Curcumin protects the rat liver from CCl4-caused injury and fibrogenesis by attenuating oxidative stress and suppressing inflammation

Hepatoprotective effect of methanolic Tanacetum parthenium extract on CCl4-induced liver damage in rats

The purpose of this study was to investigate the effects of Tanacetum Parthenium Extract (TPE) on Lipid peroxidation, antioxidant enzymes, biochemical factors, and liver enzymes in the rats damaged by Carbon Tetrachloride (CCl4). 54 male Wistar rats were divided into 9 groups each consisting of 6 rats. Two of the groups were control groups (normal and damage control groups), 4 of them were exposure groups which were respectively administered with 40, 80, and 120 mg/kg of TPE and silymarin for 14 days before being damaged by CCl4, and the other 3 groups were post-treatment groups which received 80 and 120 mg/kg of TPE and silymarin 2, 6, 24, and 48 h after being injected with CCl4. At the end of the study, biochemical factors, serum liver enzymes, malondialdehyde level, antioxidant enzymes, and liver morphology were assayed. Pre- and post-treatment with TPE could significantly decrease ALT, AST, ALP, TG, LDL, TC, and glucose levels and increase HDL, and albumin levels and catalase, SOD, and GPx activities compared to the CCl4-damaged control group. The results of this study are indicative of the antioxidant activity of TPE, its potential hepatoprotective effects, and its probable therapeutic properties for laboratory animals damaged by CCl4.

Ethanol extracts collected from the Styela clava tunic alleviate hepatic injury induced by carbon tetrachloride (CCl4) through inhibition of hepatic apoptosis, inflammation, and fibrosis

The Styela clava tunic (SCT) is known as a good raw material for preparing anti-inflammatory compounds, wound healing films, guided bone regeneration, and food additives. To investigate whether ethanol extracts of the SCT (EtSCT) could protect against hepatic injury induced by carbon tetrachloride (CCl₄) in ICR mice, alterations in serum biochemical indicators, histopathology, hepatic apoptosis, inflammation, and fibrosis were observed in ICR mice pretreated with EtSCT for 5 days before CCl₄ injection. EtSCT contained 15.6 mg/g of flavonoid and 37.5 mg/g phenolic contents with high 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (93.3%) and metal chelation activity (46.5%). The EtSCT+CCl₄-treated groups showed decreased levels of ALT, LDH, and AST, indicating toxicity and a necrotic area in the liver, while the level of ALP remained constant. The formation of active caspase-3 and enhancement of Bax/Bcl-2 expression was effectively inhibited in the EtSCT+CCl₄-treated groups. Furthermore, the levels of pro- and anti-inflammatory cytokines and the phosphorylation of p38 in the TNF-α downstream signaling pathway rapidly recovered in the EtSCT+CCl₄-treated groups. The EtSCT+CCl₄-treated groups showed a significant decrease in hepatic fibrosis markers including collagen accumulation, MMP-2 expression, TGF-β1 concentration, and phosphorylation of Smad2/3. Moreover, a significant decline in malondialdehyde (MDA) concentration and enhancement of superoxide dismutase (SOD) expression were observed in the EtSCT+CCl₄-treated groups. Taken together, these results indicate that EtSCT can protect against hepatic injury induced by CCl₄-derived reactive intermediates through the suppression of hepatic apoptosis, inflammation, and fibrosis.

Nrf2 activation is required for curcumin to induce lipocyte phenotype in hepatic stellate cells

Hepatic fibrosis is a reversible scarring response that commonly occurs with chronic liver injury. During hepatic fibrogenesis, the major effector hepatic stellate cells (HSCs) become activated, featured by disappeared intracellular lipid droplets, decreased retinoid storage, and dysregulated expression of genes associated with lipid and retinoid metabolism. Compelling evidence suggested that recovery of retinoid droplets could inhibit HSC activation, while the precise molecular basis underlying the phenotypical switch still remained unclear. In this study, curcumin increased the abundance of lipid droplets and content of triglyceride in activated HSCs. In addition, curcumin could concentration-dependently regulate genes associated with lipid and retinoid metabolism. Further, consistent results were obtained from in vivo experiments. Curcumin increased Nrf2 expression and nuclear translocation, and its binding activity to DNA, which might be associated with suppression of Kelch-like ECH-associated protein 1 in HSCs. Of interest was that Nrf2 overexpression plasmids, in contract to Nrf2 siRNA, strengthened the effect of curcumin on induction of lipocyte phenotype. In in vivo system, Nrf2 knockdown mediated by Nrf2 shRNA lentivirus not only accelerated the lipid degradation in HSCs but also promoted the progression of CCl₄-induced hepatic fibrosis in mice. Noteworthily, Nrf2 knockdown abolished the protective effect of curcumin. In conclusion, curcumin could induce lipocyte phenotype of activated HSCs via activating Nrf2. Nrf2 could be a target molecule for antifibrotic strategy.

Curcumin and Curcuma longa L. extract ameliorate lipid accumulation through the regulation of the endoplasmic reticulum redox and ER stress

For this study, we examined the effects of curcumin against acute and chronic stress, paying specific attention to ROS. We also aimed to clarify the differences between acute and chronic stress conditions. We investigated the effects of curcumin against acute stress (once/1 day CCl4 treatment) and chronic-stress (every other day/4week CCl4 treatment). Compared with acute stress, in which the antioxidant system functioned properly and aspartate transaminase (AST) and ROS production increased, chronic stress increased AST, alanine aminotransferase (ALT), hepatic enzymes, and ROS more significantly, and the antioxidant system became impaired. We also found that ER-originated ROS accumulated in the chronic model, another difference between the two conditions. ER stress was induced consistently, and oxidative intra-ER protein folding status, representatively PDI, was impaired, especially in chronic stress. The PDI-associated client protein hepatic apoB accumulated with the PDI-binding status in chronic stress, and curcumin recovered the altered ER folding status, regulating ER stress and the resultant hepatic dyslipidemia. Throughout this study, curcumin and curcumin-rich Curcuma longa L. extract promoted recovery from CCl4-induced hepatic toxicity in both stress conditions. For both stress-associated hepatic dyslipidemia, curcumin and Curcuma longa L. extract might be recommendable to recover liver activity.

Phytochemical Investigation, Antitumor Activity, and Hepatoprotective Effects of Acrocarpus fraxinifolius Leaf Extract

Preclinical Research Nine known phenolic compounds were isolated from an aqueous methanolic extract of Acrocarpus fraxinifolius Weight and Arn leaves (AFL) family Fabaceae. This extract of AFL contained approximately 169 mg gallic acid/g as assessed by HPLC. The AFL extract had marginal antitumor activity (IC₅₀  > 200 µL/mL) but showed a concentration-dependent hepatoprotective effect against CCl₄ -induced hepatotoxicity in vitro. Cell viability was increased, ALT and AST activity declined and reduced GSH concentration and SOD activity were restored as compared with silymarin. In vivo concurrent administration of AFL extract (500 mg/kg po) showed a hepatoprotective effect against gamma irradiation and CCl₄ as evidenced by reduction of TNF-α, interleukin-6, malondialdehyde, nitric oxide, DNA fragmentation, caspase-3 activity, and downregulation of its m-RNA level and decreased proapoptotic protein Bax expression. AFL extract enhanced glutathione peroxidase, superoxide dismutase, and catalase activities, reduced glutathione concentrations and upregulated the expression of antiapoptotic Bcl-2. The extract could ameliorate hepatic injuries induced by gamma irradiation and CCl₄ in rats suggesting potent hepatoprotective activity. Drug Dev Res 78 : 210-226, 2017. © 2017 Wiley Periodicals, Inc.

