Serum aminotransferase activity as a predictor of clearance of drugs metabolized by CYP isoforms in rats with acute hepatic failure induced by carbon tetrachloride

Nephroprotective Effect of Pleurotus ostreatus and Agaricus bisporus Extracts and Carvedilol on Ethylene Glycol-Induced Urolithiasis: Roles of NF-κB, p53, Bcl-2, Bax and Bak

This study was designed to assess the nephroprotective effects of Pleurotus ostreatus and Agaricus bisporus aqueous extracts and carvedilol on hyperoxaluria-induced urolithiasis and to scrutinize the possible roles of NF-κB, p53, Bcl-2, Bax and Bak. Phytochemical screening and GC-MS analysis of mushrooms’ aqueous extracts were also performed and revealed the presence of multiple antioxidant and anti-inflammatory components. Hyperoxaluria was induced in Wistar rats through the addition of 0.75% (v/v) ethylene glycol in drinking water for nine weeks. The ethylene glycol-administered rats were orally treated with Pleurotus ostreatus and Agaricus bisporus aqueous extracts (100 mg/kg) and carvedilol (30 mg/kg) daily during the last seven weeks. The study showed that Pleurotus ostreatus, Agaricus bisporus and carvedilol all successfully inhibited ethylene glycol-induced histological perturbations and the elevation of serum creatinine, serum urea, serum and urinary uric acid, serum, urinary and kidney oxalate, urine specific gravity, kidney calcium, kidney NF-κB, NF-κB p65, NF-κB p50, p53, Bax and Bak expressions as well as serum TNF-α and IL-1β levels. Moreover, the treatment decreased the reduction in urinary creatinine, urinary urea, ratios of urinary creatinine to serum creatinine and urinary urea to serum urea, Fex Urea and Bcl-2 expression in kidney. In conclusion, although Pleurotus ostreatus and Agaricus bisporus extracts and carvedilol all significantly inhibited the progression of nephrolithiasis and showed nephroprotective effects against ethylene glycol-induced kidney dysfunction, Pleurotus ostreatus and Agaricus bisporus seemed to be more effective than carvedilol. Moreover, the nephroprotective effects may be mediated via affecting NF-κB activation, extrinsic apoptosis and intrinsic apoptosis pathways.

α-Pinene Induces Apoptotic Cell Death via Caspase Activation in Human Ovarian Cancer Cells

BACKGROUND The plant-derived terpenoid, alpha-pinene is a bicyclic monoterpene potentially useful for the treatment of various diseases which also includes cancer and its types. The present investigation is about finding the anticancer activity of the alpha-pinene extracted from the leaves of Boswellia dalzielii over the PA-1 cancer cells of the human ovary. MATERIAL AND METHODS The cytotoxic activity of the alpha-pinene was evaluated using MTT and LDH assays which indicated that alpha-pinene could induce cytotoxicity in cancer-causing cells in the ovary. The consequences of alpha-pinene on the cell sequence regulation were determined by the staining technique using propidium iodide (PI) followed with flow cytometry. RESULTS The cell cycle distribution analysis showed that alpha-pinene inhibit the cycle progression from G₂ to M phase. In addition, apoptosis analysis is done through the double staining investigation using Annexin V-FITC/PI to analyze the controlled growth of alpha-pinene which is associated with the apoptosis. Caspase-3 a crucial enzyme involved in apoptosis was markedly increased in the a-pinene treated PA-1 cells. The apoptosis results reveal, that the cancer cells at the human ovary with alpha-pinene induces the significant populations of apoptotic cells. CONCLUSIONS Overall, alpha-pinene may exert anticancer effects in PA-1 cells by promoting cytotoxicity, suppression of cell sequence progression along with the programmed cell death.

The Cytochrome P450-Mediated Metabolism Alternation of Four Effective Lignans From Schisandra chinensis in Carbon Tetrachloride-Intoxicated Rats and Patients With Advanced Hepatocellular Carcinoma

It is highly valuable to study the pharmacokinetics of herbal components under the pathological condition of liver dysfunction for safe and rational use of herbal medicines. In this study, the pharmacokinetic profiles of four effective lignans from Schisandra chinensis (SC), schisandrin, schisantherin A, deoxyshisandrin and γ-schisandrin, were investigated in carbon tetrachloride (CCl₄)-intoxicated rats. The metabolism of the four lignans was also studied using microsomes from patients with advanced hepatocellular carcinoma. In situ intestinal and hepatic perfusions were conducted to clarify the contributions from impairments of gut and liver on the pharmacokinetics of the four schisandra lignans in CCl₄-intoxicated rats. The metabolism in rat and human liver microsomes and transport in Caco-2 monolayer cell model were studied to reveal the key factors for the in vivo disposition of the four lignans. When SC alcoholic extract was orally administrated to CCl₄-intoxicated rat for a short term (4 days), the pharmacokinetics of four active SC lignans was significantly changed while its hepatotherapeutic effect was not obviously observed. The plasma concentrations of the four schisandra lignans were dramatically elevated compared with the control. The Cmax, AUC and MRT were all increased or prolonged significantly while parameter CLz/F was obviously reduced in rat pretreated with CCl₄. In hepatic perfusion study and liver microsomes incubation, it was found that the hepatic metabolism of the four lignans was markedly decreased mainly due to the activity reduction of multiple CYP450 isoenzymes involved the metabolism, which, eventually, might lead to the alternation of their pharmacokinetic profiles in CCl₄-intoxicated rats or patients with advanced hepatocellular carcinoma. The pharmacokinetic studies of SC components in pathological situation of liver dysfunction are expected to provide useful data for rational and safe application of SC preparations in clinic or further pharmacological and toxicological research.

