GABA Prevents Sarcopenia by Regulation of Muscle Protein Degradation and Inflammaging in 23‐ to 25‐Month‐Old Female Mice

ABSTRACT Background Sarcopenia is the gradual decrease in skeletal muscle mass, strength and function in elderly individuals. Gamma‐aminobutyric acid (GABA) is a neurotransmitter naturally produced from glutamate by the enzyme glutamic acid decarboxylase. Age‐related decline in GABA is linked to age‐related motor and sensory decline and seems to affect sarcopenia, yet no detailed study has been conducted. In this study, we aimed to investigate the effect of GABA on improving sarcopenia by suppressing muscle protein degradation through supplementing decreased GABA in old mice. Methods GABA (10 or 30 mg/kg/day) was orally administered daily to young (3 months) and old (21–23 months) C57BL/6 mice for 7 weeks. The body weight and grip strength of the mice were measured weekly at the same time. After sacrificing the mice, the quadriceps and gastrocnemius muscles were excised from their hind limbs, and the spleen and serum were collected. Histological, biochemical and molecular analyses were conducted in various experiments. Results The administration of GABA increased muscle strength (+41%, +70% compared to the aged mouse control group, GABA at doses of 10 or 30 mg/kg/day respectively, p