Effect of menthol in experimentally induced ulcers: pathways of gastroprotection

The Role and Function of TRPM8 in the Digestive System

Transient receptor potential (TRP) melastatin member 8 (TRPM8) is a non-selective cation channel that can be activated by low temperatures (8-26 °C), cooling agents (including menthol analogs such as menthol, icilin, and WS-12), voltage, and extracellular osmotic pressure changes. TRPM8 expression has been identified in the digestive system by several research teams, demonstrating its significant involvement in tissue function and pathologies of the digestive system. Specifically, studies have implicated TRPM8 in various physiological and pathological processes of the esophagus, stomach, colorectal region, liver, and pancreas. This paper aims to comprehensively outline the distinct role of TRPM8 in different organs of the digestive system, offering insights for future mechanistic investigations of TRPM8. Additionally, it presents potential therapeutic targets for treating conditions such as digestive tract inflammation, tumors, sensory and functional disorders, and other related diseases. Furthermore, this paper addresses the limitations of existing studies and highlights the research prospects associated with TRPM8.

KCNQ1 is an essential mediator of the sex-dependent perception of moderate cold temperatures

Low temperatures and cooling agents like menthol induce cold sensation by activating the peripheral cold receptors TRPM8 and TRPA1, cation channels belonging to the TRP channel family, while the reduction of potassium currents provides an additional and/or synergistic mechanism of cold sensation. Despite extensive studies over the past decades to identify the molecular receptors that mediate thermosensation, cold sensation is still not fully understood and many cold-sensitive peripheral neurons do not express the well-established cold sensor TRPM8. We found that the voltage-gated potassium channel KCNQ1 (Kv7.1), which is defective in cardiac LQT1 syndrome, is, in addition to its known function in the heart, a highly relevant and sex-specific sensor of moderately cold temperatures. We found that KCNQ1 is expressed in skin and dorsal root ganglion neurons, is sensitive to menthol and cooling agents, and is highly sensitive to moderately cold temperatures, in a temperature range at which TRPM8 is not thermosensitive. C-fiber recordings from KCNQ1-/- mice displayed altered action potential firing properties. Strikingly, only male KCNQ1-/- mice showed substantial deficits in cold avoidance at moderately cold temperatures, with a strength of the phenotype similar to that observed in TRPM8-/- animals. While sex-dependent differences in thermal sensitivity have been well documented in humans and mice, KCNQ1 is the first gene reported to play a role in sex-specific temperature sensation. Moreover, we propose that KCNQ1, together with TRPM8, is a key instrumentalist that orchestrates the range and intensity of cold sensation.

Peppermint as a promising treatment agent in inflammatory conditions: A comprehensive systematic review of literature

Inflammation, a type of the body's defense against injury or infection, causes many chronic disorders including diabetes, cardiovascular disease, and cancer. Therefore, discovering natural compounds with numerous biological activities for the management of inflammation is highly recommended. Out of natural compounds, peppermint and its main component, menthol, has been suggested to possess antiinflammatory potential. Four databases including Web of Sciences, PubMed, Scopus, and Embase were searched to identify articles about peppermint and its antiinflammatory effects up to March 2023. Out of 3805 records screened, 14 articles met the study criteria. The evidence reviewed here proposed peppermint as an antiinflammatory agent. Peppermint may suppress inflammation by activating the AMP-activated protein kinase/unc-51 like kinase 1/nuclear factor-E2 associated factor 2 autophagy pathway, downregulating extracellular signal-regulated kinase-nuclear factor kappa B and mitogen activated protein kinases pathways, attenuating oxidative stress, suppressing the production of pro-inflammatory mediators and nitric oxide, and inducing the production of antiinflammatory prostaglandins. Due to the promising antiinflammatory effects of peppermint and the lack of human studies in this regard, future randomized clinical trials examining the effects of peppermint on inflammation and its related maladies are warranted.

Peppermint essential oil and its nano-emulsion: Potential against aflatoxigenic fungus Aspergillus flavus in food and feed

A facultative parasite called Aspergillus flavus contaminates several important food crops before and after harvest. In addition, the pathogen that causes aspergillosis infections in humans and animals is opportunistic. Aflatoxin, a secondary metabolite produced by Aspergillus flavus, is also carcinogenic and mutagenic, endangering human and animal health and affecting global food security. Peppermint essential oils and plant-derived natural products have recently shown promise in combating A. flavus infestations and aflatoxin contamination. This review discusses the antifungal and anti-aflatoxigenic properties of peppermint essential oils. It then discusses how peppermint essential oils affect the growth of A. flavus and the biosynthesis of aflatoxins. Several cause physical, chemical, or biochemical changes to the cell wall, cell membrane, mitochondria, and associated metabolic enzymes and genes. Finally, the prospects for using peppermint essential oils and natural plant-derived chemicals to develop novel antifungal agents and protect foods are highlighted. In addition to reducing the risk of aspergillosis infection, this review highlights the significant potential of plant-derived natural products and peppermint essential oils to protect food and feed from aflatoxin contamination and A. flavus infestation.

