Moringa oleifera Leaf Extract Promotes Antioxidant, Survival, Fecundity, and Locomotor Activities in Drosophila melanogaster

Aim: The study was designed to investigate antioxidant, survivability, fecundity, and locomotor activity of Moringa oleifera leaf (MOL) extract in Drosophila melanogaster.

Materials and Methods: The study was conducted at the Africa Centre of Excellence in phytomedicine Research and Development (ACEPRD), University of Jos, Nigeria, in August 2019 - March 2020. In the first place, in vitro analysis of the antioxidant activity of extracts of M. oleifera in various solvents (Aqueous, Methanol-Aqueous co-solvent (80 % v/v) and n-Hexane) were evaluated using DPPH (1,1-Diphenyl-2-Picrylhydrazyl) assay. Based on the in vitro result, the methanol extract with the best free radical scavenging activity was used in graded doses for conducting the in vivo studies, and the observations were recorded. Distilled water (1000 µL) was used alone in 10 g fly food (as negative control) or as a solvent to dissolve MOL extract or ascorbic acid (positive control) separately before mixing with the fly food. Statistical significance was taken at P<0.05

Results: The methanol extract of M. oleifera leaf (MEMOL) showed significantly (P<0.05) higher free radical scavenging ability (IC50 = 60 µg/ml) compared with the aqueous (IC50 = 100 µg/ml) and n-hexane (IC50 = 250 µg/ml) extracts respectively. The median lethal dose (LD50) of MEMOL was >2000 mg. Supplementation with MEMOL non-significantly (P>0.05) improved movement, significantly (P<0.05) increased survivability, fecundity, and total thiol level. The activities of glutathione-S-transferase (GST) and catalase (CAT) significantly (P<0.05) increased. The superoxide dismutase (SOD) activity non-significantly (P>0.05) decreased, while malondialdehyde (MDA) concentration decreased significantly (P<0.05) compared with controls, respectively.

Conclusion: In vitro study suggested better antioxidant activity of MEMOL. In vivo study also revealed that MEMOL was relatively safe in D. melanogaster, supported by high LD50, increased survivability, fecundity, locomotor ability, antioxidant enzyme activities, total thiol level, along with a concomitant decrease in MDA content.