Cytochrome P450 2E1 (CYP2E1) is a key target protein in the development of alcoholic and nonalcoholic fatty liver disease (FLD). The pathophysiological correlate is the massive production of reactive oxygen species. The role of CYP2E1 in the development of hepatocellular carcinoma (HCC), the final complication of FLD, remains controversial. Specifically, CYP2E1 has not yet been defined as a molecular target for HCC therapy. In addition, a CYP2E1-specific drug has not been developed. We have already shown that our newly developed CYP2E1 inhibitor 12-imidazolyl-1-dodecanol (I-ol) was therapeutically effective against alcoholic and nonalcoholic steatohepatitis. In this study, we investigated the effect of I-ol on HCC tumorigenesis and whether I-ol could serve as a possible treatment option for terminal-stage FLD. I-ol exerted a very highly significant antitumour effect against hepatocellular HepG2 cells. Cell viability was reduced in a dose-dependent manner, with only the highest doses causing a cytotoxic effect associated with caspase 3/7 activation. Comparable results were obtained for the model colorectal adenocarcinoma cell line, DLD-1, whose tumorigenesis is also associated with CYP2E1. Transcriptome analyses showed a clear effect of I-ol on apoptosis and cell-cycle regulation, with the increased expression of p27Kip1 being particularly noticeable. These observations were confirmed at the protein level for HepG2 and DLD-1 cells grafted on a chorioallantoic membrane. Cell-cycle analysis showed a complete loss of proliferating cells with a simultaneous increase in S-phase arrest beginning at a threshold dose of 30 μM. I-ol also reduced xenograft tumour growth in nude mice. This antitumour effect was not associated with tumour cachexia. I-ol was not toxic to healthy tissues or organs. This study demonstrates for the first time the therapeutic effect of the specific CYP2E1 inhibitor I-ol on the tumorigenesis of HCC. Our findings imply that I-ol can potentially be applied therapeutically on patients at the final stage of FLD.

Cytochrome P450 2E1 (CYP2E1)‐associated reactive oxygen species production plays an important role in the development and progression of inflammatory liver diseases such as alcoholic steatohepatitis. We developed two new inhibitors for this isoenzyme, namely 12‐imidazolyl‐1‐dodecanol (I‐ol) and 1‐imidazolyldodecane (I‐an), and aimed to test their effects on non‐alcoholic steatohepatitis (NASH). The fat‐rich and CYP2E1 inducing Lieber‐DeCarli diet was administered over 16 weeks of the experimental period to induce the disease in a rat model, and the experimental substances were administered simultaneously over the last four weeks. The high‐fat diet (HFD) pathologically altered the balance of reactive oxygen species and raised the activities of the liver enzymes alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (AP) and γ‐glutamyl‐transferase (γ‐GT); lowered the level of adiponectine and raised the one of tumor necrosis factor (TNF)‐α; increased the hepatic triglyceride and phospholipid content and diminished the serum HDL cholesterol concentration. Together with the histological findings, we concluded that the diet led to the development of NASH. I‐ol and, to a lesser extent, I‐an shifted the pathological values toward the normal range, despite the continued administration of the noxious agent (HFD). The hepatoprotective drug ursodeoxycholic acid (UDCA), which is used off‐label in clinical practice, showed a lower effectiveness overall. I‐ol, in particular, showed extremely good tolerability during the acute toxicity study in rats. Therefore, cytochrome P450 2E1 may be considered a suitable drug target, with I‐ol and I‐an being promising drug candidates for the treatment of NASH.