Hypokinetic Activity of Menthofuran on the Gastrointestinal Tract in Rodents

The acute toxicity and hypokinetic activity induced by menthofuran on the gastrointestinal tract of rodents were investigated in the present study. An absence of acute toxicity was observed. Menthofuran delayed gastric emptying at oral doses of 25, 50, and 100 mg/kg in the experimental model of phenol red, as well as it reduced the intestinal transit at oral doses of 50 and 100 mg/kg. Interestingly, a scopolamine-similar hypokinetic effect was observed for menthofuran. In the experimental model of castor oil-induced intestinal hypermotility, menthofuran (50 and 100 mg/kg) reduced the number of loose stools as observed for the normal group. Additionally, menthofuran induced a marked concentration-dependent relaxation in rat ileum segments precontracted with KCl (EC50 = 0.059 ± 0.008 μg/mL) or carbachol (EC50 = 0.068 ± 0.007 μg/mL). These results suggest the possible decrease of calcium influx underlying the effects of menthofuran on the gastrointestinal tract, which opens the door for further study regarding this potential application for the treatment of gastrointestinal disorders, noting possible limitations of its use due to adverse effects in children.

Protective effects of menthol against sepsis-induced hepatic injury: Role of mediators of hepatic inflammation, apoptosis, and regeneration

Liver dysfunction in sepsis is a major complication that amplifies multiple organ failure and increases the risk of death. Inflammation and oxidative stress are the main mediators in the pathophysiology of sepsis. Therefore, we investigated the role of menthol, a natural antioxidant, against sepsis-induced liver injury in female Wistar rats. Sepsis was induced by cecal ligation and puncture (CLP). Menthol (100 mg/kg) was given intragastric 2 h after CLP. Blood samples and liver tissues were collected 24 h after surgery. Menthol significantly (p < 0.05) attenuated the sepsis-induced elevation in serum liver enzymes and improved the hepatic histopathological changes. Menthol treatment significantly (p < 0.05) decreased hepatic levels of tumor necrosis factor-alpha, malondialdehyde, total nitrite, and cleaved caspase-3. It restored the hepatic levels of superoxide dismutase and reduced glutathione. Additionally, menthol significantly (p < 0.05) increased hepatic levels of B-cell lymphoma 2 (Bcl-2); an anti-apoptotic factor, and proliferating cell nuclear antigen (PCNA), a biomarker of regeneration and survival. Our results showed the therapeutic potential of menthol against liver injury induced by sepsis.

Peppermint essential oil: its phytochemistry, biological activity, pharmacological effect and application

Mentha (also known as peppermint), a genus of plants in the taxonomic family Lamiaceae (mint family), is widely distributed throughout temperate regions of the world. Mentha contains various constituents that are classified as peppermint essential oil (PEO) and non-essential components. PEO, consisting mainly of menthol, menthone, neomenthol and iso-menthone, is a mixture of volatile metabolites with anti-inflammatory, antibacterial, antiviral, scolicidal, immunomodulatory, antitumor, neuroprotective, antifatigue and antioxidant activities. Mounting evidence indicates that PEO may pharmacologically protect gastrointestinal, liver, kidney, skin, respiratory, brain and nervous systems, and exert hypoglycemic and hypolipidemic effects. Clinically, PEO is used for gastrointestinal and dermatological diseases, postoperative adjuvant therapy and other fields. This review aims to address the advances in the extraction and isolation of PEO, its biological activities, pharmacological effects, toxicity and applications, with an emphasis on the efficacy of PEO on burn wounds and psoriasis, providing a comprehensive foundation for research, development and application of PEO in future.

Gastrointestinal effects of Mentha aquatica L. essential oil

Found in humid regions and waterways and popularly used to treat gastrointestinal problems among other applications, the present study evaluated the M. aquatica essential oil (OEMa) as a therapeutic alternative to treat gastrointestinal disorders. Produced by steam distillation, chemical composition of OEMa was determined by GC-MS analysis. The ethanol-induced ulcer and the dose-repeated acetylsalicylic acid (ASA)-induced gastrointestinal lesions models in rats evaluated, respectively, the prophylactic and curative effects of EOMa on peptic ulcers. The EOMa's effect on gastric secretion, gastric mucus and gastrointestinal motility were evaluated in in vivo models. The curative effect of EOMa on acute colitis was evaluated using the DSS-induced colitis model in mice. Obtained in 0.17% yield (w/w), with carvone (54.82 ± 1.39 g/100 g oil) as the main constituent, EOMa (at 75 mg/kg) showed potent gastroprotective effect (> 90%) mediated by non-protein sulfhydryl compounds (NPSH) and nitric oxide (NO) modulation alongside reduction in gastric secretion volume and total acidity. EOMa did not affect gastric mucus production and gastrointestinal motility. In dose-repeated ASA-induced gastrointestinal lesions model, EOMa (at 25 mg/kg) promoted the inflammatory process resolution both in gastric and duodenal walls by modulating NPSH, NO and myeloperoxidase levels. Despite delaying in 2 days the clinical symptoms worsening, EOMa (at 25 mg/kg) was not able to protect colon tissues from DSS-induced acute colitis as evidenced by macroscopic, biochemical, and histopathological parameters. This is the first report of Mentha aquatica essential oil as a promising herbal medicine for peptic ulcers treatment together with an adjuvant effect in IBD.