Morin attenuates diethylnitrosamine-induced rat liver fibrosis and hepatic stellate cell activation by co-ordinated regulation of Hippo/Yap and TGF-β1/Smad signaling

Despite great progress in understanding the activation of hepatic stellate cells (HSCs) during liver fibrosis, therapeutic approaches to inhibit HSC activation remain very limited. Recent reports highlight Yes-associated protein (Yap) and transforming growth factor-β1 (TGF-β1) as critical regulators of HSC activation and henceforth a compound targeting Hippo/Yap and TGF-β1/Smad pathways would be a potential anti-fibrotic candidate. Morin, a dietary flavonoid, was earlier reported to inhibit HSC proliferation and induction of apoptosis of cultured HSCs, mainly by suppressing Wnt/β-catenin and NF-κB signaling, but its effect on Hippo/Yap and TGF-β1/Smad pathways was not determined. To address this concern, this study was carried out in cultured LX-2 cells and diethylnitrosamine-induced fibrotic rats. Morin activated hippo signaling through significantly increased expression of Mst1 and Lats1 with decreased expression of transcriptional effectors Yap/TAZ, thereby prevented HSC activation and also suppressed the expression of exacerbated TGF-β/Smad signaling molecules such as TGF-β1, p-Smad2/3, collagen-I, MMP-2, MMP-9 and TIMP-1 in cultured LX-2 and DEN induced fibrotic rats. Both the in vitro and in vivo results clearly showed that, morin by acting on Hippo/Yap and TGF-β1/Smad pathways, ameliorated experimental liver fibrosis, indicating that morin has potential for effective treatment of liver fibrosis.

The Antimalarial Effect of Curcumin Is Mediated by the Inhibition of Glycogen Synthase Kinase-3β

Curcumin, a bioactive compound in Curcuma longa, exhibits various pharmacological activities, including antimalarial effects. In silico docking simulation studies suggest that curcumin possesses glycogen synthase kinase-3β (GSK3β)-inhibitory properties. The involvement of GSK3 in the antimalarial effects in vivo is yet to be demonstrated. In this study, we aimed to evaluate whether the antimalarial effects of curcumin involve phosphorylation of host GSK3β. Intraperitoneal administration of curcumin into Plasmodium berghei NK65-infected mice resulted in dose-dependent chemosuppression of parasitemia development. At the highest dose tested (30 mg/kg body weight), both therapeutic and prophylactic administrations of curcumin resulted in suppression exceeding 50% and improved median survival time of infected mice compared to control. Western analysis revealed a 5.5-fold (therapeutic group) and 1.8-fold (prophylactic group) increase in phosphorylation of Ser 9 GSK3β and 1.6-fold (therapeutic group) and 1.7-fold (prophylactic group) increase in Ser 473 Akt in liver of curcumin-treated infected animals. Following P. berghei infection, levels of pro- and anti-inflammatory cytokines, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, interleukin (IL)-10, and IL-4 were elevated by 7.5-, 35.0-, 33.0-, and 2.2-fold, respectively. Curcumin treatment (therapeutic) caused a significant decrease (by 6.0- and 2.0-fold, respectively) in serum TNF-α and IFN-γ level, while IL-10 and IL-4 were elevated (by 1.4- and 1.8-fold). Findings from the present study demonstrate for the first time that the antimalarial action of curcumin involved inhibition of GSK3β.

Vitamin D3-induced hypercalcemia increases carbon tetrachloride-induced hepatotoxicity through elevated oxidative stress in mice

The aim of this study was to determine whether calcium potentiates acute carbon tetrachloride (CCl₄) -induced toxicity. Elevated calcium levels were induced in mice by pre-treatment with cholecalciferol (vitamin D3; V.D3), a compound that has previously been shown to induce hypercalcemia in human and animal models. As seen previously, mice injected with CCl₄ exhibited increased plasma levels of alanine aminotransferase, aspartate aminotransferase, and creatinine; transient body weight loss; and increased lipid peroxidation along with decreased total antioxidant power, glutathione, ATP, and NADPH. Pre-treatment of these animals with V.D3 caused further elevation of the values of these liver functional markers without altering kidney functional markers; continued weight loss; a lower lethal threshold dose of CCl₄; and enhanced effects on lipid peroxidation and total antioxidant power. In contrast, exposure to V.D3 alone had no effect on plasma markers of liver or kidney damage or on total antioxidant power or lipid peroxidation. The potentiating effect of V.D3 was positively correlated with elevation of hepatic calcium levels. Furthermore, direct injection of CaCl₂ also enhanced CCl₄-induced hepatic injury. Since CaCl₂ induced hypercalcemia transiently (within 3 h of injection), our results suggest that calcium enhances the CCl₄-induced hepatotoxicity at an early stage via potentiation of oxidative stress.

Nonionic surfactant based thymoquinone loaded nanoproniosomal formulation: in vitro physicochemical evaluation and in vivo hepatoprotective efficacy

CONTEXT

The present study was carried out to formulate thymoquinone proniosomal formulation (TQP) and evaluate their efficacy in methotrexate (Mtx) induced hepatotoxicity in rats.

OBJECTIVE

The objective of the study was to explore a new therapeutic approach focusing on hepatoprotective activity using thymoquinone proniosomal formulation.

MATERIAL AND METHODS

TQP was formulated using span60, cholesterol and phospholipid by film hydration technique. The animals were divided into six groups with five animals each receiving different treatments for 7 days. On the 8th day, rats were anesthetized with ether, blood samples were withdrawn, livers were dissected out for biochemical tests and histopathological examinations.

RESULTS AND DISCUSSION

The size of vesicle was found to be in the nanometric range with higher entrapment efficiency. The high entrapment efficiency is probably due to the lipophilic character of TQ. The morphological structure showed the outline and core of the well-identified spherical vesicle, and also displaying the retention of sealed vesicular structure. The release of TQ from developed formulation was found to be significantly higher compared to control. Mtx treated rats showed significant elevation in ALT, AST, ALP and TBARs, whereas, TQP treated group showed significant reduction.

CONCLUSION

The developed formulation (TQP) significantly inhibited the elevated levels of serum marker enzymes and showed improved histopathological deformities.

