Analgesic and anti-inflammatory activities of methanol extract from Desmodium triflorum DC in mice

In this study, we evaluated the analgesic effect of methanol extract from Desmodium triflorum DC (MDT) by using animal models of acetic acid-induced writhing response and formalin test. The anti-inflammatory effect of MDT was investigated by lambda-carrageenan-induced paw edema in mice. In order to study the anti-inflammatory mechanism of MDT, we detected the activities of glutathione peroxidase (GPx) and glutathione reductase (GRd) in the liver, the levels of interleukin-1beta (IL-1beta), tumor necrosis factor (TNF-alpha), malondialdehyde (MDA) and nitric oxide (NO) in the edema paw tissue. In the analgesic test, MDT (0.5 and 1.0 g/kg) decreased the acetic acid-induced writhing response and the licking time on the late phase in the formalin test. In the anti-inflammatory test, MDT (0.5 and 1.0 g/kg) decreased the paw edema at the 3rd, 4th, 5th and 6th hour after lambda-carrageenan administration. On the other hand, MDT increased the activities of SOD and GRd in liver tissues and decreased the MDA level in the edema paw at the 3rd hour after lambda-carrageenan-induced inflammation. MDT also affected the levels of interleukin-1beta, tumor necrosis factor-alpha, NO and MDA which were induced by lambda-carrageenan. The results suggested that MDT possessed analgesic and anti-inflammatory effects. The anti-inflammatory mechanism of MDT might be related to the decreases in the level of MDA in the edema paw via increasing the activities of SOD and GRd in the liver, and the NO level via regulating the IL-1beta production and the level of TNF-alpha in the inflamed tissues.