The Use of Menthol in Skin Wound Healing-Anti-Inflammatory Potential, Antioxidant Defense System Stimulation and Increased Epithelialization

Wound healing involves inflammatory, proliferative, and remodeling phases, in which various cells and chemical intermediates are involved. This study aimed to investigate the skin wound healing potential of menthol, as well as the mechanisms involved in its effect, after 3, 7, or 14 days of treatment, according to the phases of wound healing. Skin wound was performed in the back of Wistar rats, which were topically treated with vehicle cream; collagenase-based cream (1.2 U/g); or menthol-based cream at 0.25%, 0.5%, or 1.0% over 3, 7, or 14 days. Menthol cream at 0.5% accelerated the healing right from the inflammatory phase (3 days) by decreasing mRNA expression of inflammatory cytokines TNF-α and Il-6. At the proliferative phase (7 days), menthol 0.5% increased the activity of antioxidant enzymes SOD, GR, and GPx, as well as the level of GSH, in addition to decreasing the levels of inflammatory cytokines TNF-α, IL-6, and IL-1β and augmenting mRNA expression for Ki-67, a marker of cellular proliferation. At the remodeling phase (14 days), levels of inflammatory cytokines were decreased, and the level of Il-10 and its mRNA expression were increased in the menthol 0.5% group. Menthol presented skin wound healing activity by modulating the antioxidant system of the cells and the inflammatory response, in addition to stimulating epithelialization.

Modifying effects of menthol against benzo(a)pyrene-induced forestomach carcinogenesis in female Swiss mice

Benzo(a)pyrene (BaP) is a polycyclic aromatic hydrocarbon widespread in the environment and closely associated to tobacco use, which is an important risk factor for highly incident stomach cancer. Menthol, a monoterpene extracted from Mentha genus species, has multiple biological properties, including anti-inflammatory and gastroprotective properties, but its effects on carcinogenesis are still to be fully understood. Thus, we evaluated the modifying effects of Ment against BaP-induced forestomach carcinogenesis. Female Swiss mice received BaP by intragastrical (i.g.) administration (50 mg/kg of body weight [b wt], 2×/week), from weeks 1-5 weeks. Concomitantly, mice received Menthol at 25 (Ment25) or 50 (Ment50) mg/kg b wt (i.g, 3×/week). Animals were euthanized at weeks 5 (n = 5 mice/group) or 30 (n = 10 mice/group). At week 5, both Ment doses reduced peripheral leukocyte blood genotoxicity 4 h after the last BaP administration, but only Ment50 attenuated this biomarker 8 h after the last BaP administration. In accordance to these findings, both Ment interventions attenuated BaP-induced increase in the percentage of H2A.X-positive forestomach epithelial cells. Moreover, Ment50 reduced cell proliferation and apoptosis (i.e., Ki-67 and caspase-3, respectively) in forestomach epithelium but exerted no significant effects on NFκB, and Nrf2 protein levels. At week 30, Ment50 reduced by ~55% the incidence of BaP-induced forestomach diffuse hyperplasia and multiplicity of forestomach tumors (squamous cell papillomas and carcinomas). Our findings indicate that Ment50, administered during initiation phase, attenuates forestomach carcinogenesis by reducing early genotoxicity, cell proliferation, and apoptosis induced by BaP.

(-)-Carveol Prevents Gastric Ulcers via Cytoprotective, Antioxidant, Antisecretory and Immunoregulatory Mechanisms in Animal Models

Background: (-)-Carveol (p-Mentha-6,8-dien-2-ol) is a monocyclic monoterpenic alcohol, present in essential oils of plant species such as Cymbopogon giganteus, Illicium pachyphyllum and in spices such as Carum carvi (cumin). Pharmacological studies report its antitumor, antimicrobial, neuroprotective, vasorelaxant, antioxidant and anti-inflammatory activity.

Hypothesis/Purpose: The objective of this study was to evaluate the acute non-clinical oral toxicity, gastroprotective activity of monoterpene (-)-Carveol in animal models and the related mechanisms of action.

Methods: Acute toxicity was assessed according to OECD guide 423 in mice. Ethanol, stress, NSAIDs and pylorus ligation-induced gastric ulcer models were used to investigate antiulcer properties. The related mechanisms of action were using the ethanol-gastric lesions protocol.

Results: (-)-Carveol has low toxicity, with a lethal dose 50% (LD₅₀) equal to or greater than 2,500 mg/kg according to OECD guide nº 423. In all gastric ulcer induction methods evaluated, (-)-Carveol (25, 50, 100 and 200 mg/kg, p.o.) significantly reduced the ulcerative lesion in comparison with the respective control groups. To investigate the mechanisms involved in the gastroprotective activity, the antisecretory or neutralizing of gastric secretion, cytoprotective, antioxidant and immunoregulatory effects were evaluated. In the experimental protocol of pylorus ligation-induced gastric ulcer, (-)-Carveol (100 mg/kg) reduced (p < 0.001) the volume of gastric secretion in both routes (oral and intraduodenal). The previous administration of blockers NEM (sulfhydryl groups blocker), L-NAME (nitric oxide synthesis inhibitor), glibenclamide (K_ATP channel blocker) and indomethacin (cyclo-oxygenase inhibitor), significantly reduced the gastroprotection exercised by (-)-Carveol, suggesting the participation of these pathways in its gastroprotective activity. In addition, treatment with (-)-Carveol (100 mg/kg) increased (p < 0.001) mucus adhered to the gastric wall. Treatment also increased (p < 0.001) levels of reduced glutathione (GSH), superoxide dismutase (SOD) and interleukin-10 (IL-10). It also reduced (p < 0.001) malondialdehyde (MDA), myeloperoxidase (MPO), interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) levels.

