title: Analgesic activity of myricetin isolated from Myrica rubra Sieb. et Zucc. leaves.
abstract: Myrica rubra Sieb. et Zucc. leaves are commonly used as an astringent, antidiarrheic, and analgesics in folk medicine in China. In the present study, the analgesic activity of myricetin, a major compound in Myrica rubra Sieb. et Zucc. leaves was evaluated in vivo. The analgesic effect of myricetin was tested by a serial of models, such as acetic acid-induced writhing response, formalin-induced paw licking and hot plate test. The sedative activity was evaluated by pentobarbital-induced sleep time. Platelet aggregation induced by collagen and arachidonic acid was also performed in vitro. Myricetin showed a significant inhibition on chemical nociceptive models such as the acetic acid-induced writhing response and the licking time on the late phase in the formalin test in a dose-dependent manner, but did not manifest a signicant effect in hot plate test. Myricetin was also not able to increase the sleeping time induced by pentobarbital, which further indicated that the analgesic effect of myricetin was unrelated to sedation. In addition, myricetin inhibited the content of PGE2 in the peritoneal fluid and platelet aggregation induced by collagen and arachidonic acid in vitro. These results collectively demonstrated that myricetin possessed potent analgesic activity, which was related with peripheral analgesia, but, not with the opioid system. Myricetin may be a potent COX-1 inhibitor with anti-platelet activity.
authors.affiliation: Department of Pharmacology, Shenyang Pharmaceutical University, Shenyang, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Tong
authors.forename: Xiao-Mian
authors.initials: XM
authors.lastname: Zhou
authors.forename: Shu-Jun
authors.initials: SJ
authors.lastname: Wang
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.forename: Ying-Lin
authors.initials: YL
authors.lastname: Cao
mesh_terms: D019342:Acetic Acid; D000700:Analgesics / Q000302:isolation & purification / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D051545:Cyclooxygenase 1 / Q000378:metabolism; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D015232:Dinoprostone / Q000378:metabolism; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005260:Female; D005419:Flavonoids / Q000302:isolation & purification / Q000494:pharmacology*; D005557:Formaldehyde; D008297:Male; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D051379:Mice; D031641:Myrica / Q000737:chemistry; D010146:Pain / Q000139:chemically induced / Q000378:metabolism / Q000517:prevention & control*; D010147:Pain Measurement; D017288:Pain Threshold / Q000187:drug effects; D010529:Peritoneal Cavity; D010533:Peritoneal Lavage; D018515:Plant Leaves; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D011817:Rabbits; D012890:Sleep / Q000187:drug effects
chemical_list: D000700:Analgesics; D016861:Cyclooxygenase Inhibitors; D005419:Flavonoids; D008565:Membrane Proteins; D010975:Platelet Aggregation Inhibitors; D005557:Formaldehyde; C040015:myricetin; D051545:Cyclooxygenase 1; C496512:Ptgs1 protein, mouse; D015232:Dinoprostone; D019342:Acetic Acid