Involvement of Opioid System, TRPM8, and ASIC Receptors in Antinociceptive Effect of Arrabidaea brachypoda (DC) Bureau.

Arrabidaea brachypoda (DC) Bureau is a medicinal plant found in Brazil. Known as "cipó-una", it is popularly used as a natural therapeutic agent against pain and inflammation. This study evaluated the chemical composition and antinociceptive activity of the dichloromethane fraction from the roots of A. brachypoda (DEAB) and its mechanism of action. The chemical composition was characterized by high-performance liquid chromatography, and this fraction is composed only of dimeric flavonoids. The antinociceptive effect was evaluated in formalin and hot plate tests after oral administration (10-100 mg/kg) in male Swiss mice. We also investigated the involvement of TRPV1 (transient receptor potential vanilloid 1), TRPA1 (transient receptor potential ankyrin 1), TRPM8 (transient receptor potential melastatin 8), and ASIC (acid-sensing ion channel), as well as the opioidergic, glutamatergic, and supraspinal pathways. Moreover, the nociceptive response was reduced (30 mg/kg) in the early and late phase of the formalin test. DEAB activity appears to involve the opioid system, TRPM8, and ASIC receptors, clearly showing that the DEAB alleviates acute pain in mice and suggesting the involvement of the TRPM8 and ASIC receptors and the opioid system in acute pain relief.

Relationship between Hormonal Modulation and Gastroprotective Activity of Malvidin and Cyanidin Chloride: In Vivo and In Silico Approach.

Peptic ulcers are lesions that affect the gastrointestinal tract and that can be triggered by external factors such as alcohol use. This study investigated the gastroprotective role of two anthocyanidins, malvidin and cyanidin chloride, in an ethanol-induced gastric ulcer model in male and female mice (ovariectomized and supplemented with 17ß-estradiol or not) and aimed to evaluate the effectiveness of anthocyanidins in preventing the formation of lesions and to identify the underlying mechanisms, while considering hormonal differences. Moreover, in silico comparative analysis was performed to predict the properties and biological behaviors of the molecules. We observed that the hormonal status did not interfere with the gastroprotective action of malvidin, although antioxidant mechanisms were modulated differently depending on sex. On the other hand, cyanidin showed gastroprotective activity at different doses, demonstrating that, for the same experimental model, there is a need to adjust the effective dose depending on sex. In silico analysis showed that, despite being structurally similar, the interaction with receptors and target proteins in this study (myeloperoxidase, superoxide dismutase, catalase, and reduced glutathione) differed between the two molecules, which explains the difference observed in in vivo treatments.

Mouririelliptica: validation of gastroprotective, healing and anti-Helicobacter pylori effects.

ETHNOPHARMACOLOGICAL RELEVANCE: Mouriri elliptica Martius (Melastomataceae) is species reputed in folk medicine to heal gastric ulcer and gastritis. AIM OF THE STUDY: Methanolic extract (ME) and ethyl acetate fraction (EAF) from leaves of Mouriri elliptica were evaluated for their gastroprotective, healing, immunological, toxicological and anti-Helicobacter pylori activities. MATERIAL AND METHODS: The gastroprotective action of ME and EAF was evaluated in rodent experimental models and to elucidate mechanisms of action, the antisecretory action, involvements of NO, SH, PGE(2), anti-Helicobacter pylori action of ME was evaluated. We also used immunohistochemical (PCNA and COX-2) and immunomodulatory (murine peritoneal macrophages) assays to evaluate Mouriri elliptica effects. RESULTS: ME present gastroprotective action without antisecretory effect. Otherwise, ME showed anti-Helicobacter pylori action (MIC=0.025mug/mL) and was able to inhibit NO production by macrophages. This species also accelerate the healing of ulcerated gastric mucosa by stimulating proliferation factors (PCNA), COX-2 and maintained basal PGE(2) level independent action of NSAID in gastric mucosa. The phytochemical investigation showed that this species possesses phenolic acid derivatives, acylglycoflavonoids and condensed tannins which probably influenced their pharmacological action. CONCLUSION: All these results suggest the efficacy and safety of Mouriri elliptica in combating and healing gastric ulcer.