Conclusion: Thus, it is possible to infer that (-)-Carveol presents gastroprotective activity related to antisecretory, cytoprotective, antioxidant and immunomodulatory mechanisms.

Tablet of Spondias mombin L. Developed from Nebulized Extract Prevents Gastric Ulcers in Mice via Cytoprotective and Antisecretory Effects

Spondias mombin L. (Anacardiaceae) has a worldwide distribution and is present in all regions of Brazil. Its leaves, flowers and bark are used as teas in folk medicine to treat diseases of the digestive system. This study aimed to evaluate the acute non-clinical toxicity, gastroprotective activity, and the related mechanisms of action of nebulized extract and tablets based on dried Spondias mombin (SmNE). SmNE screening showed the presence of flavonoids (0.65%), polyphenols (25.50%), where the major compound is gallic acid. In the acute oral toxicity assay, a dose of 2000 mg/kg of SmNE administered orally in Swiss mice did not induce any behavioral changes. SmNE (250 or 500 mg/kg p.o) significantly reduced the ulcerative lesion area when compared to the control group in ethanol and non-steroidal anti-inflammatory drug (NSAIDs) models. Results showed that treatment with SmNE (250 mg/kg) reduced acid secretion and gastric content, accompanied with an increase in pH. Previous administration of indomethacin and glibenclamide reversed the protection provided by SmNE, confirming the participation of prostaglandins (PGs) and ATP-sensitive potassium channels (KATP) in its gastroprotective effect. The SmNE tablets met the pharmacopeial quality requirements with gastroprotective activity and similar protection in comparison to the isolated extract administrated. In conclusion, SmNe has a gastroprotective activity related to cytoprotective mechanisms, such as the participation of endogenous prostaglandins and KATP channels, having an anti-secretory effect with systemic action. The formulation obtained presented gastroprotective effects similar to the administration of the extract, the tablets showed favorable compression characteristics by the direct route and met the pharmacopeial quality requirements.

A Novel, Duodenal-Release Formulation of a Combination of Caraway Oil and L-Menthol for the Treatment of Functional Dyspepsia: A Randomized Controlled Trial

We conducted a randomized, placebo-controlled trial, which evaluated a novel formulation of caraway oil and L-menthol using microsphere-based site-specific targeting (COLM-SST) vs placebo in patients with functional dyspepsia (FD).

Plants against Helicobacter pylori to combat resistance: An ethnopharmacological review

Worldwide, Helicobacter pylori (H. pylori) is regarded as the major etiological agent of peptic ulcer and gastric carcinoma. Claiming about 50 percent of the world population is infected with H. pylori while therapies for its eradication have failed because of many reasons including the acquired resistance against its antibiotics. Hence, the need to find new anti-H.pylori medications has become a hotspot with the urge of searching for alternative, more potent and safer inhibitors. In the recent drug technology scenario, medicinal plants are suggested as repositories for novel synthetic substances. Hitherto, is considered as ecofriendly, simple, more secure, easy, quick, and less toxic traditional treatment technique. This review is to highlight the anti-H. pylori medicinal plants, secondary metabolites and their mode of action with the aim of documenting such plants before they are effected by cultures and traditions that is expected as necessity.

Menthol relieves acid reflux inflammation by regulating TRPV1 in esophageal epithelial cells

Transient receptor potential cation channel subfamily V member 1 (TRPV1) plays an important role in pain and inflammatory responses. Previous studies have shown that the expression of TRPV1 increases in the sensory neurons of the esophagus during the development of gastroesophageal reflux disease and esophagitis, but the response of TRPV1 in esophageal epithelial cells (EECs), which directly confront the refluxed acid, is still unknown. Here, we found that acid reflux triggered esophageal damage, which was accompanied by increased expression of TRPV1 in EECs and TRPV1 channel activity in these cells. Furthermore, menthol inhibited the Ca2+ influx induced by acid stimulation in EECs. After menthol treatment, the expression of TRPV1 in EECs was significantly reduced, and their hyperplasia was significantly reduced; finally, the inflammation pathway elicited in EECs was diminished in mice with acid reflux. These results suggest that menthol improves the clinical symptoms caused by gastroesophageal acid reflux by interfering with TRPV1 in EECs.

Systematic Analysis of Monoterpenes: Advances and Challenges in the Treatment of Peptic Ulcer Diseases

Peptic ulcer disease (PUD) is a multifactorial and complex disease caused by an imbalance of protective and aggressive factors (endogenous and exogenous). Despite advances in recent years, it is still responsible for substantial mortality and triggering clinical problems. Over the last decades, the understanding of PUD has changed a lot with the discovery of Helicobacter pylori infection. However, this disease continues to be a challenge due to side-effects, incidence of relapse from use of various anti-ulcer medicines, and the rapid appearance of antimicrobial resistance with current H. pylori therapies. Consequently, there is the need to identify more effective and safe anti-ulcer agents. The search for new therapies with natural products is a viable alternative and has been encouraged. The literature reports the importance of monoterpenes based on the extensive pharmacological action of this class, including wound healing and anti-ulcerogenic agents. In the present study, 20 monoterpenes with anti-ulcerogenic properties were evaluated by assessing recent in vitro and in vivo studies. Here, we review the anti-ulcer effects of monoterpenes against ulcerogenic factors such as ethanol, nonsteroidal anti-inflammatory drugs (NSAIDs), and Helicobacter pylori, highlighting challenges in the field.

