scholarly journals Activation of the AMPK-SIRT1 pathway contributes to protective effects of Salvianolic acid A against lipotoxicity in hepatocytes and NAFLD in mice

2020 ◽  
Vol 11 ◽  
Author(s):  
Songtao Li ◽  
Qianyu Qian ◽  
Na Ying ◽  
Jianfei Lai ◽  
Luyan Feng ◽  
...  

Background: Salvianolic acid A (Sal A), a natural polyphenol compound extracted from Radix Salvia miltiorrhiza (known as Danshen in China), possesses a variety of potential pharmacological activities. The aim of this study is to determine mechanisms of hepatoprotective effects of Sal A against lipotoxicity both in cultured hepatocytes and in a mouse model of fatty liver disease.Methods: High-fat and high-carbohydrate diet (HFCD)-fed C57BL/6J mice were employed to establish hepatic lipotoxicity in a mouse model. Two doses of Sal A were administered every other day via intraperitoneal injection (20 and 40 mg/kg BW, respectively). After a 10-week intervention, liver injury was detected by immunohistochemical and biochemical analyses. For in vitro studies, we used HepG2, a human hepatoma cell line, and exposed them to palmitic acid to induce lipotoxicity. The protective effects of Sal A on palmitic acid-induced lipotoxicity were examined in Sal A-pretreated HepG2 cells.Results: Sal A treatments attenuated body weight gain, liver injury, and hepatic steatosis in mice exposed to HFCD. Sal A pretreatments ameliorated palmitic acid-induced cell death but did not reverse effects of HFCD- or palmitate-induced activations of JNK, ERK1/2, and PKA. Induction of p38 phosphorylation was significantly reversed by Sal A in HFCD-fed mice but not in palmitate-treated HepG2 cells. However, Sal A rescued hepatic AMP-activated protein kinase (AMPK) suppression and sirtuin 1 (SIRT1) downregulation by both HFCD feeding in mice and exposure to palmitate in HepG2 cells. Sal A dose-dependently up-regulated p-AMPK and SIRT1 protein levels. Importantly, siRNA silencing of either AMPK or SIRT1 gene expression abolished the protective effects of Sal A on lipotoxicity. Moreover, while AMPK silencing blocked Sal A-induced SIRT1, silencing of SIRT1 had no effect on Sal A-triggered AMPK activation, suggesting SIRT1 upregulation by Sal A is mediated by AMPK activation.Conclusion: Our data uncover a novel mechanism for hepatoprotective effects of Sal A against lipotoxicity both in livers from HFCD-fed mice and palmitic acid-treated hepatocytes.

2015 ◽  
Vol 93 (8) ◽  
pp. 625-631 ◽  
Author(s):  
Yan Hu ◽  
Ning Zhang ◽  
Qing Fan ◽  
Musen Lin ◽  
Ce Zhang ◽  
...  

Carnosic acid (CA), found in rosemary, has been reported to have antioxidant and antiadipogenic properties. Here, we investigate the molecular mechanism by which CA inhibits hydrogen peroxide (H2O2)-induced injury in HepG2 cells. Cells were pretreated with 2.5–10 μmol/L CA for 2 h and then exposed to 3 mmol/L H2O2 for an additional 4 h. CA dose-dependently increased cell viability and decreased lactate dehydrogenase activities. Pretreatment with CA completely attenuated the inhibited expression of manganese superoxide dismutase (MnSOD) and the B-cell lymphoma-extra large (Bcl-xL), and reduced glutathione activity caused by H2O2, whereas it reversed reactive oxygen species accumulation and the increase in cleaved caspase-3. Importantly, sirtuin 1 (SIRT1), a NAD+-dependent deacetylase, was significantly increased by CA. Considering the above results, we hypothesized that SIRT1 may play important roles in the protective effects of CA in injury induced by H2O2. As expected, SIRT1 suppression by Ex527 (6-chloro-2,3,4,9-tetrahydro-1H-carbazole-1-carboxamide) and siRNA-mediated SIRT1 silencing (si-SIRT1) significantly aggravated the H2O2-induced increased level of cleaved caspase-3 but greatly reduced the decreased expression of MnSOD and Bcl-xL. Furthermore, the positive regulatory effect of CA was inhibited by si-SIRT1. Collectively, the present study indicated that CA can alleviate H2O2-induced hepatocyte damage through the SIRT1 pathway.


