ASSESSMENT OF ANTIOXIDANT, ANTIMICROBIAL, ANTIPARASITIC, AND ANTI-INFLAMMATORY PROPERTIES OF DRIED NELUMBO NUCIFERA

Abstract

Nelumbo nucifera is an important aquatic medicinal plant known for its rich phytochemical composition and diverse pharmacological properties. The present study aimed to investigate the influence of different post-harvest drying techniques on the phytochemical profile, proximate composition, and biological activities of N. nucifera. Fresh plant samples were subjected to various drying methods, including oven drying, sun drying, freeze drying, and shade drying, followed by extraction using methanol, chloroform, and aqueous solvents. Qualitative phytochemical screening revealed the presence of several bioactive secondary metabolites, including phenols, flavonoids, alkaloids, terpenoids, tannins, saponins, glycosides, and steroids, with methanolic extracts showing the highest phytochemical diversity. Proximate analysis demonstrated significant variations among drying treatments, where oven-dried samples exhibited the highest protein (34.90%) and fiber contents (24.02%), while freeze-dried samples retained higher carbohydrate (17.49%) and fat contents (8.49%). The antioxidant activity evaluated by the DPPH assay showed concentration-dependent radical scavenging activity, with the highest inhibition (81.4 ± 1.8%) observed at 500 µg/mL. Antiparasitic activity assessed through the brine shrimp lethality assay demonstrated significant dose-dependent mortality, reaching 86.7 ± 1.7% at 500 µg/mL. The methanolic extract also exhibited considerable anti-inflammatory activity by inhibiting protein denaturation, with maximum inhibition of 78.2 ± 1.9% at 500 µg/mL. Furthermore, the extract displayed notable antibacterial activity against Staphylococcus aureus, Bacillus subtilis, and Escherichia coli, with greater effectiveness against Gram-positive bacteria. Significant antifungal activity was also observed against Candida albicans, Aspergillus niger, Aspergillus flavus, and Fusarium solani. The findings suggest that drying techniques significantly influence the nutritional composition and bioactive potential of N. nucifera. Among the evaluated methods, freeze-drying and oven-drying showed superior preservation of nutritional and phytochemical constituents. Overall, N. nucifera represents a promising natural source of bioactive compounds with potential pharmaceutical, nutraceutical, antimicrobial, antioxidant, anti-inflammatory, and antiparasitic applications.