Evaluation of anti-ROS and anticancer properties of Tabebuia pallida L. Leaves

摘要

The aim of this study was to determine the in-vitro anti-ROS and in-vivo anticancer activities of Tabebuia pallida leaves (abbreviated as TPL) against Ehrlich’s ascite carcinoma (EAC) cells. The crude ethanolic extract (CEE) (70% v/v) was fractionated successively with different solvents to get petroleum ether (PEF), chloroform (CHF), ethyl acetate (EAF) and aqueous fraction (AQF). The phytochemical studies were done by standard spectrophotometric methods. The in-vitro cytotoxic and in-vivo anticancer activity were evaluated against brine shrimp nauplii and EAC-induced tumor bearing mice, respectively. Among the extracts, the EAF showed the highest phenolic (158.17?±?1.54?mg/g GAE) and flavonoid (5.43?±?0.017?mg/g CAE) contents. The total antioxidant capacity of the EAF was 2.30?±?0.080, which was higher than other extracts and the standard catechin (2.16?±?0.038). The ferrous reducing antioxidant capacity was in the following order: AAEAF??CEE??AQF??CHF??PEF. In DPPH and hydroxyl radical scavenging assay, the EAF showed the highest DPPH and hydroxyl radical scavenging activity with IC50 of 6?±?0.25?μg/ml and 3.58?±?0.28?μg/ml, respectively, when compared to the standard BHT (IC50 of 16.08?±?0.28?μg/ml). Also, EAF showed potent inhibitory activity against lipid peroxidation with IC50 of 14.33?±?0.14?μg/ml. A positive correlation (p??0.01) between the total phenolics and antioxidant potentials as well as lipid peroxidation inhibition with the hydroxyl radical scavenging was observed. In addition, the EAF showed the moderate cytotoxic effect with ED50of 8.50?±?0.70?μg/ml and significant cell growth inhibition (71.17?±?0.44%) when compared to the standards and the cell growth inhibition was positively correlated (p??0.01) with phenolic contents. Our findings suggest that the leaves of T. pallida might be considered as a new natural source for antioxidant and anticancer compounds, which could be a potent and novel candidate for anticancer therapy.