Methotrexate hepatotoxicity is associated with oxidative stress, and down-regulation of PPARγ and Nrf2: Protective effect of 18β-Glycyrrhetinic acid

18β-glycyrrhetinic acid (18β-GA) is a bioactive component of licorice with promising hepatoprotective activity. However, its protective mechanism on methotrexate (MTX) hepatotoxicity in not well defined. We investigated the hepatoprotective effect of 18β-GA, pointing to the role of peroxisome proliferator activated receptor gamma (PPARγ) and the redox-sensitive nuclear factor erythroid 2-related factor 2 (Nrf2). Wistar rats were orally administered 18β-GA (50 and 100 mg/kg) 7 days either before or after MTX injection. MTX induced significant increase in circulating liver function marker enzymes and bilirubin with concomitant declined albumin levels. Serum pro-inflammatory cytokines, and liver malondialdehyde and nitric oxide were significantly increased in MTX-induced rats. Treatment with 18β-GA significantly reduced serum enzymes of liver function, bilirubin and pro-inflammatory cytokines. 18β-GA attenuated MTX-induced oxidative stress and restored the antioxidant defenses. In addition, 18β-GA improved liver histological structure and decreased the expression of Bax whereas increased Bcl-2 expression. MTX-induced rats showed significant down-regulation of Nrf2, hemoxygenase-1 and PPARγ, an effect that was markedly reversed by 18β-GA supplemented either before or after MTX. In conclusion, 18β-GA protected against MTX-induced liver injury, possibly by activating Nrf2 and PPARγ, and subsequent attenuation of inflammation, oxidative stress and apoptosis. Therefore, 18β-GA can provide protection against MTX-induced hepatotoxicity.

A Pilot Study to Examine the Effects of an Anti-inflammatory Supplement on Eicosanoid Derivatives in Patients with Chronic Kidney Disease

BACKGROUND

Chronic kidney disease (CKD) is a progressive disease with an inverse relationship between kidney function and levels of inflammation and oxidative stress. Curcumin and Boswellia serrata have been reported to exert anti-inflammatory effects on the cyclooxygenase and lipoxygenase pathways. Therefore, the purpose of this study was to study the effects of a supplement containing curcumin and B. serrata on eicosanoid derivatives in early stage CKD patients who had not initiated hemodialysis.

METHODS

Sixteen patients with stage 2 and stage 3 CKD (56.0 ± 16.0 years, 171.4 ± 11.9 cm, 99.3 ± 20.2 kg) were randomized into a treatment group with curcumin and B. serrata or a placebo group. The dependent variables prostaglandin E₂ (PGE₂), 5-hydroxyicosatetraenoic acid, 12-hydroxyicosatetraenoic acid, 15-hydroxyicosatetraenoic acid, and 13-hydroxyoctadecadienoic acid were measured both before and after 8 weeks of supplementation. Results were analyzed by using a repeated-measures analysis of covariance for compliance and body-mass index.

RESULTS

A significant group effect (p = 0.05), and a trend for Group × Time interaction (p = 0.056) were detected for PGE₂. No significant differences were observed for any other variables.

CONCLUSIONS

This is the first article of baseline levels of the dependent variables in early stage CKD, and the first article to show a significant effect of these supplements on PGE₂ in early stage CKD. Further studies are needed to determine whether curcumin and B. serrata may be effective means to reduce inflammation in patients with CKD.

A comparative molecular docking study of curcumin and methotrexate to dihydrofolate reductase

Interaction of curcumin (CUR) with the enzyme dihydrofolate reductase (DHFR) was studied by molecular docking using AutoDock 4.2 as the docking software application. AutoDock 4.2 software serves as a valid and acceptable docking application to study the interactions of small compounds with proteins. Interactions of curcumin with DHFR were compared to those of methotrexate (MTX), a known inhibitor of the enzyme. The calculated free energy of binding (ΔG binding) shows that curcumin (ΔG = -9.02 kcal/mol; Ki = 243 nM) binds with affinity comparable to or better than MTX (ΔG = -8.78 kcal/mol; Ki = 363 nM). Binding interactions of curcumin with active site residues of the enzyme are also predicted. Curcumin appears to bind in a bent conformation making extensive VDW contacts in the active site of the enzyme. Hydrogen bonding and pi-pi interaction with key active site residues are also observed. Thus, curcumin can be considered as a good lead compound in the development of new inhibitors of DHFR, which is a potential target of anti-cancer drugs. The results of these studies can serve as a starting point for further computational and experimental studies.

Curcumin inhibits angiotensin II-induced inflammation and proliferation of rat vascular smooth muscle cells by elevating PPAR-γ activity and reducing oxidative stress

Angiotensin II (AngII)-induced production of inflammatory factors and proliferation in vascular smooth muscle cells (VSMCs) play an important role in the progression of atherosclerotic plaques. Growing evidence has demonstrated that activation of peroxisome proliferator-activated receptor-γ (PPAR-γ) effectively attenuates AngII-induced inflammation and intercellular reactive oxygen species (iROS) production. Curcumin (Cur) inhibits inflammatory responses by enhancing PPAR-γ activity and reducing oxidative stress in various tissues. The aim of the present study was to ascertain whether Cur inhibits AngII-induced inflammation and proliferation, and its underlying molecular mechanism, in VSMCs. Enzyme-linked immunosorbent assay (ELISA) and real-time PCR were used to measure the protein and mRNA expression of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Nitric oxide (NO) production was measured by Griess reaction. Western blot analysis and a DNA-binding assay were used to measure PPAR-γ activity. iROS production was measured using the DCFH-DA method. In rat VSMCs, Cur attenuated AngII‑induced expression of IL-6 and TNF-α mRNA and protein in a concentration-dependent manner, inhibited NO production by suppressing inducible NO synthase (iNOS) activity, and suppressed proliferation of VSMCs. This was accompanied by increased PPAR-γ expression and activation in Cur-pretreated VSMCs. GW9662, a PPAR-γ antagonist, reversed the anti-inflammatory effect of Cur. Moreover, Cur attenuated AngII-induced oxidative stress by downregulating the expression of p47phox, which is a key subunit of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. In conclusion, Cur inhibited the expression of IL-6 and TNF-α, decreased the production of NO, and suppressed the proliferation of VSMCs, by elevating PPAR-γ activity and suppressing oxidative stress, leading to attenuated AngII-induced inflammatory responses in VSMCs.

Modulation of hepatic stellate cells and reversibility of hepatic fibrosis

Hepatic fibrosis (HF) is the pathological component of a variety of chronic liver diseases. Hepatic stellate cells (HSC) are the main collagen-producing cells in the liver and their activation promotes HF. If HSC activation and proliferation can be inhibited, HF occurrence and development can theoretically be reduced and even reversed. Over the past ten years, a number of studies have addressed this process, and here we present a review of HSC modulation and HF reversal.

Molecular hepatoprotective effects of lipoic acid against carbon tetrachloride-induced liver fibrosis in rats: Hepatoprotection at molecular level

BACKGROUND

Liver fibrosis is a noteworthy well-being issue that can prompt the progression of liver cirrhosis and hepatocellular carcinoma. Prominently, many antioxidants have been shown to have defensive impacts against liver fibrosis.

AIM

Subsequently, in the present study, the viability of alpha-lipoic acid (α-LA) in ensuring against carbon tetrachloride (CCl₄)-actuated liver fibrosis and the mechanism(s) involved in this defensive impact were considered in rats.

RESULTS

The present results uncovered that in the CCl₄-treated group, the expression of antioxidant enzymes and matrix metalloproteinase-13 (MMP-13) messenger RNA (mRNA) was downregulated ( p < 0.05), and the levels of lipid peroxide and nitric oxide were increased ( p < 0.05) in the treated rat livers along with increased collagen deposition compared to that of the control group. Also, the gene expression levels of the proinflammatory factors interleukin-6 and tumor necrosis factor-alpha, nuclear factor-kappa B (NF-κB) p65, transforming growth factor-alpha, and inducible nitric oxide synthase (iNOS) were upregulated significantly ( p < 0.05) in the CCl₄ group. These negative impacts were all restrained by α-LA.

