Molecules

14 pages, 1715 KiB

Open AccessArticle

Components of Volatile Fractions from Eucalyptus camaldulensis Leaves from Iraqi–Kurdistan and Their Potent Spasmolytic Effects

by Dlzar A. Kheder, Omar A. M. Al-Habib, Gianluca Gilardoni and Giovanni Vidari

Molecules 2020, 25(4), 804; https://doi.org/10.3390/molecules25040804 - 13 Feb 2020

Cited by 17 | Viewed by 3845

Abstract

Inhalation of vapors from a hot tea of Eucalyptus camaldulensis Dehnh. leaves is considered by Iraqi–Kurdistan people an effective spasmolytic and antipyretic remedy for the treatment of respiratory diseases. The constituents of volatile fractions isolated by hydrodistillation from dried leaves of the plant [...] Read more.

Inhalation of vapors from a hot tea of Eucalyptus camaldulensis Dehnh. leaves is considered by Iraqi–Kurdistan people an effective spasmolytic and antipyretic remedy for the treatment of respiratory diseases. The constituents of volatile fractions isolated by hydrodistillation from dried leaves of the plant collected in Kurdistan were determined by GC-FID and GC-MS analyses. More than 90% components were identified. The most abundant constituents were 1,8-cineole, p-cymene, α-pinene, terpinen-4-ol, aromadendrene, and α-terpineol. The different volatile fractions induced relaxation on rat isolated aortic and tracheal rings in concentration-dependent manner. These effects appeared to be due to a complex interaction between various terpenoid components rather than being only due to the main oil constituent, 1,8-cineole. The KCa channel and the NO pathway were not significantly involved in the relaxation mechanism, while Ca²⁺ channels played a major role in the spasmolytic effects. Full article

(This article belongs to the Special Issue Fragrant Molecules with Pharmacological Activities)

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12 pages, 2522 KiB

Open AccessArticle

Proapoptotic Activity of Achillea membranacea Essential Oil and Its Major Constituent 1,8-Cineole against A2780 Ovarian Cancer Cells

by Ashraf N. Abdalla, Usama Shaheen, Qasem M. A. Abdallah, Guido Flamini, Majdi M. Bkhaitan, Mohamed I. S. Abdelhady, Roberta Ascrizzi and Ammar Bader

Molecules 2020, 25(7), 1582; https://doi.org/10.3390/molecules25071582 - 30 Mar 2020

Cited by 52 | Viewed by 5257

Abstract

Among the hundreds of reported Achillea species, A. membranacea (Labill.) DC. is one of the six that grow in Jordan. Many species of this genus are used in folk medicine to treat a variety of ailments and several biological and pharmacological activities have [...] Read more.

Among the hundreds of reported Achillea species, A. membranacea (Labill.) DC. is one of the six that grow in Jordan. Many species of this genus are used in folk medicine to treat a variety of ailments and several biological and pharmacological activities have been ascribed to their essential oil (EO). For this study, the EO obtained from a specimen of A. membranacea grown in Jordan was analyzed by GC-MS. Ninety-six compounds were detected, of which oxygenated monoterpenes was the predominant class (47.9%), followed by non-terpene derivatives (27.9%), while sesquiterpenes represented 14.2% of the total composition. The most abundant compound in the EO was 1,8-cineole (21.7%). The cytotoxic activity of the EO was evaluated against three cancer cell lines (MCF7, A2780 and HT29), and one normal fibroblast cell line (MRC5) by MTT assay. Significant growth inhibition was observed in EO-exposed A2780 and HT29 cells (IC₅₀ = 12.99 and 14.02 μg/mL, respectively), while MCF7 and MRC5 were less susceptible. The EO induced apoptosis and increased the preG1 events in A2780 cells. 1,8-Cineole, the major constituent of the EO, exhibited submicromolar cytotoxicity against A2780 cells, and was 42 times more selective against MRC5 cells. Its cytotoxicity against A2780 cells was comparable with that of doxorubicin, but 1,8-cineole was more selective for MRC5 normal cells. Interestingly, 1,8-cineole enhanced apoptosis in A2780, and caused a remarkable dose-dependent increase in preG1 events. Thus, 1,8-cineole has demonstrated promising cytotoxic and proapoptotic properties. Full article

