Phytochemical profiling and In Vitro Evaluation of the Biological activities of Mirabilis jalapa Linn. Stem Extracts
Abstract
Medicinal plants serve as a valuable source of bioactive compounds with significant therapeutic potential. Mirabilis jalapa Linn. (Nyctaginaceae) has traditionally been used to treat various ailments, owing to its anti-inflammatory, antioxidant, and antimicrobial properties. The objective of the present study was to investigate the phytochemical constituents and assess the antimicrobial, anti-inflammatory, antioxidant, and cytotoxic activities of stem extracts of Mirabilis jalapa Linn. The stem powder of Mirabilis jalapa Linn. was extracted using a soxhlet apparatus with different solvents. Preliminary qualitative and quantitative phytochemical analyses were carried out following standard protocols. The antibacterial activity of the extracts was evaluated by the disc diffusion method against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa. Antifungal activity was assessed against Candida albicans and Aspergillus niger. The anti-inflammatory potential was determined using the protein denaturation assay. Antioxidant activity was determined by applying the DPPH and Nitric Oxide scavenging assay. The cytotoxic activity of the ethanol extract was evaluated against SH-SY5Y human neuroblastoma cells using the MTT assay. Phytochemical analysis revealed the presence of alkaloids, triterpenoids, flavonoids, tannins, carbohydrates, saponins, and unsaturated hydrocarbons in the various solvent extracts of Mirabilis jalapa Linn. Quantitative analysis revealed the presence of alkaloid, tannin, saponin and flavonid. Among the extracts, the ethanol extract demonstrated the strongest antibacterial activity, exhibiting inhibition zones of 33 mm against Escherichia coli and 31 mm against Pseudomonas aeruginosa. It also showed appreciable antifungal activity against Candida albicans (15.33 ± 0.33 mm) and Aspergillus niger (12.33 ± 0.33 mm). The anti-inflammatory activity increased with concentration, producing inhibition of protein denaturation from 43.86 to 88.07 % over the same concentration range. The antioxidant potential of the ethanol extract was found to be concentration dependent, exhibiting significant free radical scavenging activity in the DPPH and Nitric oxide assay, with percentage inhibition increasing from 12.12 to 61.30 % for DPPH and 13.10 - 69.10 % for nitric oxide at concentrations of 100–500 µg/mL. Furthermore, the ethanol extract exhibited marked cytotoxic activity against SH-SY5Y human neuroblastoma cells, causing a dose-dependent reduction in cell viability from 87.78 to 27.91%, thereby indicating its promising antiproliferative potential. The study demonstrates that Mirabilis jalapa Linn stem possesses potent antimicrobial, anti-inflammatory, antioxidant, and cytotoxic properties, thereby supporting its ethnomedicinal significance and underscoring its potential as a natural source of bioactive molecules for future therapeutic applications