Antioxidant Properties and Computational Analysis of Bioactive Compounds in Neem Seed Methanolic Extract as Potential Anti-Inflammatory Agents

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This study aimed to investigate the antioxidant and anti-inflammatory properties of neem seed methanolic extract (NSME). Antioxidant activity of NSME was investigated using azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, ferric reducing power, and nitric oxide (NO) scavenging assays, while anti-inflammatory activity was evaluated by protein denaturation, proteinase inhibition, and membrane stabilization assays. The protective effects of NSME against oxidative injury induced by FeSO₄ were further investigated in rat liver homogenates. NSME dose-dependently inhibited ABTS (IC 50 = 45.66 μg/mL), ferric ions, and NO (IC 50 = 28.46 μg/ml). NSME significantly inhibited protein denaturation (IC 50 = 19.12 μg/mL), and proteinase activities (IC 50 = 47.65 μg/mL), and enhanced membrane stabilization (IC 50 = 40.93 μg/mL). Oxidative hepatic injury caused a significant (p<0.05) decrease in catalase, SOD, glutathione activities/levels, whereas malondialdehyde, TNF-α, and IL-6 concentrations increased. These activities/levels were significantly reversed after treatment with various concentrations of NSME. HPLC analysis identified 12 compounds in NSME, with quercetin and beta-caryophyllene as the most abundant constituents. Molecular docking showed that myricetin and quercetin exhibited strong binding affinities for COX-2 and NIK, supporting their potential contribution to the observed bioactivities. These findings demonstrates that NSME possesses antioxidant and anti-inflammatory activities and provides evidence supporting its potential as a source of bioactive compounds for the development of anti-inflammatory agents.