eng Oriental Scientific Publishing Company Biosciences Biotechnology Research Asia 0973-1245 2025-03-25 22 1 281 291 10.13005/bbra/3360 54278 article Kalyani Chepuri 1 Chidepudi Devi Sri Lalitha Naga Tulasi 1 Manikantha Dunna 2 Chittepu Pranitha 1 Kathuroju Harikrishna 1 Vadakavila Geethikalal 1 Centre for Biotechnology, University College of Engineering Science and Technology, Jawaharlal Nehru Technological University Hyderabad Kukatpally, Hyderabad, Telangana, India Health Sciences Centre, Texas Tech University, Lubbock, Texas, USA This research evaluates the biological activities of three medicinal plants: Butea monosperma, Delonix regia, and Spathodea campanulata. These plants, belonging to the Fabaceae and Bignoniaceae families, were investigated for their antibacterial, antifungal, antioxidant, and cytotoxic properties. Phytochemicals were extracted from the flowers and leaves using methanol, ethanol, and acetone. The antibacterial and antifungal activities were assessed using a disc diffusion assay against pathogens S. epidermidis, B. cereus, E. coli, K. aerogenes, P. vulgaris, S. aureus, and C. albicans. The antioxidant potential was evaluated using the DPPH assay, and the cytotoxic activity was measured using the MTT assay on human lung cancer (A549) cells. Results indicated that ethanol extracts demonstrated the highest antimicrobial efficacy against both Gram-negative and Gram-positive bacteria, as well as the fungal strain Candida albicans. The extracts also demonstrated antioxidant activity, with the Butea monosperma ethanol extract showing the highest activity at an IC₅₀ value of 61.55±1.22 μg/mL. Methanol extracts showed significant cytotoxic effects on the A549 cell line, with Butea monosperma having an IC₅₀ value of 36.12±1.01 μg/mL. These findings suggest that the extracts from these plants have potential therapeutic applications against bacterial and fungal infections, oxidative stress, and cancer cells. https://www.biotech-asia.org/vol22no1/in-vitro-evaluation-of-biological-activities-of-three-different-medicinal-plant-extracts/ Anticancer activity; Antimicrobial activity; Antioxidants; Butea monosperma; Delonix regia; Spathadea companulata