STUDIES ON ANTINEPHRITIC EFFECTS OF PLANT-COMPONENTS IN RATS .1. EFFECTS OF SAIKOSAPONINS ORIGINAL-TYPE ANTI-GBM NEPHRITIS IN RATS AND ITS MECHANISMS

This study was designed to clarify the antinephritic effects of the saikosaponins that are contained in Bupleurum falcatum L. crude saikosaponin at 1.0 mg and 5.0 mg/kg, i.p. prevented urinary protein excretion and elevation of serum cholesterol content on the 10th day after the injection of anti-GBM serum. Moreover, crude saikosaponin at 1.0 mg and 5.0 mg/kg, i.p. significantly inhibited histopathological changes such as hypercellularity and adhesion. On the other hand, saikosaponin a (5.0 mg/kg, i.p.) and d (1.0 mg and 5.0 mg/kg, i.p.) also prevented urinary protein excretion, elevation of serum cholesterol content, and histopathological changes. In the second study, to clarify the antinephritic mechanisms of saikosaponins on this model, we investigated the effect of saikosaponins on platelet aggregation, release of corticosterone and reactive oxygen species scavengers activity. Crude saikosaponin and saikosaponin d significantly inhibited the increase in platelet aggregation, and saikosaponin d enhanced the serum and intra-adrenal corticosterone levels. Crude saikosaponin and saikosaponin a inhibited the decrease in activity of scavengers (SOD, catalase, glutathione peroxidase). These results indicate that saikosaponins were effective on this model, and antinephritic mechanisms of saikosaponins were party due to anti-platelet, corticosterone releasing and enhancing action on the activity of reactive oxygen species scavengers.