广西医学

目的基于磷酸酰肌醇3⁃激酶（PI3K）/蛋白激酶B（AKT）信号通路探讨乙酰老鼠簕生物碱A（AcO⁃BOA）改善脂多糖/D⁃氨基半乳糖（LPS/D⁃GalN）诱导的小鼠急性肝损伤的作用机制。方法将48只雄性昆明小鼠随机分为正常对照组、急性肝损伤模型组、联苯双酯滴丸阳性对照组，以及AcO⁃BOA高、中、低（200 mg/kg、100 mg/kg、50 mg/kg）剂量药物组，每组8只。给予各给药组相应剂量药物灌胃，给予正常对照组和急性肝损伤模型组0.5%羧甲基纤维素钠灌胃，均为1次/d，连续给药20 d。末次给药后禁食不禁水12 h，除正常对照组（腹腔注射等量无菌生理盐水）外，给予其余组腹腔注射LPS/D⁃GalN溶液诱导小鼠发生急性肝损伤，7 h后收集所有小鼠的眼球外周血和肝脏组织样本。检测各组小鼠血清ALT、AST、碱性磷酸酶（ALP）及丙二醛水平，以及肝脏组织中AKT、PI3K、磷酸酶与张力蛋白同源物基因（PTEN）的蛋白表达情况。结果与正常对照组比较，急性肝损伤模型组小鼠肝脏外观呈明显急性肝损伤表现，AcO⁃BOA低、中、高剂量药物组小鼠急性肝损伤表现依次减轻，AcO⁃BOA高剂量药物组和联苯双酯滴丸阳性对照组小鼠肝脏外观、状态接近正常对照组。与正常对照组比较，急性肝损伤模型组小鼠血清ALT、AST、ALP及丙二醛水平均升高，肝脏组织AKT和PI3K蛋白表达水平升高，PTEN蛋白表达水平降低（P<0.05）。与急性肝损伤模型组比较，AcO⁃BOA低、中、高剂量药物组及联苯双酯滴丸阳性对照组血清ALT、AST、ALP及丙二醛水平均降低（P<0.05）；AcO⁃BOA高剂量药物组血清ALT、AST、ALP均低于AcO⁃BOA中、低剂量药物组（P<0.05）。AcO⁃BOA低、中、高剂量药物组及联苯双酯滴丸阳性对照组小鼠肝脏组织AKT和PI3K蛋白表达水平均低于急性肝损伤模型组，PTEN蛋白表达水平均高于急性肝损伤模型组。结论 AcO⁃BOA能够预防性地减轻LPS/D⁃GalN诱导的小鼠急性肝损伤，可降低血清转氨酶水平、减轻氧化应激损伤，其机制可能与上调PTEN表达、抑制PI3K/AKT信号通路活化有关。

Objective To investigate the mechanism of 4⁃acetoxy⁃2(3H)⁃benzoxazolone (AcO⁃BOA) for the improvement of lipopolysaccharide/D⁃galactosamine (LPS/D⁃GalN)⁃induced acute liver injury in mice based on phosphatidylinositol 3⁃kinase (PI3K)/protein kinase B (AKT) signaling pathway. Methods Forty⁃eight male Kunming mice were randomly divided into normal control group, acute liver injury model group, bifendate dropping pill positive control group, or high⁃, medium⁃, and low⁃dose AcO⁃BOA (200 mg/kg, 100 mg/kg, and 50 mg/kg) groups, with 8 mice in each group. Mice in various drug administration groups received intragastric administration of the corresponding dose of drug, while those in the normal control group and the acute liver injury model group received intragastric administration of 0.5% carboxymethylcellulose sodium, once daily for 20 consecutive days. After the last administration, mice were fasted for 12 h with free access to water. Except for the normal control group (intraperitoneal injection of an equal volume of sterile normal saline), all the remaining groups received intraperitoneal injection of LPS/D⁃GalN solution to induce acute liver injury in mice. Seven hours later, peripheral blood of the eyes and liver tissue samples were collected from all mice. Serum levels of ALT, AST, alkaline phosphatase (ALP), and malondialdehyde, as well as the protein expressions of AKT, PI3K, and phosphatase and tensin homolog (PTEN) in liver tissues were measured in various groups. Results Compared with the normal control group, mice in the acute liver injury model group exhibited obvious manifestations of acute liver injury in liver appearance, and the severity of acute liver injury in the low⁃, medium⁃, and high⁃dose AcO⁃BOA groups decreased progressively, whereas the liver appearance and condition of mice in the high⁃dose AcO⁃BOA group and the bifendate dropping pill positive control group were close to those of the normal control group. Compared with the normal control group, serum ALT, AST, ALP, and malondialdehyde levels were increased, AKT and PI3K protein expressions in liver tissues were increased, and PTEN protein expression was decreased in the acute liver injury model group (P<0.05). Compared with the acute liver injury model group, serum ALT, AST, ALP, and malondialdehyde levels were decreased in the low⁃, medium⁃, and high⁃dose AcO⁃BOA groups and the bifendate dropping pill positive control group (P<0.05); furthermore, serum ALT, AST, and ALP levels in the high⁃dose AcO⁃BOA group were lower than those in the medium⁃ and low⁃dose AcO⁃BOA groups (P<0.05). AKT and PI3K protein expressions in the liver tissues of the low⁃, medium⁃, and high⁃dose AcO⁃BOA groups and the bifendate dropping pill positive control group were lower than those in the acute liver injury model group, while PTEN protein expression was higher than that in the acute liver injury model group. Conclusion AcO⁃BOA can preventively alleviate LPS/D⁃GalN⁃induced acute liver injury in mice, reduce serum transaminase levels, and attenuate oxidative stress injury. Its mechanism may be related to up⁃regulating PTEN expression and inhibiting the activation of PI3K/AKT signaling pathway.