Polyenylphosphatidylcholine attenuates non-alcoholic hepatic fibrosis and accelerates its regression

Soybean polyenylphosphatidylcholine (PPC) is beneficial in liver and extrahepatic tissue injury: An update in experimental research

Polyenylphosphatidylcholine (PPC) is a purified polyunsaturated phosphatidylcholine extract of soybeans. This article updates PPC's beneficial effects on various forms of liver cell injury and other tissues in experimental research. PPC downregulates hepatocyte CYP2E1 expression and associated hepatotoxicity, as well as attenuates oxidative stress, apoptosis, lipoprotein oxidation and steatosis in alcoholic and nonalcoholic liver injury. PPC inhibits pro-inflammatory cytokine production, while stimulating anti-inflammatory cytokine secretion in ethanol or lipopolysaccharide-stimulated Kupffer cells/macrophages. It promotes M2-type macrophage polarization and metabolic reprogramming of glucose and lipid metabolism. PPC mitigates steatosis in NAFLD through inhibiting polarization of pro-inflammatory M1-type Kupffer cells, alleviating metabolic inflammation, remodeling hepatic lipid metabolism, correcting imbalances between lipogenesis and lipolysis and enhancing lipoprotein secretion from hepatocytes. PPC is antifibrotic by preventing progression of alcoholic hepatic fibrosis in baboons and also prevents CCl4-induced fibrosis in rats. PPC supplementation replenishes the phosphatidylcholine content of damaged cell membranes, resulting in increased membrane fluidity and functioning. Phosphatidylcholine repletion prevents increased membrane curvature of the endoplasmic reticulum and Golgi and decreases sterol regulatory element binding protein-1-mediated lipogenesis, reducing steatosis. PPC remodels gut microbiota and affects hepatic lipid metabolism via the gut-hepatic-axis and also alleviates brain inflammatory responses and cognitive impairment via the gut-brain-axis. Additionally, PPC protects extrahepatic tissues from injury caused by various toxic compounds by reducing oxidative stress, inflammation, and membrane damage. It also stimulates liver regeneration, enhances sensitivity of cancer cells to radiotherapy/chemotherapy, and inhibits experimental hepatocarcinogenesis. PPC's beneficial effects justify it as a supportive treatment of liver disease.

Effectiveness of phosphatidylcholine as adjunctive therapy in improving liver function tests in patients with non-alcoholic fatty liver disease and metabolic comorbidities: real-life observational study from Russia

Objective

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of abnormal results of liver function tests. Earlier research showed that polyenylphosphatidylcholine (PPC) has hepatoprotective effects and thus can be used for the treatment of NAFLD and the prevention of its progression. Accordingly, the aim of this observational study was to evaluate if PPC administered as adjunctive therapy in routine clinical practice can effectively improve liver function tests of NAFLD in Russian patients with associated metabolic comorbidities.

Design

A total of 2843 adult patients with newly diagnosed NAFLD, who had a least one of four comorbidities, namely, overweight/obesity, hypertension, type 2 diabetes mellitus, and hypercholesterolaemia, and who were prescribed 1.8 g/day of PPC as an adjunctive treatment to standard care, were enrolled during 2015-2016. Laboratory data were collected at baseline and 12 and 24 weeks of the study, and included liver function tests (aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT)), fasting plasma glucose, and lipid profile.

Results

Overall, 2263 patients (79.6%) had at least two metabolic comorbidities associated with NAFLD, and overweight/obesity was the most common comorbidity reported in 2298 (80.8%) patients. At 24 weeks, there was a significant decrease in liver enzyme levels (all p<0.001 compared with baseline). Across the four comorbidity subgroups, there was a mean drop of ALT levels ranging from 19.7 to 22.0 U/L, AST from 16.9 to 18.4 U/L, and GGT from 17.2 to 18.7 U/L. Similar findings were reported in subgroups with either one, two, three, or four comorbidities, with a significant decrease in liver enzyme levels ranging from 18.4 to 22.4 U/L for ALT, 14.8 to 18.7 U/L for AST, and 15.5 to 19.5 U/L for GGT.

