.; Hargreaves, K.M. Cannabinoid WIN 55,212-2 regulates TRPV1 phosphorylation in sensory neurons. J. Biol. Chem. 2006, 281, 32879–32890. [Google Scholar] [CrossRef]
  31. Patwardhan, A.M.; Jeske, N.A.; Price, T.J.; Gamper, N.; Akopian, A.N.; Hargreaves, K.M. The cannabinoid WIN 55,212-2 inhibits transient receptor potential vanilloid 1 (TRPV1) and evokes peripheral antihyperalgesia via calcineurin. Proc. Natl. Acad. Sci. USA 2006, 103, 11393–11398. [Google Scholar] [CrossRef] [PubMed]
  32. Carletti, F.; Gambino, G.; Rizzo, V.; Ferraro, G.; Sardo, P. Involvement of TRPV1 channels in the activity of the cannabinoid WIN 55,212-2 in an acute rat model of temporal lobe epilepsy. Epilepsy Res. 2016, 122, 56–65. [Google Scholar] [CrossRef] [PubMed]
  33. Burstein, S.H. Ajulemic acid (CT3): A potent analog of the acid metabolites of THC. Curr. Pharm. Des. 2000, 6, 1339–1345. [Google Scholar] [CrossRef] [PubMed]
  34. Di Marzo, V. Anandamide serves two masters in the brain. Nat. Neurosci. 2010, 13, 1446–1448. [Google Scholar] [CrossRef]
  35. Walker, J.M.; Huang, S.M.; Strangman, N.M.; Tsou, K.; Sanudo-Pena, M.C. Pain modulation by release of the endogenous cannabinoid anandamide. Proc. Natl. Acad. Sci. USA. 1999, 96, 12198–12203. [Google Scholar] [CrossRef]
  36. Diniz, C.R.A.F.; Biojone, C.; Joca, S.R.L.; Rantamäki, T.; Castrén, E.; Guimarães, F.S.; Casarotto, P.C. Dual mechanism of TRKB activation by anandamide through CB1 and TRPV1 receptors. PeerJ 2019, 7, e6493. [Google Scholar] [CrossRef]
  37. Pingle, S.C.; Matta, J.A.; Ahern, G.P. Capsaicin receptor: TRPV1 a promiscuous TRP channel. Handb. Exp. Pharmacol. 2007, 179, 155–171. [Google Scholar]
  38. Cesare, P.; Moriondo, A.; Vellani, V.; McNaughton, P.A. Ion channels gated by heat. Proc. Natl. Acad. Sci. USA 1999, 96, 7658–7663. [Google Scholar] [CrossRef]
  39. Fischer, M.J.; Btesh, J.; McNaughton, P.A. Disrupting sensitization of transient receptor potential vanilloid subtype 1 inhibits inflammatory hyperalgesia. J. Neurosci. 2013, 33, 7407–7414. [Google Scholar] [CrossRef]
  40. Hasan, A.; von Keller, R.; Friemel, C.M.; Hall, W.; Schneider, M.; Koethe, D.; Leweke, F.M.; Strube, W.; Hoch, E. Cannabis use and psychosis: A review of reviews. Eur. Arch. Psychiatry Clin. Neurosci. 2020, 270, 403–412. [Google Scholar] [CrossRef]
  41. Colizzi, M.; Ruggeri, M.; Bhattacharyya, S. Unraveling the Intoxicating and Therapeutic Effects of Cannabis Ingredients on Psychosis and Cognition. Front. Psychol. 2020, 11, 833. [Google Scholar] [CrossRef]
  42. Boggs, D.L.; Cortes-Briones, J.A.; Surti, T.; Luddy, C.; Ranganathan, M.; Cahill, J.D.; Sewell, A.R.; D’Souza, D.C.; Skosnik, P.D. The dose-dependent psychomotor effects of intravenous delta-9-tetrahydrocannabinol (Δ9THC) in humans. J. Psychopharmacol. 2018, 32, 1308–1318. [Google Scholar] [CrossRef]
  43. Russo, E.; Guy, G.W. A tale of two cannabinoids: The therapeutic rationale for combining tetrahydrocannabinol and cannabidiol. Med. Hypotheses. 2006, 66, 234–246. [Google Scholar] [CrossRef]
  44. D’Souza, D.C.; Perry, E.; MacDougall, L.; Ammerman, Y.; Cooper, T.; Wu, Y.T.; Braley, G.; Gueorguieva, R.; Krystal, J.H. The psychotomimetic effects of intravenous delta-9-tetrahydrocannabinol in healthy individuals: Implications for psychosis. Neuropsychopharmacology 2004, 29, 1558–1572. [Google Scholar] [CrossRef]
  45. Ranganathan, M.; D’Souza, D.C. The acute effects of cannabinoids on memory in humans: A review. Psychopharmacology 2006, 188, 425–444. [Google Scholar] [CrossRef]
  46. Ksir, C.; Hart, C.L. Cannabis and Psychosis: A Critical Overview of the Relationship. Curr. Psychiatry Rep. 2016, 18, 12. [Google Scholar] [CrossRef]
  47. Heishman, S.J.; Huestis, M.A.; Henningfield, J.E.; Cone, E.J. Acute and residual effects of marijuana: Profiles of plasma THC levels, physiological, subjective, and performance measures. Pharmacol. Biochem. Behav. 1990, 37, 561–565. [Google Scholar] [CrossRef]
  48. Hooker, W.D.; Jones, R.T. Increased susceptibility to memory intrusions and the Stroop interference effect during acute marijuana intoxication. Psychopharmacology 1987, 91, 20–24. [Google Scholar] [CrossRef]
  49. Leweke, M.; Kampmann, C.; Radwan, M.; Dietrich, D.E.; Johannes, S.; Emrich, H.M.; Münte, T.F. The effects of tetrahydrocannabinol on the recognition of emotionally charged words: An analysis using event-related brain potentials. Neuropsychobiology 1998, 37, 104–111. [Google Scholar] [CrossRef]
