Search Results (68)

Ixora chinensis Lam. has traditionally been used to treat conditions such as acne, high blood pressure, bleeding, tuberculosis, and rheumatism. This study aimed to investigate the methanolic extract of I. chinensis leaves to determine their bioactive compounds and evaluate their effects on both central and peripheral pain using in vivo and in silico approaches. The GC-MS analysis revealed 41 phytochemicals, including 14 phenolics, 4 esters, 12 terpenoids, 8 alkaloids, and 3 sulfur-containing compounds. In the glucose tolerance test, both the chloroform-soluble fraction (CF) and n-hexane fraction (NHF) exhibited p < 0.05 reductions in blood glucose levels at a dosage of 400 mg/kg with decreases of 51.94% and 46.63%, respectively, compared to the positive control (64.02%). The central analgesic evaluation showed significant (p < 0.001) enhancements in tail-flick latency for the fraction (184.94%) and CF (170.51%) following 90 min. In the pain relief assay, NHF showed inhibition (64.33%, p < 0.001) followed by an aqueous fraction (57.35%). These pharmacological findings were supported by in silico analysis. Concerning activity, 5-(dimethylamino)-1- acid phenyl ester (−8.9 kcal/mol) and 9,9-dimethyl-9H-fluoren-3-ol (−8.4 kcal/mol) displayed the strongest binding affinity to AMPK. Additionally, 2,3-diphenyl-2-cyclopropen-1-one exhibited favorable interactions with α-amylase (−8.0 kcal/mol) and α-glucosidase (−8.3 kcal/mol). Similarly, the central analgesic effect correlated with the strong μ-opioid receptor affinity of s-Triazine, 2-amino-4-(piperidinomethyl)-4-piperidino (−8.8 kcal/mol). N-Methyl-N-(4-toluenesulfonyl)-benzamide (−8.6 kcal/mol) and s-Triazine derivative (−8.9 kcal/mol) demonstrated notable COX-1 and COX-2 inhibition potential. Overall, the findings indicate I. chinensis leaves as a promising source of bioactive compounds with significant antihyperglycemic and analgesic properties. Full article

Nutritional strategies based on sourdough fermented breads with wholemeal ancient grains and legumes are emerging as promising modulators of (neuro)immune processes. This study investigated whether prolonged consumption of a sourdough bread enriched with a mixture of ancient cereals and legumes, commercially available in Italy (Primus^® bread, P^®B), modulates neuroimmune systemic responses to repeated lipopolysaccharide (LPS) challenge in mice. For this study, male C57BL/6J mice were fed for 14 days with either a standard diet (SD) or P^®B. Animals then received intraperitoneal LPS (3 mg/kg/day for 3 days) or vehicle. Body weight and food intake were monitored throughout. Pain-like behaviours were assessed by von Frey, plantar and tail flick tests, and plasma cytokine (32-plex panel), splenocyte and peritoneal macrophage cytokine expression, and expression of pro-inflammatory cytokines in sciatic nerves, dorsal root ganglia (DRG) and the spinal cord were analyzed by Reverse Transcription–quantitative Polymerase Chain Reaction (RT-qPCR). P^®B prevented LPS-induced body weight loss and reduced splenomegaly. Unlike SD mice, which exhibited widespread plasmatic cytokine upregulation, P^®B-fed mice displayed only limited increases Interleukin (IL)-1β, IL-12p40 and Tumor Necrosis Factor (TNF)α. Ex vivo cultures of splenocytes and macrophages confirmed attenuated cytokine overexpression. LPS-induced hypersensitivity to mechanical, thermal and nociceptive stimuli was significantly reduced in P^®B mice. Molecular analyses revealed that the P^®B diet blunted the pro-inflammatory cytokine expression present after LPS challenge in the sciatic nerves and DRG, with partial attenuation in the spinal cord. Our findings highlight the great potential of functional foods as affordable dietary strategies to mitigate systemic immune and neuroimmune dysregulation. Full article

