Phytochemical Composition, Antioxidant Activity and Toxicity of Aqueous Extract of Picralima nitida in Drosophila melanogaster

doi.org/10.26538/tjnpr/v4i12.19

Abstract

Picralima nitida is a rainforest plant used for the treatment and management of diabetes and some other diseases in folklore medicine. In recent years, Drosophila melanogaster has served as an excellent model organism for toxicity studies of plants and also for the study of some diseases. This study focused on the antioxidant activity, phytochemical composition, and toxicity of aqueous seed extract of P. nitida in D. melanogaster. Phytochemical and antioxidant analyses of the extract were assessed using standard methods. The toxicity of the aqueous seed extract of P. nitida (APN) was also assessed, after seven days of exposure to APN (1-32 mg/mL), based on the rate of survival, locomotive performance and antioxidant effect in flies. Quantitative phytochemical analyses of APN showed the total flavonoid content to be 58.23 ± 0.79 mg quercetin equivalent/g dry weight (DW). The phenolic content was estimated to be 45.02 ± 0.27 mg gallic acid equivalent/g DW while β-carotene and lycopene contents, were 0.039 ± 0.002 and 0.047 ± 0.001 μg/mg, respectively. The anthocyanin content was 3.98 ± 1.28 μg/mL of cyanidin-3-glucoside equivalents. The result of the in vivo study showed that APN caused a reduction in the survival and locomotive behaviour of flies at 32 mg/mL. There was also an increase in the concentration of malondialdehyde and a reduction in the activity of acetylcholinesterase, glutathione-S-transferase and superoxide dismutase at high concentration of APN. The study showed that P. nitida seeds extract, despite its medicinal benefits, is toxic at high concentrations in D. melanogaster.