2015 ◽  
Vol 10 (2) ◽  
pp. 393 ◽  
Author(s):  
Liaqat Hussain ◽  
Muhammad Sajid Hamid Akash ◽  
Madeha Tahir ◽  
Kanwal Rehman

<span><em>Sapium sebiferum</em> leaves were used to determine its hepatoprotective effects against paracetamol-induced hepatotoxicity in mice. A dose dependent study was conducted using two different doses (200 mg/kg and 400 mg/kg) of the extract of </span><em>S. sebiferum</em><span> against toxic effects of paracetamol (500 mg/kg) in experimental animal model. Silymarin (50 mg/kg) was used as standard drug to compare therapeutic effects of </span><em>S. sebiferum</em><span> with control and paracetamol-treated groups. Paracetamol significantly increased the serum levels of liver enzyme markers like alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total bilirubin, and direct bilirubin. The extract showed protective effects by normalizing the liver enzymes markers in a dose dependent manner. Histopathological results confirmed the hepatoprotective effects of leaves of </span><em>S. sebiferum</em><span>. We conclude that leaves of </span><em>S. sebiferum</em><span> have strong hepatoprotective effects against paracetamol-induced liver injury and can be used in liver injuries caused by drug-induced toxicity.</span>


2021 ◽  
Author(s):  
Chitra Jairaman ◽  
Sabine Matou-Nasri ◽  
Zeyad I Alehaideb ◽  
Syed Ali Mohamed Yacoob ◽  
Anuradha Venkataraman ◽  
...  

Abstract The bark extract of Rhizophora mucronata (BERM) was recently reported for its prominent in vitro protective effects against liver cell line toxicity caused by various toxicants, including ethanol. Here, we aimed to verify the in vivo hepatoprotective effects of BERM against ethanol intoxication. An oral administration of different concentrations (100, 200, and 400 mg/kg) of BERM prior to high-dose ethanol via intraperitoneal injection was performed in mice. On the 7th day, liver and kidney sections were dissected out for histopathological examination. The ethanol intoxication caused large areas of liver necrosis while the kidneys were not affected. Pre-BERM administration decreased ethanol-induced liver injury, as compared to the mice treated with ethanol alone. In addition, the pre-BERM administration resulted in a decrement in the level of ethanol-induced oxidative stress, revealed by a concomitant increase of GSH and a decrease of MDA hepatic levels. The BERM extract also reversed the ethanol-induced liver injury and hepatotoxicity, characterized by the low detection of TNF-α gene expression level and fragmented DNA, respectively. Altogether, BERM extract exerts antioxidative activities and present promising hepatoprotective effects against ethanol intoxication. The identification of the related bioactive compounds will be of interest for future use at physiological concentrations in ethanol-intoxicated individuals.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Joo-Yeon Kong ◽  
Seong-Chan Yeon ◽  
Hu Jang Lee ◽  
Changkeun Kang ◽  
Jin-Kyu Park ◽  
...  

Several eradication programs have been developed and executed to curb alien invasive species that tend to damage the ecological environments they colonize; however, only few studies have evaluated the utilization of carcasses of these species after eradication. Nutria (Myocastor coypus) is an invasive rodent species targeted by eradication programs in many countries. We noted that nutria produce large amounts of ursodeoxycholic acid (UDCA) in their bile. UDCA is a unique component responsible for the anti-inflammatory and hepatoprotective effects exerted by bear bile. Therefore, we sought to examine the medicinal utility of nutria carcasses by investigating the hepatoprotective effect of their bile in mice. C57BL/6 mice were injected with thioacetamide (TAA), which induced liver damage by increasing Kupffer cell infiltration. Administration of nutria bile reduced hepatic inflammation, improved hepatic function, and increased the levels of senescence marker protein 30 (an indicator of hepatocyte viability). Our results show that nutria bile exerts protective effects against TAA-induced liver injury in mice, suggesting that nutria carcasses may be used for the treatment of liver injuries.


