A Systematic Review of Drug Metabolism Studies of Plants With Anticancer Properties: Approaches Applied and Limitations.

Various studies reported conflicting results, with the results depending on the nature of the herb investigated (extracts or active constituents) and the biochemical tool (subcellular fractions, cells, or recombinant enzymes) and study system (in vitro/in vivo/ex vivo/clinical) applied. Each approach/system has its own advantages and disadvantages. Selecting the most appropriate approaches/systems allows us to extract the most meaningful and clinically relevant information on the metabolic pathways (the metabolites generated and the enzymes involved) and the potential drug interactions of herb-derived compounds for cancer therapy and prevention. Human primary hepatocytes are the best model that can be applied in any metabolic study. Human liver microsomes (HLMs) are a useful biochemical tool for preliminary drug metabolism studies. Recombinant microsomes that express specific enzymes and CYP-isoform-specific monoclonal antibodies are useful tools for enzyme inhibition studies.