Conclusions

Adjuvant treatment with PPC resulted in consistent improvements in liver enzymes in patients with newly diagnosed NAFLD and associated metabolic comorbidities.

Trial registration number

NCT00063622.

Synergy of Phospholipid-Drug Formulations Significantly Deactivates Profibrogenic Human Hepatic Stellate Cells

The pivotal role of hepatic stellate cells (HSCs) in orchestrating the bidirectional process of progression and regression of liver fibrosis makes them an ideal target for exploring new antifibrotic therapies. Essential phospholipids (EPLs), with their polyenylphosphatidylcholine (PPC) fraction, either alone or combined with other hepatoprotective substances such as silymarin, are recommended in hepatic impairment, but a scientific rationale for their use is still lacking. Herein, we compared the ability of EPLs to restore quiescent-like features in HSCs with that of dilinoleoylphosphatidylcholine (DLPC), PPC fraction’s main component. Specifically, we screened at the cellular level the antifibrotic effects of PPC formulations in the presence and absence of silymarin, by using LX-2 cells (pro-fibrogenic HSCs) and by assessing the main biochemical hallmarks of the activated and deactivated states of this cell line. We also proved the formulations’ direct effect on the motional order of cell membranes of adherent cells. LX-2 cells, examined for lipid droplets as a quiescence marker, showed that PPCs led to a more prominent deactivation than DLPC. This result was confirmed by a reduction of collagen and α-SMA expression, and by a profound alteration in the cell membrane fluidity. PPC–silymarin formulations deactivated HSCs with a significant synergistic effect. The remarkable bioactivity of PPCs in deactivating fibrogenic HSCs paves the way for the rational design of new therapeutics aimed at managing hepatic fibrosis.

Oral Phosphatidylcholine Improves Intestinal Barrier Function in Drug-Induced Liver Injury in Rats

Objective

Phosphatidylcholine (PC) is the major surface-active phospholipid and creates a hydrophobic nature to the surface. It has been reported to reverse the progression of liver fibrosis and to improve liver function. The aim of the present study was to evaluate the effects of orally administered PC on intestinal barrier function (IBF) in rats with drug-induced liver injury.

Method

Rats with carbon tetrachloride- (CCl4-) induced liver injury were treated with 100 mg/kg PC once daily for 21 days. The effects of PC therapy on (i) liver function and portal pressure, (ii) intestinal and hepatic histology, and (iii) plasma endotoxin, diamine oxidase (DAO), and tumour necrosis factor- (TNF-) α levels were investigated.

Results

PC therapy reduced portal pressure and improved the liver function in CCl4-induced liver injury. In PC-treated liver injury rats, collagen fibres were gradually decreased, while the disordered arrangement of hepatocytes and disorganized hepatic lobules were partially repaired, and inflammatory cell infiltration was decreased in the fibrous tissue. Lower inflammatory cell infiltration in the ileum improved intestinal histology, and reduced serum DAO levels were observed in PC-treated cirrhotic rats. These changes were associated with reduced inflammatory activity, as indicated by decreased serum TNF-α levels and plasma endotoxin levels.

Conclusions

These results suggest that PC therapy is hepatoprotective and is able to restore IBF and reduce endotoxaemia in rats with drug-induced liver injury.

Polyene phosphatidylcholine overcomes oxaliplatin resistance in human gastric cancer BGC823 cells

