Croton species in Madagascar: their ethnomedicinal uses, phytochemistry and biological activities

Crotonspecies collected from the wild have always been used as herbal medicines for various diseases in Madagascar. The objective of this investigation was to review the ethnomedicinal uses, phytochemistry and biological activities of Crotonspecies that are endemic to Madagascar. Relevant literature search was carried out using internet sources such as ACS, Web of Science, Wiley, SpringerLink, Scopus, Mendeley, Google Scholar, Pubmed, SciFinder, BioMed Central, Science Direct and Elsevier. Other literature sources were conference papers, book chapters, books, theses and websites. Literature sources revealed that leaves, bark, roots and twigs of Croton species are commonly used as traditional remedies for 38 human diseases and ailments in Madagascar. Cough, malaria, stomach problems, hypertension, asthma, colic and fever are the most commonly treated human diseases, including use of leafy branches of Crotonspecies as insect and lice repellents. Phytochemical compounds isolated from Crotonspecies include alkaloids, diterpenoids, essential oils, flavonoids, furanoditerpenoids and triterpenoids. Preliminary pharmacological studies indicate that crude extracts and compounds isolated from these species have antimicrobial and cytotoxic activities. In as much as the medicinal potential of Crotonspecies should be evaluated, more intensive phytochemical and pharmacological assessments should be conducted to enhance the pharmaceutical potential of the species.