Résumé
Aim To find the material foundation of treatment for diabetes in Coptidis Rhizoma ( RC ) . Methods The antihyperglycemic effect of RC alka-loids ( berberine, coptisine, palmatine, epiberberine, and jatrorrhizine) was evaluated in spontaneity diabe-tes KK-Ay mice. Results After 40 days′ oral admin-istration ( 225 mg · kg-1 · d-1 , ig ) , berberine and coptisine significantly suppressed the elevated fasting blood glucose level and ameliorated the glucose toler-ance . Body weight gain of KK-Ay mice was significant-ly decreased in the epiberberine-treated group. Berber-ine improved insulin resistance and jatrorrhizine in-creased the SOD activity, decreased the MDA level. Conclusions These results indicate that the main an-tihypoglycemic effect constituents are berberine and coptisine, while they show different mechanisms. Pal-matine, epiberberine and jatrorrhizine display different potential roles in the treatment of diabetes. The meth-ylene-dioxy groups at the C-2 , C-3 , C-9 and C-10 po-sitions are indispensable for antihyperglycemic effect of RC alkaloids.