Intrinsic or acquired resistance to oxaliplatin (L-OHP) is a major reason of treatment failure in gastric cancer and limits therapeutic success. Here we generated an oxaliplatin resistant gastric cancer cell line, BGC823/L-OHP, to investigate the effect of a hepatoprotective compound, polyene phosphatidylcholine (PPC), on conquest of oxaliplatin resistance. BGC823/L-OHP cells showed less sensitive to L-OHP directed growth inhibition than the parental BGC823 cells. PPC treatment significantly increased anti-proliferative activity of L-OHP on resistant cells and promoted L-OHP triggered apoptosis, indicating that drug resistance was overcome. Mechanistically, L-OHP incubation stimulated upregulation of an ABC family protein, ABCF2, and the expression was inhibited by PPC. Moreover, expression levels of the stemness factor Nanog and its regulator TLR4 were notably enhanced in BGC823/L-OHP cells and reduced by PPC treatment. To conclude, PPC can overcome oxaliplatin resistance in gastric cancer cells via promoting apoptosis, inhibiting ABCF2, as well via reducing cancer stem cell-like features. The combination therapeutic strategy could serve to increase oxaliplatin effectiveness in the clinic.

Interleukin-13 is involved in the formation of liver fibrosis in Clonorchis sinensis-infected mice

Clonorchiasis is a chronic infection disease often accompanied by formation of liver fibrosis. Previous study has identified that Clonorchis sinensis (C. sinensis, Cs) infection and CsRNASET2 (a member of CsESPs) immunization can drive Th2 immune response. IL-13, a multifunctional Th2 cytokine, has been widely confirmed to be profibrotic mediator. We want to determine whether IL-13 is involved in the generation of liver fibrosis during C. sinensis infection. A part of mice were infected with C. sinensis or immunized with CsRNASET2, respectively. Another part of mice were intravenously injected with rIL-13. Liver tissues of C. sinensis-infected mice were stained with hematoxylin-eosin and Masson's trichrome, respectively. The transcriptional levels of collagen-I, collagen-III, α-SMA, and TIMP-1 in the livers of infected mice and rIL-13-treated mice were measured by quantitative RT-PCR. Besides, splenocytes of C. sinensis-infected and CsRNASET2-immunized mice were isolated, respectively. The levels of IL-13 in splenocytes were detected by ELISA. Our results displayed that the livers of C. sinensis-infected mice had serious chronic inflammation and collagen deposition. The transcriptional levels of collagen-I, collagen-III, α-SMA, and TIMP-1 in the livers of C. sinensis-infected mice were obviously increased. Splenocytes from both C. sinensis-infected and CsRNASET2-immunized mice expressed high levels of IL-13. Moreover, rIL-13 treatment markedly promoted the transcriptional levels of collagen-I, collagen-III, α-SMA, and TIMP-1. These data implied that hepatic fibrosis was formed in the livers of C. sinensis-infected mice, and IL-13 induced by C. sinensis infection and CsRNASET2 immunization might favor this progression.

Ursodeoxycholyl lysophosphatidylethanolamide attenuates hepatofibrogenesis by impairment of TGF-β1/Smad2/3 signalling

BACKGROUND AND PURPOSE

Chronic hepatic inflammation results in liver fibrosis. As effective anti-fibrogenic agents are lacking, we investigated ursodeoxycholyl lysophosphatidylethanolamide (UDCA-LPE), a synthetic bile acid-phospholipid conjugate with anti-inflammatory and anti-apoptotic properties for tis effects on hepatic fibrogenesis.

EXPERIMENTAL APPROACH

To stimulate fibrogenesis, LX2 hepatic stellate cells were cultured with conditioned medium from CL48 liver cells after exposure to stress-inducing conditions - methionine-choline-deficient (MCD) medium or TNFα/cycloheximide (CHX) - with or without UDCA-LPE preincubation. Anti-fibrogenic effects of UDCA-LPE were further studied in CL48 and LX2 cells and in primary human hepatic stellate cells (HHStec) directly exposed to TGF-β1. To test UDCA-LPE in vivo, C57BL/6 mice were fed a MCD diet for 11 weeks followed by 30 mg·kg(-1) UDCA-LPE 3× per week for 2.5 weeks.

