Cytotoxic Effects of Lactobacillus Cytoplasmic Extract isolated from Guilan province dairy products on Colon Cancer Cell Line (HT-29)

Probiotic bacteria, including lactobacilli, are known to prevent many cancers. In this regard, the present study aimed to evaluate the anti-cancer effects of Lactobacillus cytoplasmic extract isolated from dairy products in Guilan province on the HT-29 colon cancer cell line.

In this study, Lactobacillus bacteria were isolated and identified from dairy products based on conventional culture and biochemical methods. Then, using specific primers, the 16S rRNA gene of the bacteria was amplified and the confirmed samples were compared with the sequences in NCBI after sequencing. Different concentrations of 0.5, 0.75, 1, 1.5, and 2 mg/mL were made from the cytoplasmic extract of the selected strain. Finally, the cytotoxicity effects of Lactobacillus cytoplasmic extract on cancer HT-29 and normal HUVEC cell lines were investigated by the MTT method.

The results of the MTT assay showed that the cytoplasmic extract of Lactobacillus dose-dependently reduced the survival and proliferation of colon cancer cells at 24 h, with the highest inhibitory effect at 2 mg/ml. Concentrations of 1, 1.5, and 2 mg/mL decreased cell viability by 50±4.87%, 40±8.61%, and 25±5.80%, respectively. The IC50 value of the cytoplasmic extract was 1.43 mg/mL for the HT29 cells. Also, cytotoxic effects on the normal HUVEC cell line were not observed.

According to the results of the study, the cytoplasmic extract of Lactobacillus isolated from dairy products reduced the growth of HT-29 cancer cells, which with further studies can be used as a biological product in the treatment and prevention of colon cancer.