The CD36-PPARγ Pathway in Metabolic Disorders.

This review paper examines the biological pathway linking growth hormone releasing peptides (GHRPs) — with a focus on the peptide hexarelin — to metabolic regulation via the scavenger receptor CD36 and the nuclear receptor PPARγ. The authors summarize evidence showing that GHRPs can activate PPARγ through CD36, and discuss how this pathway may influence key metabolic processes including atherosclerosis, hepatic cholesterol biosynthesis, and mitochondrial biogenesis in fat tissue. The paper also discusses the role of the PPARγ coactivator PGC-1 in mediating these downstream effects. The authors contextualize this pathway alongside established pharmacological approaches, such as thiazolidinediones, which also target PPARγ to improve insulin resistance in diabetic patients. The paper proposes that the GHRP-CD36-PPARγ axis represents a novel potential target for addressing metabolic disorders. As a review, the paper synthesizes existing preclinical and some clinical research but does not present original experimental data. Key limitations include the absence of new human trial data and the largely preclinical nature of much of the underlying evidence for hexarelin specifically.

Why this grade: This is a narrative review synthesizing existing literature on the CD36-PPARγ pathway and GHRPs; it presents no original experimental data and the underlying evidence base for hexarelin is predominantly preclinical.