Fig. 4
Effect of methanol extract of the V. roxburghii root and its different fractions, and morphine on hot plate test. Values are mean ± S.E.M. *p < 0.05 and **p < 0.01, significantly different from control; ANOVA followed Dunnett’s test (n = 6, per group). VRM: V. roxburghii methanol extract; VRP: V. roxburghii petroleum ether fraction; VRE: V. roxburghii ethyl acetate fraction; VRC: V. roxburghii chloroform fraction; VRA: V. roxburghii aqueous fraction