Sustainable mealworm tofu as a dietary strategy to prevent muscle atrophy induced by dexamethasone in cellular and animal models

• Mealworm protein tofu inhibits muscle atrophy in vitro and in vivo . • Hydrolysate tofu blocks myostatin, reducing dexamethasone-induced atrophy. • Intact mealworms help prevent muscle atrophy via myostatin inhibition. • Insect-plant protein gel shows promise for functional foods and nutraceuticals. • This gel supports muscle health and prevents atrophy. This study aims to evaluate the inhibitory effects of mealworm ( Tenebrio molitor larva) tofu on dexamethasone (DEX)-induced muscle atrophy. Tofu was prepared using mealworm powder (SM), protein isolate (SMPI), and hydrolysate (SMPH), and compared with soybean-only tofu (S). The effects of these tofu ethanolic extracts were assessed in vitro using C2C12 cells and in vivo using C57BL/6 N mice fed a diet containing 15 % tofu under DEX-induced muscle atrophy conditions. Treatment with SM and SMPH significantly increased the myotube diameter and decreased the expression levels of muscle degradation-related mRNA genes and proteins in C2C12 cells. In animal model, SM and SMPH improved grip strength (0.036 and 0.043 N/g body weight, respectively) and enlarged cross-sectional area (1350 and 1270 μm 2 , respectively) compared to the DEX-treated group on a normal diet (DEX CON: 0.031 N/g body weight and 1140 μm 2 , respectively). SM and SMPH reduced levels of creatine phosphokinase (428 and 440 IU/L, respectively) and myoglobin (5.31 and 5.12 ng/mL, respectively) compared with those of DEX CON (821 IU/L and 8.37 ng/mL, respectively). Moreover, SM and SMPH suppressed mRNA and protein expression related to muscle degradation. These findings suggest that mealworms, particularly in the intact (SM) and protein hydrolysate (SMPH) forms, have considerable potential as alternative protein sources to replace soybeans in the diet, thereby preventing muscle atrophy and reducing protein breakdown.