Hepatic Glutathione Levels Research Articles

Sexual dimorphism of cadmium-induced toxicity in rats: involvement of sex hormones

The toxic effect of cadmium varies with sex in experimental animals. Previous studies have demonstrated that pretreatment of male Fischer 344 (F344) rats with the female sex hormone progesterone markedly enhances the susceptibility to cadmium, suggesting a role for progesterone in the sexual dimorphism of cadmium toxicity. In the present study, we attempted to further elucidate the mechanism for sex differences in cadmium-induced toxicity in F344 rats. A single exposure to cadmium (5.0 mg Cd/kg, sc) was lethal in 10/10 (100 %) female compared with 6/10 (60 %) male rats. Using a lower dose of cadmium (3.0 mg Cd/kg), circulating alanine aminotransferase activity, indicative of hepatotoxicity, was highly elevated in the cadmium treated females but not in males. However, no gender-based differences occurred in the hepatic cadmium accumulation, metallothionein or glutathione levels. When cadmium (5.0 mg Cd/kg) was administered to young rats at 5 weeks of age, the sex-related difference in lethality was minimal. Furthermore, although ovariectomy blocked cadmium-induced lethality, the lethal effects of the metal were restored by pretreatment with progesterone (40 mg/kg, sc, 7 consecutive days) or β-estradiol (200 μg/kg, sc, 7 consecutive days) to ovariectomized rats. These results provide further evidence that female sex hormones such as progesterone and β-estradiol are involved in the sexual dimorphism of cadmium toxicity in rats.

Role of Galectin-3 in Acetaminophen-Induced Hepatotoxicity and Inflammatory Mediator Production

Galectin-3 (Gal-3) is a β-galactoside-binding lectin implicated in the regulation of macrophage activation and inflammatory mediator production. In the present studies, we analyzed the role of Gal-3 in liver inflammation and injury induced by acetaminophen (APAP). Treatment of wild-type (WT) mice with APAP (300 mg/kg, ip) resulted in centrilobular hepatic necrosis and increases in serum transaminases. This was associated with increased hepatic expression of Gal-3 messenger RNA and protein. Immunohistochemical analysis showed that Gal-3 was predominantly expressed by mononuclear cells infiltrating into necrotic areas. APAP-induced hepatotoxicity was reduced in Gal-3-deficient mice. This was most pronounced at 48-72 h post-APAP and correlated with decreases in APAP-induced expression of 24p3, a marker of inflammation and oxidative stress. These effects were not due to alterations in APAP metabolism or hepatic glutathione levels. The proinflammatory proteins, inducible nitric oxide synthase (iNOS), interleukin (IL)-1β, macrophage inflammatory protein (MIP)-2, matrix metalloproteinase (MMP)-9, and MIP-3α, as well as the Gal-3 receptor (CD98), were upregulated in livers of WT mice after APAP intoxication. Loss of Gal-3 resulted in a significant reduction in expression of iNOS, MMP-9, MIP-3α, and CD98, with no effects on IL-1β. Whereas APAP-induced increases in MIP-2 were augmented at 6 h in Gal-3(-/-) mice when compared with WT mice, at 48 and 72 h, they were suppressed. Tumor necrosis factor receptor-1 (TNFR1) was also upregulated after APAP, a response dependent on Gal-3. Moreover, exaggerated APAP hepatotoxicity in mice lacking TNFR1 was associated with increased Gal-3 expression. These data demonstrate that Gal-3 is important in promoting inflammation and injury in the liver following APAP intoxication.