Pharmacokinetics behaviors of l-menthol after inhalation and intravenous injection in rats and its inhibition effects on CYP450 enzymes in rat liver microsomes

1. l-Menthol, as a kind of monocyclic terpene, is widely used in inhalation formulations, food and tobacco. The purpose of this study was to investigate the pharmacokinetic behavior of l-menthol as well as its influence on the activities of cytochrome P450 enzymes. 2. The pharmacokinetic behaviors of l-menthol after inhalation (50 mg/kg) and intravenous injection (10 mg/kg) were investigated. A rat liver microsomal model was adopted to elucidate the inhibitory effect of l-menthol on CYP1A2, CYP2C11, CYP2D1/2, CYP2D4, CYP2E1 and CYP3A1 using phenacetin, tolbutamide, omeprazole, dextromethorphan, chlorzoxazone and testosterone as probe drugs, respectively. 3. The plasma concentration reached the C_max within 1.0 h (inhalation) and descended with the T_1/2 of 8.53 and 6.69 h for inhalation and i.v. administration, respectively. IC₅₀ for inhibition of l-menthol on CYP 450 enzymes were 4.35 μM for 2D4, 8.67 μM for 1A2, 13.02 μM for 3A1, 14.78 μM for 2D1/2, 234.9 μM for 2C11 and 525.4 μM for 2E1, respectively. 4. The results illustrate the pharmacokinetic process of l-menthol in rats and provide information for further rational applications. l-Menthol had moderate inhibitions on CYP2D4 and 1A2, which might affect the disposition of medicines primarily dependent on these pathways.

Cytoprotective, antioxidant and anti-inflammatory mechanism related to antiulcer activity of Cissampelos sympodialis Eichl. in animal models

ETHNOPHARMACOLOGICAL RELEVANCE

The leaves and roots of Cissampelos sympodialis (Menispermaceae) are used by indian tribes and in folk medicine to treat genitourinary infections, inflammation, asthma and gastrointestinal disorders.

MATERIAL AND METHODS

The standardized ethanolic extract (Cs-EtOHE) and alkaloids total fraction (Cs-TAF) obtained from aerial parts of C. sympodialis were evaluated in several models of acute gastric ulcers. The antisecretory and/or neutralizing mechanisms of the gastric acid secretion, cytoprotective, antioxidant and immunoregulatory mechanisms were also evaluated.

RESULTS

Cs-EtOHE and Cs-TAF presented a reduction in gastric mucosa lesions against ethanol, NSAIDs, hypothermic restraint-stress and gastric juice containment induced ulcer models. This activity is related to alkaloids present in the extract, and involves the participation of sulfhydryl compounds, nitric oxide, K_ATP channels, prostaglandins, decreased levels of IL-1β and TNF-α and increased levels of GSH and IL-10.

CONCLUSION

The data indicate gastroprotective activity, due to the participation of the cytoprotective, antioxidant and immunoregulatory mechanisms.

Amelioration of Ethanol-Induced Gastric Ulcers in Rats Pretreated with Phycobiliproteins of Arthrospira (Spirulina) Maxima

Phycobiliproteins of Arthrospira (Spirulina) maxima have attracted attention because of their potential therapeutic antioxidant properties. The aim of this study was to assess the possible antiulcerogenic activity of these phycobiliproteins (ExPhy) against ethanol-induced gastric ulcers in rats. To explore the possible mechanisms of action, we examined antioxidant defense enzymes (e.g., catalase, superoxide dismutase, and glutathione peroxidase), as well as the level of lipid peroxidation (MDA) and the histopathological changes in the gastric mucosa. Intragastric administration of ExPhy (100, 200, and 400 mg/kg body weight) significantly lowered the ulcer index value compared to the ulcer control group (p < 0.05). The greatest protection was provided by the concentration of 400 mg/kg. The histological study supported the observed gastroprotective activity of ExPhy, showing a reduced inflammatory response. Moreover, the alcohol-induced decrease in stomach antioxidant enzyme activity found in the ulcer control group was prevented by ExPhy pretreatment. Furthermore, ExPhy reversed the ethanol-induced increase in lipid peroxidation. In summary, the antiulcerogenic potential of ExPhy may be due, at least in part, to its anti-oxidant and anti-inflammatory effects.

The effect of menthol on acute experimental colitis in rats

Menthol is an aromatic compound with high antiinflammatory activity. The purpose of the current research is to investigate the effectiveness of menthol on acetic acid induced acute colitis in rats. Animals were injected with menthol (20 and 50 and 80mg/kg, i.p.) 24h prior to induction of colitis for 3 consecutive days. Menthol at medium and higher doses similar to dexamethasone as a reference drug significantly reduced body weight loss, macroscopic damage score, ulcer area, colon weight, colon length and improved hematocrit in rats with colitis. The histopathological examination also confirmed anti-colitic effects of menthol. Menthol also reduced significantly the colonic levels of tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β), interleukin 6 (IL-6) and myeloperoxidase (MPO) activity in inflamed colons. Thus, the findings of the current study provide evidence that menthol may be beneficial in patients suffering from acute ulcerative colitis.