  50. Lichtman, A.H.; Varvel, S.A.; Martin, B.R. Endocannabinoids in cognition and dependence. Prostaglandins Leukot. Essent. Fatty Acids 2002, 66, 269–285. [Google Scholar] [CrossRef]
  51. Wilson, R.I.; Nicoll, R.A. Endocannabinoid signaling in the brain. Science 2002, 296, 678–682. [Google Scholar] [CrossRef] [PubMed]
  52. Lu, M.L.; Agito, M.D. Cannabinoid hyperemesis syndrome: Marijuana is both antiemetic and proemetic. Clevel. Clin. J. Med. 2015, 82, 429–434. [Google Scholar] [CrossRef]
  53. Rudd, J.A.; Nalivaiko, E.; Matsuki, N.; Wan, C.; Andrews, P.L. The involvement of TRPV1 in emesis and anti-emesis. Temperature 2015, 21, 258–276. [Google Scholar] [CrossRef] [PubMed]
  54. Wilkinson, S.T.; Yarnell, S.; Radhakrishnan, R.; Ball, S.A.; D’Souza, D.C. Marijuana Legalization: Impact on Physicians and Public Health. Annu. Rev. Med. 2016, 67, 453–466. [Google Scholar] [CrossRef] [PubMed]
  55. Allen, E. Congressional Research Service Informing the legislative debate since 1914. Libr. Congr. Mag. 2019. [Google Scholar]
  56. Weidner, C.; Schmelz, M.; Schmidt, R.; Hansson, B.; Handwerker, H.O.; Torebjörk, H.E. Functional attributes discriminating mechanoinsensitive and mechano-responsive C nociceptors in human skin. J. Neurosci. 1999, 19, 10184–10190. [Google Scholar] [CrossRef]
  57. Prato, V.; Taberner, F.J.; Hockley, J.R.; Callejo, G.; Arcourt, A.; Tazir, B.; Hammer, L.; Schad, P.; Heppenstall, P.A.; Smith, E.S.; et al. Functional and molecular characterization of mechanoinsensitive “silent” nociceptors. Cell Rep. 2017, 21, 3102–3115. [Google Scholar] [CrossRef]
  58. Osborne, N.R.; Anastakis, D.J.; Davis, K.D. Peripheral nerve injuries, pain, and neuroplasticity. J. Hand. Ther. 2018, 31, 184–194. [Google Scholar] [CrossRef]
  59. Gylfadottir, S.S.; Weeracharoenkul, D.; Andersen, S.T.; Niruthisard, S.; Suwanwalaikorn, S.; Jensen, T.S. Painful and non-painful diabetic polyneuropathy: Clinical characteristics and diagnostic issues. J. Diabetes Investig. 2019, 10, 1148–1157. [Google Scholar] [CrossRef]
  60. Ziegler, D.; Rathmann, W.; Dickhaus, T.; Meisinger, C.; Mielck, A.; KORA Study Group. Neuropathic pain in diabetes, prediabetes and normal glucose tolerance: The MONICA/KORA Augsburg Surveys S2 and S3. Pain Med. 2009, 10, 393–400. [Google Scholar] [CrossRef]
  61. Petersen, K.L.; Rice, F.L.; Farhadi, M.; Reda, H.; Rowbotham, M.C. Natural history of cutaneous innervation following herpes zoster. Pain 2010, 150, 75–82. [Google Scholar] [CrossRef] [PubMed]
  62. Oaklander, A.L. The density of remaining nerve endings in human skin with and without postherpetic neuralgia after shingles. Pain 2001, 92, 139–145. [Google Scholar] [CrossRef]
  63. Polydefkis, M.; Yiannoutsos, C.T.; Cohen, B.A.; Hollander, H.; Schifitto, G.; Clifford, D.B.; Simpson, D.M.; Katzenstein, D.; Shriver, S.; Hauer, P.; et al. Reduced intraepidermal nerve fiber density in HIV-associated sensory neuropathy. Neurology 2002, 58, 115–119. [Google Scholar] [CrossRef] [PubMed]
  64. Oaklander, A.L.; Rissmiller, J.G.; Gelman, L.B.; Zheng, L.; Chang, Y.; Gott, R. Evidence of focal small-fiber axonal degeneration in complex regional pain syndrome-I (reflex sympathetic dystrophy). Pain 2006, 120, 235–243. [Google Scholar] [CrossRef]
  65. Pittenger, G.L.; Mehrabyan, A.; Simmons, K.; Dublin, C.; Barlow, P.; Vinik, A.I. Small fiber neuropathy is associated with the metabolic syndrome. Metab. Syndr. Relat. Disord. 2005, 3, 1113–1121. [Google Scholar] [CrossRef] [PubMed]
  66. Scott, L.J.; Griffin, J.W.; Luciano, C.; Barton, N.W.; Banerjee, T.; Crawford, T.; McArthur, J.C.; Tournay, A.; Schiffmann, R. Quantitative analysis of epidermal innervation in Fabry disease. Neurology 1999, 52, 1249–1254. [Google Scholar] [CrossRef]
  67. Kim, J.H.; Dougherty, P.M.; Abdi, S. Basic science and clinical management of painful and non-painful chemotherapy-related neuropathy. Gynecol. Oncol. 2015, 136, 453–459. [Google Scholar] [CrossRef]
  68. Clinical Trial Identifier: NCT03687970, A New Method for Identifying Sensory Changes in Painful Chemotherapy-Induced Peripheral Neuropathy (CIPN). Available online: https://clinicaltrials.gov/ct2/show/NCT03687970 (accessed on 28 August 2022).
