Terpenoids are occurring in all living organisms but their greatest structural and functional diversity is attained in plants. Terpenoid, or terpene is derived from the German word for turpentine, Turpentin, where the first members of this group were isolated (Langenheim, 2003). Terpenoids are a diverse group of compounds, with more than 25, 000 known types (Callow et. al. , 2000) and one of these is D-Limonene. According to Sun (2007): “D-limonene is one of the most common terpenes in nature. It is a major constituent in several citrus oils (orange, lemon, mandarin, lime, and grapefruit).
D-limonene is listed in the Code of Federal Regulations as generally recognized as safe (GRAS) for a flavoring agent and can be found in common food items such as fruit juices, soft drinks, baked goods, ice cream, and pudding. ” From a study conducted by Brudnak (2002), it was found out that terpenes such as D-Limonene can act before a cancer is established and can cause a regression of a tumor, if it is already present. Monoterpenes do this in four ways – through inducement of carcinogen detoxification, increase of cell redifferentiation, inducement of apoptosis in immortalized cells, and inhibition of cellular products of oncogenes.
If these oncogenes are not activated, they do not cause the cell to behave as a cancer and thus, cancer inhibition is possible (Brudnak, 2002). The effect of monoterpenes on cancer prevention have been long postulated and studied. Most works and studies have been done in mammals, especially in rats, human clinical trials have also been reported. However, it has still not been properly accepted, if proven true and effective, this can be a great medical breakthrough since cancer is widespread nowadays. References Brudnak, Mark. Cancer-Preventing Properties of Essential Oil Monoterpenes D-Limonene and Perillyl Alcohol.
Positive Health: Complementary Medicine magazine. Retrieved May 11, 2009, from https://www46. safesecureweb. com/positivehealth/permit/Articles/Cancer/brud53. htm Callow, J. A. Preston, R. (2000). Advances in botanical research. California: Academic Press. Langenheim, Jean H. (2003). Plant resins: chemistry, evolution, ecology, and ethnobotany. Oregon: Timber Press. Sun, Jidong (2007). D-Limonene: safety and clinical applications (Clinical report). Alternative Medicine Review. Retrieved May 11, 2009, from http://www. encyclopedia. com/doc/1G1-170236094. html