Comparison of Antibacterial and Antioxidant Activities of Ethanolic Extracts of Four Plant Species Selected from South of Saudi Arabia

One of the most ancient human medical techniques is the use of plants to treat, prevent, and cure diseases. These plants can manufacture a wide variety of natural chemicals. The present study aimed to evaluate the antibacterial activity and antioxidant capacity of ethanolic extract of four plant species (Zizyphus lotus, Lavandula dentata, Ruta graveolens, and Dodonaea viscosa). Using disc diffusion and serial dilution procedures, the antibacterial abilities of these EtPEs were evaluated. The antioxidant properties were evaluated by the FRAP method and the Folin-Ciocalteu technique was used to measure the total phenolic content. Different plant extracts showed different inhibitory effects on the tested bacteria in a dose-dependent manner. Among the tested plant extracts, D. viscose exhibited the highest antibacterial activity against P. vulgaris and S. aureus, with a minimum inhibitory concentration (MIC) value of 0.5 mg/ml. On the other hand, R. graveolens displayed the highest quantity of phenolic compounds and demonstrated the highest antioxidant activity. Notably, there was a positive correlation observed between the antioxidant activity of the plant extracts and their total phenolic content. In conclusion, the findings of this study suggest that the tested plant extracts hold potential as promising sources of natural antibacterial and antioxidant agents.