Ninjin'yoeito, a traditional Japanese medicine, attenuates age-related deficits of muscle performance, self-care motivation, and body temperature in C57BL/6 mice

Abstract

Abstract As both physiological and psychological factors influence age-associated declines in older people, the development of drug therapy with multifaceted effects is required. To investigate the utility of ninjin'yoeito (NYT) against geriatric syndromes, we evaluated the effects of NYT on age-related declines in old C57BL/6 mice (88-week-old) as a pre-clinical model of frailty progression. Here, we showed that NYT reversed the decline of rectal temperature in old mice, and also improved forelimb grip strength compared to that in the old control group without affecting skeletal muscle loss. Moreover, NYT significantly increased the duration of grooming after a sucrose solution was sprayed, which reflected self-care motivation. Finally, we revealed the anti-oxidant effects of NYT using a cell-free assay. These results suggest that NYT can improve both physiological and psychological declines associated with aging, and the mechanism may include anti-oxidant effects. NYT may have potential utility for maintaining the health of older people.