CONCLUSIONS

These outcomes show that α-LA might be compelling at forestalling collagen deposition and hepatic oxidative stress as well as downregulating the expression of hepatic proinflammatory cytokines, iNOS, and NF-κB and upregulating MMP-13 expression.

Curcumin Protects Against Intestinal Origin Endotoxemia in Rat Liver Cirrhosis by Targeting PCSK9

Intestinal origin endotoxemia always occurs in severe liver injury. The aim of the current study was to test antiendotoxemia effect of curcumin on tetrachloride (CCl₄ )-induced liver cirrhosis rats, and to elucidate the underlying molecular mechanism. Rat cirrhosis models were constructed with CCl₄ subcutaneous injections with curcumin (200 mg/kg/d) administered via gavages for 12 wk until the rats were sacrificed. We found that the administration of curcumin improved the physiological condition pertaining to activity index and temperature, and ameliorated the liver injury in CCl₄ -induced cirrhosis rats. Enzyme-linked immunosorbent assay (ELISA) and real-time quantitative polymerase chain reaction (qRT-PCR) showed that curcumin could reduce c-reaction protein levels and inflammatory cytokine (TNF-α, IL-1β, IL-6, and CINC-1/IL-8) concentrations in peripheral serum and liver tissue. Furthermore, curcumin treatment decreased lipopolysaccharide (LPS) levels in peripheral vein, but not in portal vein. As low-density lipoprotein receptor (LDLR) is the important receptor on the surface of hepatocyte during LPS detoxification process, we used qRT-PCR, western blot, and immunohistochemistry (IHC), finding that curcumin significantly increased LDLR protein levels, but not gene levels in the liver tissues. We also tested proprotein convertase subtilisin/kexin type 9 (PCSK9), one negative regulator of LDLR, by qRT-PCR, western blot, and IHC. The results showed that PCSK9 significantly decreased both gene and protein levels in the rat liver tissues of curcumin treatment. Thus, we concluded that curcumin could function to protect against intestinal origin endotoxemia by inhibiting PCSK9 to promote LDLR expression, thereby enhancing LPS detoxification as one pathogen lipid through LDLR in the liver.

Protective effect of Curcuma longa L. extract on CCl4-induced acute hepatic stress

BACKGROUND

The Curcuma longa L. (CLL) rhizome has long been used to treat patients with hepatic dysfunction. CLL is a member of the ginger family of spices that are widely used in China, India, and Japan, and is a common spice, coloring, flavoring, and traditional medicine. This study was performed to evaluate the hepatoprotective activity of CLL extract and its active component curcumin in an acute carbon tetrachloride (CCl4)-induced liver stress model.

METHODS

Acute hepatic stress was induced by a single intraperitoneal injection of CCl4 (0.1 ml/kg body weight) in rats. CLL extract was administered once a day for 3 days at three dose levels (100, 200, and 300 mg/kg/day) and curcumin was administered once a day at the 200 mg/kg/day. We performed alanine transaminase (ALT) and aspartate transaminase (AST). activity analysis and also measured total lipid, triglyceride, and cholesterol levels, and lipid peroxidation.

RESULTS

At 100 g CLL, the curcuminoid components curcumin (901.63 ± 5.37 mg/100 g), bis-demethoxycurcumin (108.28 ± 2.89 mg/100 g), and demethoxycurcumin (234.85 ± 1.85 mg/100 g) were quantified through high liquid chromatography analysis. In CCl4-treated rats, serum AST and ALT levels increased 2.1- and 1.2-fold compared with the control. AST but not ALT elevation induced by CCl4 was significantly alleviated in CLL- and curcumin-treated rats. Peroxidation of membrane lipids in the liver was significantly prevented by CLL (100, 200, and 300 mg/kg/day) on tissue lipid peroxidation assay and immunostaining with anti-4HNE antibody. We found that CLL extract and curcumin exhibited significant protection against liver injury by improving hepatic superoxide dismutase (p < 0.05) and glutathione peroxidase activity, and glutathione content in the CCl4-treated group (p < 0.05), leading to a reduced lipid peroxidase level.

CONCLUSION

Our data suggested that CLL extract and curcumin protect the liver from acute CCl4-induced injury in a rodent model by suppressing hepatic oxidative stress. Therefore, CLL extract and curcumin are potential therapeutic antioxidant agents against acute hepatotoxicity.

Curcumin ameliorates liver damage and progression of NASH in NASH-HCC mouse model possibly by modulating HMGB1-NF-κB translocation

Curcumin, a phenolic compound, has a wide spectrum of therapeutic effects such as antitumor, anti-inflammatory, anti-cancer and so on. The study aimed to investigate the underlying mechanisms of curcumin to protect liver damage and progression of non-alcoholic steatohepatitis (NASH) in a novel NASH-hepatocellular carcinoma (HCC) mouse model. To induce this model neonatal C57BL/6J male mice were exposed to low-dose streptozotocin and were fed a high-fat diet (HFD) from the age of 4weeks to 14weeks. Curcumin was given at 100mg/kg dose daily by oral gavage started at the age of 10weeks and continued until 14weeks along with HFD feeding. We found that curcumin improved the histopathological changes of the NASH liver via reducing the level of steatosis, fibrosis associated with decreasing serum aminotransferases. In addition, curcumin treatment markedly reduced the hepatic protein expression of oxidative stress, pro-inflammatory cytokines, and chemokines including interferon (IFN) γ, interleukin-1β and IFNγ-inducible protein 10, in NASH mice. Furthermore, curcumin treatment significantly reduced the cytoplasmic translocation of high mobility group box 1 (HMGB1) and the protein expression of toll like receptor 4. Nuclear translocation of nuclear factor kappa B (NF-κB) was also dramatically attenuated by the curcumin in NASH liver. Curcumin treatment effectively reduced the progression of NASH to HCC by suppressing the protein expression of glypican-3, vascular endothelial growth factor, and prothrombin in the NASH liver. Our data suggest that curcumin reduces the progression of NASH and liver damage, which may act via inhibiting HMGB1-NF-κB translocation.

Capsaicin Inhibits Dimethylnitrosamine-Induced Hepatic Fibrosis by Inhibiting the TGF-β1/Smad Pathway via Peroxisome Proliferator-Activated Receptor Gamma Activation

Capsaicin (CPS) exerts many pharmacological effects, but any possible influence on liver fibrosis remains unclear. Therefore, we evaluated the inhibitory effects of CPS on dimethylnitrosamine (DMN) and TGF-β1-induced liver fibrosis in rats and hepatic stellate cells (HSCs). CPS inhibited DMN-induced hepatotoxicity, NF-κB activation, and collagen accumulation. CPS also suppressed the DMN-induced increases in α-SMA, collagen type I, MMP-2, and TNF-α. In addition, CPS inhibited DMN-induced TGF-β1 expression (from 2.3 ± 0.1 to 1.0 ± 0.1) and Smad2/3 phosphorylation (from 1.5 ± 0.1 to 1.1 ± 0.1 and from 1.6 ± 0.1 to 1.1 ± 0.1, respectively) by activating Smad7 expression (from 0.1 ± 0.0 to 0.9 ± 0.1) via PPAR-γ induction (from 0.2 ± 0.0 to 0.8 ± 0.0) (p < 0.05). Furthermore, in HSCs, CPS inhibited the TGF-β1-induced increases in α-SMA and collagen type I expression, via PPAR-γ activation. These results indicate that CPS can ameliorate hepatic fibrosis by inhibiting the TGF-β1/Smad pathway via PPAR-γ activation.