Evaluation of traditional medicinal plant, Cissus setosa Roxb. (Vitaceae) for antiulcer property

Cissus setosa is an indigenous medicinal herb commonly used for the treatment of gastro ulcers. In the current investigation the aerial methanolic extract of C. setosa was investigated for their antiulcer activity using pylorus ligation and ethanol in experimental rats. The extract was administered at the doses of 200 and 400 mg/kg b.w. orally for 3 days. However, higher dose of the extract subsequently reduced gastric ulcer induced aberrations by pylorus ligation (70.05%) and ethanol (78.16%) as judged by their altered biochemical parameters such as free acidity, total acidity, total carbohydrate, total protein and pepsin activity. Furthermore, macroscopic examination of rat’s stomach also showed that the pretreatment with methanolic extract notably lowered the pylorus ligation and ethanol induced ulcers. As perceived in the present study, evidently, our findings basically supports the potency of the methanol extracts of C. setosa to treat gastrointestinal related disorders, thus lends pharmacological credence to the suggested folklore use.

The effects of baicalein on gastric mucosal ulcerations in mice: Protective pathways and anti-secretory mechanisms

Many flavonoids have been shown to present good results for the treatment of gastric ulcers. Baicalein, a bioactive flavonoid derived from the Scutellaria baicalensis Georgi root, possesses several biological effects, such as anti-inflammatory and antioxidant. This study was conducted to assess the gastroprotective properties of baicalein. Anti-ulcerogenic assay was performed using the protocol of ulcer induced by ethanol/HCl in mice; then, the role of presynaptic α₂-receptors, sulfhydryl (SH) compounds, nitric oxide (NO), prostaglandin (PG) and ATP-sensitive K⁺ (K_ATP) channels in gastroprotection of baicalein was investigated. The levels of reduced glutathione (GSH) and the myeloperoxidase (MPO) activity were measured in the gastric mucosa. Parameters of gastric secretion (volume, [H⁺] and pH) were determined with or without the presence of the secretagogue agent histamine, as well as mucus in gastric contents, by the pylorus ligation model. In vitro H⁺,K⁺-ATPase activity was also determined. Baicalein (10, 30 and 100 mg/kg) exhibited a dose related gastroprotective effect (P < 0.001) against acidified ethanol-induced lesions. The intraperitoneal treatment of mice with a α₂-adrenoreceptor antagonist (yohimbine; 2 mg/kg), a SH compounds blocker (N-ethylmaleimide, NEM; 10 mg/kg), a non-selective inhibitor of NO synthase (N_w-nitro-L-arginine methyl ester hydrochloride, L-NAME; 10 mg/kg), a non-selective inhibitor of cyclo-oxygenase (indomethacin; 10 mg/kg) or a K_ATP channel blocker (glibenclamide; 10 mg/kg) was able to reverse (P < 0.001) the gastroprotective response caused by baicalein (30 mg/kg). Baicalein (30 mg/kg; P < 0.05) was able to increase GSH levels and decreasing MPO activity. The intraduodenal treatment with baicalein (30 and 100 mg/kg) significantly increased (P < 0.05) the gastric mucus secretion. Additionally, the treatment with baicalein reduced (30 and 100 mg/kg; P < 0.05) the secretion volume and total acid secretion, and also increased (10, 30 and 100 mg/kg; P < 0.001) the pH value, after pylorus ligature. Baicalein (30 mg/kg) was also effective in inhibiting the effects of histamine on gastric secretion (volume, [H⁺] and pH; P < 0.001). Baicalein at 10 and 30 μg/mL showed anti-H⁺,K⁺-ATPase activity. In conclusion, the present results provide convincing evidence that baicalein could be used as a cytoprotective (preventive effect) and anti-ulcerogenic (anti-secretory effect) agent in the gastric ulcers.

Kazakh Ziziphora Species as Sources of Bioactive Substances

Ziziphora species represent the prototypical example of the Lamiaceae family. The phytochemicals present in Ziziphora include monoterpenic essential oils, triterpenes and phenolic substances belonging to the flavonoids. In Kazakh traditional medicine, Ziziphora species possess several medicinal uses. In particular, Z. bungeana Lam. and Z. clinopodioides Lam. are used for the treatment of illnesses related to the cardiovascular system or to combat different infections. Unfortunately, the majority of the information about the complex Ziziphora species is only available in Russian and Chinese language, therefore, we decided gather all available information on Kazakhstan Ziziphora, namely its content compounds, medicinal uses and published patents, to draw the attention of scientists to this very interesting plant with high medicinal potential.

