Inhibition of glutathione-S-transferase by dihydromyricetin and its kinetics analysis in liver of mice / 中国药理学通报

ABSTRACT

Aim To study the inhibition of glutathione-S-transferase by dihydromyricetin and its kinetics analysis in liver of mice.Methods Mouse liver cytochyma enzyme was obtained by different velocity centrifugation,the mouse liver glutathione-S-transferase of michaelis constant(Km),maximum velocity(Vmax)and the inhibition of glutathione-S-transferase by dihydromyricetin of 50% inhibiting concentration(IC50),inhibition constant(Ki),the type of inhibition were calculated by Lineweaver-Burk and the low of semi-effect-probit.Results It was found that dihydromyricetin inhibited the glutathione-S-transferase activity with an IC50 of(121.14?13.66)?mol?L~-1.Kinetics analysis showed the Km was 0.1460 mmol?L~-1 and Vmax was 175.44 U?mg~-1 for reduced glutathione(GSH)substrate and 0.0937 mmol?L~-1(Km)and 212.77 U?mg~-1(Vmax)for 1-chloro-2,4,-dinitrobenzene(CDNB)substrate.Kinetics studies of dihydromyricetin on glutathione-S-transferase showed the inhibition was competitive with GSH and noncompetitive with CDNB,and the inhibition constant was 0.22 mmol?L~-1 with GSH and 0.54 mmol?L~1 with CDNB.Conclusion Dihydromyricetin can inhibit the glutathione-S-transferase activity in liver of mice.