研究显示：糖尿病药物‘能减缓衰老进程增加寿命’

       二甲双胍（Metformin）通常作为2型糖尿病用药。但是发表于《美国国家科学院院刊》（PNAS）的新研究表明，该药也可能减缓衰老进程并延长寿命。
       二甲双胍属于双胍类药物。针对2型糖尿病患者，它可以通过降低人体对食物中葡萄糖的摄取并抑制肝脏合成葡萄糖，从而控制血糖水平。它也可以提高机体对胰岛素的自然响应。但研究表明，二甲双胍对健康的益处可能不仅体现在2型糖尿病的治疗上。2010年，Medical News Today报道了2项显示二甲双胍可能保护吸烟者免于罹患肺癌的研究。一项2012年的研究也发现该药或许对于治疗胰腺癌患者值得期待。
       现在，一个由比利时荷语鲁汶天主教大学Wouter De Haes领导的研究团队发现，二甲双胍可能会阻止衰老进程。
       蛔虫模型上的二甲双胍测试
       该团队在秀丽隐杆线虫（据该团队称，由于它仅有3周寿命，因此是一种研究衰老进程的理想模型）模型上进行了一系列实验。
       他们发现，二甲双胍提高了从这种蛔虫的细胞中释放的有毒分子的数量，而这种现象令人惊异地促进了虫体的长期强壮和长寿。

       在蛔虫模型C. elegans上的二甲双胍检测使研究人员发现，这种蛔虫未见皱缩、衰老减缓、保持较健康状态的时间更久。图源：Wouter De Haes“在它们衰老的进程中，这种蛔虫会变小、起皱且活动度下降。然而，经二甲双胍处理后的该种蛔虫表现出极有限的尺寸减少且未起皱。它们不仅衰老的更慢，而且更持久的保持了更加健康的水平。”Haes说到。

       不过，二甲双胍怎样发挥它的作用呢？该团队解释说，我们机体的细胞从线粒体（每个细胞的“动力室”，可触发小电流）中获得能源。这个产能过程会产生高活性氧分子。
       这些分子对机体有害。它们会损伤蛋白质、DNA并干扰正常细胞功能。但该团队称，这些分子在少量的情况下也能起到有益作用。
       “只要这些有害的氧分子在细胞中被释放的量维持在少量状态，对细胞而言会产生一种长期的正面效果。在这些活性氧粒子造成任何损伤之前，细胞会对它们的优势加以利用。”Haes解释说。
       “二甲双胍引起了有害氧分子数量的轻微增加。我们发现了这使得细胞变得更强并延长了它们的健康寿命。”抗氧化剂“可能阻止二甲双胍起效”
该团队称，之前有研究表明有害的活性氧分子促进了衰老进程。而且，人们认为抗氧化剂有可能阻止这些分子对机体造成伤害。
       然而，这些研究人员注意到，抗氧化剂可能会抵消掉二甲双胍的抗衰老效果，因为他们发现这些有害氧分子需要存在于细胞中才能使该药起效。尽管这些在蛔虫体上的发现显示了其有希望作为一种有效的抗衰老策略，但Haes谈到需要开展进一步研究：
       “我们应当保持谨慎不要把该发现过度外推于人类，但该研究有望作为将来研究的基础。”
       这项研究不是标示二甲双胍具有抗衰老潜力的惟一研究成果。去年，Medical News Today报道了一项来自美国国立衰老研究所（NIA）的研究人员的相关研究，他们发现二甲双胍处理组的小鼠相比对照组有5.83%的生命期延长。
       针对去年的那项发现，NIA领导Richard Hodes谈到：
       “人们对具有某种用途的药物怎样可能被再开发而用于其他方面的探索表现出日益浓厚的兴趣。发现一种已知的对人类安全且有效的药物或许能被进一步研究，从而有可能作为另一项用途用于健康的衰老，这是令人兴奋的。”

原文链接：

1. http://www.medicalnewstoday.com/articles/277679.php

复制代码

Diabetic drug 'slows aging process and increases lifespan,' study suggests

Metformin is a drug commonly used to treat type 2 diabetes. But new research published in the Proceedings of the National Academy of Sciences (PNAS) finds the medication may also slow the aging process and increase lifespan.
Metformin belongs to a class of drugs known as biguanides. For patients with type 2 diabetes, it helps control blood sugar by reducing the amount of glucose absorbed from food and the levels of glucose produced by the liver. It also increases the body's natural response to insulin.
But studies have suggested that the health benefits of metformin may reach further than type 2 diabetes. In 2010,Medical News Today reported on two studies that suggested metformin may protect against lung cancer in smokers. A 2012 study also found that the drug may show promise intreating patients with pancreatic cancer.
Now, a research team led by Wouter De Haes of the Katholieke Universiteit Leuven (KU Leuven) in Belgium finds that metformin may be useful for halting the aging process.

Testing metformin in roundworms

To reach their findings, the team conducted a series of experiments in the roundworm Caenorhabditis elegans- a model they say is ideal for studying the aging process as it only has a 3-week lifespan.
The team found that metformin increased the number of toxic molecules released in the worms' cells, which they were surprised to find boosted their long-term strength and longevity.


On testing metformin in the roundworm C. elegans, the researchers found the worms showed no wrinkling, aged slower and stayed healthier for longer.
Image credit: Wouter De Haes
"As they age, the worms get smaller, wrinkle up and become less mobile. But worms treated with metformin show very limited size loss and no wrinkling. They not only age slower, but they also stay healthier longer," says Haes.
But how does metformin work? The team explains that our body's cells get their energy from mitochondria - the "powerhouses" in each cell that trigger small electric currents. This process can generate highly reactive oxygen molecules.
These molecules can be harmful to the body. They can damage proteins and DNA and interfere with normal cell functioning. But the team says the molecules can also be beneficial in small amounts.
"As long as the amount of harmful oxygen molecules released in the cell remains small, it has a positive long-term effect on the cell. Cells use the reactive oxygen particles to their advantage before they can do any damage," explains Haes.
"Metformin causes a slight increase in the number of harmful oxygen molecules. We found that this makes cells stronger and extends their healthy lifespan."

Antioxidants 'may stop metformin from working'

The investigators say previous research has indicated that harmful reactive oxygen molecules are to blame for the aging process. Furthermore, it is believed that antioxidants may help prevent these molecules from causing damage.
However, the researchers note that antioxidants may counteract metformin's anti-aging effects, as they found that the harmful molecules need to be present in cells for the drug to work.
Although these findings in roundworms are promising as an effective anti-aging strategy, Haes notes that further research is needed:


"While we should be careful not to over-extrapolate our findings to humans, the study is promising as a foundation for future research."
This is not the only study to flag the anti-aging potential of metformin. Last year, Medical News Today reported on a study by researchers from the National Institutes of Aging (NIA), which found that mice who received metformin had a 5.83% increase in lifespan, compared with control mice.
Commenting on the findings of that study, Richard Hodes, director of the NIA, said:
"There is increasing interest in exploring how drugs for one use might be repurposed for another. It is exciting to discover that a drug already known to be safe and effective in humans might be further studied for a possible, alternate use for healthy aging."