Therapeutic Effects of Curcumin on Ultrasonic Morphological Characteristics of Liver in Patients with Metabolic Syndrome

Introduction:

Metabolic syndrome (METS) represent a simultaneous presence of multiple metabolic disorders in one person. Prevalence is increasing worldwide, which is probably related to increased obesity and sedentary lifestyle. Non-alcoholic steatosis or “fatty liver” is a metabolic disease caused by fat dysfunction. It can be a sign of some other disease, and can often be found in patients with metabolic disorders. Ultrasound is an acceptable method for the identification of fatty steatosis. There is evidence that when turmeric is used as a herbal diet, with its active metabolite of curcumin, can repair fatty acidosis and thus prevent progression of fatty steatosis complications such as cirrhosis and liver cancer. Goal. The aim of the study was to determine the effects of 400 mg curcuminaddition to the nutrition on ultrasound morphological characteristics of the liver in METS patients.

Methodology:

A prospective cohort study was conducted on 100 subjects with METS, treated in the family medicine practice of the Tuzla Canton, aged 35-70 years. The therapeutic effects of 400 mg curcumin on ultrasound-morphological characteristics of the liver were followed, validated by ultrasound in 50 respondents of experimental groups with METS. The data were processed by the IBM SPSS Statistics 21 statistical analysis program using parametric techniques andStudent’s t-test for paired samples.

Results:

There were 65% of women in the study. There were no statistically significant differences in the age of respondents within the analyzed groups. The use of 400 mg curcumin per day was statistically significantly improved ultrasound morphological characteristics of the liver in subjects with METS.

Conclusion:

All respondents with METS who used curcumin had beneficial effects on the morphological characteristics of the liver. Curcumin had stronger effects on subjects with METS and DM type 2 than others.

Ameliorative Effect of Curcumin-Encapsulated Hyaluronic Acid-PLA Nanoparticles on Thioacetamide-Induced Murine Hepatic Fibrosis

In this study, we developed curcumin-encapsulated hyaluronic acid–polylactide nanoparticles (CEHPNPs) to be used for liver fibrosis amelioration. CD44, the hyaluronic acid (HA) receptor, is upregulated on the surface of cancer cells and on activated hepatic stellate cells (aHSCs) rather than normal cells. CEHPNPs could bind to CD44 and be internalized effectively through endocytosis to release curcumin, a poor water-soluble liver protective agent. Thus, CEHPNPs were potentially not only improving drug efficiency, but also targeting aHSCs. HA and polylactide (PLA) were crosslinked by adipic acid dihydrazide (ADH). The synthesis of HA–PLA was monitored by Fourier-transform infrared (FTIR) and Nuclear Magnetic Resonance (NMR). The average particle size was approximately 60–70 nm as determined by dynamic light scattering (DLS) and scanning electron microscope (SEM). Zeta potential was around −30 mV, which suggested a good stability of the particles. This drug delivery system induced significant aHSC cell death without affecting quiescent HSCs, hepatic epithelial, and parenchymal cells. This system reduced drug dosage without sacrificing therapeutic efficacy. The cytotoxicity IC₅₀ (inhibitory concentration at 50%) value of CEHPNPs was approximately 1/30 to that of the free drug treated group in vitro. Additionally, the therapeutic effects of CEHPNPs were as effective as the group treated with the same curcumin dose intensity in vivo. CEHPNPs significantly reduced serum aspartate transaminase/alanine transaminase (ALT/AST) significantly, and attenuated tissue collagen production and cell proliferation as revealed by liver biopsy. Conclusively, the advantages of superior biosafety and satisfactory therapeutic effect mean that CEHPNPs hold great potential for treating hepatic fibrosis.

Insights into the Role and Interdependence of Oxidative Stress and Inflammation in Liver Diseases

The crucial roles of oxidative stress and inflammation in the development of hepatic diseases have been unraveled and emphasized for decades. From steatosis to fibrosis, cirrhosis and liver cancer, hepatic oxidative stress, and inflammation are sustained and participated in this pathological progressive process. Notably, increasing evidences showed that oxidative stress and inflammation are tightly related, which are regarded as essential partners that present simultaneously and interact with each other in various pathological conditions, creating a vicious cycle to aggravate the hepatic diseases. Clarifying the interaction of oxidative stress and inflammation is of great importance to provide new directions and targets for developing therapeutic intervention. Herein, this review is concerned with the regulation and interdependence of oxidative stress and inflammation in a variety of liver diseases. In addition to classical mediators and signaling, particular emphasis is placed upon immune suppression, a potential linkage of oxidative stress and inflammation, to provide new inspiration for the treatment of liver diseases. Furthermore, since antioxidation and anti-inflammation have been extensively attempted as the strategies for treatment of liver diseases, the application of herbal medicines and their derived compounds that protect liver from injury via regulating oxidative stress and inflammation collectively were reviewed and discussed.

Curcumin protects human adipose-derived mesenchymal stem cells against oxidative stress-induced inhibition of osteogenesis

The detrimental effects of oxidative stress on the skeletal system have been documented, and understanding the mechanisms is important to design a therapeutic strategy. As an antioxidant and anti-inflammatory agent, the active ingredient of turmeric curcumin has been used as medication for numerous complications including bone loss. However, it is unclear if curcumin could influence the osteogenic potential of mesenchymal stem cells (MSCs), particularly in oxidative injuries. Here we demonstrate that curcumin treatment protects cell death caused by hydrogen peroxide (H2O2) exposure in human adipose-derived MSCs in vitro. Importantly, curcumin is able to enhance the osteoblast differentiation of human adipose-derived MSCs that is inhibited by H2O2. Notably, both oxidative stress and the inhibition of Wnt/β-catenin signaling are attenuated by curcumin treatment. These results suggest that curcumin can promote osteoblast differentiation of MSCs and protect the inhibitory effect elicited by oxidative injury. The findings support potential use of curcumin or related antioxidants in MSC-based bone regeneration for disease related with oxidative stress-induced bone loss.

Turmeric extract and its active compound, curcumin, protect against chronic CCl4-induced liver damage by enhancing antioxidation

Background

Curcumin, a major active component of turmeric, has previously been reported to alleviate liver damage. Here, we investigated the mechanism by which turmeric and curcumin protect the liver against carbon tetrachloride (CCl₄)-induced injury in rats. We hypothesized that turmeric extract and curcumin protect the liver from CCl₄-induced liver injury by reducing oxidative stress, inhibiting lipid peroxidation, and increasing glutathione peroxidase activation.

Methods

Chronic hepatic stress was induced by a single intraperitoneal injection of CCl₄ (0.1 ml/kg body weight) into rats. Turmeric extracts and curcumin were administered once a day for 4 weeks at three dose levels (100, 200, and 300 mg/kg/day). We performed ALT and AST also measured of total lipid, triglyceride, cholesterol levels, and lipid peroxidation.