  69. Abrams, D.I.; Jay, C.; Petersen, K.; Shade, S.; Vizoso, H.; Reda, H.; Benowitz, N.; Rowbotham, M. The Effects of Smoked Cannabis in Painful Peripheral Neuropathy and Cancer Pain Refractory to Opioids; International Association of Cannabis as Medicine, Cologne: San Francisco, CA, USA, 2003; p. 28. [Google Scholar]
  70. Prentiss, D.; Power, R.; Balmas, G.; Tzuang, G.; Israelski, D.M. Patterns of marijuana use among patients with HIV/AIDS followed in a public health care setting. J. Acquir. Immune Defic. Syndr. 2004, 35, 38–45. [Google Scholar] [CrossRef]
  71. Metna-Laurent, M.; Mondésir, M.; Grel, A.; Vallée, M.; Piazza, P.V. Cannabinoid-Induced Tetrad in Mice. Curr. Protoc. Neurosci. 2017, 80, 9–59. [Google Scholar] [CrossRef]
  72. Maione, S.; Bisogno, T.; de Novellis, V.; Palazzo, E.; Cristino, L.; Valenti, M.; Petrosino, S.; Guglielmotti, V.; Rossi, F.; Di Marzo, V. Elevation of endocannabinoid levels in the ventrolateral periaqueductal grey through inhibition of fatty acid amide hydrolase affects descending nociceptive pathways via both cannabinoid receptor type 1 and transient receptor potential vanilloid type-1 receptors. J. Pharmacol. Exp. Ther. 2006, 316, 969–982. [Google Scholar]
  73. Maione, S.; Piscitelli, F.; Gatta, L.; Vita, D.; De Petrocellis, L.; Palazzo, E.; de Novellis, V.; Di Marzo, V. Non-psychoactive cannabinoids modulate the descending pathway of antinociception in anaesthetized rats through several mechanisms of action. Br. J. Pharmacol. 2011, 162, 584–596. [Google Scholar] [CrossRef] [PubMed]
  74. Todd, S.M.; Arnold, J.C. Neural correlates of interactions between cannabidiol and Δ(9) -tetrahydrocannabinol in mice: Implications for medical cannabis. Br. J. Pharmacol. 2016, 173, 53–65. [Google Scholar] [CrossRef] [PubMed]
  75. Hayakawa, K.; Mishima, K.; Hazekawa, M.; Sano, K.; Irie, K.; Orito, K.; Egawa, T.; Kitamura, Y.; Uchida, N.; Nishimura, R.; et al. Cannabidiol potentiates pharmacological effects of Delta(9)-tetrahydrocannabinol via CB(1) receptor-dependent mechanism. Brain Res. 2008, 1188, 157–164. [Google Scholar] [CrossRef] [PubMed]
  76. Fernandes, M.; Schabarek, A.; Coper, H.; Hill, R. Modification of delta9-THC-actions by cannabinol and cannabidiol in the rat. Psychopharmacologia 1974, 38, 329–338. [Google Scholar] [CrossRef]
  77. Sikand, P.; Premkumar, L.S. Potentiation of glutamatergic synaptic transmission by protein kinase C-mediated sensitization of TRPV1 at the first sensory synapse. J. Physiol. 2007, 581, 631–647. [Google Scholar] [CrossRef]
  78. Premkumar, L.S.; Sikand, P. TRPV1: A target for next generation analgesics. Curr. Neuropharmacol. 2008, 2, 151–163. [Google Scholar] [CrossRef]
  79. Premkumar, L.S.; Bishnoi, M. Disease-related changes in TRPV1 expression and its implications for drug development. Curr. Top. Med. Chem. 2011, 11, 2192–2209. [Google Scholar] [CrossRef]
  80. Milne, M.; Ashton, J.C. Effect of cannabinoids on CGRP release in the isolated rat lumbar spinal cord. Neurosci. Lett. 2016, 614, 39–42. [Google Scholar] [CrossRef]
  81. Engel, M.A.; Izydorczyk, I.; Mueller-Tribbensee, S.M.; Becker, C.; Neurath, M.F.; Reeh, P.W. Inhibitory CB1 and activating/desensitizing TRPV1-mediated cannabinoid actions on CGRP release in rodent skin. Neuropeptides 2011, 45, 229–237. [Google Scholar] [CrossRef]
  82. Cavanaugh, D.J.; Chesler, A.T.; Jackson, A.C.; Sigal, Y.M.; Yamanaka, H.; Grant, R.; O’Donnell, D.; Nicoll, R.A.; Shah, N.M.; Julius, D.; et al. Trpv1 reporter mice reveal highly restricted brain distribution and functional expression in arteriolar smooth muscle cells. J. Neurosci. 2011, 31, 5067–5077. [Google Scholar] [CrossRef]
  83. Pacher, P.; Bátkai, S.; Kunos, G. Cardiovascular pharmacology of cannabinoids. Handb. Exp. Pharmacol. 2005, 168, 599–625. [Google Scholar]
  84. Feng, L.; Uteshev, V.V.; Premkumar, L.S. Expression and Function of Transient Receptor Potential Ankyrin 1 Ion Channels in the Caudal Nucleus of the Solitary Tract. Int. J. Mol. Sci. 2019, 20, E2065. [Google Scholar] [CrossRef] [PubMed]
  85. Eroli, F.; Loonen, I.C.M.; van den Maagdenberg, A.M.J.M.; Tolner, E.A.; Nistri, A. Differential neuromodulatory role of endocannabinoids in the rodent trigeminal sensory ganglion and cerebral cortex relevant to pain processing. Neuropharmacology 2018, 131, 39–50. [Google Scholar] [CrossRef]
  86. Mohammed, M.; Madden, C.J.; Andresen, M.C.; Morrison, S.F. Activation of TRPV1 in nucleus tractus solitarius reduces brown adipose tissue thermogenesis, arterial pressure, and heart rate. Am. J. Physiol. Regul. Integr. Comp. Physiol. 2018, 315, R134–R143. [Google Scholar] [CrossRef]
  87. Hermes, S.M.; Andresen, M.C.; Aicher, S.A. Localization of TRPV1 and P2X3 in unmyelinated and myelinated vagal afferents in the rat. J. Chem. Neuroanat. 2016, 72, 1–7. [Google Scholar] [CrossRef] [PubMed]
  88. Fenwick, A.J.; Wu, S.W.; Peters, J.H. Isolation of TRPV1 independent mechanisms of spontaneous and asynchronous glutamate release at primary afferent to NTS synapses. Front. Neurosci. 2014, 8, 6. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  89. Quartu, M.; Serra, M.P.; Boi, M.; Poddighe, L.; Picci, C.; Demontis, R.; Del Fiacco, M. TRPV1 receptor in the human trigeminal ganglion and spinal nucleus: Immunohistochemical localization and comparison with the neuropeptides CGRP and SP. J. Anat. 2016, 229, 755–767. [Google Scholar] [CrossRef]
