Studies on the antinephritic effect of plant components (4): Reduction of protein excretion by berberine and coptisine in rats with original-type anti-GBM nephritis.

The present study was conducted to investigate the antinephritic effects of berberine and coptisine, which are contained in Coptidis rhizoma, on original-type anti-GBM nephritis in rats. Berberine and coptisine at the doses of 0.5, 1.0 and 5.0 mg/kg/day, i.p. were effective in inhibiting urinary protein excretion, elevation of serum cholesterol and creatinine contents as well as glomerular histopathological changes. In addition, berberine at 20 mg/kg/day, p.o. also inhibited urinary protein excretion throughout the experimental periods. Berberine and coptisine inhibited platelet aggregation in both in vitro and in vivo assays, and berberine inhibited the decline of renal blood flow. Although berberine inhibited an increase in thromboxane B2 formation, it increased the formation of 6-keto-prostaglandin F1 alpha in platelets and isolated glomeruli. These results indicate that the antinephritic effects of berberine and coptisine may be partly due to antiplatelet action and improved renal hemodynamics via changing prostanoid synthesis.