Hepatoprotective effects of Acanthopanax koreanum Nakai on alcohol and high-fat diet induced liver injury in C57BL/6j mice

Abstract

The hepatoprotective effect of Acanthopanax koreanum Nakai (AK) from Jeju Island was investigated in C57BL/6j mice challenged with alcohol and high-fat diet (HFD). Fifty-six mice were randomly divided into seven groups; normal control (NC), ethanol control (EC), ethanol + HFD control (EFC), EC + 1% AK (ECL), EC + 3% AK (ECH), EFC + 1% AK (EFL), and EFC + 3% AK (EFH). Ethanol (50%, v/v) was provided orally with dose of 2.5 mL/kg body weight at first week, and then it was increased to 4.0 mL/kg body weight for an additional 3 weeks. After 4weeks administration, the combination of HFD and ethanol exposure induced hepatic damage. Body weight was not changed in AK treatment group compared with the initial body weight. Similarly, food intake didn’t have any statistical changes in AK treatment group (P<.0001). Furthermore, weight of liver tissue was increased (P<.0001), conversely, weight of epididymal and retroperitoneal fat mass was significantly decreased in ECH group (P=0.0329 and P=0.0037). Compared with the NC group, the EC and EFC groups showed marked macro- and micro-vesicular steatosis with significantly higher plasma ALT level, there was a marked reduction in ALT level in EFH group (P<.0001). The inhibitory effects of AK on these parameters were more pronounced in the EFC group than in the EC group. CPT-1α gene expression was significantly decreased in the EFC group only, but restored by AK administration dose-dependently (P=0.0089). AK contributes to decrease cholesterol synthesis and contributing to lower plasma triglyceride (TG) (P=0.0044), hepatic total lipid (P=0.0013), liver TG (P<.0001) and total cholesterol (P=0.0003). Microsomal CYP2E1 gene expression was upregulated in the EC and EFC groups, while cytosolic alcohol dehydrogenase and peroxisomal catalase (CAT) activities were not changed. AK administration significantly enhanced ALDH activity at a higher level (P<.0001) and CAT activity at a high dose. Genes related to the inflammation were all increased in the EC and EFC groups compared to the NC group, with a bigger change in the EFC group. AK administration induced a down-regulation of TLR4, CD14, IL-6, and MCP-1 gene expression (P<.0001, P=0.0012, P=0.0264 and P=0.0257, respectively). These findings suggest that AK may have the potential to attenuate alcohol and HFD-induced fatty liver either by accelerating lipid oxidation and alcohol metabolism in the liver, or by suppressing oxidative stress and inflammatory response.;본 연구에서는 알코올과 고지방식이를 마우스에 섭취시켜 유도한 간 손상에 대해 제주 섬오가피 주정 추출물 (Acanthopanax koreanum Nakai; AK)의 간보호 효과를 검증하였다. 수컷 C57BL/6j 마우스 (8주령, n=49)를 무작위로 정상군(NC), 에탄올유도군 (low-fat & ethanol control; EC), 에탄올유도 섬오가피 저용량군 (EC + 1% AK; ECL), 에탄올유도 섬오가피 고용량군 (EC + 3% AK; ECH), 에탄올+ 고지방식이 유도군 (ethanol + high fat diet; EFC), 에탄올+ 고지방식이+ 섬오가피 저용량군 (EFC + 1% AK; EFL), 에탄올+ 고지방식이+ 섬오가피 고용량군 (EFC + 3% AK; EFH) 총 7군이 되도록 나누었다. 50% (v/v) 에탄올을 첫째주부터 2.5mL/kg body weight으로 경구투여 하였고, 실험 2주째부터 희생 전 까지 4.0mL/kg body weight을 제공하였다. 4주간의 에탄올 및 고지방식이 섭취는 조직병리검사에서 NC군에 비해 EFC군의 간에서 뚜렷한 지방 축적을 확인할 수 있었다. 혈장 ALT 레벨이 EFH그룹에서 유의적으로 감소하였다. 만성 알코올 섭취로 인해 CYP2E1의 단백질 활성이 증가하였으며, ECH와 EFH군에서 미토콘드리아의 ALDH의 활성이 현저하게 증가하였고, CAT의 활성이 ECH군에서 증가하여 간 내 알코올 분해 효과를 알 수 있었다. 혈장 TG, TC, LDL-cholesterol 수치가 NC군에 비해 EC와 EFC군에서 유의적으로 증가하였고, ECH군의 TG 레벨이 감소하였다. 간의 총 지질, hepatic TG, hepatic TC 수치가 NC군에 비해 EC와 EFC군에서 유의적으로 증가했지만, 섬오가피 섭취군은 현저하게 줄어들었다. TLR4, CD14, IL-6, MCP-1의 mRNA 발현이 EFH군에서 유의적으로 감소하였고 CPT-1 의 mRNA 발현이 ECH군에서 유의적으로 증가하였다. 이러한 결과는 알코올과 고지방식이로 간 손상을 유도했을 때, 고용량의 섬오가피 섭취가 알코올 분해 효소를 증가시키며, 각종 염증 반응과 지방을 분해하고, 지방 축적을 저해하여 간을 보호하는 효능을 기대할 수 있음을 시사한다.