  90. Chatchaisak, D.; Srikiatkhachorn, A.; Maneesri-le Grand, S.; Govitrapong, P.; Chetsawang, B. The role of calcitonin gene-related peptide on the increase in transient receptor potential vanilloid-1 levels in trigeminal ganglion and trigeminal nucleus caudalis activation of rat. J. Chem. Neuroanat. 2013, 47, 50–56. [Google Scholar] [CrossRef]
  91. Xing, J.; Li, J. TRPV1 receptor mediates glutamatergic synaptic input to dorsolateral periaqueductal gray (dl-PAG) neurons. J. Neurophysiol. 2007, 97, 503–511. [Google Scholar] [CrossRef]
  92. Mohammadi-Farani, A.; Sahebgharani, M.; Sepehrizadeh, Z.; Jaberi, E.; Ghazi-Khansari, M. Diabetic thermal hyperalgesia: Role of TRPV1 and CB1 receptors of periaqueductal gray. Brain Res. 2010, 1328, 49–56. [Google Scholar] [CrossRef]
  93. Palazzo, E.; Luongo, L.; de Novellis, V.; Berrino, L.; Rossi, F.; Maione, S. Moving towards supraspinal TRPV1 receptors for chronic pain relief. Mol. Pain. 2010, 6, 66. [Google Scholar] [CrossRef] [PubMed]
  94. Samineni, V.K.; Premkumar, L.S.; Faingold, C.L. Neuropathic pain-induced enhancement of spontaneous and pain-evoked neuronal activity in the periaqueductal gray that is attenuated by gabapentin. Pain 2017, 158, 1241–1253. [Google Scholar] [CrossRef] [PubMed]
  95. Mascarenhas, D.C.; Gomes, K.S.; Nunes-de-Souza, R.L. Role of TRPV1 channels of the dorsal periaqueductal gray in the modulation of nociception and open elevated plus maze-induced antinociception in mice. Behav. Brain Res. 2015, 292, 547–554. [Google Scholar] [CrossRef] [PubMed]
  96. Madasu, M.K.; Okine, B.N.; Olango, W.M.; Rea, K.; Lenihan, R.; Roche, M.; Finn, D.P. Genotype-dependent responsivity to inflammatory pain: A role for TRPV1 in the periaqueductal grey. Pharmacol. Res. 2016, 113, 44–54. [Google Scholar] [CrossRef]
  97. Gavva, N.R.; Bannon, A.W.; Hovland DNJr Lehto, S.G.; Klionsky, L.; Surapaneni, S.; Immke, D.C.; Henley, C.; Arik, L.; Bak, A.; Davis, J.; et al. Repeated administration of vanilloid receptor TRPV1 antagonists attenuates hyperthermia elicited by TRPV1 blockade. J. Pharmacol. Exp. Ther. 2007, 323, 128–137. [Google Scholar] [CrossRef]
  98. McPartland, J.M.; Duncan, M.; Di Marzo, V.; Pertwee, R.G. Are cannabidiol and Δ(9)-tetrahydrocannabivarin negative modulators of the endocannabinoid system? Asystematic review. Br. J. Pharmacol. 2015, 172, 737–753. [Google Scholar] [CrossRef] [Green Version]
  99. Laprairie, R.B.; Bagher, A.M.; Kelly, M.E.; Denovan-Wright, E.M. Cannabidiol is a negative allosteric modulator of the cannabinoid CB1 receptor. Br. J. Pharmacol. 2015, 172, 4790–4805. [Google Scholar] [CrossRef]
  100. Scuderi, C.; Filippis, D.D.; Iuvone, T.; Blasio, A.; Steardo, A.; Esposito, G. Cannabidiol in medicine: A review of its therapeutic potential in CNS disorders. Phytother. Res. 2009, 23, 597–602. [Google Scholar] [CrossRef]
  101. Hill, A.J.; Williams, C.M.; Whalley, B.J.; Stephens, G.J. Phytocannabinoids as novel therapeutic agents in CNS disorders. Pharmacol. Ther. 2012, 133, 79–97. [Google Scholar] [CrossRef]
  102. Al-Ghezi, Z.Z.; Miranda, K.; Nagarkatti, M.; Nagarkatti, P.S. Combination of Cannabinoids, Δ9- Tetrahydrocannabinol and Cannabidiol, Ameliorates Experimental Multiple Sclerosis by Suppressing Neuroinflammation Through Regulation of miRNA-Mediated Signaling Pathways. Front. Immunol. 2019, 10, 1921. [Google Scholar] [CrossRef]
  103. Überall, M.A. A Review of Scientific Evidence for THC:CBD Oromucosal Spray (Nabiximols) in the Management of Chronic Pain. J. Pain Res. 2020, 13, 399–410. [Google Scholar] [CrossRef] [PubMed]
  104. MacCallum, C.A.; Russo, E.B. Practical considerations in medical cannabis administration and dosing. Eur. J. Intern. Med. 2018, 49, 12–19. [Google Scholar] [CrossRef] [PubMed]
  105. Urasaki, Y.; Beaumont, C.; Workman, M.; Talbot, J.N.; Hill, D.K.; Le, T.T. Potency Assessment of CBD Oils by Their Effects on Cell Signaling Pathways. Nutrients 2020, 12, 357. [Google Scholar] [CrossRef] [PubMed]
  106. Stockings, E.; Campbell, G.; Hall, W.D.; Nielsen, S.; Zagic, D.; Rahman, R.; Murnion, B.; Farrell, M.; Weier, M.; Degenhardt, L. Cannabis and cannabinoids for the treatment of people with chronic noncancer pain conditions: A systematic review and meta-analysis of controlled and observational studies. Pain 2018, 159, 1932–1954. [Google Scholar] [CrossRef]
  107. National academies of sciences engineering and medicine. The Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and Recommendations for Research; The National Academies Press: Washington, DC, USA, 2017. [Google Scholar]
  108. Pabbidi, R.M.; Yu, S.Q.; Peng, S.; Khardori, R.; Pauza, M.E.; Premkumar, L.S. Influence of TRPV1 on diabetes-induced alterations in thermal pain sensitivity. Mol. Pain 2008, 1, 9. [Google Scholar] [CrossRef]
  109. Bishnoi, M.; Bosgraaf, C.A.; Premkumar, L.S. Preservation of acute pain and efferent functions following intrathecal resiniferatoxin-induced analgesia in rats. J. Pain 2011, 12, 991–1003. [Google Scholar] [CrossRef] [Green Version]
  110. NCT00804154; Resiniferatoxin to Treat Severe Pain Associated with Advanced Cancer Dec 2008–Dec 2014. National Institute of Dental and Craniofacial Research (NIDCR): Bethesda, MD, USA, 2022.
