This study presents evidence that Epigallo-catechin gallate (EGCG), one of the major therapeutic components of green tea, significantly and markedly extends the lifespans of C. Elegans worms under conditions of heat or oxidative stress. It did not extend their lifespans under normal conditions. Once again, it starts to seem that preventing oxidative stress is good for preventing health problems and premature death, but that eventually other age-related processes result in the systemic dysfunction that eventually kills organisms of ‘old age’.

Significant longevity-extending effects of EGCG on Caenorhabditis elegans under stress.

Free Radic Biol Med. 2008 Nov 5; PMID: 19061950

Zhang L, Jie G, Zhang J, Zhao B.

Epigallocatechin gallate (EGCG), a main active ingredient of green tea, is believed to be beneficial in association with anticarcinogenesis, antiobesity, and blood pressure reduction. Here we report that EGCG extended Caenorhabditis elegans longevity under stress. Under heat stress (35 degrees C), EGCG improved the mean longevity by 13.1% at 0.1 mug/ml, 8.0% at 1.0 mug/ml, and 11.8% at 10.0 mug/ml. Under oxidative stress, EGCG could improve the mean longevity of C. elegans by 172.9% at 0.1 mug/ml, 177.7% at 1.0 mug/ml, and 88.5% at 10.0 mug/ml. However, EGCG could not extend the life span of C. elegans under normal culture conditions. Further studies demonstrated that the significant longevity-extending effects of EGCG on C. elegans could be attributed to its in vitro and in vivo free radical-scavenging effects and its up-regulating effects on stress-resistance-related proteins, including superoxide dismutase-3 (SOD-3) and heat shock protein-16.2 (HSP-16.2), in mutant C. elegans with SOD-3Colon, two colonsgreen fluorescent protein (GFP) and HSP-16.2Colon, two colonsGFP expression. Quantitative real-time PCR results showed that the up-regulation of aging-associated genes such as daf-16, sod-3, and skn-1 could also contribute to the stress resistance attributed to EGCG. As the death rate of a population is closely related to the mortality caused by external stress, it could be concluded that the survival-enhancing effects of EGCG on C. elegans under stress are very important for antiaging research.