(This article belongs to the Special Issue Fragrant Molecules with Pharmacological Activities)

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13 pages, 3991 KiB

Open AccessFeature PaperArticle

Inhalation Administration of the Bicyclic Ethers 1,8- and 1,4-cineole Prevent Anxiety and Depressive-Like Behaviours in Mice

by Godfried Dougnon and Michiho Ito

Molecules 2020, 25(8), 1884; https://doi.org/10.3390/molecules25081884 - 18 Apr 2020

Cited by 30 | Viewed by 5237

Abstract

The anxiolytic and antidepressant-like activities of the naturally occurring monoterpene 1,8-cineole and its structural isomer 1,4-cineole were evaluated in mice via inhalation administration at doses ranging from 4 × 10⁻⁶ to 4 × 10⁻¹ mg per 400 μL of triethyl citrate. [...] Read more.

The anxiolytic and antidepressant-like activities of the naturally occurring monoterpene 1,8-cineole and its structural isomer 1,4-cineole were evaluated in mice via inhalation administration at doses ranging from 4 × 10⁻⁶ to 4 × 10⁻¹ mg per 400 μL of triethyl citrate. Mice were tested for anxiety-like behaviours by using the light–dark box test (LDB) and marble-burying test (MBT) and for depression-like symptoms by using the forced swimming test (FST) and tail suspension test (TST). Diazepam and fluoxetine were used as standard drugs for anxiolytic and antidepressant tests, respectively. The results showed that 1,8-cineole at 4 × 10⁻⁴ mg, and 1,4-cineole at 4 × 10⁻⁴ and 4 × 10⁻³ mg significantly increased the amount of time spent in the light box and the number of entries in the light box in the LDB as well as reduced the number of marbles buried in the MBT relative to those in the control, suggesting an anxiolytic effect. Similarly, 1,8-cineole at 4 × 10⁻⁴ and 4 × 10⁻² mg and 1,4-cineole at doses of 4 × 10⁻⁴ to 4 × 10⁻² mg significantly reduced immobility times in the FST and TST relative to those of the control, suggesting an antidepressant activity. The role of the GABA_A/benzodiazepine receptor system in the anxiolytic effects of 1,8- and 1,4-cineole was investigated through co-administration of flumazenil, a GABAergic system antagonist. Flumazenil reversed the effects of diazepam and 1,8-cineole, suggesting that 1,8-cineole affects the GABA_A/benzodiazepine receptors. Collectively, the results suggest that inhaled 1,8- and 1,4-cineole prevented anxiety and depressive-like symptoms in classic mice models. Full article

(This article belongs to the Special Issue Fragrant Molecules with Pharmacological Activities)

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10 pages, 2896 KiB

Open AccessCommunication

Coumarin and Moracin Derivatives from Mulberry Leaves (Morus alba L.) with Soluble Epoxide Hydrolase Inhibitory Activity

by Hong Xu Li, Myungsook Heo, Younghoon Go, Young Soo Kim, Young Ho Kim, Seo Young Yang and Wei Li

Molecules 2020, 25(17), 3967; https://doi.org/10.3390/molecules25173967 - 31 Aug 2020

Cited by 9 | Viewed by 3726

Abstract

This study identified three coumarins (1–3), and six moracin derivatives (4–9). The structures of these natural compounds were determined by the spectroscopic methods, including 1D and 2D NMR methods, and comparison with previous reported data. [...] Read more.

This study identified three coumarins (1–3), and six moracin derivatives (4–9). The structures of these natural compounds were determined by the spectroscopic methods, including 1D and 2D NMR methods, and comparison with previous reported data. All of the isolated compounds were assessed for the effects on the soluble epoxide hydrolase (sEH) inhibitory activity. Among them, compounds 1–7 exhibited significant inhibitory effect with 100% inhibitory, with IC₅₀ values of 6.9, 0.2, 15.9, 1.1, 1.2, 9.9, and 7.7 µM, respectively. A kinetic study revealed that compounds 1–4, and 6 were competitive types of inhibitors, compounds 5 and 7 were mixed types of inhibitors. These results suggest that moracin and coumarin derivatives from mulberry leaves are significant sEH inhibitors. Full article

