Limonoids as an effective Anticancer Agent: A Review

Citrus limonoids (CLs) are a group of highly oxygenated terpenoid found mostly in the seeds, fruits and peel tissues of citrus fruits such as lemons, limes, pumellos, oranges, grapefruits, bergamots, and mandarins. [10] The term limonoids was derived from limonin, which is the first tetranortriterpenoid obtained from bitter principles of citrus [6]. CLs are found as both free aglycones and corresponding -D glucosides, the former mostly occurring in seeds while the latter are formed during fruit maturation. Conversion of agycon to glycon is carried out by two enzymes, uridine diphosphoglucose- limonoid glycosyl t ransferase and limonoid D-ring lactone hydrolase. [8,9]. Glucosides have an open D ring to accommodate an attached glucose moiety; in aglycones the D-ring is closed [9] Citrus fruits are particularly high in a class of phytochemicals known as the limonoidsland recent research suggests that limonoids appearto possess substantial anticancer activity. [7] The present review focused on pharmacological studies of citrus limonoids as an anticancer agent.