Cure for Cancer in the Rainforest?

No Cures Yet, but Western Diet May Lack Triterpenes

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Lupeol, also known as fagarsterol, is a natural compound found in certain plants in the tropical rainforest, as well as in certain foods. Lupeol is of great interest to scientists who study natural compounds that have potential therapeutic properties. Research is limited to in vitro and animal studies, so it is very early in the discovery phase, but Lupeol appears to have anti-inflammatory and anti-cancer properties in some of these studies.

What is Lupeol?

Lupeol belongs to a group of compounds called triterpenes. Triterpenes are important components of plant cell membranes. These compounds act similarly to cholesterol in animal cell membranes—that is, they help keep the bilayers in plant cell membranes stable. Triterpenes have actually been the subject of 25 different clinical studies and are of interest for their cholesterol-lowering properties.

In the West, it’s been estimated that we eat about 250 mg per day of triterpenes, mostly derived from vegetable oils, cereals, fruits and vegetables. Intake of triterpenes may be much higher in Mediterranean countries and in populations with the characteristic diets rich in olive oil.

Lupeol is a triterpene with particularly interesting biologic activity. Studies that provide information about the biologic activity of Lupeol suggest that it's a multi-target agent. Key molecular pathways involved in inflammation and cancer are thought to be involved.

What are the Sources of Lupeol?

Zanthoxylum is a genus of about 250 species of trees and shrubs in the citrus family, native to warm temperate and subtropical areas worldwide. Some of the species have yellow heartwood, and the fruit of several species is used to make the spice, Sichuan pepper. Members of the genus are also sometimes used as bonsai trees.

The bark has been used in folk medicine for toothache, colic, and rheumatism. Good sources of Lupeol in this genus include Zanthoxylum riedelianum, one of the tallest trees of the lower Peruvian Amazon. Interestingly, Lupeol is also found in a plant from the Philippines, Ficus pseudopalma, which has been used as an herbal medicine for kidney stones and diabetes. A variety of different plants are now known to be good sources of Lupeol, and Lupeol is even found in vegetables such as white cabbage, pepper, cucumber, tomato; and in fruits such as olive, fig, mango, strawberry, and red grapes.

Will Rainforest Compound Help Cancer Treatment and Prevention?

Recent studies have shown that diets rich in phytochemicals (of which Lupeol is only one) can significantly reduce the risk for several common cancers by as much as 20 percent.

Whether Lupeol will prove useful in the treatment of cancer remains to be seen, but findings from in vitro and animal studies conducted so far have been interesting. Perhaps just as encouraging is the fact that Lupeol, at its effective therapeutic doses, seems not to exhibit toxicity to normal cells and tissues studied.

That said, safety and toxicity have not been evaluated in human clinical trials, and results may differ from in vitro and animal studies.

A program at the School of Medicine and Public Health, University of Wisconsin-Madison has been examining beneficial effects of Lupeol for various cancer types such as prostate, skin, pancreatic and breast cancer. Based on studies involving treatment of cancer cells from various cell lines, this group believes Lupeol has the ability to act on multiple molecular pathways.

What about Blood Cancers?

Studies with Lupeol are very preliminary, and further investigation is needed to shed light on this question. In the meantime, findings from several previous studies promise to fuel continued work.

A study conducted by Aratanechemuge and colleagues showed that Lupeol induces apoptosis (programmed cell death) of human promyelocytic HL-60 leukemia cells. This study showed that Lupeol induces changes in the cell nuclei and fragmentation of DNA (a characteristic of apoptosis) in a manner that depends on the dose of Lupeol given.

Another group of researchers, Cmoch and colleagues, showed that Lupeol induces cell death in a variety of different cancer cell lines, including T-lymphoblastic leukemia, and multiple myeloma.

Sources

Santiago LA, Mayor ABR. Lupeol: An antioxidant triterpene in Ficus pseudopalma Blanco (Moraceae). Asian Pac J Trop Biomed. 2014;4(2):109-118.

Saleem M. Lupeol, A Novel Anti-inflammatory and Anti-cancer Dietary Triterpene. Cancer Let. 2009;285(2):109-115.

Moreau RA, Whitaker BD, Hicks KB. Phytosterols, phytostanols, and their conjugates in foods: structural diversity, quantitative analysis, and health-promoting uses. Prog Lipid Res. 2002;41:457–500.

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