Analgesic and anti-inflammatory activities of a fraction rich in gaultherin isolated from Gaultheria yunnanensis (Franch.) Rehder

The analgesic and anti-inflammatory activities of a salicylate derivatives fraction (SDF) isolated from Gaultheria yunnanensis (FRANCH.) REHDER and the mechanisms of actions were investigated in the present study. The major constituent of SDF, which represented around 50% of this fraction, was a methyl salicylate diglycoside named gaultherin. SDF showed a significant inhibition on the hind paw edema in rats (200, 400 mg/kg body wt., p.o.) and ear swelling in mice (200, 400, 800 mg/kg body wt., p.o.) caused by carrageenin and croton oil, respectively. In addition, SDF (400, 800 mg/kg body wt., p.o.) inhibited only the second phase (inflammatory) in the formalin test, and showed no effect in the hot-plate test in mice. The antinociceptive activity of SDF was predominantly peripheral and independent of the opioid system. These findings demonstrate that SDF from Gaultheria yunnanensis (FRANCH.) REHDER possesses analgesic and anti-inflammatory activities, which may be mediated, at least partly, through the suppression of inflammatory mediators or their release suggested by the animal experiment. The observed effects of SDF are probably due to the presence of high content of salicylate derivatives (30%), including gaultherin, MSTG-A and MSTG-B.