Molecular genetic and biochemical responses in human airway epithelial cell cultures exposed to titanium nanoparticles in vitro

Titanium nanoparticles (NPs) have very wide application areas such as paint, cosmetics, pharmaceuticals, and biomedical applications. And, to translate these nanomaterials to the clinic and industrial domains, their safety needs to be verified, particularly in terms of genotoxicity and cytotoxicity. Therefore, in this study, we aimed to investigate of cytotoxicity and changes in gene expression profiles influenced by commonly titanium (as titanium carbide, titanium carbo-nitride, titanium (II) oxide, titanium (III) oxide, titanium (IV) oxide, titanium nitride, titanium silicon oxide) NPs in human alveolar epithelial (HPAEpiC) and pharynx (HPPC) cell lines in vitro since inhalation is an important pathway for exposure to these NPs. HPAEpiC and HPPC cells were treated with titanium (0-100 µg/mL), NPs for 24 and 48 h, and then cytotoxicity was detected by, [3-(4,5-dimethyl-thiazol-2-yl) 2,5-diphenyltetrazolium bromide] (MTT), uptake of neutral red (NR) and lactate dehydrogenase (LDH) release assays, while genotoxicity was also analyzed by cDNA array - RT-PCR assay. According to the results of MTT, NR and LDH assays, all tested NPs induced cytotoxicity on both HPAEpiC and HPPC cells in a time- and dose-dependent manner. Determining and analyzing the gene expression profiles of HPAEpiC and HPPC cells, titanium NPs showed more changes in genes related to DNA damage or repair, oxidative stress, and apoptosis. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2056-2064, 2017.

Interaction effects on cytochrome P450 both in vitro and in vivo studies by two major bioactive xanthones from Halenia elliptica D. Don

The major components, 1-hydroxy-2,3,5-trimethoxy-xanthone (HM-1) and 1,5-dihydroxy-2,3-dimethoxy-xanthone (HM-5) isolated from Halenia elliptica D. Don (Gentianaceae), could cause vasodilatation in rat coronary artery with different mechanisms. In this work, high-performance liquid chromatography coupled to ion trap time-of-flight mass spectrometry (LCMS-IT-TOF) was used to clarify the metabolic pathways, and CYP450 isoform involvement of HM-1 and HM-5 were also studied in rat. At the same time, in vivo inhibition effects of HM-1 and ethyl acetate extracts from origin herb were studied. Three metabolites of HM-5 were found in rat liver microsomes (RLMs); demethylation and hydroxylation were the major phase I metabolic reactions for HM-5. Multiple CYP450s were involved in metabolism of HM-1 and HM-5. The inhibition study showed that HM-5 inhibited Cyp1a2, 2c6 and 2d2 in RLMs. HM-1 inhibited activities of Cyp1a2, Cyp2c6 and Cyp3a2. In vivo experiment demonstrated that both HM-1 and ethyl acetate extracts could inhibit Cyp3a2 in rats. In conclusion, the metabolism of xanthones from the origin herb involved multiple CYP450 isoforms; in vitro, metabolism of HM-5 was similar to that of its parent drug HM-1, but their inhibition effects upon CYP450s were different; in vivo, Cyp3a2 could be inhibited by HM-1 and ethyl acetate extracts.

Ameliorative effects of docosahexaenoic acid on the toxicity induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin in cultured rat hepatocytes

