In vitro evaluation of anticancer properties of exopolysaccharides from Lactobacillus acidophilus in colon cancer cell lines

Abstract

The present work aims at studying the effect of exopolysaccharides (EPS) from Lactobacillus acidophilus on the colon cancer cell lines in vitro. Initial analysis showed that EPS has antioxidative properties. EPS was also found to induce cytotoxicity in two colon cancer cell lines, viz. HCT15 and CaCo2 under normoxia and hypoxia. The membrane integrity was also found to be affected in EPS-treated cells. Once the toxic concentration was determined (5 mg/ml), the effect of EPS on the messenger RNA (mRNA) expression of various genes was studied by quantitative real-time (RT)-PCR under both normoxic and hypoxic conditions. The results suggest that EPS downregulated the expression of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1α (HIF-1α) and upregulated the expression of tissue inhibitor of metalloproteinases-3 (TIMP-3), hypoxia-inducible factor-2α (HIF-2α), and hemeoxygenase-1 (HO-1). An increase in plasminogen activator inhibitor-1 (PAI-1) was also observed. These results show that EPS may inhibit the expressions of genes involved in tumor angiogenesis and survival. Increase in the expression of HO-1 also shows that EPS have antioxidative properties.

Germinated brown rice combined with Lactobacillus acidophilus and Bifidobacterium animalis subsp. lactis inhibits colorectal carcinogenesis in rats

“…Previous studies found that both supernatants and extracts of L. acidophilus decreased cell proliferation and increased apoptosis in colorectal cancer cells (Soltan Dallal et al., ). Exopolysaccharides are natural polymers of monosaccharides produced by various microorganisms which are either bound to the cell surface or released into the surrounding environment (Deepak et al., ). Lactic acid bacteria is the well‐known bacteria synthesizing EPSs which adhere to the bacterial surface followed by release in surrounding medium (El‐Deeb, Yassin, Al‐Madboly, & El‐Hawiet, ).…”

“…Exopolysaccharides synthesized by some LAB play an important role in colonization of LAB in the intestinal mucosa and show many health benefits such as antitumor, immune‐enhancing, and antioxidative properties (El‐Deeb et al., ). The EPS from L. acidophilus had antioxidative properties, reduced viability of colon cancer cell lines, downregulated the expression of genes involved in angiogenesis, and upregulated the expression of antiangiogenic genes in HCT15 and Caco‐2 cells (Deepak et al., ). A novel EPS purified from L. acidophilus exerted an antiproliferative effect on Caco‐2 cells via the apoptotic mechanism in addition to inactivating the inflammatory pathway and stimulating the immune response (El‐Deeb et al., ).…”

Oxymatrine inhibits the migration of human colorectal carcinoma RKO cells via inhibition of PAI-1 and the TGF-β1/Smad signaling pathway

“…In recent years, studies have demonstrated that PAI-1 is a potent regulator of tumor growth in vivo . Increased PAI-1 has been confirmed in many solid tumor types and was found to be associated with a poor prognosis (14–16). Thus, PAI-1 is regarded as a biochemical marker for poor prognosis and may serve as a therapeutic target for various types of cancers.…”

Functional Characterization of c-di-GMP Signaling-Related Genes in the Probiotic Lactobacillus acidophilus

“…Among the intestinal microbiota, L. acidophilus shows a strong autoaggregation phenotype and has been demonstrated to efficiently coaggregate with some pathogenic strains in vitro (Collado et al, 2008). The exopolysaccharide (EPS) produced by L. acidophilus possesses bioactive components with various health benefits, such as antioxidative properties and inducing cytotoxicity in two colon cancer cell lines (Deepak et al, 2016). Meanwhile, EPS also plays an important role in protecting microbes from adverse conditions, such as lysozyme osmosis as well the presence of bacteriophages, copper ions, or nisin (Looijesteijn et al, 2001).…”