Walsura robusta Roxb. (Meliaceae), a little-known tree with a rich limonoid profile

The plant Walsura robusta Roxb. (Meliaceae) is a robust tree largely distributed in south-east Asia, including provinces of southern China. A few traditional usages of the plant have been mentioned, notably for the treatment of microbial infections. But experimental studies using different types of plant extracts only revealed modest antibacterial effects, and no major antiparasitic activity. Walsura robusta Roxb. is a rich source of secondary metabolites. Several series of limonoids have been isolated from the leaves or the fruits of the plant, such as walsuronoid A-I, walsurins A-E, walsunoids A-I, walrobsins A-R and other cedrelone- or dihydrocedrelone-type limonoids, in addition to a few other terpenoids. All information about Walsura robusta Roxb. have been collated in this brief review. The analysis underlines the presence of two limonoids endowed with significant anticancer activities, walsuronoid B and cedrelone. They both activate the production of reactive oxygen species in cancer cells, modulate mitochondrial activities and induce apoptosis of cancer cells. Their molecular targets and mechanism of action are discussed. Walsura robusta Roxb. has a potential for the development of anticancer natural products. The use of the plant extracts could be further considered for the treatment of diseases with a cell proliferation component.