Analgesic effect of quercetin 3,7-o-dimethyl ether isolated from salvia officinalis

To evaluate the analgesic effect of flavonoid quercetin 3,7-O-dimethyl ether isolated from ethyl acetate fraction of the methanol extract of Salvia officinalis. The dried leaves of Salvia officinalis were subjected to extraction with methanol, and then it was fractioned by water and ethyl acetate solvent. The antinociceptive activity of flavonoid quercetin 3,7-Odimethyl ether isolated from ethyl acetate fraction was assessed using heat-induced (hot-plate) and chemical-induced (acetic acid and formalin) nociception models in mice and rats. Involvement of opioid system and cyclic guanosine monophosphate (cGMP) pathway were also investigated using naloxone and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), respectively. Pretreatment with quercetin 3,7-O-dimethyl ether significantly (p < 0.05) and dose-dependently increased the hot plate latency time. It also reduced the number of abdominal constrictions and paw lickings (in both early and late phases) induced by acetic acid and formalin, respectively. Naloxone and ODQ significantly attenuated the antinociceptive activity of quercetin 3,7-O-dimethyl ether in the hot plate and both phases of formalin test. Antinociceptive action of flavonoid quercetin 3,7-O-dimethyl ether support the traditional use of Salvia officinalis in folk medicine. This study provide evidence that the antinociceptive effect of quercetin 3,7O-dimethyl ether is partly mediated by opioid system and cGMP pathway. Finally, the quercetin 3,7-Odimethyl ether isolated from this plant appears to contribute for the antinociceptive property of different extracts from Salvia officinalis.