ANTIOXIDANT POTENTIAL ACTIVITY AND CYTOTOXICITY EFFECTS OF DIFFERENT PARTS OF PEANUTS (ARACHIS HYPOGAEA L.)

Abstract

Peanut skin and peel, a low economic value by-product of the peanut industry, is rich in potentially health promoting compounds. This work aimed to evaluate the efficiency of different organic solvents such as, methanol, ethanol, acetone, and aqueous extract for extraction of (total phenolics TP, total flavonoids TF and total tannins TT) from the peanut skin and peel. For each solvent, the content of total phenolics, flavonoids, tannins was determined. Antioxidant activity of different extracts was screened using the 2, 2-diphenyl-1-picryl hydrazyl (DPPH^•) radical scavenging, metal chelating activities, reducing power, and ABTS assays. The results showed that 80% acetone is the best solvent for the extraction of total phenolics (436.88 ± 0.71mg/g DW), flavonoids (340.00 ± 1.11mg/g DW) and tannins (184.63 ± 1.95 mg/g DW) and lower in peanut peel aqueous extract (135.5 ± 1.05 mg/g DW), (163 .15 ± 0.67mg/g DW) and (90.55 ± 3.63 mg/g DW). The results revealed that all extracts of the peanut skin and peel exhibited variable antioxidant activity. The highest DPPH^• scavenging activity (IC₅₀=52.18 ± 0.47µg/ml) was achieved with acetone extracts of peanut skin compared to acetone extract of peanut peel (IC₅₀=70.51 ± 0.45µg/ml). Antioxidant as measured by Fe²⁺-chelating revealed the highest activities with methanolic extract of peanut skin (86.10%) compared to peel extract (74.94%). ABTS^•+ showed the highest value with peanut skin and peel methanol extract. While the acetone skin extract showed the highest activity by reducing power assay. The present study suggests that a skin peanut acetone extract contained higher antioxidant components and potential as compared to the peel. Peanut skin acetone extract exhibited potential as an anticarcinogenic activity, but needs further investigation. It is concluded that acetone and methanol are polar among the solvent used and play a vital role in the extraction of the plant constituents. Therefore these results suggested that peanut skin might be beneficial as a potent antioxidant and anticancer agents and effectively employed as an ingredient in food applications.