Anti-inflammation effects of the total saponin fraction from Dioscorea nipponica Makino on rats with gouty arthritis by influencing MAPK signalling pathway

Background: Dioscorea nipponica Makino is widely used in traditional Chinese medicine to treat gouty arthritis. Methods: Sixty male Wistar rats were divided into six groups: the normal group, model group, colchicine group (COL) and three total saponin groups (RDN) (high dose [160 mg/kg], middle dose [80 mg/kg] and low dose [40 mg/kg]). HE staining was used to detect the histopathologic changes of the synovial tissue of joint. Immunohistochemical method was used to detect the protein expressions of P-38, p-P38, JNK, p-JNK, ERK1/2, p-ERK1/2, MEK1/2, p-MEK1/2, MKK4, p-MKK4, ICAM1, VCAM1, and PPARγin the synovial tissue of joint. Realtime PCR and WB methods were used to detect the mRNA and protein expressions of PPARγand AdipoR2 in the synovial tissue of joint. The contents of CXCL1 and ADP in the blood serum were measured by Elisa method. Results: Our study showed that RDN could improve the situation of the synovial tissue, reduce the protein expressions of MKK4, p-MEK1/2, p-JNK, p-ERK1/2, ICAM1. They could also decrease the content of CXCL1 and increase the content of ADP in the blood serum. Conclusion: RDN has good effect of anti-inflammation. This is in part realized by influencing MAPK signalling pathway. It provides a new visual angle to reveal the mechanism of RDN to treat GA.