Background: Diabetic peripheral neuropathy (DPN) is one of the most common and debilitating complications of diabetes mellitus, for which current therapies do not prevent nerve degeneration. Chitosan, a biocompatible polysaccharide with antioxidant, anti-inflammatory, and lipid-lowering properties, may exert direct neuroprotective effects. This study evaluated the impact of oral administration of chitosan on peripheral nerve function and structure in a murine model of streptozotocin (STZ)-induced diabetes. Methods: Male C57BL/6 mice were divided into three groups: Sham, untreated diabetics (T1DM) and diabetics treated with chitosan (150 mg/kg/day, 12 weeks). Metabolic, behavioral (Open Field), nociceptive (Von Frey, Tail-Flick), electrophysiological (compound motor action potential—CMAP) and histological (intraepidermal nerve fiber density—IENF) parameters were analyzed. Results: Chitosan did not significantly modify blood glucose (p = 0.3366), but showed favorable metabolic effects, reducing LDL cholesterol in T1DM+Chitosan vs. T1DM mice (43.75 ± 5.62 mg/dL vs. 82.75 ± 7.65 mg/dL, p < 0.0001) as well as triglycerides (103.5 ± 12.8 mg/dL vs. 175.5 ± 22.8 mg/dL, p < 0.0001). In nociceptive tests, chitosan ameliorated thermal hyperalgesia (Tail-Flick: T1DM 1.25 ± 0.19 s vs. T1DM+Chitosan 1.54 ± 0.16 s; p = 0.0188) and mechanical allodynia (Von Frey: T1DM 0.16 ± 0.07 g vs. T1DM+Chitosan 0.38 ± 0.15 g, p = 0.0103). Electrodiagnostically, chitosan improved CMAP amplitude (T1DM 5.756 ± 0.706 mV vs. T1DM + Chitosan 6.756 ± 0.760 mV, p = 0.0409) and reduced CMAP duration (3.161 ± 0.217 ms vs. 2.900 ± 0.080 ms, p = 0.0273). Histologically, IENF density significantly increased in the treated group (0.01991 ± 0.00246 vs. 0.01512 ± 0.00253 in T1DM; p = 0.0200). Conclusions: Oral administration of chitosan confers functional and structural neuroprotection in STZ-induced diabetic neuropathy despite persistent hyperglycemia. Full article

Background/Objectives: Lidocaine hydrochloride (LD-HCl) is the most commonly used local anesthetic in dentistry, often administered with epinephrine to extend its duration and reduce systemic absorption. However, its relatively short duration of action, the need for repeated injections, and the unpleasant taste may limit patient compliance and procedural efficiency. This study aimed to develop and evaluate a novel injectable nanoemulsion-based in situ gel depot system of LD to provide prolonged anesthetic activity. Methods: LD-loaded nanoemulsions were formulated by high-shear homogenization followed by probe sonication, employing Miglyol 812 N (oil phase), a combination of Tween 80 and soy lecithin (surfactant–co-surfactant), glycerin, and deionized water (aqueous phase). The selected nanoemulsion (S1) was dispersed in a thermoreversible poloxamer solution to form a nanoemulgel. The preparation was evaluated for globule diameter and uniformity, zeta potential, surface morphology, pH, drug content, stability, rheological behavior, injectability, and in vitro drug release. Analgesic efficacy was assessed via tail-flick and thermal paw withdrawal latency tests in Wistar rats. Cardiovascular safety was monitored using non-invasive electrocardiography and blood pressure measurements. Results: The developed nanoemulsions demonstrated a spherical shape, nanometer size (206 nm), high zeta-potential (−66.67 mV) and uniform size distribution, with a polydispersity index of approximately 0.40, while the nanoemulgel demonstrated appropriate thixotropic properties for parenteral administration. In vitro release profiles showed steady LD release (5 h), following the Higuchi model. In vivo studies showed significantly prolonged analgesic effects lasting up to 150 min (2.5 h) compared to standard LD-HCl injection (p < 0.001), with no adverse cardiovascular effects observed. Conclusions: The developed injectable LD in situ nanoemulgel offers a promising, patient-friendly alternative for prolonged anesthetic delivery in dental and operative procedures, potentially reducing the need for repeated injections and enhancing procedural comfort. Full article

