Antioxidant and Insecticidal Effect of Some Plant Extracts against Callosbruchus maculates (coleoptera: Bruchidae)

Abstract The aim of the study was to test the effect of methanolic guava leaf and pomegranate peel extracts as antioxidant and insecticide. In the Gas Chromatography and Mass spectroscopy analysis, 30 bioactive phytochemical compounds were identified in the methanolic extract of guava leaf and 23 bioactive phytochemical compounds were identified, in the methanolic extract of pomegranate peel. The fraction for guava leaf methanol extract was characterized by large amounts of caryophyllene , β- humulene and longifolene, which constituted 16.42% , 15.74% and 12.13%  respectively , while the fraction of  pomegranate peel methanol extract was characterized by large amounts of longifolene, alloaomadendrene and β- humulene which constituted 23.34% , 13.57% and 12.53%  respectively .The phenolic contents of guava leaves and pomegranate peel extracts were found to be 154.16 and 280 (mg/g extract), respectively, while total flavonoids content were 55.45 and 69.24 (mg/g extract) respectively. Studies have confirmed that the antioxidant activity of plants extracts depends on the concentration of phenolic compounds, the methanolic extracts were assayed by DPPH scavenging activity and reducing power. Both methanolic guava leaf and pomegranate peel extracts appeared antioxidant activity in reducing power and DPPH scavenging activity assay, while the methanolic pomegranate peel extract was the more effective one compared with guava leaf extract. Insecticidal effects of these extracts on insect beetle cowpea were studied by determination LC50 which were 1.22 and 2.3 % for pomegranate peel and Guava leaves methanol extracts, respectively. The biochemical effects of these extracts were studied. Total protein, total carbohydrate and lipids increased but decreased acetylcholine esterase, GOT and GPT .The results showed that peels of pomegranate greatest influential extract and attributed this to the large content of phenols and Flavonoids.

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