I’ll curate this 2020 rodent study through its summary graphic and caption:
“Type 2 diabetes exhibits elevated levels of circulating fatty acids and CD36. This results in excessive fatty acids binding with CD36 to suppress AMPK [adenosine 5′ monophosphate-activated protein kinase, a key player in regulating energy metabolism].
Inactivation of AMPK breaks homeostasis in lipid metabolism and the antioxidative system, and subsequently induces cardiac oxidative stress, inflammation, and fibrosis. These damages contribute to diabetic cardiomyopathy.
SFN [sulforaphane] treatment significantly induces AMPK activation, which:
- Enhances mitochondrial fatty acids oxidation via PPARα/CPT-1B and PGC1-α pathways; and
- Inhibits SCD-1 to down-regulate lipid synthesis.
This greatly alleviates cardiac lipid accumulation.
NRF2-mediated antioxidative effects can be activated via AMPK/AKT/GSK3β pathway, developing another pathway to confront cardiac oxidative damage.
AMPK is indispensable in SFN-mediated cardiac prevention against T2D.”
https://www.metabolismjournal.com/article/S0026-0495(19)30217-3/fulltext “Protective effects of sulforaphane on type 2 diabetes-induced cardiomyopathy via AMPK-mediated activation of lipid metabolic pathways and NRF2 function” (not freely available)
1. A human-mouse relative age perspective:
- Experiments started with subjects at 2-months-old, equivalent to 20 human years. Treatment subjects ate a high-fat diet.
- Sulforaphane was injected subcutaneously at 0.5 mg/kg every working day. It didn’t have significant effects on cardiac lipid accumulation at 5 months (a 30-year-old human), but did at 8 months (a 42-year-old human).
2. This study demonstrated that for sulforaphane to produce evidenced Nrf2 pathway effects, it first activated the AMPK/AKT/GSK3β pathway. For 5 days a week, over periods of human-equivalent decades.
3. CPT-1B pictured above is carnitine palmitoyltransferase-1B, an enzyme in the outer membrane of mitochondria. It controls transfer of long-chain fatty acyl CoA into mitochondria to convert fat into energy.
AMPK pathway activation also subsequently activates “PPARα/CPT-1B and PGC1-α pathways.” See A case for carnitine supplementation for a review.