Effects of Bupleurum scorzoneraefolium, Bupleurum falcatum, and saponins on nephrotoxic serum nephritis in mice

Bupleuri radix is a commonly prescribed Oriental herbal medicine containing extracts of different Bupleuri species. We wished to determine whether two of these species, Bupleurum scorzoneraefolium and Bupleurum falcatum, or their active ingredients, saikosaponins a, c, and d, could prevent the development of immune-complex nephritis in nephrotoxic serum treated mice. Immune-complex nephritis was created in C57BL/6 mice by administration of nephrotoxic serum containing anti-basement membrane antibodies. Mice were next given one of five treatments: Bupleurum scorzoneraefolium, Bupleurum falcatum, saikosaponin a, saikosaponin c, or saikosaponin d. Proteinuria, blood urea nitrogen, creatinine, and renal histological changes were then examined. Saikosaponin c almost completely prevented the development of nephritis, although immune-complex deposition was not affected. Bupleurum falcatum and saikosaponin d had a significant, although lesser effect, and Bupleurum falcatum and saikosaponin a showed no effect. The mechanism of action of saikosaponin c and the reasons for the difference between the two bupleuri species should be investigated further in order to find the best way to utilize the therapeutic effect of Bupleuri radix on nephritis.