Microbiological and pharmacological investigation of phytochemicals extracted from selected ethnomedicinal plants with their potential against food pathogen

This study investigates the phytochemical composition and biological activities of five ethnomedicinal plants: Zingiber officinale (Ginger), Ocimum basilicum (Basil), Origanum syriacum (Za'atar), Origanum vulgare (Oregano), and Salvia rosmarinus (Rosemary). These plants are traditionally used for their therapeutic properties, yet a comparative evaluation of their bioactivities is limited. Total phenolic and flavonoid contents were quantified using standard colorimetric assays. Antimicrobial activity was assessed against selected bacterial and fungal strains using the agar well diffusion method. Antioxidant capacity was evaluated via the DPPH assay, and cytotoxicity was tested on HCT-116 (colorectal cancer) and HNO-97 (tongue carcinoma) cell lines using MTT assays. Rosemary exhibited the highest phenolic content (189.28 mg/g), while Ginger had the highest flavonoid content (43.13 mg/g). Rosemary demonstrated the strongest antibacterial activity, notably against S. aureus (31 ± 0.5 mm), and Oregano showed significant inhibition against S. enterica (23 ± 0.1 mm). In antifungal assays, Rosemary had the largest inhibition zones against A. flavus (40 ± 0.6 mm) and A. niger (36 ± 0.3 mm). Basil and Za'atar also exhibited notable antifungal activity. Rosemary showed moderate antioxidant activity with an IC50 value of 37.42 µg/mL. Cytotoxicity testing revealed IC50 values of 14.91 µg/mL and 22.3 µg/mL for Rosemary against HCT-116 and HNO-97 cells, respectively. The findings highlight S. rosmarinus as a potent source of antimicrobial, antioxidant, and anticancer compounds. The diverse phytochemical profiles and bioactivities across the studied plants suggest that each offers unique therapeutic potential. These results support further investigation into their clinical applications, particularly concerning bioavailability, mechanisms of action, and potential synergistic effects.