加齢：高齢マウスにおいてブドウ種子抽出物が示す抗老化作用

A natural compound in grape seeds — the flavonoid, procyanidin C1 — increases the health and lifespan of old mice by interfering with cells that promote ageing, according to a study published in Nature Metabolism. However, future research will be needed to determine its exact mechanisms of biological action and any potential relevance to humans.

When exposed to chemicals or radiation, or as we naturally age, cells can become senescent, thereby altering or ceasing their normal function. The gradual accumulation of senescent cells is thought to contribute to age-associated decline in physical function and multiple age-related pathologies.

Yu Sun and colleagues screened a panel of natural extracts in a model involving cultured human prostate cells. They revealed that grape seed extract and one of its key components — procyanidin C1 (PCC1) — is effective at selectively killing senescent cells, while leaving normal cells intact. In several mouse models in which senescent cells contribute to disease, such as those generated after exposure to radiation, PCC1 injections reduced the number of senescent cells and led to health improvements. PCC1 also improved chemotherapeutic outcomes in immunocompromised mice. Furthermore, fortnightly injections of PCC1 into 91 old mice (48 males and 43 females aged 24–27 months, equivalent to a human age of 75–90 years) increased their remaining lifespan by over 60% or increased their total lifespan by approximately 9%.

The authors note that the exact molecular mechanism of action of PCC1 requires further clarification. Although PCC1 injections appear to have been well tolerated in mice in preclinical trials, research is needed to establish what constitutes a safe dose and whether these findings are applicable to humans.