A Novel Combination of Withaferin A and Sulforaphane Inhibits Epigenetic Machinery, Cellular Viability and Induces Apoptosis of Breast Cancer Cells

Abstract

With cancer often classified as a disease that has an important epigenetic component, natural compounds that have the ability to regulate the epigenome become ideal candidates for study. Humans have a complex diet, which illustrates the need to elucidate the mechanisms of interaction between these bioactive compounds in combination. The natural compounds withaferin A (WA), from the Indian winter cherry, and sulforaphane (SFN), from cruciferous vegetables, have numerous anti-cancer effects and some report their ability to regulate epigenetic processes. Our study is the first to investigate the combinatorial effects of low physiologically achievable concentrations of WA and SFN on breast cancer cell proliferation, histone deacetylase1 (HDAC1) and DNA methyltransferases (DNMTs). No adverse effects were observed on control cells at optimal concentrations. There was synergistic inhibition of cellular viability in MCF-7 cells and a greater induction of apoptosis with the combinatorial approach than with either compound administered alone in both MDA-MB-231 and MCF-7 cells. HDAC expression was down-regulated at multiple levels. Lastly, we determined the combined effects of these bioactive compounds on the pro-apoptotic BAX and anti-apoptotic BCL-2 and found decreases in BCL-2 and increases in BAX. Taken together, our findings demonstrate the ability of low concentrations of combinatorial WA and SFN to promote cancer cell death and regulate key epigenetic modifiers in human breast cancer cells.

Combating breast cancer using combination therapy with 3 phytochemicals: Piperine, sulforaphane, and thymoquinone

“…HDAC expression also was downregulated at multiple levels, and a reduction in antiapoptotic BCL-2 and increase in proapoptotic Cancer May 15, 2019 BAX was observed. 43 Further study regarding the effect of this combination on the regulation of epigenetic mechanisms involved in breast cancer prevention demonstrated that it downregulated the level of cyclin D1 and CDK4, and pRB. In contrast, the level of E2F mRNA and the tumor suppressor p21 were increased independently of p53.…”

“…28 Combination therapy with chemotherapeutics may work in a synergistic or additive manner, lowering the therapeutic dosage of one agent and thereby reducing toxic effects. 5 Several chemotherapeutic drugs have been tested in combination with PIP, SFN, and TQ, as described below (the summarized mechanisms of action of the combinations are shown in Table 4 [8][9][10][11]16,[29][30][31][32][33][34][35][36][37][38][39][40][41][42][43] ).…”

“…A synergistic inhibition of MCF‐7 cellular viability and a greater induction of apoptosis were observed using the SFN plus withaferin A combination approach in both MDA‐MB‐231 and MCF‐7 cells compared with single administrations of either compound. HDAC expression also was downregulated at multiple levels, and a reduction in antiapoptotic BCL‐2 and increase in proapoptotic BAX was observed . Further study regarding the effect of this combination on the regulation of epigenetic mechanisms involved in breast cancer prevention demonstrated that it downregulated the level of cyclin D1 and CDK4, and pRB.…”

Epigenetic polypharmacology: A new frontier for epi‐drug discovery

“…Previous studies conducted by Meeran et al revealed that a diet containing compounds with HDAC and DNMT inhibitory activities altered the epigenome, resulting in the modulation of various aberrant epigenetics patterns in tumor‐related genes . Therefore, Paul et al decided to evaluate the effects deriving from the combination of genistein 38 and sulforaphane 39 (Combination E, Figure ) .…”

“…121 Previous studies conducted by Meeran et al 120 revealed that a diet containing compounds with HDAC and DNMT inhibitory activities altered the epigenome, resulting in the modulation of various aberrant epigenetics patterns in tumor-related genes. 75,122 Therefore, Paul et al decided to evaluate the effects deriving from the combination of genistein 38 and sulforaphane 39 (Combination E, Figure 3). 123 Genistein 38/sulforaphane 39 combination decreased the HDAC2 and HDAC3 expression both at protein and mRNA levels, downregulating KLF4, essential in stem cells formation, as well as hTERT that is known to be activated when KLF4 binds its promoter region.…”