This 2021 review subject was metformin’s role in autophagy:
“Metformin had been used as the first choice for treating diabetes for almost a century. Autophagy is responsible for recycling and degrading cellular components, which significantly affects cell functions in physiology and pathology.
Effects of metformin on autophagy mainly depend on corresponding signaling pathways in specific organs or tissues. Metformin can induce autophagy in cells of many organs and tissues via affirmed signaling pathways, such as AMPK-related signaling pathways.
Different signaling pathways (alone or in combination) mediated the process of metformin affecting autophagy in different organs or tissues. It is necessary to combine effects of metformin on autophagy with pharmacological effects on pathologies in different organs or tissues, which would provide indications for future metformin applications.”
https://www.sciencedirect.com/science/article/pii/S0753332221000718 “The effects of metformin on autophagy”
I characterized this review as Part 2 of Broccoli sprouts activate the AMPK pathway because that study’s experimental evidence showed sulforaphane activation of the AMPK pathway was a predecessor to sulforaphane’s main effects of Nrf2 pathway activation. This review didn’t even mention Nrf2 activation.
Do all of metformin’s cited effects apply to daily intake of broccoli sprouts? Probably not, but most people who take metformin every day aren’t healthy.