Result

We found that turmeric extract and curcumin significantly protect against liver injury by decreasing the activities of serum aspartate aminotransferase and alanine aminotransferase and by improving the hepatic glutathione content, leading to a reduced level of lipid peroxidase.

Conclusions

Our data suggest that turmeric extract and curcumin protect the liver from chronic CCl₄-induced injury in rats by suppressing hepatic oxidative stress. Therefore, turmeric extract and curcumin are potential therapeutic antioxidant agents for the treatment of hepatic disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-016-1307-6) contains supplementary material, which is available to authorized users.

The Protective Properties of the Strawberry (Fragaria ananassa) against Carbon Tetrachloride-Induced Hepatotoxicity in Rats Mediated by Anti-Apoptotic and Upregulation of Antioxidant Genes Expression Effects

The strawberry (Fragaria ananassa) has been extensively used to treat a wide range of ailments in many cultures. The present study was aimed at evaluating the hepatoprotective effect of strawberry juice on experimentally induced liver injury in rats. To this end, rats were introperitoneally injected with carbon tetrachloride (CCl₄) with or without strawberry juice supplementation for 12 weeks and the hepatoprotective effect of strawberry was assessed by measuring serum liver enzyme markers, hepatic tissue redox status and apoptotic markers with various techniques including biochemistry, ELISA, quantitative PCR assays and histochemistry. The hepatoprotective effect of the strawberry was evident by preventing CCl₄-induced increase in liver enzymes levels. Determination of oxidative balance showed that strawberry treatment significantly blunted CCl₄-induced increase in oxidative stress markers and decrease in enzymatic and non-enzymatic molecules in hepatic tissue. Furthermore, strawberry supplementation enhanced the anti-apoptotic protein, Bcl-2, and restrained the pro-apoptotic proteins Bax and caspase-3 with a marked reduction in collagen areas in hepatic tissue. These findings demonstrated that strawberry (F. ananassa) juice possessed antioxidant, anti-apoptotic and anti-fibrotic properties, probably mediated by the presence of polyphenols and flavonoids compounds.

Perilipin 5 restores the formation of lipid droplets in activated hepatic stellate cells and inhibits their activation

Hepatic stellate cells (HSC) are major effectors during hepatic fibrogenesis. The activation of HSC is coupled to the loss of lipid droplets (LDs), which are specialized organelles composed of neutral lipids surrounded by perilipins. LDs have emerged as a focal point of interest in understanding the metabolic regulation of intrahepatic lipids during lipid-mediated liver fibrogenesis. Perilipin 5 (Plin5) is a newly identified LD protein in the perilipin family, which plays a key role in regulating aspects of intracellular trafficking, signaling, and cytoskeletal organization in hepatocytes. Recent work in Plin5 knockout mice suggests a role in high fat diet-induced hepatic lipotoxicity. The current report is to evaluate the impact of Plin5 on HSC activation and to elucidate the underlying mechanisms. We now show that high fat diet-induced liver fibrosis is accompanied by an approximate 75% reduction in Plin5 in HSC, and that spontaneous activation of primary HSC produces temporally coincident loss of Plin5 expression and LD depletion. As modulating lipid content in HSC is a suggested strategy for inhibition of HSC activation and treatment of hepatic fibrosis, we asked whether exogenous Plin5 expression in primary HSC would reverse the activation phenotype and promote LD formation. Recombinant lentiviral Plin5 expression in primary mouse HSC restored the formation of LDs, increased lipid content by inducing expression of pro-lipogenic genes and suppressing expression of pro-lipolytic genes, and suppressed HSC activation (~two fold reduction in expression of procollagen and α-smooth muscle actin, two unique biomarkers for activated HSC). In addition, the expression of exogenous Plin5 in HSC attenuated cellular oxidative stress by reducing cellular reactive oxygen species, elevating cellular glutathione, and inducing gene expression of glutamate-cysteine ligase. Taken together, our results indicate that expression of Plin5 plays a critical role in the formation of LDs, the elevation of lipid content in HSC, and the inhibition of the activation of HSC.

2,2'-Fluorine mono-carbonyl curcumin induce reactive oxygen species-Mediated apoptosis in Human lung cancer NCI-H460 cells

In this paper, we synthesized three fluorine-substituted mono-carbonyl curcumin analogs and evaluated their cytotoxicity against several cancer cells by the MTT assay. The results exhibited that all the three compounds were more active than the leading curcumin. Especially, 2,2'-F mono-carbonyl curcumin, 1a, surfaced as an important lead compound displaying almost 4-fold cytotoxicity relative to curcumin. More importantly, 1a was more stable in (RPMI)-1640 medium and more massive uptake than curcumin, which may be relationship to their cytotoxicity, apoptotic acitivity and reactive oxygen species generation. And then, the generation of reactive oxygen species can disrupt the intracellular redox balance, induce lipid peroxidation, cause the collapse of the mitochondrial membrane potential and ultimately lead to apoptosis. The results not only suggest that 2,2'-F mono-carbonyl curcumin (1a) may cause cancer cells apoptosis through reactive oxygen species-Mediated pathway, but also gives us an important information for design of mono-carbonyl curcumin analog.

Amomum cardamomum L. ethyl acetate fraction protects against carbon tetrachloride-induced liver injury via an antioxidant mechanism in rats

Background

Medicinal herb-derived drug development has become important in the relief of liver pathology. Amomun cardamomum is traditionally used therapeutically in Korea to treat various human ailments including dyspepsia, hiccupping, and vomiting. We investigated to assess the protective effect of A. cardamomum on carbon tetrachloride (CCl₄)-induced liver damage through antioxidant activity in hepatic tissues of Sprague–Dawley rats.

Methods

Antioxidant properties of different fractions from A. cardamomum from ethanol extracts were evaluated by an in vitro free radical scavenging systems. The protective effect of the ethyl acetate fraction from A. cardamomum (EAAC) against CCl₄-induced cytotoxicity was determined by a cell viability assay using HepG2 hepatocarcinoma cells. In vivo study, the influence of EAAC concentrations of 100 and 200 mg/kg following CCl₄-induced hepatic injury was assessed. Serum levels of glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), and alkaline phosphatase (ALP) were determined, as was lipid peroxidation (malondialdehyde, MDA). Effect of EAAC on liver detoxification enzymes including superoxide dismutase (SOD), total glutathione (GSH), and glutathione S-transferase (GST) activity was measured in rat liver homogenates. Liver cytochrome P450 (CYP2E1) expression level was determined by quantification of mRNA.

Results

Phytochemical analysis of A. cardamomum indicated that EAAC was enriched in total polyphenol and total flavonoid. Most of the tannins were confined to the hexane fraction. Hepatoprotective properties of EAAC were evident, with significantly reduced serum levels of GOT, GPT, and ALP compared with the control group. Improved hepatic antioxidant status was evident by increased SOD, GSH, and GST enzymes in rat liver tissue. Liver lipid peroxidation induced by CCl₄ was apparent by increased intracellular MDA level. EAAC suppressed lipid peroxidation as evidenced by the significant decrease in MDA production. Expression of CYP2E1 was also significantly decreased at the higher concentration of EAAC, indicating the hepatoprotective efficacy of EAAC on acute liver damage.

