In vitro Antioxidant and Anticancer Properties of Hydroethanolic Extracts and Fractions of Ageratum conyzoides

Abstract

Background: Cancer is still a major public health burden in many countries and despite the research strides made in respect of therapeutic interventions, challenges still abound in cancer treatment. Ageratum conyzoides has increasingly been used in folklore for the treatment of a wide range of diseases including cancer. Aim: This study was aimed at investigating the antioxidant and anticancer potentials as well as the phytochemical constituents of 50% hydroethanolic crude extracts and fractions of leaf extracts of Ageratum conyzoides. Methodology: Antioxidant activities were evaluated by the DPPH, Folin-Ciocalteau and glutathione assays. The in vitro 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay was used for the determination of anticancer activities of the plant samples against four selected human cell lines: leukemic (Jurkat), prostate (LNCap), breast (MCF-7), and normal human prostate (PNT2) cell lines. The selectivity indices were also estimated. Mean EC 50 and IC 50 values were compared by one way ANOVA. Results: The extracts scavenged DPPH in a dose dependent manner similar to the standard compound, butylated hydroxy toluene. The whole plant extract had the strongest activity with EC 50 value of 0.3±0.03 mg/ml. The leaf extract recorded the highest total phenol content of 1602.3±36.7 mg/g GAE. Glutathione was not detected in any of the crude extracts. The leaf extract as well as the chloroform and ethylacetate fractions exhibited interesting cytotoxicities on Jurkat cells with IC 50 values of 15.1±0.3 μg/ml, 6.36±1.6 μg/ml and 4.6±0.1 μg/ml, respectively compared to curcumin, 0.002±0 μg/ml. Also, the leaf extract, chloroform and ethylacetate fractions were strongly selective against Jurkat cells with SI values of 66.33, 15.72 and 21.74, respectively compared to curcumin (SI = 2.3). The presence of tannins, saponins and terpenoids were concentrated in the leaf and flower extracts of the plant. Conclusion: The present investigations have shown that Ageratum conyzoides possesses remarkable antioxidant and anticancer properties, which lend support to the use of the plant in folklore as an anticancer agent. Further studies are required determine the active principle(s).