Phenolic profile and biopesticidal potential of <i>Moringa oleifera</i> extracts: antioxidant and insecticidal activities against stored pests

This study investigated the phenolic composition of <i>Moringa oleifera</i> organ extracts via RP-HPLC. In addition, their antioxidant and insecticidal potential were assessed. Polyphenols, flavonoids and condensed tannin levels depend on the different plant parts. Phenolic composition was distinguished by the presence of quercetin-3-O-galactoside as the major compound with high insecticidal activity due to their phenolic composition. So, repellent proprieties against two stored pest species <i>Tribolium castaneum</i> and <i>Sitophilus oryzae</i> without food substrate were assessed. In addition, contact toxicity toward <i>T. castaneum</i> with wheat flour substrate was investigated. The repulsive dose of <i>Moringa</i> extracts from different morphological organs was more marked for leaves compared to stems, seeds and flowers with the lowest repulsive dose (RD₅₀ = 0.069 µl/cm²) for <i>T. castaneum</i>. Moreover, <i>M. oleifera</i> MeOH extracts from different morphological organs exhibited a contact toxicity potential against <i>T. castaneum</i> with and without wheat flour substrate. MeOH extracts of <i>M. oleifera</i> from leaves caused the highest mortality percentages (83.33%) after 48 h of exposure for both concentrations of 0.9 and 1.9 µl/cm² towards <i>T. castaneum</i> on wheat flour substrate. To reduce pesticide, Drumstick could offer an effective protection to <i>T. castaneum</i> and <i>S. oryzae</i>.