Conclusion

These results indicated that EAAC has a significant hepatoprotective activity on CCl₄-induced acute hepatic injury in rats, which might be derived from its antioxidant properties and CYP2E1 downregulation.

Comparative study of antifibrotic activity of some magnesium-containing supplements on experimental liver toxicity. Molecular study

INTRODUCTION

Liver fibrosis is the excessive accumulation of extracellular matrix (ECM) proteins including collagen that occurs in most types of chronic liver diseases. This study aimed to investigate and compare the therapeutic efficacy of different magnesium (Mg)-containing supplements (formulations A, B, and C) on carbon tetrachloride (CCl₄)-induced liver fibrosis in rats.

METHODS

Liver fibrosis was induced by intraperitoneal injection of rats with CCl₄ (1:1 in olive oil, 2 mL/kg, three times/week) for 4 weeks, and then rats were orally treated with different Mg-containing supplements (formulations A, B, and C) once daily for another one month. Liver fibrosis was quantified by evaluation of expressions of Collagen I, transforming growth factor β-1 (TGFβ1), platelet-derived growth factor-C (PDGF-C), nuclear factor kappa-β (NF-κβ), and measurement of hepatic collagen (hydroxyproline) level. Also, malondialdehyde (MDA), nitric oxide (NO), glutathione (GSH) level, superoxide dismutase (SOD), and glutathione-S-transferase (GST) activities were estimated.

RESULTS

CCl₄ administration significantly elevated expressions of the studied genes, hepatic hydroxyproline, MDA, and NO levels and caused depletion of GSH level, decreased SOD, and GST activities when compared with those of their corresponding control, p < 0.05. All magnesium supplements significantly inhibited expressions of the studied genes and attenuated the hepatic hydroxyproline level as compared with those of CCl₄-treated group_; p < 0.05; for NF-κβ, the highest inhibition was by formulations B and C. Regarding Collagen I, TGFβ1, and hepatic hydroxyproline content, the highest inhibition was by Formulation C, and Formulation A revealed highest inhibition for PDGF-C. All magnesium supplements revealed normalization of oxidant and antioxidants parameters. Histopathological examination supports the biochemical and molecular findings.

CONCLUSION

Mg supplements were effective in the treatment of hepatic CCl₄-induced fibrosis-rat model.

Activation of PPARγ/P53 signaling is required for curcumin to induce hepatic stellate cell senescence

Activation of quiescent hepatic stellate cells (HSCs) is the major event in hepatic fibrogenesis, along with enhancement of cell proliferation and overproduction of extracellular matrix. Although inhibition of cell proliferation and induction of apoptosis are potential strategies to block the activation of HSCs, a better understanding of the senescence of activated HSCs can provide a new therapeutic strategy for prevention and treatment of liver fibrosis. The antioxidant curcumin, a phytochemical from turmeric, has been shown to suppress HSC activation in vitro and in vivo. The current work was aimed to evaluate the effect of curcumin on senescence of activated HSCs and to elucidate the underlying mechanisms. In this study, curcumin promoted the expression of senescence marker Hmga1 in rat fibrotic liver. In addition, curcumin increased the number of senescence-associated β-galactosidase-positive HSCs in vitro. At the same time, curcumin induced HSC senescence by elevating the expression of senescence markers P16, P21 and Hmga1, concomitant with reduced abundance of HSC activation markers α-smooth muscle actin and α1(I)-procollagen in cultured HSCs. Moreover, curcumin affected the cell cycle and telomerase activity. We further demonstrated that P53 pharmacological inhibitor pifithrin-α (PFT-α) or transfection with P53 siRNA abrogated the curcumin-induced HSC senescence in vitro. Meanwhile, curcumin disruption of P53 leading to increased senescence of activated HSCs was further verified in vivo. Further studies indicated that curcumin promoted the expression of P53 through a PPARγ activation-dependent mechanism. Moreover, promoting PPARγ transactivating activity by a PPARγ agonist 15d-PGJ2 markedly enhanced curcumin induction of senescence of activated HSCs. However, the PPARγ antagonist PD68235 eliminated curcumin induction of HSC senescence. Taken together, our results provided a novel insight into the mechanisms underlying curcumin inhibition of HSC activation through inducing senescence.

Hepatoprotective Effects of Chinese Medicinal Herbs: A Focus on Anti-Inflammatory and Anti-Oxidative Activities

The liver is intimately connected to inflammation, which is the innate defense system of the body for removing harmful stimuli and participates in the hepatic wound-healing response. Sustained inflammation and the corresponding regenerative wound-healing response can induce the development of fibrosis, cirrhosis and eventually hepatocellular carcinoma. Oxidative stress is associated with the activation of inflammatory pathways, while chronic inflammation is found associated with some human cancers. Inflammation and cancer may be connected by the effect of the inflammation-fibrosis-cancer (IFC) axis. Chinese medicinal herbs display abilities in protecting the liver compared to conventional therapies, as many herbal medicines have been shown as effective anti-inflammatory and anti-oxidative agents. We review the relationship between oxidative stress and inflammation, the development of hepatic diseases, and the hepatoprotective effects of Chinese medicinal herbs via anti-inflammatory and anti-oxidative mechanisms. Moreover, several Chinese medicinal herbs and composite formulae, which have been commonly used for preventing and treating hepatic diseases, including Andrographis Herba, Glycyrrhizae Radix et Rhizoma, Ginseng Radix et Rhizoma, Lycii Fructus, Coptidis Rhizoma, curcumin, xiao-cha-hu-tang and shi-quan-da-bu-tang, were selected for reviewing their hepatoprotective effects with focus on their anti-oxidative and ant-inflammatory activities. This review aims to provide new insight into how Chinese medicinal herbs work in therapeutic strategies for liver diseases.

Potential effects of curcumin on peroxisome proliferator-activated receptor-γ in vitro and in vivo

Natural peroxisome proliferator-activated receptor-γ (PPAR-γ) agonists are found in food and may be important for health through their anti-inflammatory properties. Curcumin (Cur) is a bright yellow spice, derived from the rhizome of Curcuma longa Linn. It has been shown to have many biological properties that appear to operate through diverse mechanisms. Some of these potentially beneficial effects of Cur are due to activation of the nuclear transcription factor PPAR-γ. It is reported (using in vitro and in vivo models) that Cur plays a potential role against several diseases. In this review article, we present the current literature on the effects of Cur on the modulation of inflammatory processes that are mediated through PPAR-γ.