Objective: Morphine is a widely used analgesic for severe pain, but tolerance is a major challenge in long-term pain management. This study examined the potential of Daflon^® to enhance morphine’s pain-relieving effects and to reduce tolerance in a rat model with neuropathic pain induced by partial sciatic nerve transection (PSNT). Methods: Male Wistar rats were divided into five groups: (1) Sham + Saline, (2) PSNT + Saline, (3) PSNT + morphine, (4) PSNT + Daflon, and (5) PSNT + morphine + Daflon. Morphine tolerance was induced through continuous intrathecal infusion (15 µg/µL/h, i.t.) for 7 days, starting on day 7 post-PSNT, while Daflon was administered orally (50 mg/kg/day, oral) for 7 days. Pain relief was assessed using tail-flick and paw withdrawal on days 1, 4, and 7 after osmotic pump implantation. Spinal cords were collected for immunohistochemistry to analyze glial expression, and serum biomarkers (TNF-α, IL-1β, IL-6, and IL-10) were measured to evaluate neuroinflammation. Results: The results showed that oral Daflon significantly enhanced morphine’s analgesic effects, evidenced by improved pain thresholds in all behavioral tests. Moreover, Daflon reduced morphine tolerance. Mechanistically, Daflon upregulated the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and activated heme oxygenase-1 (HO-1), reducing oxidative stress and modulating neuroinflammation through glial regulation. Combining morphine and Daflon reduces pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) and enhances anti-inflammatory IL-10 serum level, showing a synergistic effect in managing neuropathic pain with greater efficacy and lower drug dependence. Histology and immunohistochemistry evaluations further confirmed that morphine and Daflon co-treatment substantially reduced mononuclear cell infiltration, astrocyte activation (as indicated by GFAP expression), and microglial activation (as indicated by Iba-1 expression) compared to single treatment. Conclusions: Our findings suggest that dual therapy synergistically targets both oxidative stress and inflammatory pathways, leading to stronger neuroprotection and pain relief. Importantly, the combination approach may allow for lower opioid dosages, minimizing the risks of opioid-related side effects. Overall, morphine and Daflon co-administration offers a promising and safer strategy for managing neuropathic pain and preserving spinal cord integrity. Full article

The neuropeptide’s multifaceted involvement in various components of neural homeostasis impacts pain and behavioral regulation. One of the highly potent neuropeptides is dermorphin, extracted from the skin of the Amazon frog (Phyllomedusa sauvagei). The unique feature of dermorphin is the D-Ala residue in its sequence, which has inspired researchers to search for dermorphin analogs for use as pharmaceuticals. The primary objective of this study is to synthesize several new linear and cyclic dermorphin analogs and evaluate them as potential non-invasive analgesics. By exploring our method for converting linear peptides into 2,5-diketopiperazine(2,5-DKP) derivatives, which stabilize peptide structures, we synthesize several new dermorphin linear peptides and chimeric cyclopeptidomimetics. These compounds were tested in vitro and in vivo to determine their biological activities and potential applicability as pharmaceuticals. For the evaluation of in vitro opioid activity, the “Guinea Pig Ileum” (GPI) test was used. D2 showed the highest activity, and cyclopeptides D3 and D4 showed high activity. We can assume that dermorphin analogues D2, D3, and D4 are potent agonists of µ-type opioid receptors and have high opioid activity. However, this needs to be verified using molecular modeling methods in further research. The analgesic effects of dermorphins have been evaluated in the “Hot-Plate” and “Tail-Flick” tests. In rats, D2 dermorphin analogues demonstrated dose-dependent analgesic effect in the “Water Tail-Flick” test after intranasal administration. A smaller dose of 0.5 µg/kg resulted in 40% analgesia and a short-term state of stupor. The maximum long-lasting analgesia was observed at a dose of 1.0 µg/kg, which induced complete stupor. The analgesic effect of peptide D2 after intraperitoneal administration at a 5.0 mg/kg dose was over 50%. The “Open-Field” test demonstrated a dose-dependent (15, 50, 150 μg/kg) peptide D2 suppression effect on behavioural reactions in rats following intranasal administration. A new modification of linear peptides, combined with a 2,5-DKP scaffold (D3 and D4), proved promising for oral use based on the results of analgesic effect evaluation in mice following intragastric administration. Full article

