Targeting apoptosis pathways in cancer with magnolol and honokiol, bioactive constituents of the bark of Magnolia officinalis

Magnolol and honokiol, main active compounds from the bark of Magnolia officinalis, have been found to have various pharmacological actions, including anti-oxidative, anti-inflammatory, anti-tumor, and anti-microbial properties, without appreciable toxicity. Recently, the anti-tumor activity of magnolol and honokiol has been extensively investigated. Magnolol and honokiol were found to possess anti-tumor activity by targeting the apoptosis pathways, which have been considered as targets for cancer therapies. This review will focus on the mechanisms by which magnolol and honokiol act on apoptosis pathways in cancer that have been characterized thus far, including the death receptormediated pathway, mitochondria- mediated pathway, caspase-mediated common pathway, and regulation of apoptosis-related proteins. These breakthrough findings may have important implications for targeted cancer therapy and modern applications of traditional Chinese medicine.