Protective effect of Trigonella foenum-graecum and Cinnamomum zeylanicum against diabetes induced oxidative DNA damage in rats

Abstract

Diabetes mellitus has become a global epidemic as its prevalence is steadily increasing everywhere at an alarming rate, most markedly in the India. Traditional Indian system of medicine based on herbal therapies is being practiced since ancient times and has been proved very effective against number of diseases. Trigonella foenum-graecum (Tfg) and Cinnamomum zeylanicum (Cz), the two spices, possess multiple medicinal properties. Hence present study is aimed to evaluate the protective effects of these plants on the oxidative DNA damage in diabetic rats. The presence of DNA base oxidation was investigated by modified comet assay which uses bacterial repair enzymes, formamidopyrimidine glycosylase and Endonuclease III which can measure oxidatively damaged purines and pyrimidines, respectively. Diabetes induced alteration in total antioxidant capacity (TAC), generation of superoxide anion and the levels of GSH, GSSG, NADH, NAD+, NADPH and NADP+ were monitored. Diabetes was induced by intravenous injection of alloxan, followed by oral administration of aqueous suspension of Tfg seeds and bark of Cz. Treatment of Tfg and Cz significantly restored the altered level of superoxide anion, TAC, ratios of GSH/GSSG, NAD(P)H/NAD(P)+ and NADH/NAD+ in the diabetic group. Furthermore, both the treatment effectively decreased the level of oxidatively damaged purine and pyrimidine bases.