2007 ◽  
Vol 100 (2) ◽  
pp. 115-120 ◽  
Author(s):  
Zhi-ming Wu ◽  
Tao Wen ◽  
Yu-fen Tan ◽  
Yan Liu ◽  
Feng Ren ◽  
...  

2020 ◽  
Vol 11 ◽  
Author(s):  
Youli Yao ◽  
Along Zuo ◽  
Qiyu Deng ◽  
Shikang Liu ◽  
Tianying Zhan ◽  
...  

The circadian clock plays a key role in our daily physiology and metabolism. Alcohol consumption disrupts the circadian rhythm of metabolic genes in the liver; however, the potential contribution of circadian clock modulation to alcoholic liver disease (ALD) is unknown. We identified a novel liver protective agent, physcion, which can alleviate fat accumulation and inflammation in ALD mice via reprogramming the hepatic circadian clock. The model of alcoholic hepatitis was established by intragastrically administering ethanol. In vitro, physcion was investigated by treating HepG2 cells with ethanol. The role of circadian clock in Physcion caused liver protection was tested by knocking down the core circadian gene Bmal1. Physcion application caused reduced lipogenesis and alleviated inflammation in alcohol-induced mice. In alcoholic hepatosteatosis models, physcion upregulated the core circadian genes. And the circadian misalignment triggered by ethanol was efficiently reversed by physcion. Physcion attenuated lipogenesis via reprogramming the circadian clock in HepG2 cells. Suppression of Bmal1 by RNA interference abolished the protective of physcion. In addition, Physcion binds to the active pocket of BMAL1 and promotes its expression. The study identified the novel liver protective effects of physcion on alcohol-induced liver injury, and modulation of the core circadian clock regulators contributes to ALD alleviation. More importantly, strategies targeting the circadian machinery, for example, Bmal1, may prove to be beneficial treatment options for this condition.


2021 ◽  
Vol 12 ◽  
Author(s):  
Xichuan Wei ◽  
Chuanhong Luo ◽  
Yanan He ◽  
Haozhou Huang ◽  
Fei Ran ◽  
...  

Background:Triphala is a traditional polyherbal formula used in Indian Ayurvedic and Chinese Tibetan medicine. A wide range of biological activities have been attributed to Triphala, but the impact of various extraction methods on efficacy has not been determined.Purpose: The study aimed to evaluate Triphala extracts obtained by various methods for their hepatoprotective effects and molecular mechanisms in a mouse model of carbon tetrachloride (CCl4)-induced liver injury.Methods: HPLC fingerprinting was used to characterize the chemical characteristics of Triphala extracts obtained by (a) 0.5 h ultrasonication, (b) 2 h reflux, and (c) 4 h reflux. Hepatoprotective efficacy was evaluated in a mouse model of CCl4-induced liver damage. Serum levels of alanine transaminase (ALT) and aspartate aminotransferase (AST) were measured, as well as the liver antioxidant and inflammatory markers malondialdehyde superoxide dismutase glutathione peroxidase (GSH-Px), TNF-α, and IL-6. Gene and protein expression of Nrf-2 signaling components Nrf-2, heme oxygenase (HO-1), and NADPH Quinone oxidoreductase (NQO-1) in liver tissue were evaluated by real-time PCR and western blotting.Results: Chemical analysis showed a clear difference in content between extracts produced by ultrasonic and reflux methods. The pharmacological analysis showed that all three Triphala extracts reduced ALT, AST, MDA, TNF-α, and IL-6 levels and increased SOD and GSH-Px. Triphala extracts also induced transcript and protein expression of Nrf-2, HO-1, and NQO-1.Conclusion: Triphala extract prevents CCl4-induced acute liver injury. The ultrasonic extract of Triphala was most effective, suggesting that hepatoprotection may be related to the larger tannins via activation of Nrf-2 signaling.


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