Cytotoxicity of Probiotics from Philippine Commercial Dairy Products on Cancer Cells and the Effect on Expression ofcfosandcjunEarly Apoptotic-Promoting Genes andInterleukin-1βandTumor Necrosis Factor-αProinflammatory Cytokine Genes

Abstract

This study determined cytotoxicity of probioticLactobacillusspp. from Philippine dairy products on cancer cells and normal fibroblasts and their effects on expression of early apoptotic-promotingcfos, cjunand proinflammatory cytokineIL-1β,TNF-αgenes. Cultures were from Yakult, Bear Brand Probiotic Drink, Nido3+ Powdered Milk. Filter-sterilized supernatants from cultures ofLactobacillusspp. were evaluated for cytotoxicity to colon cancer cells (HT-29 and HCT116), leukemia cells (THP-1), and normal human dermal fibroblasts (HDFn) using PrestoBlue. Bleomycin was the positive control. Absolute quantification of transcript levels was conducted using qRT-PCR. Cytotoxicity index profiles on HDFn, THP-1 of all probiotic supernatants and negative controls suggest nontoxicity to the cells when compared to bleomycin, whereas all probiotic supernatants were found to be cytotoxic to HT-29 and HCT-116 colon cancer cell lines. Expression ofcfos, cjuntranscripts was significantly upregulated in HT-29 and HCT116 cells treated with probiotic supernatants compared to untreated baseline levels (P<0.05). Expression ofIL-1βandTNF-αby lipopolysaccharide-treated macrophages was significantly downregulated in cells with probiotic supernatants compared to those exposed to MRS medium (P<0.05). Results provide strong support for the role ofLactobacillusspp. studied in anticancer therapy and in prevention of inflammation that may act as precursor to carcinogenesis.