Supplimentary Data

This study investigated the efficacy of two natural compounds—Celastrol, a heat shock protein (HSP) inducer, and Cblin peptide, a ubiquitination inhibitor—in counteracting muscle atrophy under real microgravity conditions. Both agents independently attenuated microgravity-induced reductions in myotube thickness, myosin heavy chain (MyHC) protein levels, and atrogene expression. Celastrol primarily enhanced HSP expression, while Cblin peptide inhibited IRS-1 degradation, thereby promoting IGF-1 signaling. Despite their distinct molecular actions, no synergistic or additive effects were observed when combined. These findings highlight the potential of Celastrol and Cblin peptide as functional ingredients for mitigating muscle atrophy, particularly in the context of space travel. Notably, Cblin peptide is abundant in glycinin-rich soybean protein, and Celastrol is derived from the root of Tripterygium wilfordii (Taiwan vine). Future applications may include incorporating these plant-derived compounds into space foods to improve the quality of life for astronauts in space.