Dpph Antioxidant Activity, Phytochemical Screening and Antimicrobial Evaluation of Rosemary Methanol Leaf Extract

Rosemary (Rosmarinus officinalis) is a herb renowned for its culinary (food ingredient) and medicinal uses. This study investigated the antioxidant, phytochemical, and antimicrobial properties of Rosemary methanol leaf extract. The extract exhibited concentration-independent activity with 2,2-Diphenyl-1-picrylhydrazyl (DPPH). At 20 µg/ml, the extract showed 25.10 ± 1.49% inhibition, while the standard (vitamin C) showed 30.70 ± 0.05%. At 40 µg/ml, the extract showed 30.00 ± 0.00%, and the standard (vitamin C) 47.20 ± 0.07%. At 60 µg/ml, the extract showed 24.50 ± 0.09%, and the standard (vitamin C) 19.90 ± 0.05%. At 80 µg/ml, the extract showed 30.00 ± 0.00%, and the standard (vitamin C) 11.80 ± 0.05%. At 100 µg/ml, both the extract and the standard (vitamin C) showed 30.00 ± 0.00%. These results indicate excellent antioxidant potential. Phytochemical screening revealed the presence of flavonoids, phenolic compounds, steroids, tannins, alkaloids, glycosides, and saponins. The extract demonstrated antimicrobial activity against various microorganisms, such as Staphylococcus aureus (zone of inhibition: 10.00 ± 0.00 mm), Escherichia coli (11.00 ± 0.70 mm), and Candida albicans (16.50 ± 1.06 mm). These findings suggest that Rosemary methanol leaf extract possesses significant antioxidant and antimicrobial properties, supporting its traditional use in herbal medicine and its potential applications in food preservation and pharmaceuticals.