Th2 cytokine‐mediated methimazole‐induced acute liver injury in mice

Drug-induced liver injury (DILI) is a major safety concern in drug development and clinical practice. The pathogenesis of DILI usually involves the participation of the parent drug or metabolites that either affect cellular function or elicit an immune response. However, the mechanisms leading to DILI are unknown in most cases. Methimazole (MTZ) is used as an antithyroid drug and is well known to have induced liver injuries such as cholestatic hepatitis in a small number of human cases. Immune-mediated reactions were also suggested to play a role in MTZ-induced acute liver injury, but the mechanism underlying this process has not been elucidated. To address this issue, we measured plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, hepatic glutathione levels, hepatic expression of CD4⁺ Th cell-related transcriptional factors, cytokines and chemokines, plasma interleukin (IL)-4 levels and histopathological changes in the liver following MTZ (450 mg kg⁻¹ , p.o.) administration in mice. The hepatic expression of mRNA for Th2 cell-related factors, such as GATA-binding protein, macrophage inflammatory protein-2 (MIP-2) and plasma IL-4 levels, as well as plasma AST and ALT levels, was significantly increased in mice treated with MTZ. These changes were markedly enhanced by pre-treatment with L-buthionine sulfoximine (3 mmol kg⁻¹, i.p.) and MTZ (15 mg kg⁻¹, p.o.). Neutralization of IL-4 using a monoclonal anti-mouse IL-4 antibody (100 µg/mouse, single i.p.) suppressed the hepatotoxic effect of MTZ. In conclusion, this report is the first to demonstrate that Th2 cytokine-mediated immune responses are involved in MTZ-induced acute liver injury in mice.

Evaluation of hepatotoxicity and oxidative stress in rats treated with tert-butyl hydroperoxide

Although tert-butyl hydroperoxide (t-BHP) is commonly used to induce oxidative stress, little is known about the time- or dose-dependence of its oxidative effects. In this study, we examined hepatotoxicity and oxidative stress in male rats at various times (0–24h) after t-BHP (0, 0.2, 0.5, 1 or 3mmol/kg, ip) treatment. Serum hepatotoxicity parameters were increased from 2h following 1mmol/kg t-BHP and reached their maximum values at 8h. Plasma malondialdehyde levels were maximally elevated by 62% at 0.5h and returned to control levels by 4h. Hepatic glutathione levels were decreased between 0.5 and 2h, and hepatic glutathione disulfide levels were increased at 2h. Interestingly, hepatic glutathione levels were increased at 24h, which may be attributed to up-regulation of glutathione synthesis through induction of gamma-glutamylcysteine ligase expression. The elevation of hepatotoxic parameters and plasma MDA was observed from 0.5 to 1mmol/kg t-BHP, respectively, in a dose-dependent manner. Considering that the maximal dose resulted in 20% lethality, 1mmol/kg of t-BHP may be suitable for evaluating antioxidant activity of tested compounds. Our results provide essential information to characterize the t-BHP-induced oxidative stress and hepatotoxicity.

Enhancement of acetaminophen-induced chronic hepatotoxicity in restricted fed rats: a nonclinical approach to acetaminophen-induced chronic hepatotoxicity in susceptible patients

Acetaminophen (APAP) is a commonly used and effective analgesic and antipyretic agent. However, some patients encounter hepatotoxicity after repeated APAP dosing at therapeutic doses. In the present study, we focused on the nutritional state as one of the risk factors of APAP-induced chronic hepatotoxicity in humans and investigated the contribution of undernourishment to susceptibility to APAP-induced chronic hepatotoxicity using an animal model mimicking undernourished patients. Rats were divided into 2 groups: the ad libitum fed (ALF) and the restricted fed (RF) rats and were assigned to 3 groups (n = 8/group) for each feeding condition. The animals were given APAP at 0, 300 and 500mg/kg for 99 days under each feeding condition. Plasma and urinary glutathione-related metabolites and liver function parameters were measured during the dosing period and hepatic glutathione levels were measured at the end of the dosing period. In the APAP-treated ALF rats hepatic glutathione levels were increased and hepatic function parameters were not changed, but in the APAP-treated RF rats hepatic glutathione levels were decreased at 500mg/kg and hepatic function parameters were increased at 300 and 500mg/kg. Moreover the urinary endogenous metabolite profile after long-term treatment with APAP in the ALF and RF rats was similar to that in human non-responders and responders to APAP-induced chronic hepatotoxicity, respectively. In conclusion, the RF rats were more sensitive to APAP-induced chronic hepatotoxicity than the ALF rats and were considered to be a useful model to estimate the contribution of the nutritional state of patients to APAP-induced chronic hepatotoxicity.

