Differential cellular interaction of Sutherlandia frutescens extracts on tumorigenic and non-tumorigenic breast cells

Abstract

Sutherlandia frutescens (SF) is a traditional Africanmedicinal aid employed for the treatment of various ailments such as inflammation, pulmonary asthma and congestion. The present study was conducted to demonstrate the differential cellular interaction of aqueous SF extracts in a breast adenocarcinoma epithelial cell line (MCF-7) and a non-tumorigenic breast cell line (MCF-12A) by means of polarization-optical differential interference contrast microscopy, crystal violet staining, light microscopy and flowcytometry. Results showed that aqueous SF extracts induced cell death inMCF-7 andMCF-12A via two types of cell death namely apoptosis and autophagy. Effects on proliferation and cytotoxicity were investigated by means of crystal violet staining. The latter indicated that, at a 1/10 dilution, the tumorigenic MCF-7 cell line was more prominently affected when compared to the nontumorigenic MCF-12A cell line. Apoptosis induction was demonstrated by qualitative and quantitative light microscopy and cell cycle progression studies, while autophagy induction was assessed by an increase inmicrotubule- associated protein light chain 3 (LC3) levels (a specific marker of autophagy). The MCF-7 tumorigenic cells, however, were more susceptible to these extracts when compared to the non-tumorigenic MCF-12A cells. Data obtained contribute towards understanding the differential cellular interaction exerted by aqueous SF extracts in tumorigenic versus non-tumorigenic breast cells. Results will enable researchers to further study cell death mechanisms induced by these aqueous extracts and to identify active compounds for evaluation in anticancer therapy and potential in vivo efficacy.