The 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is an environmental contaminant toxicant that mediates carcinogenic effects associated with oxidative DNA damage. Docosahexaenoic acid (DHA) with antioxidant functions has many biochemical, cellular, and physiological functions for cells. The present study assessed, for the first time, the ameliorative effect of DHA in alleviating the toxicity of TCDD on primary cultured rat hepatocytes (HEPs). In vitro, isolated HEPs were incubated with TCDD (5 and 10 μM) in the presence and absence of DHA (5, 10, and 20 μM) for 48 h. The cell viability was detected by 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyltetrazolium bromide (MTT) assay and lactate dehydrogenase (LDH) release. DNA damage was analyzed by liver micronucleus assay and 8-oxo-2-deoxyguanosine (8-OH-dG) level. In addition, total antioxidant capacity (TAC) and total oxidative stress (TOS) were assessed to determine the oxidative injury in HEPs. The results of MTT and LDH assays showed that TCDD decreased cell viability but not DHA. On the basis of increasing treatment concentrations, the dioxin caused significant increases of micronucleated HEPs and 8-OH-dG as compared to control culture. TCDD also led to significant increases in TOS content. On the contrary, in cultures treated with DHA, the level of TAC was significantly increased during treatment in a concentration-dependent fashion. DHA showed therapeutic potential against TCDD-mediated cell viability and DNA damages. As conclusion, this study provides the first evidence that DHA has protective effects against TCDD toxicity on primary cultured rat hepatocytes.

Genotoxic and oxidative damage potentials in human lymphocytes after exposure to terpinolene in vitro

Terpinolene (TPO) is a monocyclic monoterpene found in the essential oils of various fir and pine species. Recent reports indicated that several monoterpenes could exhibit antioxidant effects in both human and animal experimental models. However, so far, the nature and/or biological roles of TPO have not been elucidated in human models yet. The aim of this study was to investigate the genetic, oxidative and cytotoxic effects of TPO in cultured human blood cells (n = 5) for the first time. Human blood cells were treated with TPO (0-200 mg/L) for 24 and 48 h, and then cytotoxicity was detected by lactate dehydrogenase (LDH) release and [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assay, while DNA damage was also analyzed by micronucleus assay, sister chromatid exchanges assay and 8-oxo-2-deoxyguanosine (8-OH-dG) level. In addition, biochemical parameters [total antioxidant capacity (TAC) and total oxidative stress (TOS)] were examined to determine oxidative effects. The results of LDH and MTT assays showed that TPO (at concentrations greater than 100 mg/L) decreased cell viability. In our in vitro test systems, it was observed that TPO had no genotoxicity on human lymphocytes. Again, TPO (at 10, 25, 50 and 75 mg/L) treatment caused statistically important (p < 0.05) increases of TAC levels in human lymphocytes without changing TOS levels. In conclusion, TPO can be a new resource of therapeutics as recognized in this study with its non-genotoxic and antioxidant features.

Intestinal and hepatic expression of cytochrome P450s and mdr1a in rats with indomethacin-induced small intestinal ulcers

BACKGROUND

Non-steroidal anti-inflammatory drugs induce the serious side effect of small intestinal ulcerations (SIUs), but little information is available regarding the consequences to drug metabolism and absorption.

AIM

We examined the existence of secondary hepatic inflammation in rats with indomethacin (INM)-induced SIUs and assessed its relationship to the cytochrome P450 (CYP) and P-glycoprotein (mdr1a), the major drug-metabolizing factors in the small intestine and the liver.

METHODS

Gene expression of the CYP family of enzymes and mdr1a was measured with quantitative real-time polymerase chain reaction (qPCR). Vancomycin (VCM), a poorly absorbed drug, was administered intraduodenally to rats with SIUs.

RESULTS

INM induced SIUs predominantly in the lower region of the small intestine with high expression of inflammatory markers. Liver dysfunction was also observed, which suggested a secondary inflammatory response in rats with SIUs. In the liver of rats with SIUs, the expression of CYP2C11, CYP2E1, and CYP3A1 was significantly decreased, and loss of CYP3A protein was observed. Although previous studies have shown a direct effect of INM on CYP3A activity, we could not confirm any change in hepatic CY3A4 expression (major isoform of human CYP3A) in vitro. The plasma VCM concentration was increased in rats with SIUs due to partial absorption from the mucosal injury, but not in normal mucosa.

CONCLUSIONS

INM-induced SIUs had a subtle effect on intestinal CYP expression, but had an apparent action on hepatic CYP, which was influenced, at least in part, by the secondary inflammation. Furthermore, drug absorption was increased in rats with SIUs.

Investigation of cytotoxic, genotoxic and oxidative properties of carvacrol in human blood cells

Carvacrol (CVC), a major constituent of genera Origanum and Thymus, is such a substance that has attracted attention because of its wide variety of beneficial biological activities such as antibacterial, antifungal, and anticancer effects. However, there are limited data on the cytogenetic and antioxidant effects of CVC in cultured human blood cells. The aim of this study was to investigate for the first time the genetic, oxidative, and cytotoxic effects of CVC in cultured human blood cells ( n = 5). Human blood cells were treated with CVC (0–200 mg/L) for 24 and 48 h and then cytotoxicity detected by lactate dehydrogenase (LDH) release and (3-(4,5-dimethyl-thiazol-2-yl) 2,5-diphenyltetrazolium bromide) (MTT) assay, while DNA damage was also analyzed by micronucleus (MN) assay, chromosomal aberration (CA) assay and 8-oxo-2-deoxyguanosine (8-OH-dG) level. In addition, biochemical parameters (total antioxidant capacity [TAC] and total oxidative stress [TOS]) were examined to determine the oxidative effects. The results of LDH and MTT assays showed that CVC (at concentrations above 100 mg/L) decreased cell viability. In our in vitro test systems, it was observed that CVC had no mutagenic effects on human lymphocytes. On the other hand, CVC (at 50, 75, and 100 mg/L) treatment caused statistically important ( p < 0.05) increases in TAC and TOS levels (at 150 and 200 mg/L) on human lymphocytes. In conclusion, CVC can be a new resource of therapeutics as recognized in this study with their nonmutagenic and antioxidant features.

