This is an interesting review of Ferulic Acid and Berberine
https://openheart.bm.../1/e001801.long
the key initial part is this: Ferulic acid, a bacterial metabolite of anthocyanins, seems likely to be a primary mediator of the health benefits associated with anthocyanin-rich diets,
It seems to help with improving the quality of mitochondria (particularly with Berberine and Melatonin)