The Inhibition of Proliferation and Invasion of Human Colon Carcinoma Cell Line (Caco-2 cells) by Cell-free Supernatants from Lactobacillus Rhamnosus and Lactobacillus Acidophilus

Background: The epidemiological studies indicated that colorectal cancer is one of the most common types of cancer in the world and is considered a leading cause of cancer-related death. The present study aimed to investigate the inhibitory effect of lactobacillus acidophilus supernatant (LAS) and lactobacillus rhamnosus supernatant (LRS) on the growth and invasiveness of the human colon carcinoma cell line (Caco2) in-vitro. Methods: In this experimental study, the anti-proliferative activity and anti-invasion potential of LAS and LRS were determined by MTT and transwell chambers assays, respectively. The expression of mitochondrial membrane potential-9 (MMP-9) and matrix metalloproteinase-12 (MMP12) genes were analyzed by real-time PCR.Results: The results indicated that supernatants of these two lactobacilli had cytotoxic effects on Caco-2 cells at a concentration of 25% v/v and higher. Thus, the minimum concentrations (25% V/V) of supernatants were chosen for further experiments. LAS and LRS could significantly suppress the invasiveness of Caco-2 cells. Also, the expression of MMP12 was significantly increased in Caco-2 cells when treated with LAS, whereas LRS had no significant effect on the invasive capacity and the gene expression levels of MMP12. The expression of MMP-9 was statistically decreased in Caco2 cells treated with LAS and LRS (P<0.00001).Conclusion: In general, it was shown that LAS and LRS exert anti-cancer activity against the growth, invasion, and metastasis of Caco2 cells in-vitro. It seems that these two bacteria could be used as prophylactic and therapeutic agents for the prevention and treatment of colorectal cancer.