(This article belongs to the Special Issue Fragrant Molecules with Pharmacological Activities)

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10 pages, 1588 KiB

Open AccessArticle

Chemical Composition of Essential Oil from Flower of ‘Shanzhizi’ (Gardenia jasminoides Ellis) and Involvement of Serotonergic System in Its Anxiolytic Effect

by Nan Zhang, Mu Luo, Lei He and Lei Yao

Molecules 2020, 25(20), 4702; https://doi.org/10.3390/molecules25204702 - 14 Oct 2020

Cited by 18 | Viewed by 4021

Abstract

Gardenia jasminoides Ellis is a famous fragrant flower in China. Previous pharmacological research mainly focuses on its fruit. In this study, the essential oil of the flower of ‘Shanzhizi’, which was a major variety for traditional Chinese medicine use, was extracted by hydro [...] Read more.

Gardenia jasminoides Ellis is a famous fragrant flower in China. Previous pharmacological research mainly focuses on its fruit. In this study, the essential oil of the flower of ‘Shanzhizi’, which was a major variety for traditional Chinese medicine use, was extracted by hydro distillation and analyzed by GC-MS. Mouse anxiety models included open field, elevated plus maze (EPM), and light and dark box (LDB), which were used to evaluate its anxiolytic effect via inhalation. The involvement of monoamine system was studied by pretreatment with neurotransmitter receptor antagonists WAY100635, flumazenil and sulpiride. The monoamine neurotransmitters contents in the prefrontal cortex (PFC) and hippocampus after aroma inhalation were also analyzed. The results showed that inhalation of G. jasminoides essential oil could significantly elevated the time and entries into open arms in EPM tests and the time explored in the light chamber in LDB tests with no sedative effect. WAY100635 and sulpiride, but not flumazenil, blocked its anxiolytic effect. Inhalation of G. jasminoides essential oil significantly down-regulated the 5-HIAA/5-HT in the PFC and reduced the 5-HIAA content in hippocampus compared to the control treatment. In conclusion, inhalation of gardenia essential oil showed an anxiolytic effect in mice. Monoamine, especially the serotonergic system, was involved in its anxiolytic effect. Full article

(This article belongs to the Special Issue Fragrant Molecules with Pharmacological Activities)

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13 pages, 4006 KiB

Open AccessArticle

Effects of Tangerine Essential Oil on Brain Waves, Moods, and Sleep Onset Latency

by Supaya Chandharakool, Phanit Koomhin, Jennarong Sinlapasorn, Sarunnat Suanjan, Jantamas Phungsai, Noppharat Suttipromma, Sumethee Songsamoe, Narumol Matan and Apsorn Sattayakhom

Molecules 2020, 25(20), 4865; https://doi.org/10.3390/molecules25204865 - 21 Oct 2020

Cited by 34 | Viewed by 12235

Abstract

Tangerine (Citrus tangerina) is one of the most important crops of Thailand with a total harvest that exceeds 100,000 tons. Citrus essential oils are widely used as aromatherapy and medicinal agents. The effect of tangerine essential oil on human brain waves [...] Read more.

Tangerine (Citrus tangerina) is one of the most important crops of Thailand with a total harvest that exceeds 100,000 tons. Citrus essential oils are widely used as aromatherapy and medicinal agents. The effect of tangerine essential oil on human brain waves and sleep activity has not been reported. In the present study, we therefore evaluated these effects of tangerine essential oil by measurement of electroencephalography (EEG) activity with 32 channel platforms according to the international 10–20 system in 10 male and 10 female subjects. Then the sleep onset latency was studied to further confirm the effect on sleep activity. The results revealed that different concentrations, subthreshold to suprathreshold, of tangerine oil gave different brain responses. Undiluted tangerine oil inhalation reduced slow and fast alpha wave powers and elevated low and mid beta wave powers. The subthreshold and threshold dilution showed the opposite effect to the brain compared with suprathreshold concentration. Inhalation of threshold concentration showed effectively decreased alpha and beta wave powers and increased theta wave power, which emphasize its sedative effect. The reduction of sleep onset latency was confirmed with the implementation of the observed sedative effect of tangerine oil. Full article

(This article belongs to the Special Issue Fragrant Molecules with Pharmacological Activities)