In vitro assessment of cytogenetic and oxidative effects of α-pinene

α-Pinene (α-pinene), a bicyclic monoterpene, is present in the oils of many species of coniferous trees, most notably the pine, and is known for its diverse biological properties such as antimicrobial, anti-inflammatory, antiproliferative and antioxidant. However, there are limited data on the cytogenetic and antioxidant effects of α-pinene in cultured human blood cells (n = 5) for the first time. The purpose of this study was to investigate the genetic, oxidative, and cytotoxic effects of α-pinene in cultured human blood cells (n = 5) for the first time. Human blood cells were treated with α-pinene (0 to 200 mg/L) for 24 and 48 h, and then cytotoxicity was detected by lactate dehydrogenase (LDH) release and (3-(4,5-dimethyl-thiazol-2-yl) 2,5-diphenyltetrazolium bromide) (MTT) assay, while DNA damage was also analyzed by micronucleus (MN) assay, chromosomal aberration (CA) assay and 8-oxo-2-deoxyguanosine (8-OH-dG). In addition, biochemical parameters (total antioxidant capacity (TAC) and total oxidative stress (TOS)) were examined to determine oxidative effects. The results of LDH and MTT assays showed that α-pinene (at 200 mg/L) decreased cell viability. In our in vitro test systems, it was observed that α-pinene did not cause any statistically important changes in the rates of studied genotoxicity endpoints but dose-dependent alterations were observed in TAC and TOS levels. α-Pinene treatment caused increases in TAC levels (at 25 and 50 mg/L) and decreases in TOS levels (only at 200 mg/L) on human lymphocytes. In conclusion, the findings of the present study confirm for the first time that α-pinene could be a significant source of natural antioxidant compound that may have beneficial health effects.

Ameliorative effect of supplementation with L-glutamine on oxidative stress, DNA damage, cell viability and hepatotoxicity induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin in rat hepatocyte cultures

The most potent of the dioxins, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), is a persistent and ubiquitous environmental contaminant. And the health impact of exposure to TCDD is of great concern to the general public. Recent data indicate that L-glutamine (Gln) has antioxidant properties and may influence hepatotoxicity. The objective of the present study was undertaken to explore the effectiveness of Gln in alleviating the hepatotoxicity of TCDD on primary cultured rat hepatocytes. Gln (0.5, 1 and 2 mM) was added to cultures alone or simultaneously with TCDD (0.005 and 0.01 mM). The hepatocytes were treated with TCDD and Gln for 48 h. Then cell viability was detected by [3-(4,5-dimethyl-thiazol-2-yl) 2,5-diphenyltetrazolium bromide] (MTT) assay and lactate dehydrogenase (LDH) release, while total antioxidant capacity (TAC), total glutathione (TGSH) and total oxidative stress (TOS) levels were determined to evaluate the oxidative injury. The DNA damage was also analyzed by liver micronucleus assay (MN) and 8-oxo-2-deoxyguanosine (8-OH-dG). The results of MTT and LDH assays showed that TCDD decreased cell viability but not L-glutamine. TCDD also increased TOS level in rat hepatocytes and significantly decreased TAC and TGSH levels. On the basis of increasing doses, the dioxin in a dose-dependent manner caused significant increases of micronucleated hepatocytes (MNHEPs) and 8-OH-dG as compared to control culture. Whereas, in cultures exposured with Gln alone, TOS levels were not changed and TAC and TGSH together were significantly increased in dose-dependent fashion. The presence of Gln with TCDD modulated the hepatotoxic effects of TCDD on primary hepatocytes cultures. Noteworthy, Gln has a protective effect against TCDD-mediated DNA damages. As conclusion, we reported here an increased potential therapeutic significance of L-glutamine in TCDD-mediated hepatic injury for the first time.