Antiproliferative and antioxidant activity of Aegle marmelos (Linn.) leaves in Dalton′s Lymphoma Ascites transplanted mice

Objective:The present investigation was performed to evaluate the antiproliferative and antioxidant activity of Aegle marmelos leaves in Dalton's Lymphoma Ascites (DLA)-bearing mice.Materials and Methods:The DLA cells maintained in vivo in Swiss albino mice were used for developing ascitic tumor in mice by intraperitoneal transplantation. The standardized 50% ethanolic extract of A. marmelos leaves (AMEE) was administered intraperitoneally in dose levels 200 and 400 mg/kg, after 24 hours of tumor inoculation in mice for two weeks.Results:The AMEE treatment significantly prevented (P<0.001) the increase in body weight due to tumor cell growth and increased the mean survival time of the tumor-bearing mice as compared to the untreated DLA control mice. The treatment of DLA-bearing mice brought down the Alanine Aminotransferase (ALAT), Aspartate Aminotransferase (ASAT), and alkaline phosphatase to normal levels. The extract decreased the levels of hepatic lipid peroxidation and increased the levels of hepatic antioxidants Glutathione, Superoxide Dismutase (SOD), and catalase. All the changes observed with AMEE treatment were dose dependent.Conclusion:The hydroalcoholic extract of A. marmelos exhibits strong antitumor and antioxidant activities in DLA-bearing mice.

Oxidative Stress and the ER Stress Response in a Murine Model for Early-Stage Alcoholic Liver Disease

Alcoholic liver disease (ALD) is a primary cause of morbidity and mortality in the United States and constitutes a significant socioeconomic burden. Previous work has implicated oxidative stress and endoplasmic reticulum (ER) stress in the etiology of ALD; however, the complex and interrelated nature of these cellular responses presently confounds our understanding of ethanol-induced hepatopathy. In this paper, we assessed the pathological contribution of oxidative stress and ER stress in a time-course mouse model of early-stage ALD. Ethanol-treated mice exhibited significant hepatic panlobular steatosis and elevated plasma ALT values compared to isocaloric controls. Oxidative stress was observed in the ethanol-treated animals through a significant increase in hepatic TBARS and immunohistochemical staining of 4-HNE-modified proteins. Hepatic glutathione (GSH) levels were significantly decreased as a consequence of decreased CBS activity, increased GSH utilization, and increased protein glutathionylation. At the same time, immunoblot analysis of the PERK, IRE1α, ATF6, and SREBP pathways reveals no significant role for these UPR pathways in the etiology of hepatic steatosis associated with early-stage ALD. Collectively, our results indicate a primary pathogenic role for oxidative stress in the early initiating stages of ALD that precedes the involvement of the ER stress response.

Protective effects of &amp;lt;i&amp;gt;Hemidesmus indicus&amp;lt;/i&amp;gt; var. pubescens root extract on paracetamol induced hepatic damage

Hemidesmus indicus (L.) R. Br. var. pubescens (W. & A.) H k. f. was evaluated for hepatoprotective property against paracetamol induced hepatotoxicity in Wistar albino rats. In this study, methanol extract of the leaves of H. indicus var. pubescens at doses 200 and 400 mg/kg body weight were administered p.o. along with paracetamol at the dose 1 g/kg b.w for 7 days. . On the 8 th day, serum biochemical estimations were carried out to measure the serum levels of SGOT, SGPT, ALP, total proteins, albumin and total bilirubin. Histopathological examination of liver sections was also performed to study the extent of damage to hepatic parenchyma. Preliminary phytochemical screening of the extract was carried out to find out the presence of various phytoconstituents. HPTLC fingerprint profiles of the detected phytoconstituents were also obtained. Daily administration of paracetamol caused profound hepatic damage as evidenced by the significant elevation of liver transaminases, alkaline phosphatase, total bilirubin and triglycerides. Hepatotoxicity also caused a significant fall in serum levels of total proteins, albumin and high density lipoprotein. There was significant depletion of hepatic levels of glutathione. These biochemical aberrations were corrected in the animals pretreated with HILM 200 and 400 mg/kg. Phytochemical screening of the extract revealed the presence of vital phytoocnstituents in the extract which could have contributed to the hepatoprotective effect of the plant. The findings of the study prove that H. indicus var. pubescens possess significant hepatoprotective properties.