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16 pages, 4538 KiB

Open AccessArticle

Nootkatone, a Dietary Fragrant Bioactive Compound, Attenuates Dyslipidemia and Intramyocardial Lipid Accumulation and Favorably Alters Lipid Metabolism in a Rat Model of Myocardial Injury: An In Vivo and In Vitro Study

by M.F. Nagoor Meeran, Sheikh Azimullah, M Marzouq Al Ahbabi, Niraj Kumar Jha, Vinoth-Kumar Lakshmanan, Sameer N. Goyal and Shreesh Ojha

Molecules 2020, 25(23), 5656; https://doi.org/10.3390/molecules25235656 - 30 Nov 2020

Cited by 23 | Viewed by 3145

Abstract

In the present study, we assessed whether nootkatone (NKT), a sesquiterpene in edible plants, can provide protection against dyslipidemia, intramyocardial lipid accumulation, and altered lipid metabolism in a rat model of myocardial infarction (MI) induced by subcutaneous injections of isoproterenol (ISO, 85 mg/kg) [...] Read more.

In the present study, we assessed whether nootkatone (NKT), a sesquiterpene in edible plants, can provide protection against dyslipidemia, intramyocardial lipid accumulation, and altered lipid metabolism in a rat model of myocardial infarction (MI) induced by subcutaneous injections of isoproterenol (ISO, 85 mg/kg) on days 9 and 10. The rats were pre- and co-treated with NKT (10 mg/kg, p.o.) administered daily for 11 days. A significant reduction in the activities of myocardial creatine kinase and lactate dehydrogenase, as well as non-enzymatic antioxidants, and alterations in lipids and lipoproteins, along with a rise in plasma lipid peroxidation and intramyocardial lipid accumulation, were observed in ISO-treated rats. ISO administration induced alterations in the activities of enzymes/expressions that played a significant role in altering lipid metabolism. However, NKT treatment favorably modulated all biochemical and molecular parameters altered by ISO and showed protective effects against oxidative stress, dyslipidemia, and altered lipid metabolism, attributed to its free-radical-scavenging and antihyperlipidemic activities in rats with ISO-induced MI. Additionally, NKT decreased the accumulation of lipids in the myocardium as evidenced from Oil red O staining. Furthermore, the in vitro observations demonstrate the potent antioxidant property of NKT. The present study findings are suggestive of the protective effects of NKT on dyslipidemia and the underlying mechanisms. Based on our findings, it can be suggested that NKT or plants rich in NKT can be promising for use as a phytopharmaceutical or nutraceutical in protecting the heart and correcting lipid abnormalities and dyslipidemia, which are risk factors for ischemic heart diseases. Full article

(This article belongs to the Special Issue Fragrant Molecules with Pharmacological Activities)

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12 pages, 2080 KiB

Open AccessArticle

Effects of Sesame Oil Aroma on Mice after Exposure to Water Immersion Stress: Analysis of Behavior and Gene Expression in the Brain

by Hiroaki Takemoto, Chiharu Take, Keito Kojima, Yamato Kuga, Tomoya Hamada, Tomoka Yasugi, Nanami Kato, Kazuo Koike and Yoshinori Masuo

Molecules 2020, 25(24), 5915; https://doi.org/10.3390/molecules25245915 - 14 Dec 2020

Cited by 8 | Viewed by 3086

Abstract

(1) Background: Sesame has been popular as a healthy food since ancient times, and effects of the aroma component of roasted sesame are also expected. However, little research has been reported on its scent; (2) Methods: Jcl:ICR male mice were housed under water [...] Read more.