The impaired disposition of probe drugs is due to both liver and kidney dysfunctions in CCl(4)-model rats

The carbon tetrachloride (CCl(4))-treated model involving mature Sprague-Dawley rats has been historically relied upon to study liver injury and regeneration and to test drug efficacy and disposition. However, there few studies about phase II metabolic enzymes changes in CCl(4)-model rats. The metabolic and excretion tests of phenacetin and acetaminophen (APAP), and the mRNA test of cytochrome P4501A2 (CYP1A2) and phase II metabolic enzymes [sulfotransferase 1A1 (SULT1A1) and UDP-glucuronosyltransferase 1A6 (UGT1A6)] were studied in model rats after CCl(4) pretreatment. The result showed that the function and structure of liver and kidney was impaired by CCl(4) pretreatment, and a significant difference has been observed in the mRNA content of CYP1A2 (p<0.01) in model group, but there was no significant difference on the mRNA content of SULT1A1 and UGT1A6 in both groups. Compared to the control group, a significant higher content of phenacetin (p<0.01) and sulfate-APAP (AS, p<0.01) was observed in the metabolic tests of phenacetin and APAP. Statistically significant differences in cumulative urinary excretion levels of APAP, AG and AS for CCl(4) model rats were observed also. We have shown that impaired disposition of probe drugs in this model was due to both liver and kidney dysfunction in CCl(4)-model rats and we should consider the development of a new liver damage model without renal impairment.

Eicosapentaenoic acid protects against 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced hepatic toxicity in cultured rat hepatocytes

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a persistent and ubiquitous environmental contaminant. The health impact of TCDD exposure is of great concern to the general public. Recent reports have implied that eicosapentaenoic acid (EPA) might be a potential chemopreventive agent and influence hepatotoxicity. The aim of the current study was to explore the effectiveness of EPA in alleviating the toxicity of TCDD on primary cultured rat hepatocytes. EPA (5, 10 and 20 μM) was added to cultures alone or simultaneously with TCDD (5 and 10 μM). Rat hepatocytes were treated with TCDD and EPA for 48 h, and then cytotoxicity was detected by [3-(4,5-dimethyl-thiazol-2-yl) 2,5-diphenyltetrazolium bromide] (MTT) assay and lactate dehydrogenase (LDH) release, while total antioxidant capacity (TAC) and total oxidative stress (TOS) levels were determined to evaluate the oxidative injury. The DNA damage was also analyzed by liver micronucleus assay (LMN) and 8-oxo-2-deoxyguanosine (8-OH-dG). The results of MTT and LDH assays showed that TCDD but not EPA decreased cell viability. TCDD also increased TOS level and significantly decreased TAC level in rat hepatocytes in a clear dose dependent manner. On the basis of increasing doses, the dioxin caused significant increases of micronucleated hepatocytes (MNHEPs) and 8-OH-dG as compared to control culture. Whereas, in cultures treated with EPA alone, TOS level did not change and the level of TAC significantly increased. The presence of EPA with TCDD minimized the toxic effects of the dioxin on primary hepatocytes cultures. Noteworthy, EPA has a protective effect against TCDD-mediated DNA damages.

Propolis protects against 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced toxicity in rat hepatocytes

The present experiment was undertaken to determine the effectiveness of propolis in alleviating the toxicity of TCDD on cultured primary rat hepatocytes. Propolis (25, 50 and 100 μM) was added to plain culture or simultaneously with TCDD (5 and 10 μM). The hepatocytes were treated with TCDD and propolis for 48 h. Then cell viability was detected by [3-(4,5-dimethyl-thiazol-2-yl) 2,5-diphenyltetrazolium bromide] (MTT) assay and lactate dehydrogenase (LDH) release, while total antioxidant capacity (TAC) and total oxidative stress (TOS) levels were determined to evaluate the oxidative injury. The DNA damage was also analyzed by liver micronucleus assay (LMN) and 8-oxo-2-deoxyguanosine (8-OH-dG). The results of MTT and LDH assays showed that TCDD decreased cell viability. TCDD also increased TOS level and decreased TAC level in rat hepatocytes. On the basis of increasing doses, the TCDD caused significant increases of micronucleated hepatocytes (MNHEPs) and 8-OH-dG levels as compared to control culture. In cultures treated with propolis alone, cell viability and TOS level were not affected, while the level of TAC was significantly increased in dose-dependent fashion. The presence of propolis with TCDD modulated its toxic effects on primary hepatocytes cultures. Noteworthy, propolis has a protective effect against TCDD-mediated DNA damages.

Protective effects of baicalin on carbon tetrachloride induced liver injury by activating PPARγ and inhibiting TGFβ1

CONTEXT

Traditional Chinese herbal medicines have attracted considerable attention in many countries with treatment of several end-stage liver diseases.

OBJECTIVE

The present study investigated the protective effects of baicalin on hepatotoxicity and hepatic fibrosis and explored the role of transforming growth factor β1 (TGFβ1) and peroxisome proliferator activated receptors γ (PPARγ) on the rat liver injury model.

MATERIALS AND METHODS

The rat liver injury model was introduced by subcutaneous injection of carbon tetrachloride (CCl(4)) for 8 weeks. At week 5, rats were treated with baicalin of different doses or silymarin. Detection of biochemical indicators, histological analysis, and enzyme-linked immunosorbent assays were employed to evaluate severity of liver inflammation, and western blotting and RT-PCR assay were performed to evaluate TGFβ1 and PPARγ pathway related proteins and gene expression.