Protective effects of chlorogenic acid against ischemia/reperfusion injury in rat liver: molecular evidence of its antioxidant and anti-inflammatory properties

Hepatic ischemia and reperfusion injury (I/R) is accompanied by excessive reactive oxygen species and resultant sterile inflammation. Chlorogenic acid (CGA), one of the most abundant polyphenols in the human diet, has been shown to exert potent anti-inflammatory, antibacterial and antioxidant activities. Thus, the purpose of the present study was to investigate protective effects of CGA and its molecular mechanisms against hepatic I/R injury. Rats were subjected to 60 min of partial hepatic ischemia followed by 5 h of reperfusion. CGA (2.5, 5 and 10 mg/kg, ip) was administered twice: 10 min prior to ischemia and 10 min before reperfusion. CGA treatment resulted in marked improvement of hepatic function and histology, and suppressed oxidative stress, as indicated by hepatic lipid peroxidation and glutathione level. Levels of serum tumor necrosis factor-α, inducible nitric oxide synthase and cyclooxygenase-2 protein and mRNA expressions were up-regulated after I/R; these effects were attenuated by CGA. Immunoblot results showed that CGA reduced I/R-induced toll-like receptor 4 overexpression, nuclear translocation of nuclear factor kappa B and interferon regulatory factor-1, high-mobility group box-1 release into extracellular milieu, and enhanced heme oxygenase-1 expression and nuclear translocation of nuclear factor erythroid 2-related factor 2. Our results suggest that CGA alleviates I/R-induced liver injury and that this protection is likely due to inhibition of inflammatory response and enhancement of antioxidant defense systems. Therefore, CGA might have potential as an agent for use in clinical treatment of hepatic I/R injury.

Dangfei Liganning Capsules ( ) Attenuate the Susceptibility of Rat Nonalcoholic Fatty Liver to Carbon Tetrachloride Toxicity

To test whether nonalcoholic hepatic steatosis sensitizes carbon tetrachloride (CCl4)-induced liver injury, and to assess the therapeutic effect of Chinese medicine extracts of Dangfei Liganning capsules and their potential underlying mechanisms. Male Wistar rats were fed a high-fat diet to induce nonalcoholic fatty liver disease (NAFLD) or a normal diet (N). Eight weeks later, a nonlethal dose of CCl4 was applied intraperitoneally. From the start, HF-CCl4 rats were administered daily Dangyao extracts (D), Dangfei Liganning capsules (DF), or Diammonium Glycyrrhizinate (G) intragastrically. Rats were sacrificed 48 h after CCl4 administration. In addition to serum biochemistry, liver histopathology was observed using hematoxylin-eosin (HE) and oil red O staining, and hepatic levels of triglyceride (TG), malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), caspase-3 activation and cytochrome P450 (CYP2E1) expression were assessed. There was almost no response to the nonlethal dose of CCl4 in the N control group. However, the HF group demonstrated massive steatosis, and elevated levels of serum ALT and AST, liver MDA, CYP2E1, and caspase-3 activation, whereas the levels of GSH and SOD were significantly decreased. All indexes assessed were dramatically worse in the HF-CCl4 group compared to the HF group, in addition to the more severe steatosis, hepatocyte ballooning, and inflammatory infiltration apparent in the centrilobular area. The medicines we tested affected the pathological changes in HF-CCl4 rats to differing degrees: DF and G led to improvements in all of the above examined indexes, including an obvious improvement in histopathology, and DF improved serum ALT and MDA levels more markedly than G, whereas D extracts produced only mild liver injury attenuation. Liver with NAFLD is more sensitive to hepatotoxicity; furthermore, the disrupted balance of oxidative stress and anti-oxidant defense contributes to the underlying mechanisms. Dangfei Liganning capsules potentially decrease this toxic susceptibility and alleviate liver injury in non-alcoholic fatty liver.