Determination of Menthol in Plasma and Urine by Gas Chromatography/Mass Spectrometry (GC/MS)

Menthol, a monoterpene, is a principal component of peppermint oil and is used extensively in consumer products as a flavoring aid. It is also commonly used medicinally as a topical skin coolant; to treat inflammation of the mucous membranes, digestive problems, and irritable bowel syndrome (IBS); and in preventing spasms during endoscopy and for its spasmolytic effect on the smooth muscle of the gastrointestinal tract. Menthol has a half life of 3-6 h and is rapidly metabolized to menthol glucuronide which is detectable in urine and serum following menthol use. We describe a method for the determination of total menthol in human plasma and urine using liquid/liquid extraction, gas chromatography/mass spectrometry (GC/MS) in selected ion monitoring mode and menthol-d4 as the internal standard. Controls are prepared with menthol glucuronide and all samples undergo enzymatic hydrolysis for the quantification of total menthol. The method has a linear range of 5-1000 ng/mL, and coefficient of variation <10%.

Gastroprotective effects of thymol on acute and chronic ulcers in rats: The role of prostaglandins, ATP-sensitive K(+) channels, and gastric mucus secretion

Thymol, a monoterpene phenol derivative of cymene, is found in abundance in the essential oils of Thymus, Origanum, and Lippia species. The present study investigated the gastroprotective actions of thymol (10, 30, and 100 mg/kg, p.o.) in the acute (ethanol- and nonsteroidal anti-inflammatory drug-induced ulcers) and chronic (acetic acid-induced ulcers) ulcer models in rats. Some of the mechanisms underlying to the gastroprotective effect of thymol were investigated in the ethanol-induced ulcer model. Gastric secretion parameters (volume, pH, and total acidity) were also evaluated by the pylorus ligature model, and the mucus in the gastric content was determined. The anti-Helicobacter pylori activity of thymol was performed using the agar-well diffusion method. Thymol (10, 30, and 100 mg/kg) produced dose dependent reduction (P < 0.01) on the total lesion area in the ethanol-induced ulcer model. The gastroprotective response caused by thymol (30 mg/kg) was significantly attenuated (P < 0.001) by intraperitoneal treatment of rats with indomethacin (a non-selective inhibitor of cyclo-oxygenase, 10 mg/kg) and glibenclamide (ATP-sensitive K(+) channel blocker, 10 mg/kg), but not by DL-Propargylglycine (PAG, a cystathionine-γ-lyase inhibitor, 25 mg/kg) and Nw-nitro-L-arginine methyl ester hydrochloride (L-NAME, a non-selective inhibitor of nitric oxide synthase, 70 mg/kg). Thymol (30 and 100 mg/kg) also reduced the ulcer index (P < 0.05) and the total lesion area (P < 0.001) in the indomethacin- and acetic-acid-induced ulcer models, respectively. In the model pylorus ligature, the treatment with thymol failed to significantly change the gastric secretion parameters. However, after treatment with thymol (30 and 100 mg/kg), there was a significant increase (P < 0.01) in mucus production. Thymol no showed anti-H. pylori activity in vitro. Collectively, the present results provide convincing evidence that thymol displays gastroprotective actions on the acute and chronic ulcer models through mechanisms that involve increased in the amount of mucus, prostaglandins, and ATP-sensitive K(+) channels.

Helicteres sacarolha A. St.- Hil. et al.: gastroprotective and possible mechanism of actions in experimental animals

ETHNOPHARMACOLOGICAL RELEVANCE

Helicteres sacarolha A. St.- Hil. et al. popularly known in Brazil as 'semente-de-macaco', is widely employed in the popular medicine in many of parts of Brazil in the alleviation of symptoms of ailments such as peptic ulcer and inflammation. Up to the present, there is no study addressing the gastroprotective activity of the hydroethanolic extract of H. sacarolha and its possible mechanism of actions.

MATERIALS AND METHODS

The hydroethanolic (70%) extract of H. sacarolha (HEHs) was obtained by maceration. The gastroprotective activity was assessed using gastric ulcer models induced by acidified ethanol, piroxicam, and water restraint stress in mice and rats at doses of 20, 50 and 250mg/kg p.o. Mechanistic studies involved the antisecretory assay evaluated with pylorus ligation in rats and pre-treatments with appropriate antagonists/inhibitors such as yohimbine, glibenclamide, indomethacin and l-NAME, effect on catalase and myeloperoxidase activities and gastric mucus determination using acidified ethanol- induced ulcer in mice.

RESULTS

HEHs at all doses tested demonstrated potent gastroprotective activities in the acute ulcer models. The gastroprotective activity of HEHs was attenuated by pre-treatments with yohimbine, glibenclamide, indomethacin and l-NAME. HEHs effectively reduced basal gastric juice production without any effect on the free and total acidity. The gastroprotective action of HEHs involved increasing the antioxidant enzyme catalase and mucus secretion and inhibition of neutrophyl infiltration as reflected by the reduction in the myeloperoxidase activity.

CONCLUSION

The results of this study gave a scientific support for the popular use of the leaves of H. sacarolha in the treatment of gastric ulcers and that it has a multi-targeted action.

Simultaneous quantification of multiple volatile active components in rat plasma using a headspace-solid phase dynamic extraction method coupled to gas chromatography-tandem mass spectroscopy: application in a pharmacokinetic study of Longhu Rendan pills

A HS-SPDE-GC-MS/MS method for investigating pharmacokinetics of l-menthol, borneol, isoborneol, and camphor in rat plasma after oral administration of LRPs.