(1) Background: Sesame has been popular as a healthy food since ancient times, and effects of the aroma component of roasted sesame are also expected. However, little research has been reported on its scent; (2) Methods: Jcl:ICR male mice were housed under water immersion stress for 24 h. Then, the scent of saline or sesame oil was inhaled to stress groups for 90 min. We investigated the effects of sesame oil aroma on the behavior and brains of mice; (3) Results: In an elevated plus maze test, the rate of entering to open arm and the staying time were decreased by the stress. These decrements were significantly enhanced by sesame oil aroma. Stress had a tendency to increase the serum corticosterone concentration, which was slightly decreased by the aroma. Expression of Kruppel-like factor-4 (Klf-4) and Dual-specificity phosphatase-1 (Dusp-1) in the striatum were increased by water immersion stress, and the level of Klf-4 and Dusp-1 in the striatum and hippocampus were significantly attenuated by sesame oil aroma (4) Conclusions: The present results strongly suggest that the odor component of sesame oil may have stress suppressing effects. Moreover, Klf-4 and Dusp-1 may be sensitive stress-responsive biomarkers. Full article

(This article belongs to the Special Issue Fragrant Molecules with Pharmacological Activities)

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14 pages, 1473 KiB

Open AccessArticle

Subjective Effects of Inhaling Kuromoji Tea Aroma

by Eri Matsubara, Takeshi Morikawa, Norihisa Kusumoto, Koh Hashida, Naoyuki Matsui and Tatsuro Ohira

Molecules 2021, 26(3), 575; https://doi.org/10.3390/molecules26030575 - 22 Jan 2021

Cited by 7 | Viewed by 3410

Abstract

Teas and various herbal teas are well-known beverages and are commonly consumed around the world. In this study, we focused on kuromoji tea. Kuromoji is a deciduous shrub of the Lauraceae family, and the plucked leaves and branches have been drunk as a [...] Read more.

Teas and various herbal teas are well-known beverages and are commonly consumed around the world. In this study, we focused on kuromoji tea. Kuromoji is a deciduous shrub of the Lauraceae family, and the plucked leaves and branches have been drunk as a tea in production areas for a long time. However, no studies have investigated the subjective and physiological effects of kuromoji tea. In this study, the effects of kuromoji tea were examined on the basis of the measurements of heart rate variability and cerebral blood flow, core body temperature and subjective assessments. Moreover, the results of this study showed that a pleasant subjective feeling could be obtained by sniffing the aroma of kuromoji teas, especially tea leaves. It was also found that the aroma of kuromoji teas has the potential to stimulate saliva secretion and increase subjective and physiological excitements in the oral cavity. 1,8-Cineole, linalool, terpinen-4-ol, carvone and geraniol were determined in both kuromoji leaves and branches. In this study, the beneficial effects of kuromoji teas when drunk conventionally were investigated. Full article

(This article belongs to the Special Issue Fragrant Molecules with Pharmacological Activities)

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14 pages, 4550 KiB

Open AccessArticle

Individual and Combined Inhalational Sedative Effects in Mice of Low Molecular Weight Aromatic Compounds Found in Agarwood Aroma

by Kimberly P. Castro and Michiho Ito

Molecules 2021, 26(5), 1320; https://doi.org/10.3390/molecules26051320 - 2 Mar 2021

Cited by 5 | Viewed by 2554

Abstract

Agarwood is known to have a sedative effect and the less studied volatile aromatic constituents it contains may have contribution to the activity. In this study, two Kyara grade (highest-grade agarwood in Japan) samples were extracted using headspace-solid phase microextraction (HS-SPME) and analyzed [...] Read more.

Agarwood is known to have a sedative effect and the less studied volatile aromatic constituents it contains may have contribution to the activity. In this study, two Kyara grade (highest-grade agarwood in Japan) samples were extracted using headspace-solid phase microextraction (HS-SPME) and analyzed through gas chromatography-mass spectrometry (GC-MS). Six low molecular weight aromatic compounds (LACs) and one structurally simple compound (diethylene glycol monoethyl ether) present in the aromas were individually evaluated for inhalational sedative activity in mice through open field test. Doses of 0.0001 g/L to 1 g/L were prepared for each compound and administered to mice (n = 6/dose/compound). Results revealed all compounds decreased spontaneous motor activity at almost all doses. Strongest sedative activity of each compound reduced total spontaneous motor activity by more than half against control, demonstrating their contribution to agarwood aroma and potential as independent sedating agents. Mixtures of compounds using their most effective dose were made and evaluated again for inhalational sedative effect. Interestingly, the combination of all compounds showed no significant effect and even caused stimulation in mice movements. This result suggests antagonistic-like interaction between the compounds, which is probably due to structural similarities. Consequently, it implies the other constituents present in agarwood, along with LACs, are also important to the overall sedative activity. Full article