Background and aims Alcoholic steatohepatitis (ASH)—the inflammation of fatty liver—is caused by chronic alcohol consumption and represents one of the leading chronic liver diseases in Western Countries. ASH can lead to organ dysfunction or progress to hepatocellular carcinoma (HCC). Long-term alcohol abstinence reduces this probability and is the prerequisite for liver transplantation—the only effective therapy option at present. Elevated enzymatic activity of cytochrome P450 2E1 (CYP2E1) is known to be critically responsible for the development of ASH due to excessively high levels of reactive oxygen species (ROS) during metabolization of ethanol. Up to now, no rational drug discovery process was successfully initiated to target CYP2E1 for the treatment of ASH. Methods In this study, we applied a rational drug design concept to develop drug candidates (NCE) including preclinical studies. Results A new class of drug candidates was generated successfully. Two of the most promising small compounds named 12-Imidazolyl-1-dodecanol (abbr.: I-ol) and 1-Imidazolyldodecane (abbr.: I-an) were selected at the end of this process of drug discovery and developability. These new ω-imidazolyl-alkyl derivatives act as strong chimeric CYP2E1 inhibitors at a nanomolar range. They restore redox balance, reduce inflammation process as well as the fat content in the liver and rescue the physiological liver architecture of rats consuming continuously a high amount of alcohol. Conclusions Due to its oral application and therapeutic superiority over an off-label use of the hepatoprotector ursodeoxycholic acid (UDCA), this new class of inhibitors marks the first rational, pharmaceutical concept in long-term treatment of ASH.

Cytochrome P450 2E1 (CYP2E1) and its production of ROS play an essential role in the development and progression of inflammatory liver diseases such as alcoholic steatohepatitis. For this isoenzyme we have developed two new inhibitors - 12-imidazolyl-1-dodecanol (I-ol) and 1-imidazolyldodecane (I-an) - and wanted to test their effect on the related disease of non-alcoholic steatohepatitis (NASH). The fat-rich Lieber-DeCarli diet, which was administered over the entire experimental period of 16 weeks, was used for disease induction in the rat model, while the experimental substances were administered in parallel over the last four weeks. This high-calorie diet pathologically altered the ROS balance, the amount of adipocytokines, TNF-α and lipids as well as the activities of liver enzymes. Together with the histological examinations, the conclusion could be drawn that the diet led to the formation of NASH. I-ol and to a lesser extent I-an were able to shift the pathological values towards the normal range - despite continued administration of the noxious agent. I-ol, in particular, showed an extremely good tolerability in the acute toxicity study in rats. Thus, CYP2E1 appears to be a suitable drug target as well as I-ol and I-an promising drug candidates for the treatment of NASH.

Catalytic activities of native human CYP3A4-mediated reactions as well as drug interactions were directly evaluated by isolated reconstituted human CYP3A4: NADPH-cytochrome P450 reductase systems. The SDS-PAGE pure CYP3A4 and human NADPH-cytochrome P450 reductase had been incorporated into a binary vesicular phospholipid system of dilauroyl-phosphatidyl-choline and phosphatidyl-serine which had proven to achieve optimal nifedipine oxidase activity (19.6 nmol nifedipine oxidized x min(-1) x nmol CYP3A4(-1)). The IC50 values of ketoconazole (CAS 65 277-42-1) (approximately 3 micromol/l), quinidine (CAS 56-54-2) (approximately 5 micromol/l), mifepristone (CAS 84 371-65-3) (-8 micromol/l), 17alpha-ethinylestradiol (CAS 57-63-6) (approximately 17 micromol/l), cimetidine (CAS 51 481-61-9) (approximately 46 micromol/l), FK 506 (tacrolimus) (CAS 104 987-11-3) (approximately 53 micromol/l), naringenin (CAS 480-41-1) (approximately 87 micromol/l), and cyclosporine A (CAS 59 865-13-3) (approximately 90 micromol/l) indicate that all these drugs have an inhibitory effect on nifedipine (CAS 21 829-25-4) metabolism, whereas the drug quinine (CAS 130-95-0) did not elicit any significant inhibition.

