Analgesic and anti-inflammatory property of the methanol extract from Ligustrum morrisonense leaves in rodents.

Ligustrum morrisonense Kaneh and Sasaki (abbreviated as LM), an endemic Ligustrum plant in Taiwan, is similar to Ligustrum lucidum, which is usually used for curing hepatic and inflammatory disorders. The aim of this study was to evaluate the analgesic and anti-inflammatory properties of LM by chemical-induced algesia and carrageenan-induced inflammation in rodents. Its triterpenoid contents were measured by using high performance liquid chromatography-photodiode array detector. LM leaf extracts effectively inhibited writhing responses induced by 1% acetic acid and biphasic-licking responses caused by 1% formalin. LM leaf extract also reduced the edema induced by 1% carrageenan. Furthermore, LM leaf extract reduced the abdominal Evan's blue extravasations caused by lipopolysaccharide (LPS), serotonin, histamine and bradykinin. LM leaf extract has higher contents of amyrin and lupeol among six assayed triterpenoid compounds. In conclusion, LM is a potential analgesic and anti-inflammatory Ligustrum plant, and its anti-inflammatory effects are partially related to decreasing microvascular permeability via inflammatory mediators and inhibiting cyclooxygenase-2 activity.