Gastroprotective effects of goniothalamin against ethanol and indomethacin-induced gastric lesions in rats: Role of prostaglandins, nitric oxide and sulfhydryl compounds

Goniothalamin (GTN), a styryl-lactone, is a secondary metabolite naturally found in its enantiomeric form (R) in plants of the genus Goniothalamus (Annonaceae). The antiproliferative activity against human tumor cell lines reported in several studies suggest that the α,β-unsaturated δ-lactone moiety emerges as a key Michael acceptor for cysteine residues or other nucleophilic biological molecules. Our group reported on the in vivo activity of (R)- and (S)-GTN as well as its racemic form (rac-GTN) in both Ehrlich solid tumor and carrageenan-induced paw edema in mice, without side effects in the effective doses. Despite the rich body of data on the in vitro GTN biological activity, much less is known about its in vivo pharmacological action. Herein we describe the gastroprotective activity of rac-GTN on chemical-induced gastric ulcers models in rats. GTN has a potent gastroprotective effect on ethanol-induced ulcers (effective dose50=18mg/kg) and this activity is dependent on sulfhydryl compounds and prostaglandins generation, but independent of nitric oxide (NO), gastric secretion and mucus production. We hypothesize that goniothalamin may act as a mild irritant, inducing the production of sulfhydryl compounds and prostaglandins, in a process known as adaptive cytoprotection. This hypothesis is supported by the fact that Michael acceptors are the most potent inducers of antioxidant response (as activation of Nrf2 pathway) through generation of mild oxidative stress and that gastroprotective activity of goniothalamin is inhibited after pre-treatment with NEM (N-ethylmaleimide) and NSAID (non-steroidal anti-inflammatory drugs), highlighting the importance of sulfhydryl compounds and prostaglandins on GTN activity.

Gastroprotective effect and mechanism of patchouli alcohol against ethanol, indomethacin and stress-induced ulcer in rats

Pogostemonis Herba is an important Chinese medicine widely used in the treatment of gastrointestinal dysfunction. Patchouli alcohol (PA), a tricyclic sesquiterpene, is the major active constituent of Pogostemonis Herba. This study aimed to investigate the possible anti-ulcerogenic potential of PA and the underlying mechanism against ethanol, indomethacin and water immersion restraint-induced gastric ulcers in rats. Gross and histological gastric lesions, biochemical and immunological parameters were taken into consideration. The gastric mucus content and the antisecretory activity were analyzed through pylorus ligature model in rats. Results indicated that oral administration with PA significantly reduced the ulcer areas induced by ethanol, indomethacin and water immersion restraint. PA pretreatment significantly promoted gastric prostaglandin E2 (PGE2) and non-protein sulfhydryl group (NP-SH) levels, upregulated the cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) mRNA expression, and considerably boosted the gastric blood flow (GBF) and gastric mucus production in comparison with vehicle. In addition, PA modulated the levels of interleukin-6 (IL-6), interleukin-10 (IL-10) and tumor necrosis factor-α (TNF-α). The levels of glutathione (GSH), catalase (CAT) and malonaldehyde (MDA) were also restored by PA. However, the gastric secretion parameters (pH, volume of gastric juice and pepsin) did not show any significant alteration. These findings suggest that PA exhibited significant gastroprotective effects against gastric ulceration. The underlying mechanisms might involve the stimulation of COX-mediated PGE2, improvement of antioxidant and anti-inflammatory status, preservation of GBF and NP-SH, as well as boost of gastric mucus production.

Anti-ulcer activity of essential oil constituents

Essential oils have attracted considerable worldwide attention over the last few decades. These natural products have wide-ranging pharmacological activities and biotechnological applications. Faced with the need to find new anti-ulcer agents and the great effort on the development of drugs for the treatment of ulcers, in this review, the anti-ulcer activities of 21 bioactive compounds found in essential oils are discussed.

The gastroprotective effect of menthol: involvement of anti-apoptotic, antioxidant and anti-inflammatory activities

The aim of this research was to investigate the anti-apoptotic, antioxidant and anti-inflammatory properties of menthol against ethanol-induced gastric ulcers in rats. Wistar rats were orally treated with vehicle, carbenoxolone (100 mg/kg) or menthol (50 mg/kg) and then treated with ethanol to induce gastric ulcers. After euthanasia, stomach samples were prepared for histological slides and biochemical analyses. Immunohistochemical analyses of the cytoprotective and anti-apoptotic heat-shock protein-70 (HSP-70) and the apoptotic Bax protein were performed. The neutrophils were manually counted. The activity of the myeloperoxidase (MPO) was measured. To determine the level of antioxidant functions, the levels of glutathione (GSH), glutathione peroxidase (GSH-Px), glutathione reductase (GR) and superoxide dismutase (SOD) were measured using ELISA. The levels of the pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) and the anti-inflammatory cytokine interleukin-10 (IL-10) were assessed using ELISA kits. The menthol treated group presented 92% gastroprotection compared to the vehicle-treated group. An increased immunolabeled area was observed for HSP-70, and a decreased immunolabeled area was observed for the Bax protein in the menthol treated group. Menthol treatment induced a decrease in the activity of MPO and SOD, and the protein levels of GSH, GSH-Px and GR were increased. There was also a decrease in the levels of TNF-α and IL-6 and an increase in the level of IL-10. In conclusion, oral treatment with menthol displayed a gastroprotective activity through anti-apoptotic, antixidant and anti-inflammatory mechanisms.