Longevity Briefs: Metformin May Boost Mitochondrial 'Spring Cleaning'

Getting your Trinity Audio player ready...

Longevity briefs provides a short summary of novel research in biology, medicine, or biotechnology that caught the attention of our researchers in Oxford, due to its potential to improve our health, wellbeing, and longevity.

Why is this research important: Dysfunctional mitochondria (the ‘power plants’ of the cell) contribute to both the ageing process and the development of type II diabetes. Cells have the ability to break down damaged components in a process called autophagy (literally meaning ‘self-eating’), or mitophagy when applied to mitochondria. However, dysfunctional mitochondria can stop producing the ‘eat me signals’ necessary to trigger this process. Metformin is a diabetes treatment and potential anti-ageing drug that, besides increasing cells’ sensitivity to insulin, can also enhance autophagy. However, we don’t know to what extent this effect extends to mitochondria.

What did the researchers do: In this study, researchers recruited 45 newly diagnosed type II diabetes patients who were not previously taking any drugs for the disease. They were randomly assigned either metformin, voglibose (another blood sugar-lowering treatment) or a placebo for 3 months. Researchers then studied RNA and protein markers for mitophagy in these patients, as well as the structure of their mitochondria using an electron microscope.

Mitochondria were scored based on their structure viewed under an electron microscope.
*Metformin upregulates mitophagy in patients with T2DM: A randomized placebo‐controlled study*

Key takeaway(s) from this research: Of the three treatments, only metformin increased markers of mitophagy, while also reducing the visible mitochondrial shape distortions that are associated with type II diabetes. These benefits do not seem to be the result of reduced blood sugar, since voglibose did not produce these effects. This study sheds more light on metformin’s mechanism of action, and suggests that it improves mitochondrial function in part by boosting the removal of damaged mitochondria. If this effect is confirmed in larger studies, metformin could also be explored as a way to target mitophagy in other diseases.