Altered Glutathione Homeostasis in Heart Augments Cardiac Lipotoxicity Associated with Diet-induced Obesity in Mice

Obesity-related cardiac lipid accumulation is associated with increased myocardial oxidative stress. The role of the antioxidant glutathione in cardiac lipotoxicity is unclear. Cystathionine β-synthase (Cbs) catalyzes the first step in the trans-sulfuration of homocysteine to cysteine, which is estimated to provide ∼50% of cysteine for hepatic glutathione biosynthesis. As cardiac glutathione is a reflection of the liver glutathione pool, we hypothesize that mice heterozygous for targeted disruption of Cbs (Cbs(+/-)) are more susceptible to obesity-related cardiolipotoxicity because of impaired liver glutathione synthesis. Cbs(+/+) and Cbs(+/-) mice were fed a high fat diet (60% energy) from weaning for 13 weeks to induce obesity and had similar increases in body weight and body fat. This was accompanied by increased hepatic triglyceride but no differences in hepatic glutathione levels compared with mice fed chow. However, Cbs(+/-) mice with diet-induced obesity had greater glucose intolerance and lower total and reduced glutathione levels in the heart, accompanied by lower plasma cysteine levels compared with Cbs(+/+) mice. Higher triglyceride concentrations, increased oxidative stress, and increased markers of apoptosis were also observed in heart from Cbs(+/-) mice with diet-induced obesity compared with Cbs(+/+) mice. This study suggests a novel role for Cbs in maintaining the cardiac glutathione pool and protecting against cardiac lipid accumulation and oxidative stress during diet-induced obesity in mice.

A combination of ischemic preconditioning and allopurinol protects against ischemic injury through a nitric oxide-dependent mechanism

This study examined the cytoprotective mechanisms of a combination of ischemic preconditioning (IPC) and allopurinol against liver injury caused by ischemia/reperfusion (I/R). Allopurinol (50 mg/kg) was intraperitoneally administered 18 and 1 h before sustained ischemia. A rat liver was preconditioned by 10 min of ischemia, followed by 10 min of reperfusion, and then subjected to 90 min of ischemia, followed by 5 h of reperfusion. Rats were pretreated with adenosine deaminase (ADA), 3,7-dimethyl-1-[2-propargyl]-xanthine (DMPX), and N-nitro- l-arginine methyl ester ( l-NAME) before IPC. Hepatic nitrite and nitrate and eNOS protein expression levels were increased by the combination of IPC and allopurinol. This increase was attenuated by ADA, DMPX, and l-NAME. I/R induced an increase in alanine aminotransferase activity, whereas it decreased the hepatic glutathione level. A combination of IPC and allopurinol attenuated these changes, which were abolished by ADA, DMPX, and l-NAME. The increase in the liver wet weight-to-dry weight ratio after I/R was attenuated by the combination of IPC and allopurinol. In contrast, hepatic bile flow was decreased after I/R, which was attenuated by the combination of IPC and allopurinol. These changes were restored by l-NAME. I/R induced a decrease in the level of mitochondrial dehydrogenase, whereas it increased mitochondrial swelling. A combination of IPC and allopurinol attenuated these changes, which were restored by ADA, DMPX, and l-NAME. Our findings suggest that a combination of IPC and allopurinol reduces post-ischemic hepatic injury by enhancing NO generation.

