H.R. Correia, S. Balseiro

It is generally assumed that all living beings die under specific and lethal stress conditions. However, here we show that a biomolecule called PL1, from one of the oldest known tree species, immortalizes yeast, the eukaryotic organism Saccharomyces cerevisiae, in fatal and combined oxidative and thermal stress conditions.

In the last 3 years, we have developed a new and rapid technique for the identification of lifespan-extending biomolecules in baker's yeast. In the investigation of the extracts effects of more than 700 species of plants, we have found that the biomolecule PL1 has an extraordinary protective effect, preventing the death of the yeast organisms induced by extreme stress conditions. From an initial yeast suspension containing 1 g of yeast extract per 100 ml of distilled water, two suspensions are prepared in two different tubes: the Experimental suspension (ES), containing 100 μL of yeast suspension, 100 μL of the aqueous PL1, and 100 μL of aqueous blue methylene (1%); and the Control suspension (CS), containing 100 μL of yeast suspension, 100 μL of distilled water, and 100 μL of aqueous blue methylene (1%). The two suspensions are microwaved at 900 W for 30 seconds. Live (colorless) and dead (dark blue) yeast organisms are visualized using a microscope. As expected, all yeast organisms in the CS exposed to the combined stresses are dead. However, surprisingly all yeast organisms in the ES survive. Yeast viability was also accessed by using glicose protocol, confirming the results. We also have found that, using the same procedure, resveratrol reduces yeast mortality in 10%, and some medicinal plant extracts have a positive effect between 5 and 15%. In conclusion, our findings suggest that PL1 have powerful effects that can reduce molecular instability and, therefore, could have an important role in the prevention and therapy of ageing-associated diseases.

Keywords (Optional): 
Lethal Stress