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

Md Mahbubur Rahman,A H M Khurshid Alam,Ashik Mosaddik,Md Golam Sadik,Rezwan Ali,Muhammad Ali Khan,Md Golam Mostofa,A S M Sakhawat Hossain

doi:10.1186/s40816-019-0111-5

Abstract

BackgroundThe 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.MethodsThe 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.ResultsAmong 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: AA>EAF > 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.ConclusionsOur 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.

Highlights

In the last decades, our understanding about the term “oxidative stress” (OS), an imbalance between the production and scavenging of reactive oxygen species (ROS) by a living system, has been widened considerably [1].OS induced by ROS such as hydroxyl, peroxyl and superoxide radicals, have the tendency to become stable through electron pairing with biological macromolecules such as proteins, lipids and DNA in healthy human cells [2, 3]
Cell lines Ehrlich’s ascite carcinoma (EAC) cells were obtained by the courtesy of Indian Institute of Chemical Biology (IICB), Kolkata, India
Cell growth inhibition In vivo tumor cell growth inhibition was carried out by the method previously described by Sur and Ganguly [67]

Summary

Introduction

Our understanding about the term “oxidative stress” (OS), an imbalance between the production and scavenging of reactive oxygen species (ROS) by a living system (e.g. cells), has been widened considerably [1].OS induced by ROS such as hydroxyl, peroxyl and superoxide radicals, have the tendency to become stable through electron pairing with biological macromolecules such as proteins, lipids and DNA in healthy human cells [2, 3]. Antioxidants are secondary molecules or metabolites that act as ROS scavenger and activator of cellular antioxidative enzymes to prevent the damages induced by OS in biological system. Naturally occurring antioxidants from plant polyphenols are getting more attention in terms of practical usage as safe and potent bioactive compounds. It has been reported that the scavenging properties of ROS are mainly due to the presence of bioactive compounds such as, flavonoids, polyphenols, carotenoids and vitamin E and C [7, 8]. 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

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