Cordycepin이 orotic acid 유발 지방간 흰쥐의 과산화 지질 농도 및 항산화 활성에 미치는 영향

눈꽃 동충하초, 번데기 동충하초, Cordycepin 고함유 번데기 동충하초 분말을 식이 중에 각각 3% 수준으로 첨가하여 10일간 흰쥐에 급여한후 임상생화학적 특성 및 조직 내 항산화 활성 및 간 조직에 미치는 영향을 검토하였다. 체중 증가량과, 식이 섭취량은 각 실험군 모두 감소 하였으나, 음료섭취량은 증가하였다. 간 손상 임상지표인 AST, ALT, LDH, ALP 활성도 각 실험군 모두 저하하였으며, 대조군과 비교하여 간 조직의 상대 중량도 감소하였다. 각 조직과 혈청의 과산화지질(TBARS)을 측정한 결과 대조군에 비해 각 실험군에서 유의적으로 감소하였으며, 그 중 Cordycepin 고함유 번데기 동충하초 분말을 투여한 군에서 가장 낮은 함량을 보였다. 특히 Cordycepin 고함유 번데기 동충하초는 간장 조직 내에서 높은 과산화지질 억제작용을 나타내어 조직 내 항산화물질로 잘 알려진 glutathione농도 또한 대조군에 비해 높은 함량을 보였다. 간장 내 지방산화를 촉진하는 Fe와 생체내 항산화물질로 잘 알려진 Zn을 측정한 결과 동충하초 첨가 식이를 섭취한 군에서 증가하였다. 이상의 실험결과 Cordycepin 고함유 번데기 동충하초는 항 동맥경화 작용 뿐만 아니라 간 조직 내 항산화 물질 증가에 의한 산화스트레스를 경감시킴으로써 향후 간 독성 개선 효능을 가지는 건강기능식품 개발의 소재로 활용될 가능성이 높은 것으로 판단되어 진다. This study is aimed to evaluate the protective effect of Cordycepin-enriched Cordyceps militaris (CM<TEX>${\alpha}$</TEX>) strain on orotic acid (OA)-induced fatty liver in rats. OA treatment induced the retardation of body weight gain and enlargement of the liver. The activities of liver marker enzymes, alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), Alk. phosphatase and Cholinesterase were increased when treated with OA, but these parameters were significantly decreased in the CM<TEX>${\alpha}$</TEX> group. The current study observed significant elevations of thiobarbituric acid-reactive substance (TBARS) levels. However, among the OA groups, the CM<TEX>${\alpha}$</TEX> group showed significantly low TBARS levels of hepatic homogenate. The OA group resulted in a significant decrease in the levels of plasma and hepatic glutathione, but these reductions were significantly increased in the CM<TEX>${\alpha}$</TEX> group. These effects were more pronounced in the CM<TEX>${\alpha}$</TEX> group than in the PJ or CM groups in Orotic acid treated rats. Accordingly, Cordycepin-enriched Cordyceps militaris (CM<TEX>${\alpha}$</TEX>) may be an ideal candidate for hepatoprotective effects in animal models.

Effect of exposure to perfluorooctanoic acid on hepatic antioxidants in mice

The present study was undertaken to evaluate hepatic antioxidants status in female mice after exposure to perfluorooctanoic acid (PFOA). A total number of 20 female mice were subjected to the study; out of them, 15 mice were treated with PFOA. PFOA solutions were prepared at 0.1, 0.5, and 1 mg/ml of deionized water and administered to the mice by gavage once daily for 3 weeks at a volume of 10 ml/kg. Controls (five mice) received an equivalent volume of deionized water. The results revealed significant increase in liver weight at dose of 5 (p < 0.01) and 10 mg/kg body weight (b.w., p < 0.01). Both hepatic total glutathione level and hepatic catalase activity were significantly increased (p < 0.01) at dose of 5 mg/kg b.w. On the other hand, hepatic glutathione reductase activity was significantly increased at dose of 10 mg/kg b.w. In this model system, PFOA administration was effective in inducing oxidative stress particularly reflected in the liver.