Background: Chronic pain poses a major global health burden, often inadequately managed by conventional analgesics due to limited efficacy and side effects. In this context, plant-based therapies offer a promising alternative. This study aimed to evaluate the antioxidant and analgesic potential of four medicinal plants traditionally used for pain relief: Morus alba, Angelica archangelica, Valeriana officinalis, and Passiflora incarnata. Methods: Phytochemical analyses quantified total phenolic acid, flavonoid, and polyphenolic acid contents in the extracts. Antioxidant activity was assessed using the ABTS radical scavenging assay. Analgesic effects were evaluated in vivo using the hot-plate and tail-flick tests in mice treated for 14 days with plant extracts or paracetamol. Results: Morus alba showed the highest polyphenolic content and strongest antioxidant activity (IC₅₀ = 0.0695 mg/mL). In analgesic tests, Angelica archangelica demonstrated the most significant effect in the hot-plate test (72.2% increase in latency), while Valeriana officinalis had the highest efficacy in the tail-flick test (41.81%), exceeding paracetamol’s performance in that model. Conclusions: While antioxidant activity correlated with polyphenol content, analgesic effects appeared to involve additional mechanisms. These findings support the potential of Angelica archangelica and Valeriana officinalis as effective natural alternatives for pain relief. Full article

Background/Objectives: Indomethacin (IND) is a widely used non-steroidal anti-inflammatory drug (NSAID) effective in managing pain and inflammation. However, its therapeutic use is often limited by gastrointestinal irritation and low bioavailability. This study aimed to evaluate the biocompatibility, release kinetics, and analgesic potential of IND-loaded chitosan (CHIT)-stabilized lipid vesicles (IND-ves) in comparison to free IND, focusing on their in vivo effects and impact on somatic nociceptive reactivity in mice. Methods: IND-ves were prepared using a molecular droplet self-assembly technique, followed by CHIT coating to enhance stability and control drug release. Mice were administered either free IND or IND-ves, and various physiological parameters, including liver and kidney function, oxidative stress markers, immune cell activity, and histopathological changes in key organs, were assessed. Plasma drug release kinetics and analgesic effects were evaluated using the tail-flick test. Results: Both IND and IND-ves demonstrated good biocompatibility, with no significant changes in hematological, biochemical, or immunological profiles. IND-ves exhibited a sustained release profile, with drug release initiating at 30 min and peaking at 3 h, while free IND displayed a rapid release and potential gastric mucosal damage. IND-ves did not induce oxidative stress or inflammation and maintained organ integrity, particularly protecting against gastric injury. Additionally, the prolonged release profile of IND-ves contributed to extended analgesic effects in the tail-flick test. Conclusions: CHIT-stabilized lipid vesicles offer a promising drug delivery system for IND, enhancing drug release, prolonging analgesic efficacy, and minimizing gastrointestinal irritation. These findings suggest that IND-ves could serve as a safer and more effective alternative for NSAID therapy. Full article

Hydrazones, characterized by their C=N–NH functional group, are promising candidates in medicinal chemistry due to their ability to interact with biological targets. This study evaluated the anti-inflammatory and analgesic properties of N-pyrrolylcarbohydrazide (1) and four pyrrole hydrazone derivatives (1A–D) in male Wistar rats (6 weeks old). Anti-inflammatory activity was assessed using a carrageenan-induced paw edema model, while formalin, tail flick, and paw withdrawal tests evaluated analgesia. Compound 1 exhibited dose-dependent anti-inflammatory activity. At 20 mg/kg, significant edema reductions were observed at the 2nd (p = 0.035) and 3rd hours (p = 0.022), while at 40 mg/kg, reductions remained significant at the 2nd (p = 0.008) and 3rd hours (p = 0.046). Compound 1A showed pronounced effects at 20 mg/kg at the 2nd (p = 0.005), 3rd (p < 0.001), and 4th hours (p = 0.004). Other compounds demonstrated minimal or no activity. Analgesic evaluation revealed that at 40 mg/kg, compound 1 significantly reduced paw-licking time in the second phase (p = 0.038). Compounds 1B, 1C, and 1D exhibited transient effects in the first phase only (p < 0.05). Compound 1A lacked significant analgesic activity. The findings suggest that structural modifications may enhance efficacy for broader therapeutic applications. Full article

