AbstractThis study evaluated the effects of Aronia melanocarpa fruit juice (AMFJ) on the liver in a model of high-fat, high-fructose (HFHF) diet-induced metabolic syndrome (MS). Fifty rats were allocated to five groups – Control, MS, MS+AMFJ2.5, MS+AMFJ5, and MS+AMFJ10. The control group was fed a standard diet, while the other groups were provided a HFHF diet. During MS induction, daily oral treatment was performed. Control and MS groups received 10.0 mL kg−1 distilled water, while the other three groups received AMFJ at doses of 2.5, 5.0, and 10.0 mL kg−1, respectively. After 10 weeks, liver samples were collected and inspected histologically as well as immunohistochemically to determine the expression of Bax, Bcl-2, and MAC387. Bax/Bcl-2 ratio was calculated. In MS rats, steatotic, inflammatory and degenerative alterations of the liver were detected, Bax and MAC387 were markedly elevated, while Bcl-2 was non-significantly reduced. The Bax/Bcl-2 ratio significantly increased. The histopathological alterations were prevented by the AMFJ treatment. Compared to MS group, Bax and MAC387 values were significantly lower and Bcl-2 value was higher resulting in significantly lower (P < 0.001) Bax/Bcl-2 ratio in all AMFJ-treated groups. AMFJ, administered during MS induction in rats, prevented the occurrence of inflammatory, steatotic, degenerative, and pro-apoptotic changes in the liver.