Cape aloes - A review of the phytochemistry, pharmacology and commercialisation of Aloe ferox

Aloe ferox Mill. (= A. candelabrum A. Berger), commonly known as the bitter aloe or Cape aloe, is a polymorphic species indigenous to South Africa. The plant has been used since ancient times as a generic chemopreventive and anti-tumour remedy in folk medicine and it has a well-documented history of use as a laxative. In addition to the plethora of traditional medicinal uses, A. ferox has recently gained popularity as an ingredient in cosmetic formulations and food supplements. Anti-oxidant, antimicrobial, anti-inflammatory, anticancer and antimalarial activities, etc. have been reported. In addition, the ability of Cape aloes to enhance the transport of poorly permeable drugs has enjoyed recent research interest. Due to its medicinal and commercial importance it has been a popular research topic for natural product scientists who have isolated several chromones and anthrones from the leaf exudate and finished product (bitters). A summary of the historical and modern day uses, commercialisation, chemical composition and biological properties of this coveted ethnomedicinally and commercially important species is presented.