Mouse strain-dependent caspase activation during acetaminophen hepatotoxicity does not result in apoptosis or modulation of inflammation

The mechanisms of acetaminophen (APAP)-mediated hepatic oncotic necrosis have been extensively characterized. However, it was recently demonstrated that fed CD-1 mice have a transient caspase activation which initiates apoptosis. To evaluate these findings in more detail, outbred (Swiss Webster, SW) and inbred (C57BL/6) mice were treated with APAP with or without pan-caspase inhibitor and compared to the apoptosis model of galactosamine (GalN)/endotoxin (ET). Fasted or fed APAP-treated C57BL/6 mice showed no evidence of caspase-3 processing or activity. Interestingly, a minor, temporary increase in caspase-3 processing and activity (150% above baseline) was observed after APAP treatment only in fed SW mice. The degree of caspase-3 activation in SW mice after APAP was minor compared to that observed in GalN/ET-treated mice (1600% above baseline). The pancaspase inhibitor attenuated caspase activation and resulted in increased APAP-induced injury (plasma ALT, necrosis scoring). The caspase inhibitor did not affect apoptosis because regardless of treatment only <0.5% of hepatocytes showed consistent apoptotic morphology after APAP. In contrast, >20% apoptotic cells were observed in GalN/ET-treated mice. Presence of the caspase inhibitor altered hepatic glutathione levels in SW mice, which could explain the exacerbation of injury. Additionally, the infiltration of hepatic neutrophils was not altered by the fed state of either mouse strain. Conclusion: Minor caspase-3 activation without apoptotic cell death can be observed only in fed mice of some outbred strains. These findings suggest that although the severity of APAP-induced liver injury varies between fed and fasted animals, the mechanism of cell death does not fundamentally change.

Comparative Study of the Hepatoprotective Efficacy of Artemisia iwayomogi and Artemisia capillaris on Ethanol‐Administered Mice

We compared the effects of ethylacetate extracts from Artemisia iwayomogi (AIE) and Artemisia capillaris (ACE) on ethanol-induced hepatic injury in mice. Ethanol (25% v/v, 5 g/kg body weight) was orally administered once a day for 6 wk. AIE or ACE was provided in the diet (0.05 g/100 g diet). AIE and ACE did not affect hepatic alcohol dehydrogenase activity but did significantly inhibit cytochrome P450 2E1 activity. Hepatic acetaldehyde dehydrogenase 2 activity significantly increased in the AIE group compared to the control group. AIE caused a significant decrease in plasma acetaldehyde levels and aspartate transaminase and lactate dehydrogenase activities, whereas ACE slightly decreased these values compared to the control. Hepatic catalase activity and glutathione levels were significantly increased by AIE and ACE supplements, whereas glutathione peroxidase activity was higher only in the AIE group compared to the control group. AIE and ACE supplements significantly lowered the plasma cholesterol concentration and increased the HDL-cholesterol/total cholesterol ratio compared to the control group. Compared to the control, both AIE and ACE groups showed a significant decrease in hepatic triglyceride levels and an increase in fecal triglyceride excretion simultaneous with inhibition hepatic activities of fatty acid synthase, phosphatidate phosphohyrolase, fatty acid β-oxidation, and carnitine palmitoyltransferase. AIE significantly lowered hepatic cholesterol levels and increased fecal cholesterol levels compared to the control. These results indicate that AIE and ACE exhibit hepatoprotective and hypolipidemic properties by enhancing hepatic alcohol, antioxidant, and lipid metabolism. AIE seemed to have more potent hepatoprotective effects than ACE.

Bioassay-guided fractionation of a hepatoprotective and antioxidant extract of pea by-product