  111. Mitchell, K.; Lebovitz, E.E.; Keller, J.M.; Mannes, A.J.; Nemenov, M.I.; Iadarola, M.J. Nociception and inflammatory hyperalgesia evaluated in rodents using infrared laser stimulation after Trpv1 gene knockout or resiniferatoxin lesion. Pain 2014, 155, 733–745. [Google Scholar] [CrossRef]
  112. Brown, D.C.; Agnello, K.; Iadarola, M.J. Intrathecal resiniferatoxin in a dog model: Efficacy in bone cancer pain. Pain 2015, 156, 1018–1024. [Google Scholar] [CrossRef]
  113. Salas, M.M.; Clifford, J.L.; Hayden, J.R.; Iadarola, M.J.; Averitt, D.L. Local Resiniferatoxin Induces Long-Lasting Analgesia in a Rat Model of Full Thickness Thermal Injury. Pain Med. 2017, 18, 2453–2465. [Google Scholar] [CrossRef]
  114. Yu, S.; Premkumar, L.S. Ablation and regeneration of peripheral and Central TRPV1 Expressing Nerve Terminals and the Consequence of Nociception. The Open Pain J. 2015, 8, 1–9. [Google Scholar] [CrossRef]
  115. ClinicalTrials.gov Identifier: NCT04044742, A Phase 3 Study to Evaluate the Efficacy and Safety of Resiniferatoxin for Pain Due to Osteoarthritis of the Knee. Available online: https://clinicaltrials.gov/ct2/show/NCT04044742 (accessed on 28 August 2022).
  116. Clinical Trials.gov Identifier: NCT00804154, Resiniferatoxin to Treat Severe Pain Associated with Advanced Cancer. Available online: https://clinicaltrials.gov/ct2/show/NCT00804154 (accessed on 28 August 2022).
  117. Ashina, M.; Hansen, J.M.; Do, T.P.; Melo-Carrillo, A.; Burstein, R.; Moskowitz, M.A. Migraine and the trigeminovascular system—40 years and counting. Lancet Neurol. 2019, 18, 795–804. [Google Scholar] [CrossRef]
  118. Edvinsson, L.; Haanes, K.A.; Warfvinge, K.; Krause, D.N. CGRP as the target of new migraine therapies-successful translation from bench to clinic. Nat. Rev. Neurol. 2018, 14, 338–350. [Google Scholar] [CrossRef] [PubMed]
  119. Rhyne, D.N.; Anderson, S.L.; Gedde, M.; Borgelt, L.M. Effects of Medical Marijuana on Migraine Headache Frequency in an Adult Population. Pharmacotherapy 2016, 36, 505–510. [Google Scholar] [CrossRef] [PubMed]
  120. Greco, R.; Demartini, C.; Zanaboni, A.M.; Piomelli, D.; Tassorelli, C. Endocannabinoid System and Migraine Pain: An Update. Front Neurosci. 2018, 12, 172. [Google Scholar] [CrossRef]
  121. Williamson, E.M.; Evans, F.J. Cannabinoids in clinical practice. Drugs 2000, 60, 1303–1314. [Google Scholar] [CrossRef]
  122. Papanastassiou, A.M.; Fields, H.L.; Meng, I.D. Local application of the cannabinoid receptor agonist, WIN 55,212–2, to spinal trigeminal nucleus caudalis differentially affects nociceptive and non-nociceptive neurons. Pain 2004, 107, 267–275. [Google Scholar] [CrossRef]
  123. Bradshaw, H.B.; Walker, J.M. The expanding field of cannabimimetic and related lipid mediators. Br. J. Pharmacol. 2005, 144, 459–465. [Google Scholar] [CrossRef]
  124. Pacher, P.; Bátkai, S.; Kunos, G. The endocannabinoid system as an emerging target of pharmacotherapy. Pharmacol. Rev. 2006, 58, 389–462. [Google Scholar] [CrossRef]
  125. Hill, M.N.; Hillard, C.J.; Bambico, F.R.; Patel, S.; Gorzalka, B.B.; Gobbi, G. The therapeutic potential of the endocannabinoid system for the development of a novel class of antidepressants. Trends Pharmacol. Sci. 2009, 30, 484–493. [Google Scholar] [CrossRef]
  126. Piomelli, D. The molecular logic of endocannabinoid signalling. Nat. Rev. Neurosci. 2003, 4, 873–884. [Google Scholar] [CrossRef]
  127. Di Marzo, V.; De Petrocellis, L.; Bisogno, T. The biosynthesis, fate and pharmacological properties of endocannabinoids. Handb. Exp. Pharmacol. 2005, 168, 147–185. [Google Scholar]
  128. Tsuboi, K.; Uyama, T.; Okamoto, Y.; Ueda, N. Endocannabinoids and related N-acylethanolamines: Biological activities and metabolism. Inflamm Regen. 2018, 38, 28. [Google Scholar] [CrossRef] [PubMed]
  129. Fu, J.; Oveisi, F.; Gaetani, S.; Lin, E.; Piomelli, D. Oleoylethanolamide, an endogenous PPAR-alpha agonist, lowers body weight and hyperlipidemia in obese rats. Neuropharmacology 2005, 48, 1147–1153. [Google Scholar] [CrossRef] [PubMed]
  130. Ahern, G.P. Activation of TRPV1 by the satiety factor oleoylethanolamide. J. Biol. Chem. 2003, 278, 30429–30434. [Google Scholar] [CrossRef]
  131. Hansen, H.S.; Diep, T.A. N-acylethanolamines, anandamide and food intake. Biochem. Pharmacol. 2009, 78, 553–560. [Google Scholar] [CrossRef] [PubMed]
