Japanese Researchers Discover Compound That May Slow Age-Related Muscle Loss

On a Friday in late July, researchers at Kyushu University in Fukuoka announced they had isolated a compound that might slow one of aging's most relentless processes: the gradual weakening of muscle. The compound, a sulfur-based molecule called LASSS, appears to protect and strengthen a protein called HGF—hepatocyte growth factor—that the body naturally uses to repair damaged muscle tissue. The finding emerged from work led by professor Ryuichi Tatsumi at the university's Faculty of Agriculture, and it suggests a path toward interventions that could preserve strength and function as people grow older.

The problem the researchers were trying to solve is deceptively simple. HGF exists in the body throughout life and plays a crucial role in muscle repair and regeneration. But as we age, something happens to it. The protein doesn't disappear; instead, it undergoes a chemical alteration called nitration, a process that degrades its ability to do its job. Muscle fibers that should be repaired remain damaged. Over time, this contributes to the progressive loss of muscle mass and strength that characterizes aging. Tatsumi and his team wondered whether a compound with strong antioxidant properties might protect HGF from this chemical damage, either by preventing nitration altogether or by counteracting the functional loss it causes.

They tested two candidates: glutathione trisulfide and lipoic acid trisulfide, both molecules containing three sulfur atoms linked in sequence. In their initial experiments, both compounds suppressed the nitration of HGF. But LASSS produced something unexpected. When mixed with HGF, it didn't simply neutralize the reactive molecules causing damage. Instead, it appeared to interact directly with the protein and induce a subtle structural change, creating what the researchers began calling "Super HGF." This enhanced version bound more strongly to its target receptor and resisted the chemical damage that normally degrades the protein's function. "This exceeded our expectations," Tatsumi said of the results. "We knew trisulfides had diverse biological functions, but we never expected that simply mixing HGF with LASSS would produce such a striking effect."

The implications extend beyond aging alone. Muscle loss isn't only a problem of time. People confined to bed for extended periods—whether recovering from surgery, illness, or injury—experience rapid muscle deterioration. The same mechanism that fails with age accelerates under immobility. If LASSS can protect HGF function, it might help preserve muscle in these situations too, allowing people to recover faster and more completely. The researchers believe the compound could eventually benefit not just humans but animals as well, helping aging cats and dogs maintain independence and quality of life in their later years.

What remains ahead is the long path from laboratory discovery to clinical application. The initial findings are promising, but they represent early-stage research. The team will need to conduct further studies to understand how LASSS behaves in living organisms, whether it can be safely administered to humans, and at what doses it might be effective. There are questions about how it would be delivered, how long its effects might last, and whether the results in controlled experiments would translate to real-world benefit. But the discovery itself—that a simple sulfur-based compound can fundamentally alter how a key repair protein functions—opens a door that researchers will now work to walk through.