KEY RESULTS

Expression of α-smooth muscle actin (α-SMA), α1-collagen, vimentin and TGF-β1 was down-regulated by up to 93% by UDCA-LPE in LX-2 cells cultured with conditioned medium. Also, UDCA-LPE inhibited Smad3 phosphorylation in CL48 cells incubated with MCD medium or TNFα/CHX and in LX2 cells exposed to conditioned medium. UDCA-LPE also decreased phosphorylated Smad3 and Smad2 directly induced by TGF-β1. Inhibition of TGF-β1/Smad2/3 signalling with down-regulation of target genes was confirmed in HHStec. In vivo, UDCA-LPE decreased hepatic α-SMA, α1-collagen and TGF-β1 expression and markedly lowered α-SMA protein and collagen deposition in MCD mice.

CONCLUSIONS AND IMPLICATIONS

By blocking TGF-β1/Smad2/3 signalling, UDCA-LPE suppressed key mediators of hepatic fibrogenesis. Thus, UDCA-LPE could be suitable for prevention of fibrotic progression of chronic liver disease.

Dietary lecithin improves dressing percentage and decreases chewiness in the longissimus muscle in finisher gilts

The influence of dietary lecithin at doses of 0, 4, 20 or 80 g/kg fed to finisher gilts for six weeks prior to slaughter on growth performance, carcass quality and pork quality was investigated. M. longissimus lumborum (loin) was removed from 36 pig carcasses at 24h post-mortem for Warner-Bratzler shear force, compression, collagen content and colour analyses. Dietary lecithin increased dressing percentage (P=0.009). Pork chewiness and collagen content were decreased by dietary lecithin (P<0.05, respectively), suggesting that improved chewiness may be due to decreased collagen content. However, dietary lecithin had no effect on shear force, cohesiveness or hardness (P>0.05, respectively). Dietary lecithin reduced loin muscle L* values and increased a* values (P<0.05, respectively) but no changes on b* values (P=0.56). The data showed that dietary lecithin improved dressing percentage and resulted in less chewy and less pale pork.

Activity of essential phospholipids (EPL) from soybean in liver diseases

Essential phospholipids (EPL) contain a highly purified extract of polyenylphosphatidylcholine (PPC) molecules from soybean. The main active ingredient is 1,2-dilinoleoylphosphatidylcholine (DLPC), which differentiates it from other phospholipids, lecithins, or extracts from other sources. Although EPLis widely used in liver diseases of various origins, its mode of action and pharmacological and clinical evidence of its efficacy have not yet been concisely reviewed. This paper critically summarizes experimental and clinical results. With regard to in-vitro and animal tests, EPL influenced membrane-dependent cellular functions and showed anti-oxidant, anti-inflammatory, anti-fibrotic, apoptosis-modulating, regenerative, membrane-repairing and -protective, cell-signaling and receptor-influencing, as well as lipid-regulating effects in intoxication models with chemicals or drugs. Clinical studies, primarily from European and Asian countries, have shown improvement in subjective symptoms; clinical, biochemical and imaging findings; and histology in liver indications such as fatty liver of different origin, drug hepatotoxicity, and adjuvant in chronic viral hepatitis and hepatic coma. The available studies characterize EPL as evidence-based medicine, although further long-term controlled clinical trials are required to precisely determine its benefit for alleviating symptoms, improving well-being, inducing histological changes and slowing the progression of liver disease. EPL-related relevant side effects were not observed.

Histological changes associated with mesotherapy for fat dissolution

Mesotherapy is a form of medical therapy popular in Europe and South America. It is used for treating a variety of medical conditions, including the treatment of localized fat deposits and cellulite. Phosphatidylcholine/deoxycholate injections are a popular technique to treat localized fat accumulations and have recently become synonymous with mesotherapy, although their history and technique are distinct. To treat localized fat deposits, phosphatidylcholine (PC) and deoxycholate (DC) are utilized. To date, there have been no published histological studies that explain the mechanism of action of PC and DC.Method. In this study the authors have obtained skin biopsies from a patient who had undergone mesotherapy with PC and DC. Punch biopsies were taken at one and two weeks after the procedure.Results. Each of the biopsies taken at one and two weeks after treatment with PC and DC showed a normal epithelium and dermis, with a mixed septal and lobular panniculitis. The fat lobules were infiltrated by increased numbers of lymphocytes and, in particular, macrophages. The macrophages consisted of conventional forms, foam cells, and multinucleated fat-containing giant cells. The inflammation was associated with serous atrophy and microcyst formation.Conclusion. This study demonstrates that mesotherapy with PC and DC affects the subcutaneous fat. We theorize that the reduction of subcutaneous fat likely follows inflammatory-mediated necrosis and resorption.

