Abstract
The monoterpenes are a new class of anticancer drugs having efficacy in both cancer prevention and treatment. We have shown that the monocyclic monoterpenes limonene and perillyl alcohol can prevent chemically-induced rat mammary carcinomas if fed either during the initiation stage or the promotion/progression stage of carcinogenesis. In addition, these terpenes can induce the complete regression of the majority of advanced mammary carcinomas without toxicity. The activities associated with tumor regression include the inhibition of the prenylation of small G proteins and the synthesis of ubiquinone. In addition, regressing tumors have elevated levels of TGFβ and its activating receptor. Both rodents and humans metabolize limonene to similar compounds. Based on these findings limonene is currently undergoing clinical testing in cancer patients.
