Garlic Compound Triggers Fat Tissue to Rejuvenate Aging Muscles

Age-related muscle decline, known as sarcopenia, is one of the most impactful drivers of frailty and loss of independence in older adults. Finding safe, accessible interventions to preserve muscle function is a high priority in longevity medicine. This study zeroes in on a garlic-derived compound that appears to do exactly that — through a surprisingly elegant multi-organ signaling mechanism.

The research team investigated S-1-propenyl-L-cysteine (S1PC), a sulfur-containing amino acid derivative found abundantly in aged black garlic extract. Despite growing interest in S1PC as a nutraceutical, its precise molecular targets were unknown. The researchers systematically mapped its mechanism of action in cell culture, animal models, and a human cohort.

The key discovery is that S1PC activates liver kinase B1 (LKB1) by enhancing its complex formation with two regulatory proteins, STRAD and MO25. This activated LKB1 then phosphorylates SIRT1, a well-established longevity-associated deacetylase. The net effect in white adipose tissue (WAT) is a significant increase in the secretion of extracellular NAMPT (eNAMPT), an enzyme that drives NAD+ biosynthesis in peripheral tissues.

Critically, this adipose-secreted eNAMPT was shown to specifically target the hypothalamus. This hypothalamic signaling then produced measurable gains in skeletal muscle force and improved composite frailty indices in aged mice. In human participants with healthy adipose mass, S1PC supplementation also elevated circulating eNAMPT levels, suggesting translational relevance.

The implications are significant: this study identifies a natural compound that activates a fat-brain-muscle axis involving NAD+ metabolism, LKB1, and SIRT1 — all central nodes in aging biology. Caveats include the abstract-only access, industry co-authorship conflicts, and the need for larger, controlled human clinical trials to confirm muscle-function benefits.