  132. Liao, H.T.; Lee, H.J.; Ho, Y.C.; Chiou, L.C. Capsaicin in the periaqueductal gray induces analgesia via metabotropic glutamate receptor-mediated endocannabinoid retrograde disinhibition. Br. J. Pharmacol. 2011, 163, 330–345. [Google Scholar] [CrossRef]
  133. Millan, M.J. Descending control of pain. Prog. Neurobiol. 2002, 66, 355–474. [Google Scholar] [CrossRef]
  134. Heinricher, M.M.; Tavares, I.; Leith, J.L.; Lumb, B.M. Descending control of nociception: Specificity, recruitment and plasticity. Brain Res. Rev. 2009, 60, 214–225. [Google Scholar] [CrossRef]
  135. Roychowdhury, S.M.; Fields, H.L. Endogenous opioids acting at a medullary mu-opioid receptor contribute to the behavioral antinociception produced by GABA antagonism in the midbrain periaqueductal gray. Neuroscience 1996, 74, 863–872. [Google Scholar] [CrossRef]
  136. Starowicz, K.; Nigam, S.; Di Marzo, V. Biochemistry and pharmacology of endovanilloids. Pharmacol Ther. 2007, 114, 13–33. [Google Scholar] [CrossRef]
  137. Jones, S.L. Dipyrone into the nucleus raphe magnus inhibits the rat nociceptive tail-flick reflex. Eur. J. Pharmacol. 1996, 318, 37–40. [Google Scholar] [CrossRef]
  138. Heinricher, M.M.; Neubert, M.J. Neural basis for the hyperalgesic action of cholecystokinin in the rostral ventromedial medulla. J. Neurophysiol. 2004, 92, 1982–1989. [Google Scholar] [CrossRef] [PubMed]
  139. Drew, G.M.; Lau, B.K.; Vaughan, C.W. Substance P drives endocannabinoid-mediated disinhibition in a midbrain descending analgesic pathway. J. Neurosci. 2009, 29, 7220–7229. [Google Scholar] [CrossRef] [PubMed]
  140. Behbehani, M.M.; Jiang, M.; Chandler, S.D. The effect of [Met] enkephalin on the periaqueductal gray neurons of the rat: An in vitro study. Neuroscience 1990, 38, 373–380. [Google Scholar] [CrossRef]
  141. Vaughan, C.W.; Ingram, S.L.; Connor, M.A.; Christie, M.J. How opioids inhibit GABA-mediated neurotransmission. Nature 1997, 390, 611–614. [Google Scholar] [CrossRef]
  142. Finn, D.P.; Jhaveri, M.D.; Beckett, S.R.; Roe, C.H.; Kendall, D.A.; Marsden, C.A.; Chapman, V. Effects of direct periaqueductal grey administration of a cannabinoid receptor agonist on nociceptive and aversive responses in rats. Neuropharmacology 2003, 45, 594–604. [Google Scholar] [CrossRef]
  143. de Novellis, V.; Luongo, L.; Guida, F.; Cristino, L.; Palazzo, E.; Russo, R.; Marabese, I.; D’Agostino, G.; Calignano, A.; Rossi, F.; et al. Effects of intra- ventrolateral periaqueductal grey palmitoylethanolamide on thermoceptive threshold and rostral ventromedial medulla cell activity. Eur. J. Pharmacol. 2012, 676, 41–50. [Google Scholar] [CrossRef]
  144. Kawahara, H.; Drew, G.M.; Christie, M.J.; Vaughan, C.W. Inhibition of fatty acid amide hydrolase unmasks CB1 receptor and TRPV1 channel-mediated modulation of glutamatergic synaptic transmission in midbrain periaqueductal grey. Br. J. Pharmacol. 2011, 163, 1214–1222. [Google Scholar] [CrossRef]
  145. Hermann, H.; De Petrocellis, L.; Bisogno, T.; Schiano Moriello, A.; Lutz, B.; Di Marzo, V. Dual effect of cannabinoid CB1 receptor stimulation on a vanilloid VR1 receptor-mediated response. Cell. Mol. Life. Sci. 2003, 60, 607–616. [Google Scholar] [CrossRef] [PubMed]
  146. Back, F.P.; Carobrez, A.P. Periaqueductal gray glutamatergic, cannabinoid and vanilloid receptor interplay in defensive behavior and aversive memoryformation. Neuropharmacology 2018, 135, 399–411. [Google Scholar] [CrossRef]
  147. Campos, A.C.; Guimarães, F.S. Involvement of 5HT1A receptors in the anxiolytic- like effects of cannabidiol injected into the dorsolateral periaqueductal gray of rats. Psychopharmacology 2008, 199, 223–230. [Google Scholar] [CrossRef]
  148. Lopez-Alvarez, V.M.; Puigdomenech, M.; Navarro, X.; Cobianchi, S. Monoaminergic descending pathways contribute to modulation of neuropathic pain by increasing-intensity treadmill exercise after peripheral nerve injury. Exp. Neurol. 2018, 299, 42–55. [Google Scholar] [CrossRef] [PubMed]
  149. Mason, P. Contributions ofthe medullary raphe and ventromedial reticular region to pain modulation and other homeostatic functions. Annu. Rev. Neurosci. 2001, 24, 737–777. [Google Scholar] [CrossRef] [PubMed]
  150. Qing-Ping, W.; Nakai, Y. The dorsal raphe: An important nucleus in pain modulation. Brain. Res. Bull. 1994, 34, 575–585. [Google Scholar] [CrossRef]
