Evaluation of antioxidant and cytotoxic activities of different extracts of folk medicinal plant Hapllophyllum tuberculatum

Hapllophyllum tuberculatum (H. tuberculatum) is a folk medicine used traditionally in Oman for the treatment of arthritis, nausea, fever, gastric pains, intestinal worms and malaria. The design of this study is to prepare different polarity extracts of H. tuberculatum and to evaluate antioxidant and cytotoxic activities by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and brine shrimp lethality (BSL) methods. The coarse leave samples were extracted with methanol by using a Soxhlet method and the obtained methanol extract was defatted and fractionated by different polarity of solvents with increasing polarity to give hexane, chloroform, ethyl acetate, butanol, and water extracts, respectively. The high antioxidant activity was obtained in the ethyl acetate extract and the lowest was in the methanol extract and the order of activity was ethyl acetate > butanol > water > chloroform > hexane > methanol extract. The cytotoxic activity results showed that the hexane, chloroform and ethyl acetate extracts have killed all the shrimp larvae at the concentration of 500 μg/ml. The highest IC50 was found in the chloroform extract and the lowest IC50 was found in the butanol extract and the order of activity was chloroform > ethyl acetate > hexane > water > methanol > butanol extract. Significant antioxidant and cytotoxic activities results were found first time of Omani H. tuberculatum species which is traditionally used as folk medicine all over the world, including Oman. Therefore, the highest activity ethyl acetate extract could be used as a natural antioxidant. The present study is the first report on the evaluation of antioxidant and cytotoxic activities of different polarity extracts of Omani H. tuberculatum species.