The phenolic content, antioxidant, antitumor, and enzyme inhibitory activities of commonly used medicinal herbs from a Unani system of medicine were investigated using four different extraction methods. Among the plants studied, the Hyssopus officinalis L, Origanum vulgare L, and Portulaca oleracea L. extracts showed the highest amount of total phenolics (64.40, 60.35, and 58.81 mg GAE/g) and revealed significant antioxidant activities. The plants also showed a maximum cytotoxic activity as indicated by H. officinalis (82%), O. vulgare (75%), and P. oleracea (72%) showed more than 70% cytotoxicity for breast cancer cells, 82% of the cells were dead at the concentration of 500 mg/mL. The plants H. officinalis, P. oleracea, O. vulgare, and Rubia cordifolia L. revealed more than 80% inhibition towards xanthine oxidase and comprising maximum 70% of inhibition for superoxide dismutase. From results we conclude that there is a strong correlation between phenolic content, antioxidant, and enzyme inhibitory activity among these plants, indicating phenolics are the major compounds for these biological activities. Furthermore, this study provides the basis for the therapeutic importance of studied plants as latent inhibitors of oxidative stress and antitumor cell proliferation which correlate with the ethnobotanical data contained in the Unani system of medicine.
Keywords: Antioxidant; Antitumor; Total phenolics; Unani medicine; Xanthine oxidase.