Prevention and Therapy of Cancer by Dietary Monoterpenes

Abstract

Monoterpenes are nonnutritive dietary components found in the essential oils of citrus fruits and other plants. A number of these dietary monoterpenes have antitumor activity. For example, d-limonene, which comprises >90% of orange peel oil, has chemopreventive activity against rodent mammary, skin, liver, lung and forestomach cancers. Similarly, other dietary monoterpenes have chemopreventive activity against rat mammary, lung and forestomach cancers when fed during the initiation phase. In addition, perillyl alcohol has promotion phase chemopreventive activity against rat liver cancer, and geraniol has in vivo antitumor activity against murine leukemia cells. Perillyl alcohol and d-limonene also have chemotherapeutic activity against rodent mammary and pancreatic tumors. As a result, their cancer chemotherapeutic activities are under evaluation in Phase I clinical trials. Several mechanisms of action may account for the antitumor activities of monoterpenes. The blocking chemopreventive effects of limonene and other monoterpenes during the initiation phase of mammary carcinogenesis are likely due to the induction of Phase II carcinogen-metabolizing enzymes, resulting in carcinogen detoxification. The post-initiation phase, tumor suppressive chemopreventive activity of monoterpenes may be due to the induction of apoptosis and/or to inhibition of the post-translational isoprenylation of cell growth-regulating proteins. Chemotherapy of chemically induced mammary tumors with monoterpenes results in tumor redifferentiation concomitant with increased expression of the mannose-6-phosphate/insulin-like growth factor II receptor and transforming growth factor beta1. Thus, monoterpenes would appear to act through multiple mechanisms in the chemoprevention and chemotherapy of cancer.

Isolation, characterization and evaluation of antimicrobial and cytotoxic activity of estragole, obtained from the essential oil of croton zehntneri (euphorbiaceae)

“…They are used as flavor additives in food, beverages, and perfumes. Recent studies have shown that monoterpenes exert antitumor activities, and suggest that these components can be a new class of chemotherapeutic agents (Elson and Yu 1994, Kellof et al 1996, Crowell 1999.…”

Essential oil of Lithraea molleoides (Vell.): chemical composition and antimicrobial activity

“…Moreover, limonene, the major Table 1. component (89.89%) found in the essential oil of Lithraea molleoides (Vell. ), although bereft of antimicrobial activity (17) has anti-carcinogenic activity (2) and can be used in medical dissolution of gallstones (6,10). The results of the analysis of the chemical composition of the essential oil of Lithraea molleoides (Vell.)…”

Isolation and screening of d-limonene-resistant microorganisms

“…Beyond their desirable fragrances, some of these d-limonene oxygenated derivates, e.g. perillyl alcohol, carveol, carvone, geraniol and menthol, have shown biological activity in vivo against certain types of tumors, not only preventing the formation or progression of cancer, but also regressing the existing malignant tumors (8). These characteristics greatly enhance industrial interest in such compounds.…”