In our recently published study we have detected in livers from Sprague-Dawley rats given fructose-enriched diet (FED) and developed NAFLD, increased hepatic triglycerides (+198%), increased hepatic cholesterol (+89%) and hypertriglyceridemia (+223%).The genetic risk factors involved in the pathogenesis of NAFLD are poorly understood.Methods: We investigated the gene expressions of: 1. Microsomal triglyceride transfer protein (MTP) involved in hepatic lipid synthesis, storage and export.2. Manganese-dependent superoxide dismutase 2 (MnSOD2), encoding proteins involved in the response to oxidant stress.3. Peroxisome proliferator-activated receptor (PPAR)-a involved in hepatic fatty acid oxidation, in rats that were administered FED (n = 6) or standard rat chow (n = 3) for five weeks.Intrahepatic messenger RNA (mRNA) levels of MTP, MnSOD2 and PPAR-a were measured by real-time polymerase chain reaction using Taqman gene expression assays (Applied Biosystems, Foster City, CA) in FED rats and in standard rat chow.Results: In the FED rats, liver histology demonstrated diffused macrovesicular and micro-vesicular steatosis.1. MTP mRNA level was statistically significant decreased in FED rats (by 85%) (P < 0.0001) compared with the standard rat chow.2. MnSOD2 mRNA level was statistically significant decreased in FED rats (by 80%) (P < 0.001) compared with the standard rat chow.3. PPAR-a mRNA level was statistically significant decreased in FED rats (by 95%) (P < 0.0001) compared with the standard rat chow.Conclusions: the reduced expression of MTP, MnSOD2 and PPAR-a in the FED rats implies these genes are involved in the pathogenesis of NAFLD.Further studies are needed to confirm our results.

Abstract The inhibitory potency of four alkylphospholipids: rac-1-O-phosphocholine-2-hydroxy-octadecane (rac-2-OH), rac-1-O-phosphocholine-2-O-acetyl-octadecane (rac-2-O-acetyl), rac-1- O-phosphocholine-2-amino-octadecane (rac-2-NH2) and rac-1-O-phosphocholine-2-N-acetyloctadecane (rac-2-N-acetyl), on the cytochrome P450-dependent monooxygenase activity has been evaluated. The IC50 values of the alkylphosphocholines with 7-ethoxycoumarin as substrate in liver microsomal fractions of PB-treated rats and with a reconstituted CYP2B1: NADPH-P450-reductase system are in the range of 3.2D5.0 μм and 2.8D3.5 μм, respectively. Lineweaver-Burk plots with the inhibitors in concentrations that were found to cause roughly a 50% inhibition and with 7-ethoxycoumarin as substrate revealed for all four alkylphospholipids a competitive inhibition type. The degree of the competitive inhibition is quantified by the Ki values. With liver microsomal fractions of PB-treated rats, the Ki values of rac-2-OH (Ki = 1.36 μм) and rac-2-O-acetyl (Ki = 1.33 μm) differs slightly from those of rac-2-NH2 (Ki = 2.2 μм) and rac-2-N-acetyl (Ki = 2.2 μм), but with the reconstituted CYP2B1: NADPHP450- reductase system all Ki values are in the small range of 1.8 D 2.6 μм, indicating that the short substituted group at the 2-position (OH; O-acetyl; NH2; N-acetyl) of the long chain octadecanol part of the phosphodiesters exhibit no essential role on the strong inhibitory potency of these alkylphosphocholines on the 7-ethoxycoumarin-O-deethylase activity.

This study assesses the diagnostic accuracy of transferrinuria and an albumin-specific dipstick assay for detection of renal target organ damage (microalbuminuria) in hypertensive patients in a general practice setting. A spot urine sample of 130 nondiabetic patients with elevated office blood pressure readings (>140 and/or 90 mmHg) was investigated by measuring albumin to creatinine ratio (ACR) and transferrin to creatinine ratio (TCR) and by using an albumin-specific dipstick test (Micral®). ACR was considered as comparative gold standard. TCR was elevated (>0.19 mg/mmol) in 26 urine samples (20.0% of the test samples). ACR was raised in 29 samples (22.3% of the test samples). Elevated TCR had a sensitivity of 97% and specificity of 91% for detection of microalbuminuria. Positive predicting value for microalbuminuria was 65%; negative predicting value was 99%. Correlation between ACR and TCR was strong ( r =0.96). Dipstick testing for albumin was positive in 23 urine samples (17.7% of the test samples), 27 (20.8%) tests were false positive and six (4.6%) false negative. When dipstick was positive, the sensitivity of detecting microalbuminuria was 79%, and specificity 73%. In conclusion, detection of urinary transferrin in nondiabetic patients with hypertension is strongly associated with urinary albumin excretion. However, assessment of TCR does not identify additional patients with microalbuminuria compared to measurement of ACR alone. The semiquantitative Micral test offers a simple and valuable method to screen hypertensive patients for microalbuminuria in a primary care setting.