Identification of bioactive compounds in Lactobacillus paracasei subsp. paracasei NTU 101-fermented reconstituted skim milk and their anti-cancer effect in combination with 5-fluorouracil on colorectal cancer cells
Chemotherapy is currently used to treat colorectal cancer (CRC), the most common cancer worldwide. However, chemotherapeutic drugs are limited by serious side effects or drug resistance. In this study, bioactive compound(s), a mixture of palmitic acid, stearic acid, and glyceryl 1,3-dipalmitate (PSG), in Lactobacillus paracasei subsp. paracasei NTU 101-fermented skim milk ethanol extract (NTU 101-FMEE) were isolated and identified. PSG significantly decreased CRC cell viability at dosages that were not cytotoxic to normal colon epithelial cells or macrophages. Moreover, the inhibitory effect of the combination of PSG and 5-fluorouracil (5-FU) was significantly greater than that of 5-FU alone (p < 0.05). PSG up-regulated the activities of apoptosis-related proteins and down-regulated the nuclear factor-κB signaling pathway compared to levels in the control group. Overall, PSG purified from NTU 101-FMEE possesses the potential to ameliorate CRC by improving the effects of adjuvant chemotherapy drugs and reducing side effects.