RESULTS

The administration of baicalin could significantly improve histological changes of CCl(4) treated rat livers and return biochemical indicators for liver injury to nearly baseline level. In addition, the increased expression of TGFβ1 was markedly suppressed by baicalin, and decreased expression of PPARγ was also dramatically elevated by baicalin as well. The hepatoprotective effects of baicalin may be conferred by elevating the level of PPARγ contributing to down-regulation of TGFβ1 signaling pathway and suppression of hepatic stellate cell activation.

CONCLUSIONS

The studies demonstrated that baicalin is a potent and promising antifibrotic drug in the treatment of hepatic fibrosis.

TOP1 and 2, polysaccharides from Taraxacum officinale, attenuate CCl(4)-induced hepatic damage through the modulation of NF-kappaB and its regulatory mediators

In this work, we estimate the inhibitory effect of two polysaccharides from Taraxacum officinale (TOP) on CCl(4)-induced oxidative stress and inflammation in Sprague-Dawley rats. TOP1 and 2 (304, 92 mg/kg bw) were administered for 7 days via a stomach sonde, and hepatitis was induced by a single dose of CCl(4) (50% CCl(4)/olive oil; 0.5 mL/kg bw) administration. CCl(4) significantly elevated serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities. Histopathological observation further revealed that CCl(4)-induced moderate levels of inflammatory cell infiltration, centrilobular fatty change, apoptosis, and necrosis. However, TOPs pretreatment markedly decreased AST and ALT activities as well as hepatic lesions. TOPs also increased free radical scavenging activity, as exhibited by a lowered TBARS concentration. TOPs pretreatment also reversed other hepatitis-associated symptoms, including GSH depletion, inhibited anti-oxidative enzyme activities, up-regulation of NF-kappaB and increased expression of its regulatory inflammatory mediators, such as inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, tumor necrosis factor (TNF)-alpha, and interleukin (IL)-1beta. These results suggest that TOPs have a hepatoprotective effect by modulating inflammatory responses and ameliorating oxidative stress.

Pharmacokinetics of bicyclol in rats with acute hepatic failure

The aim of present study is to evaluate the pharmacokinetics of bicyclol in carbon tetrachloride (CCl(4))-intoxicated rats. The plasma concentration of bicyclol was detected in rats after a single oral or intravenous administration by high-performance liquid chromatography (HPLC) analysis. Rat intestinal and hepatic perfusion models were employed to clarify the respective effect of gut and liver on the pharmacokinetics of bicyclol in acute hepatic failure (AHF) rats. Rat in vitro microsomal incubation was also conducted. The bioavailability of bicyclol was increased 3.1-fold after CCl(4) intoxication in rats. The area under the curve (AUC)((0-infinity)), C(max), and clearance (CL) of bicyclol after intravenous administration were 13.4 mg h l(-1), 18.8 mg l(-1), and 1.8 l h(-1) kg(-1) in control rats, and 130 mg h l(-1), 33.1 mg l(-1), and 0.15 l h(-1) kg(-1) in AHF rats, respectively. In the present study we investigated the pharmacokinetics of bicyclol in CCl(4)-intoxicated rats and differentiated the respective role of intestine and liver by using in situ intestinal and hepatic perfusion in rats, and in vitro rat microsomes incubation. The studies are expected to provide a better understanding related to the alteration of pharmacokinetics of bicyclol in pathological situation.

Quercetin prevents oxidative stress in cirrhotic rats

Our aim was to study the protective effect of quercitin on liver cirrhosis induced by carbon tetrachloride (CCl(4)) in rats and its relationship with liver morphology. Thirty male Wistar rats weighing 200-250 g were randomly divided into three groups: control, CCl(4), and CCl(4)+ quercetin. Rats in the experimental groups were given CCl(4) (0.5 ml/kg i.p.), diluted 1:6 in vegetable oil (5 mmol/kg body wt), at 10:00 p.m. every 4 days for 17 weeks. Quercetin (500 microl/kg i.p.; 150 micromol/kg body wt) or vehicle was administered at 6:00 p.m. for the last 3 weeks of the study. Control group rats were given only olive oil for the same period. At the end of the 17 weeks, all rats were sacrificed. Blood samples were taken for determination of serum indicators (ALT, AST, total bilirubin, conjugated bilirubin, factor V) and the livers were dissected out and divided into two parts: one was homogenized and the supernatant was used for measurement of superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPx) activities, as well as lipid peroxidation. The other part was used for the histopathological study. CCl(4) caused a marked rise in serum levels of ALT, AST, total bilirubin, and conjugated bilirubin, as well as a decrease in factor V (P<0.05). Lipid peroxidation levels were significantly increased, whereas GSH, SOD, catalase, GPx, and GST levels were decreased in the liver of CCl(4)-treated rats. Quercetin (50 mg/kg/day) successfully attenuated these effects of CCl(4). We conclude that quercetin has beneficial effects on liver fibrosis in rats by enhancing antioxidant enzyme activity and decreasing the pro-oxidant effect.

