Hydrolyzed peptides from purple perilla (Perilla frutescens L. Britt.) seeds improve muscle synthesis and exercise performance in mice

The purple perilla (Perilla frutescens L. Britt.) seed peptides (PPSP) were obtained and their improvement of muscle synthesis and exercise performance was investigated in this work. Results showed that the weight-average molecular weight of the PPSP was 869 Dalton. The PPSP were rich in branched-chain amino acids (18.82 g/100 g) and anti-fatigue amino acids, including glutamate (Glu), aspartic acid (Asp), and arginine (Arg). After the administration of PPSP at 1.2 g kg^-1 day^-1 for 4 weeks, the muscle coefficient and muscle fiber thickness in mice displayed a distinct (p < .05) increase via the upregulation of myogenic differentiation (MyoD) and myogenin (MyoG). The improved muscle strength and exercise tolerance were also observed. Simultaneously, the levels of the biochemical blood markers associated with fatigue and the glycogen degradation in liver and muscle were significantly (p < .05) suppressed. These results suggested that PPSP could effectively promote muscle synthesis and ameliorate exercise fatigue. PRACTICAL APPLICATIONS: Purple perilla is an annual herbal plant and widely grown in Asian countries as an important crop and food. It is believed that the protein content of purple perilla seeds can reach 23.7%, and the protein is rich in essential amino acids. However, the information about the beneficial effects of their proteins or peptides on muscle synthesis and anti-exercise fatigue were still limited. The present results discovered that the PPSP can effectively promote the growth of muscle tissue and improve exercise tolerance. It is indicated that PPSP may have a potential application value in partly or completely replacing animal proteins such as whey protein.

Keywords: exercise fatigue; muscle growth; myogenic factor; peptides; purple perilla.