Abstract: The article aims to study the effects of diminazene aceturate (DIZE) activation of Angiotensin-converting enzyme 2 (ACE2) on mitochondrial structure and function by establishing a high-fat diet-induced non-alcoholic fatty liver disease(NAFLD) model. Twenty-six male SD rats were selected, nine rats were fed with basal feed as a contral group, the remaining rats were fed with high-fat feed for modeling. After 4 weeks, the NAFLD model was successfully established by the confirmation of pathohistological examination. Then, the rats with successful modeling were randomly divided into Model group and DIZE group(eight rats per group),Model group rats were continued to be fed hight-fat feed and treated with 3 mL saline by intragastric administration, DIZE group rats were treated with 15 mg·(kg·d)^-1 DIZE as gavage. The contral group continued to be fed with common feed, and the same amount of normal saline was gavage administered. In the tenth week, serum and liver samples were collected from rats for the following tests:1) The kit was used to detect TG and TC content in serum; 2)The content of AngII and Ang1-7 in liver tissues were determined by ELISA; 3) Western blotting method was used to test the protein expression of ACE2, mitochondrial fusion protein (Mfn1, OPA1), fission protein (Fis1, Drp1) and uncoupling protein 1 (UCP1); 4) RT-qPCR to test mRNA expression of mitochondrial biogenesis and mitochondrial respiratory chain complex-related genes. Results:1) The fat deposition was found in HE staining after 4 weeks of high-fat feeding, obviously, which indicates that the NAFLD modeling of rats was successfully established; 2) Compared with the CON group, the serum levels of TG and TC in the MOD group rats were significantly higher (P<0.05), while the DIZE group was significantly lower (P<0.05) compared with the MOD group; 3) Compared with CON group, ACE2 protein expression level in MOD group was extremely significant decreased (P<0.01), and the ratio of AngⅡ/Ang1-7 was significantly increased (P<0.05), however, compared with model group, the results were opposite in DIZE group (P<0.01); 4) The expression levels of fusion, fission and UCP1 protein were significantly or extremely significant reduced in model group compared to the control group (P<0.01 or P<0.05), DIZE could upregulate the expression levels of fusion, fission and UCP1 protein extremely(P<0.01); 5) Compared with the CON group, the expression levels of mRNA in mitochondrial biogenesis and mitochondrial respiratory chain complex I and III genes were extremely significant downregulated in the MOD group (P<0.01), nevertheless, compared with model group, DIZE group shows the opposite results(P<0.01 or P<0.05). The results demonstrated that DIZE could activate ACE2, thereby alleviating the inhibitory effects on mitochondrial biogenesis, fusion, fission, and respiratory chain-related parameters induced by a high-fat diet, ultimately achieving therapeutic effects for NAFLD. This study elucidates a new idea of DIZE for the treatment of non-alcoholic fatty liver disease, which manifests DIZE has potential research value as a new use of an old drug.

Key words: diminazene aceturate (DIZE), non-alcoholic fatty liver disease, angiotensin-converting enzyme 2 (ACE2), mitochondria, rat