Recent advances in cancer chemoprevention with phytochemicals

Over the past few decades, phytochemicals widely present in edible plants have exhibited compelling positive biological impact on human health, including treating some cancers. In some cases, metabolites and artificially modified products of these natural compounds have shown better chemopreventive effects than their natural counterparts. Along with direct chemopreventive strategies using phytochemicals to treat cancer by leading to cell cycle arrest, autophagy and apoptosis, natural compounds have been shown to reverse adverse epigenetic regulation, including altering DNA methylation and histone modification, modulating miRNA expression, promoting expression of phase II enzyme for detoxification, balancing inflammation responses, recovering circadian rhythm from misalignment, and modifying gut microbiota. These have all become part of indirect but effective and novel strategies in cancer prevention using phytochemicals. Therefore, in this review, we are going to summarize some findings of phytochemicals in cancer chemoprevention via several distinct strategies, both to highlight promising treatments and to encourage new ideas for future studies.