Determination of the Levels of DNA Damage Induced by Chinese Herbal Medicine Using Differential Pulse Voltammetry

KeyWord:differential pulse voltammetry(DPV)  Chinese herbal medicine  DNA damage  8-hydorxy-2-deoxyano-sine(8-OHdG)  genotoxicity

Abstract:

      Effects of DNA damage induced by Chinese herbal medicine were studied by differential pulse voltammetric(DPV) method.The voltammeitric behaviour of 8-hydorxy-2-deoxyano-sine(8-OHdG) in the phosphate buffer(pH 5.0) was investigated at a glassy carbon electrode by cyclic voltammetry(CV) and DPV.A well-defined oxidation peak of 8-OHdG at +0.5 V was found£¬and its current intensity was proportional to concentration of 8.OHdG in the range of 1.0¡Á10-6-7.1¡Á10-4 mol/L.The regression equation was Ip(¦ÌA)=0.004 3c(mol/L)+4¡Á10-8(r=0.999 8) and the detection limit(S/N=3) was 3.5¡Á10-7 mol/L.The method was applied in analysis of the levels of 8-OHdG in the calf thymus DNA(ctDNA) exposed to concentration of 40 g/L of glycyrrhiza£¬cherokee rose£¬eucommia ulmoides£¬pinellia£¬nux vomica extract for 2 h£¬respectively£¬and the blood of Kunming mice exposed to low and high concentration of nux vomica extract by mouth injection for 30 consecutive days.The results showed that glycyrrhiza£¬cherokee rose£¬eucommia ulmoides£¬pinellia extract could not cause ctDNA oxidative damage£¬and nux vomica extract can cause DNA oxidative damage to the formation of 8-OHdG in the average level of (3.2¡À0.2)¦Ìmol/L.The average levels of 8-OHdG were (2.0 ¡À 0.1) ¦Ìmol/L and (5.3 ¡À 0.3) ¦Ìmol/L in the blood after a long-term administration of low concentration and high concentration of nux vomica extracts of Kunming mice£¬respectively.The study indicated that nux vomica contained the potential genotoxicity.