  151. Schweimer, J.; Ungless, M. Phasic responses in dorsal raphe serotonin neurons to noxious stimuli. Neuroscience 2010, 171, 1209–1215. [Google Scholar] [CrossRef] [PubMed]
  152. Sagheddu, C.; Aroni, S.; De Felice, M.; Lecca, S.; Luchicchi, A.; Melis, M.; Muntoni, A.L.; Romano, R.; Palazzo, E.; Guida, F.; et al. Enhanced serotonin and mesolimbic dopamine transmissions in a rat model of neuropathic pain. Neuropharmacology 2015, 97, 383–393. [Google Scholar] [CrossRef]
  153. Campos, A.C.; Ferreira, F.R.; Guimarães, F.S. Cannabidiol blocks long-lasting behavioral consequences of predator threat stress: Possible involvement of 5HT1A receptors. J. Psychiatr. Res. 2012, 46, 1501–1510. [Google Scholar] [CrossRef]
  154. Russo, E.B.; Burnett, A.; Hall, B.; Parker, K.K. Agonistic properties of cannabidiol at 5-HT1a receptors. Neurochem. Res. 2005, 30, 1037–1043. [Google Scholar] [CrossRef]
  155. Martín-Sánchez, E.; Furukawa, T.A.; Taylor, J.; Martin, J.L. Systematic Review and Meta-analysis of Cannabis Treatment for Chronic Pain. Pain Med. 2009, 10, 1353–1368. [Google Scholar] [CrossRef]
  156. Bergamaschi, M.M.; Queiroz, R.H.; Chagas, M.H.; de Oliveira, D.C.; De Martinis, B.S.; Kapczinski, F.; Quevedo, J.; Roesler, R.; Schröder, N.; Nardi, A.E.; et al. Cannabidiol Reduces the Anxiety Induced by Simulated Public Speaking in Treatment-Naïve Social Phobia Patients. Neuropsychopharmacology 2011, 36, 1219–1226. [Google Scholar] [CrossRef]
  157. Zanelati, T.V.; Biojone, C.; Moreira, F.A.; Guimarães, F.S.; Joca, S.R. Antidepressant-like effects of cannabidiol in mice: Possible involvement of 5-HT1A receptors. Br. J. Pharmacol. 2010, 159, 122–128. [Google Scholar] [CrossRef] [PubMed]
  158. Horwood, L.J.; Fergusson, D.M.; Coffey, C.; Patton, G.C.; Tait, R.; Smart, D.; Letcher, P.; Silins, E.; Hutchinson, D.M. Cannabis and depression: An integrative data analysis of four Australasian cohorts. Drug Alcohol Depend. 2012, 126, 369–378. [Google Scholar] [CrossRef] [PubMed]
  159. Mack, A.; Joy, J. Marijuana as Medicine? The Science Beyond the Controversy; National Academies Press: Washington, DC, USA, 2000. [Google Scholar]
  160. Miller, A.D.; Ruggiero, D.A. Emetic reflex arc revealed by expression of the immediate-early gene c-fos in the cat. J. Neurosci. 1994, 14, 871–888. [Google Scholar] [CrossRef] [PubMed]
  161. Consroe, P.; Musty, R.; Rein, J.; Tillery, W.; Pertwee, R. The Perceived Effects of Smoked Cannabis on Patients with Multiple Sclerosis. Eur. Neurol. 1997, 38, 44–48. [Google Scholar] [CrossRef] [PubMed]
  162. Kogan, M.N.; Mechoulam, R. Cannabinoids in health and disease. Dialogues Clin. Neurosci. 2007, 9, 413–430. [Google Scholar] [CrossRef]
  163. Sarrafpour, S.; Urits, I.; Powell, J.; Nguyen, D.; Callan, J.; Orhurhu, V.; Simopoulos, T.; Viswanath, O.; Kaye, A.D.; Kaye, R.J.; et al. Considerations and Implications of Cannabidiol Use During Pregnancy. Curr. Pain Headache Rep. 2020, 24, 38. [Google Scholar] [CrossRef]
  164. Frau, R.; Miczán, V.; Traccis, F.; Aroni, S.; Pongor, C.I.; Saba, P.; Serra, V.; Sagheddu, C.; Fanni, S.; Congiu, M.; et al. Prenatal THC exposure produces a hyperdopaminergic phenotype rescued by pregnenolone. Nat. Neurosci. 2019, 22, 1975–1985. [Google Scholar] [CrossRef] [Green Version]
  165. Andrews, P.L.; Horn, C.C. Signals for nausea and emesis: Implications for models of upper gastrointestinal diseases. Auton. Neurosci. 2006, 125, 100–115. [Google Scholar] [CrossRef]
  166. Hornby, P.J. Central neurocircuitry associated with emesis. Am. J. Med. 2001, 111, 106S–112S. [Google Scholar] [CrossRef]
  167. Parker, L.A.; Mechoulam, R.; Schlievert, C. Cannabidiol, a non-psychoactive component of cannabis and its synthetic dimethylheptyl homolog suppress nausea in an experimental model with rats. NeuroReport 2002, 13, 567–570. [Google Scholar] [CrossRef]
  168. Miller, A.D. Central mechanisms of vomiting. Dig. Dis. Sci. 1999, 44, 39S–43S. [Google Scholar] [PubMed]
  169. Martin, B.R.; Wiley, J.L. Mechanism of action of cannabinoids: How it may lead to treatment of cachexia, emesis, and pain. J. Support. Oncol. 2004, 2, 305–316. [Google Scholar] [PubMed]
  170. Cangemi, D.J.; Kuo, B. Practical Perspectives in the Treatment of Nausea and Vomiting. J. Clin. Gastroenterol. 2019, 53, 170–178. [Google Scholar] [CrossRef] [PubMed]