A proteomic method for analysis of CYP450s protein expression changes in carbon tetrachloride induced male rat liver microsomes

Carbon tetrachloride (CCl(4)) is a well-known model compound for producing chemical hepatic injury. Cytochrome P450 is an important monooxygenase in biology. We investigated the CYP450 protein expression in the in vivo hepatotoxicity of rats induced by CCl(4). In this experiment, CCl(4) were administered to male rats, and their livers at 24h post-dosing were applied to the proteomic analysis. Blood biochemistry and histopathology were examined to identify specific changes. At the same time, a novel acetylation stable isotopic labeling method coupled with LTQ-FTICR mass spectrometry was applied to disclose the changes of cytochrome P450 expression amounts. The quantitative proteomics method demonstrated its correlation coefficient was 0.9998 in a 100-fold dynamic range and the average ratio of the labeled peptides was 1.04, which was very close to the theoretical ratio of 1.00 and the standard deviation (S.D.) of 0.21. With this approach, 17 cytochrome P450 proteins were identified and quantified with high confidence. Among them, the expression amount of 2C11, 3A2, and 2 E1 were down-regulated, while that of 2C6, 2B2, and 2B1 were up-regulated.

Change of drug excretory pathway by CCl4-induced liver dysfunction in rat

Liver dysfunction affects the pharmacokinetics of drugs. The liver plays an important role in drug excretion as well as drug metabolism and pharmacokinetics. In the present study, the relationship between changes in the cefmetazole (CMZ) excretory pathway and the degree of liver dysfunction induced by CCl(4) treatment was investigated. CMZ is mainly excreted as an unchanged form in feces in control rats. Depending on the serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT), urinary CMZ excretion was increased, whereas fecal CMZ excretion was decreased in rat with liver dysfunction. The AUC of CMZ in rats with severe liver dysfunction was approximately 2-fold higher than that in control rats. Since drug transporters could be involved in drug excretion, changes in the expression of representative hepatic drug transporters in liver dysfunction were investigated by rat DNA microarray. Basolateral solute carrier transporters such as Ntcp, Oct1, and Oatp2 were decreased and basolateral ATP-binding cassette transporters such as Mrp3 and Mrp4 were increased by the CCl(4) treatment. On the other hand, canalicular Mrp2 and Bsep were decreased, but Mdr1 was increased. However, the transporter system for CMZ has not been identified yet. In conclusion, we clarified that the fecal and urinary excretory profiles of CMZ were changed clearly depending on the serum AST and ALT levels in liver dysfunction. The changes in the CMZ excretory pathway might be responsible for the changes in the expression of drug transporters.

Influence of chronic hepatic failure on disposition kinetics of valproate excretion through a phase II reaction in rats treated with carbon tetrachloride

The influence of chronic hepatic failure on the disposition kinetics of valproate (VPA) excretion via a phase II reaction was examined in rats treated with carbon tetrachloride (1.0 mg/kg, s.c., 3 times a week) for 2 or 3 months. There was no significant difference in the plasma concentration-time courses of VPA among the control and two treated groups up to 120 min after i.v. administration of VPA (75 mg/kg), but subsequently the plasma concentrations of the treated groups declined significantly below the control levels. Expression of Mrp2 mRNA in the liver of the treated groups was significantly lower than in the control group; conversely that in the kidney was significantly higher. The enzyme activity of UGTs in the liver of the treated groups decreased significantly, but UGT1A8 mRNA expression in the duodenum was increased about 3-fold. Cumulative excretion of VPA glucuronide (VPA-G) in bile of the treated groups was reduced significantly, while that in urine was markedly increased. In conclusion, the area under the VPA plasma concentration-time curve was decreased significantly in rats with chronic hepatic failure owing to increased excretion of VPA-G via the kidney as a result of induction of Mrp2, and inhibition of enterohepatic circulation of VPA-G.

Development of dosage design of hepatic metabolizing drugs using serum albumin level in chronic hepatic failure

We have previously reported good correlations among serum aminotransferase (AST) activity, metabolic enzyme activity of CYPs, and total clearance (CL(tot)) of probe drugs in rats with acute hepatic failure induced by CCl4. In this study, we searched for new biochemical indicators that correlate with hepatic function and tried to simulate appropriate drug dosage in chronic hepatic failure. Model rats were prepared by administration of CCl4 (1 ml/kg, s.c., 3 times/week) and used at 48 h after the last administration. Serum albumin concentration was time-dependently decreased and correlated well with 3 major biologic determinants of drug clearance, hepatic blood flow (HBF), intrinsic clearance (CL(int)), and the unbound fraction of drugs in plasma (fp) after intravenous administration of cyclophosphamide, tolbutamide, zonisamide, and chlorzoxazone (as probe drugs for low hepatic extraction) and propranolol and lidocaine (as high-hepatic extraction drugs). By calculating these parameters based on prediction equations by the level of albumin, CL(tot) was obtained. As a result of having evaluated this model using administration of cyclosporin, there was a statistically significant relationship between predicted CL(tot) and observed CL(tot). In conclusion, the value of serum albumin level is a useful parameter that correlates well with chronic hepatic function. We have shown that this quantitative administering design using serum albumin level can predict appropriate dosages of hepatic metabolizing drugs in chronic hepatic failure.