Treatment with silybin-vitamin E-phospholipid complex in patients with hepatitis C infection

The aim of this study was to evaluate the hepatoprotective and anti-inflammatory effects of silybin-phospholipids and vitamin E complex (SPV complex), by determining cytokine patterns and various markers of liver disease. Forty Caucasian patients with chronic HCV infection were recruited and divided into two groups: 30 were treated with SPV complex for 3 months, while the other 10 did not receive any treatment. Ten other subjects without HCV infection but with staeatosic diagnosis were recruited and treated with SPV complex. Biochemical and hepatic principal parameters were investigated at 0 (T0) and 3 months (T3). The group of HCV patients treated showed an improvement trend of hepatic indecises and viral load, and had a significant and persistent reduction of ALT (P = 0.02) and AST serum level (P = 0.01). In this group cytokines showed a statistically significant increase of IL-2 (P = 0.03) and IL-6 were significantly reduced (P = 0.02) at T0 and T3. After the treatment the group of hepatic steatosics showed a significant decrease in ALT (P = 0.02), AST (0.008), gammaGT (0.004) alkaline phosphatase (0.05), total cholesterol (P = 0.03), fasting glucose (P = 0.008), insulinemia (0.0006), HOMA value (0.002) and C-reactive protein (CRP; 0.04). There was a significant reduction of IFN-gamma, TNF-alpha, and IL-6 (P = 0.02, 0.05 and 0.04, respectively). The data suggest that the SPV complex exerts hepatoprotective, anti-inflammatory and antifibrotic effects. This new compound may therefore be useful in clinical practice in patients with chronic hepatitis C who cannot undergo conventional antiviral therapy.

Bioconjugation of oligonucleotides for treating liver fibrosis

Liver fibrosis results from chronic liver injury due to hepatitis B and C, excessive alcohol ingestion, and metal ion overload. Fibrosis culminates in cirrhosis and results in liver failure. Therefore, a potent antifibrotic therapy is urgently needed to reverse scarring and eliminate progression to cirrhosis. Although activated hepatic stellate cells (HSCs) remain the principle cell type responsible for liver fibrosis, perivascular fibroblasts of portal and central veins as well as periductular fibroblasts are other sources of fibrogenic cells. This review will critically discuss various treatment strategies for liver fibrosis, including prevention of liver injury, reduction of inflammation, inhibition of HSC activation, degradation of scar matrix, and inhibition of aberrant collagen synthesis. Oligonucleotides (ODNs) are short, single-stranded nucleic acids, which disrupt expression of target protein by binding to complementary mRNA or forming triplex with genomic DNA. Triplex forming oligonucleotides (TFOs) provide an attractive strategy for treating liver fibrosis. A series of TFOs have been developed for inhibiting the transcription of alpha1(I) collagen gene, which opens a new area for antifibrotic drugs. There will be in-depth discussion on the use of TFOs and how different bioconjugation strategies can be utilized for their site-specific delivery to HSCs or hepatocytes for enhanced antifibrotic activities. Various insights developed in individual strategy and the need for multipronged approaches will also be discussed.

