Mealworm (Tenebrio molitor)-derived protein supplementation attenuates skeletal muscle atrophy in hindlimb casting immobilized rats

This study aimed to investigate the effect of mealworm (Tenebrio molitor) derived protein supplementation on skeletal muscle atrophy of hindlimb casted immobilized rats. Twenty-four six-week-old male Sprague-Dawley rats were randomly divided into three groups: control sedentary group (CD, n = 8), control diet casting group (CDC, n = 8), and the mealworm-derived protein supplemented casting group (MDC, n = 8). CD and CDC group was supplemented AIN-76G diet and mealworm-derived protein supplemented diet for MDC group was substituted as 5% casein protein to 5% mealworm protein for 5 weeks and left hindlimb casting immobilization using casting tape for CDC and MDC group was done 1 week before sacrifice. After 5 weeks of mealworm supplementation, the soleus muscle weight of the MDC group was significantly higher compared to the CDC group. In addition, the level of muscle protein synthesis factors p-Akt/Akt, p-4EBP1/4EBP1, and p-S6K/S6K significantly increased in the MDC group compared to the CDC group. On contrary, the level of muscle protein degradation factors (MuRF1 and atrogin-1) was significantly lower in the MDC group than that of the CDC group. These results suggest that mealworm-derived protein supplementation may have a significant role in the prevention of skeletal muscle atrophy via stimulation of muscle protein synthesis factors and inhibition of muscle protein degradation factors, and therefore a promising intervention in sarcopenia.