Background: Pain is a major clinical and socioeconomic problem worldwide. The available therapies are not always effective and are often associated with the multiple adverse effects that reduce their clinical application. Natural compounds are an important group of pharmaceuticals that may be used in pain management. We aimed to investigate the analgesic activity of the sanguinarine–chelerythrine from Coptis chinensis. Methods: The analgesic and anti-inflammatory activity of the sanguinarine–chelerythrine fraction of C. chinensis extract (SC 5 and 10 mg/kg), sanguinarine (SAN 1 and 2 mg/kg) and chelerythrine (CHEL 4 and 8 mg/kg) was assessed in tail flick and formalin tests. A microscopic and macroscopic examination of stomach mucosae was performed. TNFα and MMP-9 levels were measured with ELISA kits. Results: Morphine (MORF), CHEL and SC prolongated the tail withdrawal latency, with comparable analgesic activity between MORF and CHEL 8 mg/kg. MORF, CHEL 8 mg/kg, and SAN 2 mg/kg ameliorated the pain reaction in the neurogenic phase of the formalin test. In the inflammatory phase of the formalin test, all tested substances exerted analgesic activity. SAN, CHEL and SC additionally reduced TNFα and MMP-9 secretion. Conclusions: Our results confirmed analgesic effects of CHEL and SC with CHEL analgesic activity comparable to MORF. All investigated substances exerted significant anti-inflammatory activity without concomitant gastrotoxicity. Full article

Background/Objectives: Approximately one in five individuals will experience major depressive disorder (MDD), and 30% exhibit resistance to standard antidepressant treatments, resulting in a diagnosis of treatment-resistant depression (TRD). Historically, opium was used effectively to treat depression; however, when other medications were introduced, its use was discontinued due to addiction and other hazards. Recently, kappa opioid receptor (KOR) antagonism has been proposed as a potential mechanism for treating TRD. The main research question is whether commonly used psychotropic medications possess KOR antagonist properties and whether this characteristic could contribute to their efficacy in TRD. Methods: We investigated the antinociceptive effects of many psychotropic medications and their interactions with the opioid system. Mice were tested with a hotplate or tail-flick after being injected with different doses of these agents. Results: The antidepressants mianserin and mirtazapine (separately) induced dose-dependent antinociception, each yielding a biphasic dose–response curve. Similarly, the antidepressant venlafaxine produced a potent effect and reboxetine produced a weak effect. The antipsychotics risperidone and amisulpride exhibited a dose-dependent antinociceptive effect. The sedative–hypnotic zolpidem induced a weak bi-phasic dose-dependent antinociceptive effect. All seven psychotropic medications elicited antinociception, which was reversed by the non-selective opiate antagonist naloxone and, separately, by the kappa-selective antagonist Nor-BNI. Conclusions: Clinical studies are mandatory to establish the potential efficacy of augmentation of the treatment with antidepressants with these drugs in persons with treatment-resistant depression and the optimal dosage of medications prescribed. We suggest a possible beneficial effect of antidepressants with kappa antagonistic properties. Full article

Kappa opioid receptor (KOR) agonists have well-established antinociceptive effects. However, many KOR agonists have negative side effects, which limit their therapeutic potential. Some researchers have suggested that the development of biased agonists that preferentially stimulate KOR G-protein pathways over β-arrestin pathways may yield drugs with fewer adverse side effects. This was investigated in the current study. We describe the synthesis and characterization of three U50,488 analogues, 1, 2, and 3. We evaluated the acute and chronic antinociceptive effects of these compounds in mice using the warm-water tail flick assay and in a paclitaxel-induced neuropathic pain model. Side effects were investigated using open-field, passive wire hang, rotarod, elevated zero maze, conditioned place aversion, and whole-body plethysmography, with some tests being conducted in KOR or β-arrestin2 knock out mice. All compounds were highly potent, full agonists of the KOR, with varying signaling biases in vitro. In the warm-water tail withdrawal assay, these agonists were ~10 times more potent than U50,488, but not more efficacious. All KOR agonists reversed paclitaxel-induced neuropathic pain, without tolerance. Compound 3 showed no significant side effects on any test. Signaling bias did not correlate with the antinociceptive or side effects of any compounds and knockout of β-arrestin2 had no effect on U50,488-induced sedation or motor incoordination. These findings highlight the therapeutic potential of 3, with its lack of side effects typically associated with KOR agonists, and also suggest that G-protein signaling bias is a poor predictor of KOR agonist-induced side effects. Full article