  171. Smith, T.N.; Walsh, A.; Forest, C.P. Cannabinoid hyperemesis syndrome: An unrecognized cause of nausea and vomiting. JAAPA 2019, 32, 1–5. [Google Scholar] [CrossRef] [PubMed]
  172. Richards, J.R.; Lapoint, J.M.; Burillo-Putze, G. Cannabinoid hyperemesis syndrome: Potential mechanisms for the benefit of capsaicin and hot water hydrotherapy in treatment. Clin. Toxicol. 2018, 56, 15–24. [Google Scholar] [CrossRef]
  173. Richards, J.R. Cannabinoid Hyperemesis Syndrome: Pathophysiology and Treatment in the Emergency Department. J. Emerg. Med. 2018, 54, 354–363. [Google Scholar] [CrossRef]
  174. Dezieck, L.; Hafez, Z.; Conicella, A.; Blohm, E.; O’Connor, M.J.; Schwarz, E.S.; Mullins, M.E. Resolution of cannabis hyperemesis syndrome with topical capsaicin in the emergency department: A case series. Clin. Toxicol. 2017, 55, 908–913. [Google Scholar] [CrossRef]
  175. Storr, M.A.; Sharkey, K.A. The endocannabinoid system and gut-brain signalling. Curr. Opin. Pharmacol. 2007, 7, 575–582. [Google Scholar] [CrossRef]
  176. Mortimer, T.L.; Mabin, T.; Engelbrecht, A.M. Cannabinoids: The lows and the highs of chemotherapy-induced nausea and vomiting. Future Oncol. 2019, 15, 1035–1049. [Google Scholar] [CrossRef]
  177. May, M.B.; Glode, A.E. Dronabinol for chemotherapy-induced nausea and vomiting unresponsive to antiemetics. Cancer Manag. Res. 2016, 8, 49–55. [Google Scholar]
  178. Schicho, R.; Donnerer, J.; Liebmann, I.; Lippe, I.T. Nociceptive transmitter release in the dorsal spinal cord by capsaicin-sensitive fibers after noxious gastric stimulation. Brain Res. 2005, 1039, 108–115. [Google Scholar] [CrossRef] [PubMed]
  179. Darmani, N.A.; Chebolu, S.; Zhong, W.; Trinh, C.; McClanahan, B.; Brar, R.S. Additive antiemetic efficacy of low-doses of the cannabinoid CB(1/2) receptor agonist Δ(9)-THC with ultralow-doses of the vanilloid TRPV1 receptor agonist resiniferatoxin in the least shrew (Cryptotis parva). Eur. J. Pharmacol. 2014, 722, 147–155. [Google Scholar] [CrossRef] [PubMed]
  180. Peters, J.H.; McDougall, S.J.; Fawley, J.A.; Andresen, M.C. TRPV1 marks synaptic segregation of multiple convergent afferents at the rat medial solitary tract nucleus. PLoS ONE 2011, 6, e25015. [Google Scholar] [CrossRef]
  181. Huda, R.; Chang, Z.; Do, J.; McCrimmon, D.R.; Martina, M. Activation of astrocytic PAR1 receptors in the rat nucleus of the solitary tract regulates breathing through modulation of presynaptic TRPV1. J. Physiol. 2018, 596, 497–513. [Google Scholar] [CrossRef]
  182. Andrews, P.L.; Okada, F.; Woods, A.J.; Hagiwara, H.; Kakaimoto, S.; Toyoda, M.; Matsuki, N. The emetic and anti-emetic effects of the capsaicin analogue resiniferatoxin in Suncus murinus, the house musk shrew. Br. J. Pharmacol. 2000, 130, 1247–1254. [Google Scholar] [CrossRef]
  183. Badri, H.; Smith, J.A. Emerging targets for cough therapies; NK1 receptor antagonists. Pulm. Pharmacol. Ther. 2019, 59, 101853. [Google Scholar] [CrossRef] [PubMed]
  184. Lorusso, V.; Russo, A.; Giotta, F.; Codega, P. Management of Chemotherapy Induced Nausea and Vomiting (CINV): A Short Review on the Role of Netupitant- Palonosetron (NEPA). Core Evid. 2020, 15, 21–29. [Google Scholar] [CrossRef]
  185. Johnston, K.D. The potential for mu-opioid receptor agonists to be anti-emetic in humans: A review of clinical data. Acta Anaesthesiol. Scand. 2010, 54, 132–140. [Google Scholar] [CrossRef]
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Louis-Gray, K.; Tupal, S.; Premkumar, L.S. TRPV1: A Common Denominator Mediating Antinociceptive and Antiemetic Effects of Cannabinoids. Int. J. Mol. Sci. 2022, 23, 10016. https://doi.org/10.3390/ijms231710016

AMA Style

Louis-Gray K, Tupal S, Premkumar LS. TRPV1: A Common Denominator Mediating Antinociceptive and Antiemetic Effects of Cannabinoids. International Journal of Molecular Sciences. 2022; 23(17):10016. https://doi.org/10.3390/ijms231710016

Chicago/Turabian Style

Louis-Gray, Kathleen, Srinivasan Tupal, and Louis S. Premkumar. 2022. "TRPV1: A Common Denominator Mediating Antinociceptive and Antiemetic Effects of Cannabinoids" International Journal of Molecular Sciences 23, no. 17: 10016. https://doi.org/10.3390/ijms231710016

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