Effect of turmeric on oxidative stress induced by D-galactose in Drosophila melanogaster

Abstract

When administered at high levels, D-galactose can induce oxidative stress as a result of an accumulation of reactive oxygen species. In this study, the antioxidative effect of turmeric against this induced stress in Drosophila melanogaster was investigated through measurement of lipid peroxide levels and catalase activity. These parameters are compared among four test groups of flies: Group I, the untreated control; Group II given 0.18% turmeric; Group III, given 6.5% D-galactose; and Group IV given 0.18% turmeric and 6.5% D-galactose in combination. The different treatments were administered to separate cultures of fly larvae. Tests for thiobarbituric acid reactive substances (TBARS) and catalase activities were conducted on pooled whole body homogenates of emergent adult flies from each test group. The TBARS assay results showed that lipid peroxide levels in the Group IV flies decreased by 53.58% when compared to Group III, indicating an antioxidative effect attributed to the free radical scavenging activity of the active ingredient curcumin in turmeric. It is less likely that the antioxidative enzyme activity is stimulated by turmeric since, compared to the controls, catalase activities in Groups II, III and IV decreased. The activity of the enzyme did not vary significantly among the D-galactose treated flies with or without the turmeric. Other indicators of decreased oxidative stress by turmeric at varying concentrations using insect models are recommended in future studies.