Rotten Egg Gas May Be Key to Human Longevity

A gaseous compound called hydrogen sulfide may play a wide-ranging role in staving off aging, according to a team of scientists from University of South China, Hunan.

Hydrogen sulfide may have an effect on the age-related gene Klotho to promote longevity. Klotho can improve longevity by inhibiting IIS signaling, inducing FOXO (forkhead box proteins) derepression, and decreasing angiotensin II-induced oxidative stress (Zhang Y et al)

Hydrogen sulfide (H2S) is a colorless, poisonous, flammable gas with the characteristic foul odor of rotten eggs. A few breaths of air containing high levels of this gas can cause death. Lower, longer-term exposure can cause eye irritation, headache, and fatigue.

Human body produces small amounts of hydrogen sulfide and uses it as a signaling molecule.

“Hydrogen sulfide is produced within the human body, and has a variety of important physiological effects. For example, it relaxes the vascular endothelium and smooth muscle cells, which is important to maintaining clean arteries as one ages,” said Dr Zhi-Sheng Jiang of the University of South China’s Institute of Cardiovascular Disease, senior author of the paper published in the journal Molecular and Cellular Biology (full paper).

“H2S has been gaining increasing attention as an important endogenous signaling molecule because of its significant effects on the cardiovascular and nervous systems.”

Dr Jiang said the evidence is mounting that hydrogen sulfide slows aging by inhibiting free-radical reactions, by activating SIRT1, an enzyme believed to be a regulator of lifespan, and probably through its interactions with a gene age-related called Klotho, which appears to have its own market basket of anti-aging activity.

The gene Klotho, which appears to be upregulated by hydrogen sulfide, is thought to extend lifespan via a number of different pathways, some of which promote production of endogenous antioxidants, according to the scientists.

“Produced in the kidneys, it has direct angiotensin-converting enzyme (ACE) inhibiting activity; that is, it’s an ACE inhibitor, just like certain drugs that mitigate high blood pressure. Not surprisingly, plasma hydrogen sulfide declines with age, and is lower in spontaneously hypertensive rats than in those with normal blood pressure. More generally, a lack of hydrogen sulfide is implicated in cardiovascular disease.”

A decline in hydrogen sulfide is also thought to undermine neurological health. Endogenous hydrogen sulfide has been found wanting in an animal model of Parkinson’s disease, and is found to be depressed in the brains of patients with Alzheimer’s disease. There are even suggestions, mostly in animal models, but also in human studies, that hydrogen sulfide may be protective against cancer.

“Data available so far strongly suggest that H2S may become the next potent agent for preventing and ameliorating the symptoms of aging and age-associated diseases,” Dr Jiang said. “In the future, people may take H2S via food, or as an anti-aging supplement.”

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Bibliographic information: Zhang Y et al. Hydrogen sulfide: the next potent preventive and therapeutic agent in aging and age-associated diseases. Mol. Cell. Bio., published online ahead of print January 07, 2013; doi: 10.1128/MCB.01215-12