Cell Aging Delayed

GRAZ, AUSTRIA, March 24, 2014

Whether in salads, for frying fish or meat or just as a snack on white bread - for millennia olive oil has been one of the tastiest natural products.. And it is one of the healthiest be-cause of the high content of unsaturated fatty acids and additional substances, which are present in minute amounts in olives (and in virgin olive oil "extra virgine"). A particularly valuable one is 3-hydroxytyrosol. "The substance is said to protect the cells and thus delays aging and prevents various diseases," says Margit Winkler, researcher at the Austrian Centre of Industrial Biotechnology (acib). This is due to the antioxidant effect, which is even stronger than that of ascorbic acid, the well-known antioxidant Vitamin C from citrus fruits.

No wonder that the substance is always in demand as a natural food supplement or as a component for cosmetics. The crux of the matter is the availability of 3-hydroxytyrosol: olive trees grow in limited geographic areas and olives should remain a valuable and tasty food and not become the raw material for a substance that is present only in minimal amounts. The separation is difficult and expensive, says Margit Winkler.

A research group of acib and the Swiss industrial partner Lonza has found a way to produce the valuable substance biotechnologically. A patent has been filed and it will be scientifically published shortly. The biotechnological route uses bacteria (Escherichia coli) as a cell factory. The researchers have integrated a new enzyme from another microorganism (called Nocardia), which is able to convert a cheap, low-carbon acid (3,4-Dihydroxyphenylacetic acid, DOPAC) into the valuable 3-hydroxytyrosol. The entire reaction was improved so that the otherwise for this complicated conversion necessary cofactors are no longer needed - the high art of biotechnology.

"Fed with DOPAC, at laboratory scale there is a turnover of 100 percent using our modified Escherichia coli cell factories," explains acib-scientist Winkler. The next step is transferring the process to an industrial scale.

Antioxidants and Cancer
Oxidative stress damages living cells: They form very active "radicals", which react with everything that comes their way. This causes cancer or an even faster cell death. For example, skin cells exposed to UV light show such oxidative stress. The skin ages faster, dries out, becomes wrinkled. In the worst case, skin cancer is the long-term consequence. Antioxidants neutralize the free radicals and decrease the risk of damages dramatically. 3-hydroxytyrosol has already been tested in many studies and showed "cytoprotective effect": Protection of cells was shown with intestinal and brain cells, cells of the cardiovascular system, liver and various other cell types. For the authors of the studies, 3-hydroxytyrosol can prevent cancer, is anti-inflammatory and has a positive effect on the cardiovascular system.

Reference: "ChemCatChem: Whole cell carboxylate reduction for the synthesis of 3-hydroxytyrosol," Kamila Napora-Wijata, Karen Robins, Antonio Osorio-Lozada and Margit Winkler; http://onlinelibrary.wiley.com/doi/10.1002/cctc.201300913/abstract