The course and outcome of infection with the parasitic protozoa Leishmania major depends on the host immune response which, itself, depends mainly on the cytokine milieu, especially early in the infection. It is widely accepted that INF-γ, TNF-α, and IL-12 usually favor a protective response, while IL-4, IL-5, IL-10, and IL-13 favor a pathogenic one. These and other cytokines also play a major role in Leishmania-induced hyperalgesia via two possible pathways, one involving prostaglandins and the other sympathetic amines as final mediators, preceded by a cascade of cytokines, among which TNF-α seems to play a pivotal role via a still unclear mechanism of action. This study investigates the effects of anti-TNF-α antibody (Infliximab) on L. major-induced hyperalgesia in susceptible BALB/c mice using the hot plate and tail flicks tests, as well as the levels of many cytokines in the infected paws of mice using the ELISA technique. In addition, the parasite burden was assessed using the serial dilution method. Our results show that Infliximab can reduce the induced hyperalgesia, up-regulate TNF-α, IL-1β, and keratinocyte-derived chemokine (KC), and down-regulate IL-10 and IL-17 in the paws of infected mice. Infliximab may also have beneficial effects on the prognosis of cutaneous leishmaniasis by reducing the parasite burden. Full article

Background/Objectives: The antinociceptive and anti-inflammatory effects of a patent-pending ointment containing plant extracts from Eucalyptus globulus, Curcuma longa, Hamamelis virginiana, Echinacea purpurea, and Zingiber officinale were evaluated. Methods: Plant extracts were chemically characterized by gas chromatography–mass spectroscopy. The antinociceptive activity of the ointment was assessed using the hot plate, tail flick, and formalin tests, whereas the anti-inflammatory activity was measured using the acute and chronic TPA-induced ear edema tests. Mechanisms of action were evaluated using inhibitors from signaling pathways related to pain response and by using histological analysis and assessing the expression and activity of pro-inflammatory mediators. Results: The ointment showed antinociceptive and anti-inflammatory effects like those observed with diclofenac gel (1.16% v/v) and ketoprofen gel (2.5% v/v). The antinociceptive actions of the ointment are mediated by the possible participation of the opiodergic system and the nitric oxide pathway. The anti-inflammatory response was characterized by a decrease in myeloperoxidase (MPO) activity and by a reduction in ear swelling and monocyte infiltration in the acute inflammation model. In the chronic model, the mechanism of action relied on a decrease in pro-inflammatory mediators such as COX-2, IL-1β, TNF-α, and MPO. An in-silico study with myristic acid, one of the compounds identified in the ointment’s plant mixture, corroborated the in vivo results. Conclusions: The ointment showed antinociceptive activities mediated by the decrease in COX-2 and NO levels, and anti-inflammatory activity due to the reduction in IL-1β and TNFα levels, a reduction in MPO activity, and a decrease in NF-κB and COX-2 expression. Full article

Introduction: Cannabis sativa L. (CSL) extract has pain-relieving potential due to its cannabinoid content, so the effects of two CSL extracts on alleviating neuropathic pain were investigated in vivo. Methods and groups: Male Wistar rats (n = 130) were divided into groups and received vincristine (0.1 mg/kg) and gabapentin (60 mg/kg) to induce and relieve neuropathic pain or CSL extracts (D and B). The mRNA and protein expression of the cannabinoid receptors type 1 and 2 (CB1R, CB2R) were evaluated in the cerebral cortex, hippocampus, and lymphocytes. Behavioural tests (Tail-Flick and von Frey) were performed on all animals. Results: VK-induced neuropathic pain was accompanied by decreased CB1R protein level and CB2R mRNA expression in the cortex. Gabapentin relieved pain and increased CB1R protein levels in the hippocampus compared to the vincristine group. Hippocampus CB1R protein expression increased with the administration of extract D (10 mg/kg, 40 mg/kg) and extract B (7.5 mg/kg, 10 mg/kg) compared to VK group. In the cerebral cortex CSL decreased CB1R protein expression (10 mg/kg, 20 mg/kg, 40 mg/kg of extract B) and mRNA level (5 mg/kg, 7.5 mg/kg of extract B; 20 mg/kg of extract D) compared to the VK-group.CB2R protein expression increased in the hippocampus after treatment with extract B (7.5 mg/kg) compared to the VK-group. In the cerebral cortex extract B (10 mg/kg, 20 mg/kg) increased CB2R protein expression compared to VK-group. Conclusion: Alterations in cannabinoid receptor expression do not fully account for the observed behavioural changes in rats. Therefore, additional signalling pathways may contribute to the initiation and transmission of neuropathic pain. The Cannabis extracts tested demonstrated antinociceptive effects comparable to gabapentin, highlighting the antinociceptive properties of Cannabis extracts for human use. Full article