Fruits and vegetables waste products offer a cheap and practical source of potent antioxidants that could be used as functional ingredients. The hydroalcoholic extract (PE) of pea (Pisum sativum L.) waste (husks) was evaluated for hepatoprotective and antioxidant activities, using CCl4-induced oxidative stress and hepatic damage in rats. PE significantly inhibited CCl4-induced elevation of serum ALT and AST by 45.3, 17.8%, respectively and normalized the levels of serum total protein and albumin in hepatotoxic rats. It afforded 31.2% protection against hepatic lipid peroxidation, recovered hepatic glutathione and protein thiols levels (by 161.3, 55.9%, respectively), restored the glutathione-peroxidase activity (by 42.7%) and significantly increased the glutathione-S-transferase activity (by 10%). PE also inhibited CCl4-induced elevation of hepatic NO levels by 34.2%. The active PE extract was fractionated using different solvents of increasing polarity and its fractions were tested for their hepatoprotective and antioxidant activities, using the same model. Chromatographic fractionation of the active n-butanol fraction led to the isolation of four flavonoid glycosides viz., quercetin-3-sophorotrioside (F1), quercetin-3-O-(6-O-feruloyl-β-D-glucopyranosyl (1→2)- β-D-glucopyranosyl (1→2)- β-D-glucopyranoside (F2), quercetin-3-O-(6-O-sinapoyl-β-D-glucopyranosyl (1→2)- β-D-glucopyranosyl (1→2)- β-D-glucopyranoside (F3) and quercetin-3-O-rutinoside (F4). The isolated compounds were quantified in PE, using a validated HPLC method. F2 (0.1312%) was the major compound, followed by F1 (0.0753%, calculated as rutin) and F3 (0.0273%, calculated as F2). Besides, low amounts of F4 (0.0049%) were also detected. According to our findings, pea by-product contained biologically active constituents which can be utilized for upgrading of this by-product to obtain high value added products for nutraceutical use.

Nanotechnology for therapy and imaging of liver diseases

Nanotechnology has been considered for the improved delivery of various therapeutic agents, including drugs and genes. Indeed, liposomes and nanoparticles equipped with homing devices for the targeting of receptors over-expressed on the hepatic tissue have improved the treatment of various liver diseases. In this review, various nanotechnology approaches employed for the treatment/imaging of liver disease, either in preclinical or in clinic are discussed.

Amelioration ofD-Galactosamine-Induced Acute Liver Injury in Rats by Dietary Supplementation with Betaine Derived from Sugar Beet Molasses

The effects of betaine supplementation on D-galactosamine-induced liver injury were examined in terms of hepatic and serum enzyme activities and of the levels of glutathione and betaine-derived intermediates. The rats induced with liver injury showed marked increases in serum enzyme activity, but those receiving dietary supplementation of 1% betaine showed enzyme activity levels similar to a control group without liver injury. Administration of betaine also increased both hepatic and serum glutathione levels, even following D-galactosamine injection. The activity of glutathione-related enzymes was markedly decreased following injection of D-galactosamine, but remained comparable to that of the control group in rats receiving 1% betaine. The concentrations of hepatic S-adenosyl methionine and cysteine showed similar trends to that observed for hepatic glutathione levels. These results indicate that 1% betaine has a hepatoprotective effect by increasing hepatic and serum glutathione levels along with glutathione-related enzyme activities in rats.

Chronic caffeine intake decreases circulating catecholamines and prevents diet-induced insulin resistance and hypertension in rats

We tested the hypothesis that long-term caffeine intake prevents the development of insulin resistance and hypertension in two pathological animal models: the high-fat (HF) and the high-sucrose (HSu) diet rat. We used six groups of animals: control; caffeine-treated (Caff; 1g/l in drinking water during 15d); HF; caffeine-treated HF (HFCaff); HSu; caffeine-treated HSu (HSuCaff). Insulin sensitivity was assessed using the insulin tolerance test. Blood pressure, weight gain, visceral fat, hepatic glutathione, plasma caffeine, insulin and NO, and serum NEFA and catecholamines were measured. Caffeine reversed insulin resistance and hypertension induced by both the HF and HSu diets. In the HF-fed animals caffeine treatment restored fasting insulin levels to control values and reversed increased weight gain and visceral fat mass. In the HSu group, caffeine reversed fasting hyperglycaemia and restored NEFA to control values. There were no changes either in plasma NO or in hepatic glutathione levels. In contrast, caffeine totally prevented the increase in serum catecholamines induced by HF and HSu diets. To test the hypothesis that inhibition of the sympathetic nervous system prevents the development of diet-induced insulin resistance we administered carvedilol, an antagonist of β1, β2 and also α1 adrenoceptors, to HF and HSu rats. Carvedilol treatment fully prevented diet-induced insulin resistance and hypertension, mimicking the effect of caffeine. We concluded that long-term caffeine intake prevented the development of insulin resistance and hypertension in HF and HSu models and that this effect was related to a decrease in circulating catecholamines.