Obesity-induced increase of CYP2E1 activity and its effect on disposition kinetics of chlorzoxazone in Zucker rats

This study was designed to investigate the induction of CYP2E1 in obese Zucker rats and its effect on the disposition kinetics of chlorzoxazone (CZX). CZX 20mg/kg was administered to three groups of rats: normal Zucker rats fed a normal diet (ND), normal Zucker rats fed a high-fat diet (HF), and genetically obese Zucker rats fed a normal diet (OB). The values of the area under the plasma concentration-time curve from 0 to infinity (AUC(infinity)) of CZX were in the order of ND>HF>OB rats. The AUC(infinity) values of total 6-hydroxychlorzoxazone (6OHCZX-T), which is considered to be a CYP2E1 metabolic marker, were in the opposite order. The values of the AUC(infinity) ratio (6OHCZX-T/CZX) in ND, HF and OB rats were approximately 0.2, 0.3 and 0.4, respectively. The CZX concentration in fat was much higher than the concentrations in plasma, liver and kidney in all groups. Induction of CYP2E1 protein was greater in both liver and fat of OB rats than in those of HF rats. Microsomal activity of CYP2E1 in liver and fat was also in the order of OB>HF>NM rats. These results suggest that CYP2E1 may be induced in liver and fat of obese patients, thereby potentially altering the disposition kinetics of not only CZX, but also other lipophilic drugs metabolized by CYP2E1.

Serum aminotransferase activity as a predictor for estimation of total clearance of hepatically metabolized drugs in rats with acute hepatic failure

The levels of serum aminotransferase activity, including aspartate aminotransferase (AST), in rats with acute hepatic failure at 24 h after an oral administration of CCl4 (0.01-0.5 ml/kg) were about 15-50 times higher (up to nearly 5000 IU/l) than those of vehicle control rats (about 85 IU/l). The values of total clearance (CL(tot)) of cyclosporin A, doxorubicin, tacrolimus and zonisamide in the CCl4-treated rats were decreased to about 1/2-1/3 of those in control rats. There were good correlations between AST activity and hepatic intrinsic clearance (CL(int)) (r=0.733-0.949) for the above drugs, as well as for chlorzoxazone, caffeine, lidocaine and tolbutamide after the intravenous administration of each drug in rats with acute hepatic failure. However, the slope of the linear regression equation, i.e., the ratio of decrease of CL(int) against increase of AST activity, differed markedly among these drugs. We found that there is a good correlation (r=0.953) between the values of the slope and the CL(int) of normal rats for these drugs, except for caffeine. In summary, the linear regression equation enables us to predict the decrease of CL(tot) in rats with acute hepatic failure to be predicted from the increase in serum AST activity. This approach may be useful as a guide for the dose modification of drugs for patients with acute hepatic failure.

Selective protection of curcumin against carbon tetrachloride-induced inactivation of hepatic cytochrome P450 isozymes in rats

We investigated the effects of curcumin, a major antioxidant constituent of turmeric, on hepatic cytochrome P450 (CYP) activity in rats. Wistar rats received curcumin-containing diets (0.05, 0.5 and 5 g/kg diet) with or without injection of carbon tetrachloride (CCl(4)). The hepatic CYP content and activities of six CYP isozymes remained unchanged by curcumin treatment, except for the group treated with the extremely high dose (5 g/kg). This suggested that daily dose of curcumin does not cause CYP-mediated interaction with co-administered drugs. Chronic CCl(4) injection drastically decreased CYP activity, especially CYP2E1 activity, which is involved in the bioactivation of CCl(4), thereby producing reactive free radicals. Treatment with curcumin at 0.5 g/kg alleviated the CCl(4)-induced inactivation of CYPs 1A, 2B, 2C and 3A isozymes, except for CYP2E1. The lack of effect of curcumin on CYP2E1 damage might be related to suicidal radical production by CYP2E1 on the same enzyme. It is speculated that curcumin inhibited CCl(4)-induced secondary hepatic CYPs damage through its antioxidant properties. Our results demonstrated that CYP isozyme inactivation in rat liver caused by CCl(4) was inhibited by curcumin. Dietary intake of curcumin may protect against CCl(4)-induced hepatic CYP inactivation via its antioxidant properties, without inducing hepatic CYPs.