The effect of interval training and omega-3 on endoplasmic reticulum stress in the liver tissue of nonalcoholic fatty liver disease (NAFLD) rats

Endoplasmic reticulum stress (ERS) plays an important role in the development of non-alcoholic fatty liver disease (NAFLD). In this study, the effect of omega-3 consumption and interval exercise alone or in combination on ERS in rats with NAFLD was investigated.

In this experimental study, 40 male Wistar rats (mean weight 156.98±7.82) were divided into 5 groups: Control-Normal (CN), NAFLD, NAFLD-Training (TRNAF), NAFLD-Supplement (SUPNAF) and NAFLD-Training-Supplement (TRSUPNAF). The supplement groups received 1 g of Omega3 (per kg of body weight) orally during the intervention period. Interval training program including running on treadmill with a speed of 14-28 meters per minute, was performed 5 days a week for eight weeks.

Induction of NAFLD increased GRP78, CHOP, ALT and AST (p=0.0001). The expression of GRP78 and CHOP was significantly decreased in TRNAF (p=0.0001 and p=0.001 respectively) and SUPNAF (p=0.0001 and p=0.001 respectively) groups compared to NAFLD. ALT and AST also significantly decreased in TRNAF (p=0.0001 and p=0.0001) and SUPNAF (p=0.0001 and p=0.001 respectively) groups. The combined intervention of interval training with omega-3 supplement was not significant compared to the effect of each intervention alone on GRP78, CHOP, ALT and AST (p<0.05).

Interval training and omega-3 consumption inhibited ER stress in liver tissue through reduction in GRP78 and CHOP expression. However, the simultaneous effect of interval training and omega-3 on ERS needs more research.