(This article belongs to the Special Issue Fragrant Molecules with Pharmacological Activities)

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18 pages, 7723 KiB

Open AccessArticle

Ezetimibe-Loaded Nanostructured Lipid Carrier Based Formulation Ameliorates Hyperlipidaemia in an Experimental Model of High Fat Diet

by Yogeeta O. Agrawal, Umesh B. Mahajan, Vinit V. Agnihotri, Mayur S. Nilange, Hitendra S. Mahajan, Charu Sharma, Shreesh Ojha, Chandragouda R. Patil and Sameer N. Goyal

Molecules 2021, 26(5), 1485; https://doi.org/10.3390/molecules26051485 - 9 Mar 2021

Cited by 15 | Viewed by 3271

Abstract

Ezetimibe (EZE) possesses low aqueous solubility and poor bioavailability and in addition, its extensive hepatic metabolism supports the notion of developing a novel carrier system for EZE. Ezetimibe was encapsulated into nanostructured lipid carriers (EZE-NLCs) via a high pressure homogenization technique (HPH). A [...] Read more.

Ezetimibe (EZE) possesses low aqueous solubility and poor bioavailability and in addition, its extensive hepatic metabolism supports the notion of developing a novel carrier system for EZE. Ezetimibe was encapsulated into nanostructured lipid carriers (EZE-NLCs) via a high pressure homogenization technique (HPH). A three factor, two level (2³) full factorial design was employed to study the effect of amount of poloxamer 188 (X1), pressure of HPH (X2) and number of HPH cycle (X3) on dependent variables. Particle size, polydispersity index (PDI), % entrapment efficiency (%EE), zeta potential, drug content and in-vitro drug release were evaluated. The optimized formulation displays pragmatic inferences associated with particle size of 134.5 nm; polydispersity index (PDI) of 0.244 ± 0.03; zeta potential of −28.1 ± 0.3 mV; % EE of 91.32 ± 1.8% and % CDR at 24-h of 97.11%. No interaction was observed after X-ray diffraction (XRD) and differential scanning calorimetry (DSC) studies. EZE-NLCs (6 mg/kg/day p.o.) were evaluated in the high fat diet fed rats induced hyperlipidemia in comparison with EZE (10 mg/kg/day p.o.). Triglyceride, HDL-c, LDL-c and cholesterol were significantly normalized and histopathological evaluation showed normal structure and architecture of the hepatocytes. The results demonstrated the superiority of EZE-NLCs in regard to bioavailability enhancement, dose reduction and dose-dependent side effects. Full article

(This article belongs to the Special Issue Fragrant Molecules with Pharmacological Activities)

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22 pages, 3782 KiB

Open AccessReview

Allicin, the Odor of Freshly Crushed Garlic: A Review of Recent Progress in Understanding Allicin’s Effects on Cells

by Jan Borlinghaus, Jana Foerster (née Reiter), Ulrike Kappler, Haike Antelmann, Ulrike Noll, Martin C. H. Gruhlke and Alan J. Slusarenko

Molecules 2021, 26(6), 1505; https://doi.org/10.3390/molecules26061505 - 10 Mar 2021

Cited by 60 | Viewed by 16249

Abstract

The volatile organic sulfur compound allicin (diallyl thiosulfinate) is produced as a defense substance when garlic (Allium sativum) tissues are damaged, for example by the activities of pathogens or pests. Allicin gives crushed garlic its characteristic odor, is membrane permeable and [...] Read more.

The volatile organic sulfur compound allicin (diallyl thiosulfinate) is produced as a defense substance when garlic (Allium sativum) tissues are damaged, for example by the activities of pathogens or pests. Allicin gives crushed garlic its characteristic odor, is membrane permeable and readily taken up by exposed cells. It is a reactive thiol-trapping sulfur compound that S-thioallylates accessible cysteine residues in proteins and low molecular weight thiols including the cellular redox buffer glutathione (GSH) in eukaryotes and Gram-negative bacteria, as well as bacillithiol (BSH) in Gram-positive firmicutes. Allicin shows dose-dependent antimicrobial activity. At higher doses in eukaryotes allicin can induce apoptosis or necrosis, whereas lower, biocompatible amounts can modulate the activity of redox-sensitive proteins and affect cellular signaling. This review summarizes our current knowledge of how bacterial and eukaryotic cells are specifically affected by, and respond to, allicin. Full article

