Toxicity and in vitro antioxidant potential of Curcuma longa Linn and Zingiber officinale Rosc rhizomes in Drosophila melanogaster

Medicinal plants like Curcuma longa and Zingiber officinale contain phytochemicals which have antioxidant properties. The study evaluated the antioxidant effect of Curcuma longa and Zingiber officinale on the survival of Drosophila melanogaster administered isoniazid. Drosophila melanogaster aged 3-5 days old were exposed to different concentrations (5-1000 mg/ 5 g diet) of isoniazid, and extract for 7 days to determine the lethal concentration (LC50). A 14-day survival assay was performed to evaluate the effect of isoniazid and the herbal extract on the survival rate of Drosophila melanogaster. The antioxidant activity of the herbal extract on the stable 2,2- diphenyl-1- picrylhydrazyl (DPPH) was also evaluated. The result showed an antioxidant activity greater than that of a standard, silymarin. An increase in survival rate of the fruit flies was observed at the lowest dose of the extract, when compared to those fed diet only. In conclusion, this study provided valuable insights into the antioxidant properties of the herbal extract, highlighting its potential benefits, while further research to elucidate the effects of phytochemicals especially at high doses is necessary. The results also underscore the importance of considering various factors in toxicity assessments as they affect fly survival.