Grape seed extract proanthocyanidin antagonizes aristolochic acid I-induced liver injury in rats by activating PI3K-AKT pathway.

Aristolochic acid is internationally recognized as a carcinogen. It has been shown that the main toxic mechanism of aristolochic acid on the liver and kidney is the induction of ROS-induced oxidative stress damage. To investigate whether proanthocyanidins (GSPE), a natural antioxidant product from grape seed extract, could antagonize AA-I-induced liver injury. Thirty-two SD rats were selected and divided into aristolochic acid exposure group (AA-I), normal control group, GSPE group and GSPE intervention group. The protective effects of GSPE on AA-I liver injury were evaluated by examining the body weight, liver index, liver function and liver pathological sections of rats. The results of body weight, liver index, liver function and liver pathological sections of rats showed that GSPE had antagonistic effects on AA-I-induced liver injury. antioxidant enzyme activity in the GSPE intervention group was significantly higher than that in the aristolochic acid group, apoptotic cells were significantly lower than that in the aristolochic acid group, protein and mRNA expression of PI3K-AKT and BCL-2 were significantly higher than that in the aristolochic acid group, BAX, The protein and mRNA expression of BAX, CASPAES-3, CASPAES-9 were significantly lower than those of the aristolochic acid group. GSPE can antagonize aristolochic acid-induced hepatotoxicity, and its mechanism of action is to antagonize aristolochic acid I-induced liver injury by inhibiting PI3K-AKT pathway-mediated hepatocyte apoptosis.

Rotenone induces hepatotoxicity in rats by activating the mitochondrial pathway of apoptosis.

As a pesticide extracted from plants, rotenone is widely used to control plant pests. In order to explore the safety of rotenone in the environment, we took 60 healthy male SD rats and randomly divided them into rotenone low-dose group, rotenone medium-dose group, rotenone high-dose group, dimethyl sulfoxide group (DMSO), and control group. After 28 days of oral administration, the rat liver tissue ultrastructure, liver function, oxidative stress indexs, mitochondrial function, and apoptosis-related factors were tested to evaluate the hepatotoxicity and toxicological mechanism of rotenone. The results showed that rotenone significantly increased the hepatic index of rats and the activity of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum. Rotenone can reduce the number of endoplasmic reticulum of hepatocyte, concentrate chromatin and make the hepatocyte nuclears irregular. Rotenone weakened the ATP synthesis ability in mitochondria, decreased the activity of ATP enzyme in mitochondria, and increased the mitochondrial membrane potential in the high-dose group. And it induced oxidative stress damage to the mitochondria of rat liver cells. Rotenone can upregulate the expression of pro-apoptotic factors and downregulate the expression of anti-apoptotic factors. These results indicate that oral rotenone in rats induced hepatotoxicity in a dose-dependent manner. The mechanism of rotenone poisoning is that oxidative stress damages organelles of hepatocyte such as mitochondria and endoplasmic reticulum, resulting in their function being weakened or lost, leading to hepatocyte apoptosis.

Association of Geography and Access to Health Care Providers With Long-Term Prescription Opioid Use in Medicare Patients With Severe Osteoarthritis: A Cohort Study.

OBJECTIVE: To evaluate the variation in long-term opioid use in osteoarthritis (OA) patients according to geography and health care access. METHODS: We designed an observational cohort study among OA patients undergoing total joint replacement (TJR) in the Medicare program (2010 through 2014). The independent variables of interest were the state of residence and health care access, which was quantified at the primary care service area (PCSA) level as categories of number of practicing primary care providers (PCPs) and categories of rheumatologists per 1,000 Medicare beneficiaries. The percentage of OA patients taking long-term opioids (≥90 days in the 360-day period immediately preceding TJR) within each PCSA was the outcome variable in a multilevel, generalized linear regression model, adjusting for case-mix at the PCSA level and for policies, including rigor of prescription drug monitoring programs and legalized medical marijuana, at the state level. RESULTS: A total of 358,121 patients with advanced OA, with a mean age of 74 years, were included from 4,080 PCSAs. The unadjusted mean percentage of long-term opioid users varied widely across states, ranging from 8.9% (Minnesota) to 26.4% (Alabama), and this variation persisted in the adjusted models. Access to PCPs was only modestly associated with rates of long-term opioid use between PCSAs with highest (>8.6) versus lowest (<3.6) concentration of PCPs (adjusted mean difference 1.4% [95% confidence interval 0.8%, 2.0%]), while access to rheumatologists was not associated with long-term opioid use. CONCLUSION: We note a substantial statewide variation in rates of long-term treatment with opioids in OA, which is not fully explained by the differences in access to health care providers, varying case-mix, or state-level policies.