Effects of low and moderate treadmill exercise on liver of d-galactose-exposed aging rat model

Aging increases liver susceptibility to diseases and it causes inflammation in liver tissue which can lead to fibrosis. Studies suggest that aging is caused by the accumulation of free radicals. Lack of physical activity can lower hormone levels and increase free radicals that can accelerate the aging process. Hence, physical activity is very important to maintain functions of organs. This research was aimed to study the effects of low and moderate treadmill exercise on d-Galactose-exposed aging rat model by evaluating the degree of hepatic fibrosis, number of M1 and M2, and M1/M2 ratio. Twenty-four 3-month-old male Wistar aging model rats were randomly divided into four groups, that is, three treatment groups with daily 300 mg kgBW^-1 d-Galactose injection administrated intraperitoneally for 4 weeks and 1 control group with normal saline injection. Two of the d-Galactose treated groups were given low and moderate treadmill exercise for 4 weeks. It was concluded that low intensity treadmill exercise significantly lowered the degree of d-Galactose-exposed hepatic fibrosis, and moderate treadmill exercise was able to restore the injured liver tissue back to the non-aging state. Administration of d-Galactose causes inflammation marked by the elevated number of M1 and M2 macrophages. Moderate treadmill exercise drove M1/M2 ratio back to the control condition.