Effects of
phellodendrine (OB-5) on crescentic-type
anti-GBM nephritis in rats and the cell number of the various leukocyte subpopulations in the glomeruli of the nephritic rats were investigated. OB-5 at 25, 50 and 100 mg/kg/day, p.o. prevented the urinary
protein excretion by the 19th day after i.v.-injection of
anti-GBM serum. In the OB-5-treated rats, plasma
cholesterol and
creatinine contents were lower than those of the control rats throughout the 40-day experimental period. Histopathological observations demonstrated that OB-5 inhibited the incidence of crescent formation, adhesion and fibrinoid
necrosis in the glomeruli by the 41st day. OB-5 did not affect the plasma antibody titer against rabbit
gamma globulin. The increases in total leukocytes, macrophages, cytotoxic/suppressor T cells, Ia positive cells, and
IL-2 receptor positive cells in the glomeruli in OB-5, 100 mg/kg-treated rats as well as those of the animals treated with
azathioprine or
cyclosporin A were lower than those of the
anti-GBM nephritic control. These results indicate that OB-5 was effective in crescentic-type
anti-GBM nephritis and the antinephritic mechanisms of this agent may be due to its ability to inhibit the proliferation or the migration of macrophages and cytotoxic T lymphocytes in the glomeruli.