RESUMO
Objective:To investigate the inhibitory effect of Epibueropyridinium A on aldose reductase.Methods: Aldose reductase was extracted from cattle crystalline lens.Besides Epibueropyridinium A,the reactive system also contained DL-glyceraldehyde,aldose reductase,and NADPH.The activity changes of aldose reductase were detected at 340 nm.Epalrestat was taken as the positive control.The inhibitory type,Ki and IC_(50) were determined by double reciprocal plot,quadratic drawing,and drawing of inhibitor's concentration to inhibitory ratio,respectively.Results: Epibueropyridinium A significantly inhibited the activity of aldose reductase in a competitive manner,with IC_(50) being 4.2 ?g/ml and Ki being 4.88 ?g/ml.Conclusion: Epibueropyridinium A is competitive inhibitor of aldose reductase.
RESUMO
Objective:To investigate the effect of Epibueropyridinium A(EA),extracted from Scrophularia ningpoensis,in prevention of D-galactose-induced cataract in rats.Methods: SD rats were randomly divided into 5 groups (n=10),namely,the normal control,cataract model,20 mg/kg EA,10 mg/kg EA,and positive control groups.The cataract model was induced by intraabdominal administration of D-galactose into rats.Rats of the 2 EA groups received corresponding amount of EA and those in the positive control group received epalrestat(10 mg/kg) or VitE(30 mg/kg).The changes of the lens were examined with slit lamp microscope at defined time points.The activities of superoxide dismutase(SOD) and the content of malonaldehyde(MDA) and sorbitol were determined in the lens 3 and 6 weeks later.Results: EA obviously improved the lens opacification in the 2 EA groups compared to cataract model group,and the improvement in high EA group was more obvious than that in the low EA group(P