Berberine: a potential adjunct for the treatment of gastrointestinal cancers?

Gastrointestinal cancers are among the most prevalent cancers in the general population. Despite effective early diagnostics and intervention, the gastrointestinal cancer-related mortality still remains elevated. Berberine (BBR) is a benzyl tetra isoquinoline alkaloid exracted from several plants. BBR is nontoxic to human normal cells, but suppresses the growth of different tumor cells: melanoma, epidermoid carcinoma, hepatoma, oral carcinoma, glioblastoma, prostatic carcinoma, and gastric carcinoma. In particular, BBR seems to suppress the proliferation of gastrointestinal cancers in a number of preclinical models. Several mechanisms of action have been hypothesized and demonstrated: immunomodulation, inhibition of topoisomerase enzymes, suppression of the EGF receptor, Her2/neu, and the VEGF receptor, induction of p53, Cip1/p21, Kip1/p27, Rb expression, induction of apoptosis (by regulation of MMPs pathway, caspases, Bax, and Smac/DIABLO), inhibition of arylamin N-acetyltransferase activity, and regulation of microRNAs expression. The aim of this review is to summarize the pharmacological effects of BBR on animal and human gastrointestinal cancers.