Induction of Apoptosis and Reduction of Endogenous Glutathione Level by the Ethyl-Acetate Soluble Fraction of the Methanol Extract of the Roots of Potentilla fulgens in Cancer Cells

Abstract

Potentilla fulgens root traditionally used as a folk remedy in Meghalaya, India. However, systematic evaluation of its anticancer efficacy was limited. We investigated the anticancer potentials of the various extracts prepared by partitioning of the methanol extract of the root with the aim to discover major contributing factors from the most effective fractions. Methanol extract of P. fulgens roots (PRE) was prepared by maceration which was subsequently fractionated into hexane, ethyl-acetate (EA) and n-butanol soluble fractions. Various assays (clonogenic assay, Flow cytometry analysis, western blot, semiquantitative RT-PCR and the level of endogenous glutathione) were used to evaluate different parameters, such as Cell survivability, PARP-1 proteolysis, expression pattern of anti-apoptotic and γ-glutamyl-cysteine synthetase heavy subunit (GCSC) genes in both MCF-7 and U87 cancer cell lines. Since the EA-fraction showed most efficient growth inhibitory effect, it was further purified and a total of nine compounds and some monomeric and dimeric flavan-3-ols were identified and characterized. Three compounds viz., epicatechin (EC), gallic acid (GA) and ursolic acid (UA) were taken on the basis of their higher yield and 10 μg/ml of each was mixed together. The concentration used in this study for PRE, EA- and Hex-fraction was 100 μg/ml, which was higher than the IC50 value. Apoptotic cell death in the PRE, EA-fraction and EC+GA+UA treated cancer cell cultures was significantly greater than in normal cells due to suppression of anti-apoptotic protein Bcl2 following treatment. Depletion of glutathione by downregulating GCSC was also observed. Induction of apoptosis and lowering the level of glutathione are considered to be positive activity for an anticancer agent. Therefore, modulation of GSH concentration in tumor cells by PRE and its EA-fraction opened up the possibility of a new therapeutic approach because these plant products are not harmful to normal cells and may regulate the tumor cellular response to different anticancer treatments. Thus, it would be interesting to examine efficacy of these plant products or EA-fraction in human cancer treatment.

Copper as a target for prostate cancer therapeutics: copper-ionophore pharmacology and altering systemic copper distribution

“…Glutathione (GSH) is the major cellular antioxidant and plays an essential role in protecting cells against ROS accumulation and toxicity [40, 41]. An imbalance in cellular GSH homeostasis caused by either GSH oxidation (to GSSG), or by GSH efflux, can diminish the antioxidant capacity of the cell and often contributes to cell death [40–42]. We determined the GSH:GSSG ratio in both PrEC and TRAMP-C1 cells, as a well-established marker for antioxidant capacity (Figure 3F[iii]) [40, 41].…”

Cytotoxic analysis and chemical characterization of fractions of the hydroalcoholic extract of the Euterpe oleracea Mart. seed in the MCF-7 cell line

“…The epicatechin, along with gallic and ursolic acid, induced the apoptosis and depletion of simple glutathione in neoplastic cells (MCF‐7 and U87) . It is noteworthy that the epicatechin showed little or no cytotoxicity in normal cells …”

Methanolic extract of Potentilla fulgens root and its ethyl-acetate fraction delays the process of carcinogenesis in mice

“…The ethyl-acetate (EA) soluble fraction of methanolic extract of P . fulgens root exhibited more efficient growth-inhibitory effect in MCF-7 and U87 cancer cell lines than hexane and n-butanol soluble fraction 23 . This observation prompted further purification of EA-fraction and a total of nine compounds including two new ursane type triterpenoids, Fulgic acid A and Fulgic acid B with a good antioxidant activity were identified 24 .…”

“…fulgens is significantly low, it is of interest to establish a causal mechanism. Since it is difficult to evaluate its anticancer role in RAN-mediated cancer in human system because of interference by other compounding factors like tobacco, alcohol consumption and diverse food-habits, many studies on anticancer effects of different Potentilla sp have been examined in human cancer cell lines 21–23 . The present study, we have examined the potential anticancer role of P .…”