Olijven tegen darmkanker*
Uit een Spaanse studie blijkt hoe bioactieve stoffen in de schil van olijven darmkankercellen tot celdood kunnen aanzetten. In de schil en de waslaag op de schil van olijven zit het triterpeen maslinic zuur. Dit zuur zet darmkankercellen aan tot celdood.
Study Shows Olive Skins Defend against Colon Cancer
The emerging area of nutritional science continues to identify new compounds in foods which play a crucial role in preventing or reducing the risk of a number of chronic conditions. One of the oldest foods known, the nutritionally-rich olive, is once again in the news due to a new European study.
Faculty researchers from the University of Granada and the University of Barcelona are the first to study the precise molecular mechanisms of a compound found in high concentrations in the protective wax-like coating of olives. It is a pentacylic triterpene called maslinic acid. The study results suggest that this compound has the potential to provide significant natural defense against colon cancer.
There are some 4,000 triterpenes known, and they are found in a variety of plant and animal sources. Triterpenes frequently demonstrate bioactivity as antibacterials, antivirals, and antifungals. Triterpenes are precursors to steroids. Pentacyclic triterpenoids are abundant in the plant kingdom.
Previous studies with maslinic acid and oleanic acid derived from olives have identified the ability to inhibit proliferation and induce apoptosis (the programmed death of cells) in HT29 colon-cancer cells. This new study conducted and researched by Reyes-Zurita, Rufino-Palomares, Lupianez, and Cascante from the respective universities' Departments of Biochemistry and Molecular Biology, now identifies the exact pathways. They describe their findings as follows:
"Treatment with maslinic acid results in a significant inhibition of cell proliferation in a dose-dependent manner and causes apoptotic death in colon-cancer cells. We found that it inhibits considerably the expression of Bcl-2 whilst increasing that of Bax; it also stimulates the release of mitochondrial cytochrome-c and activates caspase-9 and caspase-3. All these results point clearly to the activation of the mitochondrial apoptotic pathway in response to the treatment of HT29 colon-cancer cells with maslinic acid."
Olives offer a wonderful nutritional profile of vitamins including E, A, and many of the B vitamins. They contain the minerals zinc, copper, iron, calcium, magnesium and phosphorus as well as dietary fiber, some protein, monosaturated fat, polyphenols and flavonoids. Naturally-ripened purple/black olives contain anthocyanins, the plant pigment high in anti-oxidants .
Olives and olive oil are predominant in the Mediterranean diet. They are highly beneficial, affecting numerous biological processes including cancer. From the results of this study, the average consumer can appreciate that maslinic acid in the the pomace of olive skins is another discovery joining the ranks of many other foods shown to be powerful cancer-fighters. They've always been there to keep us well as long as we gratefully ingest them.
Reyeszurita et al. Maslinic acid, a natural triterpene from Olea europaea L., induces apoptosis in HT29 human colon-cancer cells via the mitochondrial apoptotic pathway. Cancer Letters, 2009; 273 (1): 44 DOI:
10.1016/j.canlet.2008.07.033 (Maart
2009)
