Résumé:
The present study investigates the influence of geo-environmental heterogeneity on the phytochemical constitution and biological efficacy of the hydroethanolic extract of Moringa oleifera lam. seeds harvested from three climatically divergent Algerian regions: Mostaganem (Mediterranean coastal), Adrar (hyper-arid), and Tamanrasset (mountainous hyper-arid Sahara). Various methods like DPPH radical scavenging assay, protein inhibition assay and well diffusion assay were used to determine the antioxidant activity, Anti-inflammatory activity and antibacterial activity respectively. Quantitative methods like Follin ciocalteau assay, vanillin-HCl assay, Ferric chloride assay and Aluminum chloride assay were used to determine the total phenolic content, condensed tannins, hydrolysable tannins, and total flavonoid content respectively. A comprehensive comparative analysis revealed significant regional disparities (significance determined using ANOVA, p < 0.05) in physicochemical and phytochemical traits. Seeds from Mostaganem exhibited the highest dry matter content (99.25 ± 0.32%), mineral matter (6.44 ± 0.39%), and the lowest organic matter (93.55± 0.35%), coupled with the phytochemical profile, total phenolic content (TPC: 34.83 ± 4.33 mg GAE/g DW), condensed tannins (CT: 7.25 ± 0.29 mg CE/g DW), and hydrolysable tannins (HT: 2.29 ± 0.07 mg GAE/g DW), with Tamanrasset having the highest phytochemical profiles (TPC: 37.76 ± 2.22 mg GAE/g DW), (TFC: 6.04 ± 0.89 mg QE/g DW), and (CT: 12.26 ± 0.77 mg CE/g DW). Antioxidant capacity, evaluated via DPPH radical scavenging assay, demonstrated a dose-dependent inhibition, with the lowest IC₅₀ observed in Tamanrasset (2.13 ± 0.05 mg/mL), outperforming Mostaganem (2.64 ± 0.08 mg/mL) and Adrar (3.25 ± 0.10 mg/mL). Protein denaturation inhibition assay revealed potent anti-inflammatory activity, particularly in Mostaganem (49.72 ± 2.22%) and Adrar (49.26 ± 1.65%) samples, closely approximating the reference drug diclofenac (52.96 ± 1.22%). Antibacterial tests against Pseudomonas aeruginosa, Bacillus cereus, Proteus mirabilis, Klebsiella pneumonia, Salmonella paratyphi with Staphylococcus aureus and Escherichia coli demonstrating superior inhibition zones in Tamanrasset and Adrar extracts (15.3 ± 0.5 mm and 13.6 ± 0.4 mm, respectively), indicating robust antimicrobial potential. Multivariate principal component analysis (PCA) underscored
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the strong correlation between environmental stressors (temperature, altitude, and edaphic factors) and the biosynthesis of bioactive metabolites. These findings emphasize that eco-climatic determinants substantially modulate the therapeutic capacity of Moringa oleifera, making regional provenance a critical factor in standardizing raw materials for phytopharmaceutical and nutraceutical applications.
