OBJECTIVEGaultheria yunnanensis. are used widespreadly in the south of China to treat rheumatoid arthritis. The aim of this study was to provide an experimental basis for G. yunnanensis to therapy rheumatoid arthritis.

METHODWe prepared water extracts, ethanol extracts, n-butanol extracts, ethyl acetate extracts and the rest of ethanol extracts from G. yunnanensis. Then, the n-butanol extracts were applied to macroporous resin and eluted with water, 30% ethanol, and 95% ethanol. Rheumatoid arthritis was induced by Freund's complete adjuvant injected into right postpedes in Wistar rats which was utilized to elucidate the anti-inflammatory effect of different extracted liquid of G. yunnanensis. Rats were intragastric injected (ig) with extracts as experimental group or normal saline as control group.

RESULTFreund's complete adjuvant induced arthritis was successfully established: paw edema were increased after Freund's complete adjuvant injection, peaked at 2 or 3 day, then decreased, the paw edema were increased again at 7 or 8 day, and persisted 15 d. Water extracts, n-butanol extracts or ethyl acetate extracts could a significantlly decrease the paw edema as compared with the control group (P < 0.05, P < 0.01). The effect of n-butanol extracts was the most powerful. Further, n-butanol extracts eluant with water and 30% ethanol decreased the paw edema. The activity of extracts eluant with 30% ethanol was stronger than that of eluant with water.

CONCLUSIONG. yunnanensis displays considerable effects against Freund s complete adjuvant induced arthritis in rats, which is in concordance with clinical practice. n-Butanol extracts and both of the eluants with water and 30% ethanol produce a significant decrease in the paw edema. 30% ethanol eluants show a stronger activity than others. The effects against rheumatoid arthritis of different parts of G. yunnanensis differ in degree. It is deserved to explore the potential mechanisms of anti-inflammtion of the G. yunnanensis, especially the n-butanol extracts eluant with 30% ethanol.

Animals ; Arthritis, Experimental ; drug therapy ; Disease Models, Animal ; Drug Evaluation, Preclinical ; Drugs, Chinese Herbal ; administration & dosage ; Female ; Gaultheria ; chemistry ; Male ; Random Allocation ; Rats ; Rats, Wistar