Suppressive effects of Sairei-to on mesangial proliferation in a rat model of glomerulonephritis

Background Sairei-to (TJ-114) is a Japanese herbal medicine of standardized quality, originating from traditional Chinese medicine. In the present in vivo study, we investigated the suppressive effects of TJ-114, Shosaiko-to (TJ-9), and Saiboku-to (TJ-96) on mesangioproliferative glomerulonephritis (MsPGN) in rats. We evaluated the efficacy of these drugs on proteinuria, mesangial cell proliferation, and superoxide dismutase (SOD) activity.Methods MsPGN was induced in Wistar rats by intravenous injection of rabbit anti-rat thymocyte serum (ATS). TJ-114, TJ-9, or TJ-96 (500mg/kg per day) was orally administered to the rats in drinking water from the day of ATS injection (day 0) to day 8, when rats were killed and kidney specimens were collected. The degree of mesangial cell proliferation was evaluated by immunostaining for proliferating cell nuclear antigen (PCNA) or macrophage antigen (ED-1). SOD activity in the homogenate of the renal cortex was also evaluated.Results The amount of urinary albumin was significantly decreased only in the TJ-114-treated group compared with the disease control group (P < 0.05). The number of PCNA- or ED-1-positive cells was significantly decreased in all the treatment groups (P < 0.05, respectively, compared with the disease control group). SOD activity in the renal cortex homogenate was significantly augmented in all the treatment groups, most markedly in the TJ-96- and TJ-114-treated groups (P < 0.01, respectively, compared with the disease control group).Conclusions These results suggest that TJ-114 suppresses the proliferation of mesangial cells through its antioxidative activity.