The effects of dietary verbascoside on blood and liver oxidative stress status induced by a high n-6 polyunsaturated fatty acids diet in piglets

Twenty-four weaned female Hypor piglets (10.9 ± 0.1 kg mean BW) were used to evaluate the antioxidant effect of a natural extract, titrated in verbascoside, on blood and liver oxidative status in relation to a high intake of n-6 PUFA, inducing oxidative stress. Piglets were assigned to 1 of 3 experimental groups; the first group was fed a diet with 9% sunflower oil (T1) and the second received the sunflower oil diet supplemented with 5 mg of verbascoside/kg feed from Verbenaceae extract (Lippia spp.; T2). The third group was fed a control diet (CTR), in which an isoenergetic replacement of oil by starch was done. Blood samples were collected at the beginning and the end of the trial (30 d). At the end of the trial, the animals were slaughtered and the liver specimens were collected. Oxidative stress markers, including total antiradical activity, superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase (CAT) activities, were determined in blood samples. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), and γ-glutamyl transferase (GGT) plasma levels were also evaluated. Immunohistochemistry and western blot analyses were performed in liver to evaluate heat shock protein (Hsp) 70, Hsp90, and Kupffer and Ito cell activation. Liver activities of SOD, GPX, and CAT were also determined. Total antiradical activity in blood and red blood cells were affected (P < 0.01) by dietary treatments. The n-6 PUFA supplementation at a high dosage for 30 d induced oxidative stress, decreasing total antiradical activity in blood and red blood cells (CTR vs. T1 + T2; P < 0.01) and plasma CAT activity (CTR vs. T1 + T2; P = 0.088) and increasing ALT value (CTR vs. T1 + T2; P < 0.01). Also, in liver, the CAT and GPX activities tended to be lower in pigs fed n-6 PUFA diets than pigs fed a control diet (CTR vs. T1 + T2; = 0.090 and = 0.085, respectively). The liver samples presented a normal architecture and no Ito and Kupffer cell activations were observed. In liver, the SOD activity tended to be lower in the T1 group (P = 0.064) than in the CTR and T2 groups. Moreover, the level of Hsp70 was higher (P < 0.01) in the T1 group than the CTR and T2 groups. These data suggest that the dose of dietary verbascoside partially restores the antioxidant status of the liver without affecting the systemic responses to oxidative stress induced by a high-fat diet.

Improvement of the liver pathology by the aqueous extract and the n-butanol fraction of Sida pilosa Retz in Schistosoma mansoni-infected mice

ETHNOPHARMACOLOGICAL RELEVANCE

Sida pilosa Retz (Malvaceae) is a plant used in Africa for the treatment of intestinal helminthiasis, lower abdominal pains and dysmenorrhea.

AIM OF THE STUDY

In order to determine the potential use of S. pilosa in the treatment of schistosomiasis mansoni, we evaluated the schistosomicidal, antioxidant and anti-fibrotic properties of the aqueous extract and the n-butanol fraction of its aerial parts.

MATERIAL AND METHODS

S. pilosa aqueous extract (SpAE) at 100, 200 and 400mg/kg and n-butanol fraction (SpBF) at 50, 100 and 200mg/kg were administered per os to Schistosoma mansoni-infected mice for 4 weeks. Praziquantel (100mg/kg × 5 days) was used as reference drug. After sacrifice, worm burden and egg count, transaminases and proteins levels were evaluated. Malondialdehyde (MDA), lipid hydroperoxydes (LOOH), catalase (CAT), superoxide dismutase (SOD), eosinophil peroxidase (EPO) and myeloperoxidase (MPO) were also measured. The anti-fibrotic effect of the plant was evaluated by the determination of hydroxyproline and γ-interferon (IFN-γ).

RESULTS

The treatment of S. mansoni-infected mice by SpAE or SpBF resulted in a moderate reduction of worm burden and egg load in the liver and intestine. Both SpAE and SpBF significantly reversed the increasing liver proteins, MDA, LOOH and CAT levels induced by the infection. Moreover, SOD activity was improved by SpAE and SpBF. Schistosomiasis mansoni considerably increased the EPO (p<0.001) and MPO activities (p<0.001). SpAE treatment significantly reduced EPO and MPO activities at all doses. SpBF failed to reduce the increasing MPO and decreased EPO only at the highest dose. S. mansoni-infection induced an increase in hydroxyproline content (p<0.001) and a decrease in IFN-γ level (p<0.001). Both SpAE and SpBF significantly reduced hepatic hydroxyproline content, while only SpAE (p<0.05) improved IFN-γ level.

CONCLUSION

These results suggest that the liver pathology in schistosomiasis mansoni is improved by S. pilosa aqueous extract, which disclosed a moderate schistosomicidal, but strong antioxidant and anti-fibrotic activities. The n-butanol fraction was however less active than the aqueous extract.

Protective Effect of Gallotannin-Enriched Extract Isolated from Galla Rhois against CCl₄-Induced Hepatotoxicity in ICR Mice

To investigate the toxicity, protective effects, and action mechanism of gallotannin-enriched extracts isolated from Galla Rhois (GEGR) against carbon tetrachloride (CCl₄)-induced hepatotoxicity in Institute for Cancer Research (ICR) mice, alterations in serum biochemical indicators, histopathological structure, antioxidative status, hepatic apoptosis-related proteins, and liver fibrosis regulating factors were measured in mice pretreated with GEGR for five days before CCl₄ injection. The GEGR/CCl₄ treated group showed decreased levels of three serum marker enzymes (ALP, AST, and ALT) representing liver toxicity, although LDH levels remained constant. Necrotic area indicating hepatic cell death significantly inhibited, while malondialdehyde (MDA) concentration and superoxide dismutase (SOD) expression were dramatically recovered in the GEGR preadministrated group. In mechanism analyses of GEGR, the formation of active caspase-3 and enhancement of Bax/Bcl-2 expression was effectively inhibited in the GEGR/CCl₄ treated group. The level of pro-inflammatory cytokines, TNF-α and IL-6, as well as the phosphorylation of p38 and JNK in the TNF-α downstream signaling pathway was rapidly recovered in the GEGR/CCl₄ treated group, while anti-inflammatory cytokine (IL-10) increased slightly in the same group. Furthermore, the GEGR/CCl₄ treated group showed a significant decrease in collagen accumulation results from alleviation of MMP-2 expression, TGF-β1 secretion and the phosphorylation of Smad2/3. Taken together, these results suggest that GEGR may induce remarkable protective effects against hepatic injury induced by CCl₄ treatment through upregulation of the anti-inflammatory and antioxidant system.

Simultaneous activation of Nrf2 and elevation of antioxidant compounds for reducing oxidative stress and chronic inflammation in human Alzheimer's disease

Despite extensive research, neither the incidence nor the rate of progression of Alzheimer's disease (AD) has significantly changed. Some biochemical and genetic defects that initiate and promote AD include: (a) increased oxidative stress, (b) chronic inflammation (c) mitochondrial dysfunction, (d) Aß1-42 peptides generated from the amyloid precursor protein (APP), (e) proteasome inhibition, and (f) mutations in APP, presenilin-1 and presenilin-2 genes. Increased oxidative stress appears to precede other biochemical and genetic defects. Oxidative damage induces chronic inflammation. Therefore, reducing these defects simultaneously may reduce the development and progression of AD. Previous studies with individual antioxidants produced consistent benefits in animal models of AD; however, a similar approach produced inconsistent results in human AD. This review proposes a hypothesis that simultaneous elevation of the levels of antioxidant enzymes and antioxidant compounds is necessary for optimally reducing oxidative stress and chronic inflammation in human AD. Supplementation can enhance the levels of antioxidant compounds; but elevation of antioxidant enzymes requires activation of Nrf2. This review discusses activation and regulation of Nrf2. The need for multi- antioxidants that can affect multi-targets has been proposed without specific recommendations. This review proposes a micronutrient mixture that would simultaneously enhance the levels of antioxidant enzymes and antioxidant compounds in human AD.