(This article belongs to the Special Issue Fragrant Molecules with Pharmacological Activities)

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29 pages, 13037 KiB

Open AccessFeature PaperReview

Smell and Stress Response in the Brain: Review of the Connection between Chemistry and Neuropharmacology

by Yoshinori Masuo, Tadaaki Satou, Hiroaki Takemoto and Kazuo Koike

Molecules 2021, 26(9), 2571; https://doi.org/10.3390/molecules26092571 - 28 Apr 2021

Cited by 40 | Viewed by 16333

Abstract

The stress response in the brain is not fully understood, although stress is one of the risk factors for developing mental disorders. On the other hand, the stimulation of the olfactory system can influence stress levels, and a certain smell has been empirically [...] Read more.

The stress response in the brain is not fully understood, although stress is one of the risk factors for developing mental disorders. On the other hand, the stimulation of the olfactory system can influence stress levels, and a certain smell has been empirically known to have a stress-suppressing effect, indeed. In this review, we first outline what stress is and previous studies on stress-responsive biomarkers (stress markers) in the brain. Subsequently, we confirm the olfactory system and review previous studies on the relationship between smell and stress response by species, such as humans, rats, and mice. Numerous studies demonstrated the stress-suppressing effects of aroma. There are also investigations showing the effects of odor that induce stress in experimental animals. In addition, we introduce recent studies on the effects of aroma of coffee beans and essential oils, such as lavender, cypress, α-pinene, and thyme linalool on the behavior and the expression of stress marker candidates in the brain. The transfer of volatile components into the brain is also discussed while using the results of thyme linalool as an example. These studies may provide a good opportunity to connect chemical research at the molecular level with neuropharmacological approaches in the future. Full article

(This article belongs to the Special Issue Fragrant Molecules with Pharmacological Activities)

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19 pages, 2507 KiB

Open AccessArticle

Effects of Thai Local Ingredient Odorants, Litsea cubeba and Garlic Essential Oils, on Brainwaves and Moods

by Apsorn Sattayakhom, Sumethee Songsamoe, Gorawit Yusakul, Kosin Kalarat, Narumol Matan and Phanit Koomhin

Molecules 2021, 26(10), 2939; https://doi.org/10.3390/molecules26102939 - 15 May 2021

Cited by 15 | Viewed by 4843

Abstract

The functional food market is growing with a compound annual growth rate of 7.9%. Thai food recipes use several kinds of herbs. Lemongrass, garlic, and turmeric are ingredients used in Thai curry paste. Essential oils released in the preparation step create the flavor [...] Read more.

The functional food market is growing with a compound annual growth rate of 7.9%. Thai food recipes use several kinds of herbs. Lemongrass, garlic, and turmeric are ingredients used in Thai curry paste. Essential oils released in the preparation step create the flavor and fragrance of the famous tom yum and massaman dishes. While the biological activities of these ingredients have been investigated, including the antioxidant, anti-inflammatory, and antimicrobial activities, there is still a lack of understanding regarding the responses to the essential oils of these plants. To investigate the effects of essential oil inhalation on the brain and mood responses, electroencephalography was carried out during the non-task resting state, and self-assessment of the mood state was performed. The essential oils were prepared in several dilutions in the range of the supra-threshold level. The results show that Litsea cubeba oil inhalation showed a sedative effect, observed from alpha and beta wave power reductions. The frontal and temporal regions of the brain were involved in the wave alterations. Garlic oil increased the alpha wave power at lower concentrations; however, a sedative effect was also observed at higher concentrations. Lower dilution oil induced changes in the fast alpha activity in the frontal region. The alpha and beta wave powers were decreased with higher dilution oils, particularly in the temporal, parietal, and occipital regions. Both Litsea cubeba and turmeric oils resulted in better positive moods than garlic oil. Garlic oil caused more negative moods than the others. The psychophysiological activities and the related brain functions require further investigation. The knowledge obtained from this study may be used to design functional food products. Full article

(This article belongs to the Special Issue Fragrant Molecules with Pharmacological Activities)

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