The role of the natural compound naringenin in AMPK-mitochondria modulation and colorectal cancer inhibition.

Background: Although AMP-activated protein kinase (AMPK) has been extensively studied in cellular processes, the understanding of its substrates, downstream functions, contributions to cell fate and colorectal cancer (CRC) progression remains incomplete.

Purpose: The aim of this study was to investigate the effects and mechanisms of naringenin on CRC.

Methods: The biological and cellular properties of naringenin and its anticancer activity were evaluated in CRC. In addition, the effect of combined treatment with naringenin and 5-fluorouracil on tumor growth in vitro and in vivo was evaluated.

Results: The present study found that naringenin inhibits the proliferation of CRC and promote its apoptosis. Compared with the naringenin group, naringenin combined with 5-fluorouracil had significant effect on inhibiting cell proliferation and promoting its apoptosis. It is showed that naringenin activates AMPK phosphorylation and mitochondrial fusion in CRC. Naringenin combined with 5-fluorouracil significantly reduces cardiotoxicity and liver damage induced by 5-fluorouracil in nude mice bearing subcutaneous CRC tumors, and attenuates colorectal injuries in azoxymethane/DSS dextran sulfate (AOM/DSS)-induced CRC. The combination of these two drugs alters mitochondrial function by increasing reactive oxygen species (ROS) levels and decreasing the mitochondrial membrane potential (MMP), thereby stimulating AMPK/mTOR signaling. Mitochondrial dynamics are thereby regulated by activating the AMPK/p-AMPK pathway, and mitochondrial homeostasis is coordinated through increased mitochondrial fusion and reduced fission to activate apoptosis in cancer cells.

Conclusions: Our data suggest that naringenin is important for inhibiting CRC proliferation, possibly through the AMPK pathway, to regulate mitochondrial function and induce apoptosis in CRC.