Addressing liver fibrosis with liposomes targeted to hepatic stellate cells

Liver fibrosis is a chronic disease that results from hepatitis B and C infections, alcohol abuse or metabolic and genetic disorders. Ultimately, progression of fibrosis leads to cirrhosis, a stage of the disease characterized by failure of the normal liver functions. Currently, the treatment of liver fibrosis is mainly based on the removal of the underlying cause of the disease and liver transplantation, which is the only treatment for patients with advanced fibrosis. Hepatic stellate cells (HSC) are considered to be key players in the development of liver fibrosis. Chronically activated HSC produces large amounts of extracellular matrix and enhance fibrosis by secreting a broad spectrum of cytokines that exert pro-fibrotic actions in other cells, and in an autocrine manner perpetuate their own activation. Therefore, therapeutic interventions that inhibit activation of HSC and its pro-fibrotic activities are currently under investigation worldwide. In the present study we applied targeted liposomes as drug carriers to HSC in the fibrotic liver and explored the potential of these liposomes in antifibrotic therapies. Moreover, we investigated effects of bioactive compounds delivered by these liposomes on the progression of liver fibrosis. To our knowledge, this is the first study demonstrating that lipid-based drug carriers can be selectively delivered to HSC in the fibrotic liver. By incorporating the bioactive lipid DLPC, these liposomes can modulate different processes such as inflammation and fibrogenesis in the fibrotic liver. This dual functionality of liposomes as a drug carrier system with intrinsic biological effects may be exploited in new approaches to treat liver fibrosis.

The effect of a silybin-vitamin e-phospholipid complex on nonalcoholic fatty liver disease: a pilot study

Oxidative stress leads to chronic liver damage. Silybin has been conjugated with vitamin E and phospholipids to improve its antioxidant activity. Eighty-five patients were divided into 2 groups: those affected by nonalcoholic fatty liver disease (group A) and those with HCV-related chronic hepatitis associated with nonalcoholic fatty liver disease (group B), nonresponders to treatment. The treatment consisted of silybin/vitamin E/phospholipids. After treatment, group A showed a significant reduction in ultrasonographic scores for liver steatosis. Liver enzyme levels, hyperinsulinemia, and indexes of liver fibrosis showed an improvement in treated individuals. A significant correlation among indexes of fibrosis, body mass index, insulinemia, plasma levels of transforming growth factor-beta, tumor necrosis factor-alpha, degree of steatosis, and gamma-glutamyl transpeptidase was observed. Our data suggest that silybin conjugated with vitamin E and phospholipids could be used as a complementary approach to the treatment of patients with chronic liver damage.

Effects of a new bioactive lipid-based drug carrier on cultured hepatic stellate cells and liver fibrosis in bile duct-ligated rats

In the fibrotic liver, hepatic stellate cells (HSC) produce large amounts of collagen and secrete variety of mediators that promote development of fibrosis in this organ. Therefore, these cells are considered an attractive target for antifibrotic therapies. We incorporated the bioactive lipid dilinoleoylphosphatidylcholine (DLPC) into the membrane of liposomes, and then we evaluated its effect on hepatic stellate cell activation and liver fibrosis. To target DLPC-liposomes to HSC, human serum albumin modified with mannose 6-phosphate (M6P-HSA) was coupled to the surface of these liposomes. In vitro, the effects of the carrier were determined in primary cultures of HSC, Kupffer cells, and liver endothelial cells using real-time reverse transcription-polymerase chain reaction. In vivo DLPC-liposomes were tested in bile duct-ligated rats. Targeted M6P-HSA-DLPC-liposomes and DLPC-liposomes significantly reduced gene expression levels for collagen 1alpha1, alpha-smooth muscle actin (alpha-SMA), and transforming growth factor-beta (TGF-beta) in cultured HSC. In fibrotic livers, DLPC-liposomes decreased gene expression for TGF-beta and collagen 1alpha1 as well as alpha-SMA and collagen protein expression. In contrast, M6P-HSA-DLPC-liposomes enhanced expression of profibrotic and proinflammatory genes in vivo. In cultured Kupffer and endothelial cells M6P-HSA liposomes influenced the expression of proinflammatory genes. Both types of liposomes increased hepatocyte glycogen content in fibrotic livers, indicating improved functionality of the hepatocytes. We conclude that DLPC-containing liposomes attenuate activation of cultured HSC. In fibrotic livers, M6P-HSA-mediated activation of Kupffer and endothelial cells probably counteracts this beneficial effect of DLPC-liposomes. Therefore, these bioactive drug carriers modulate the activity of all liver cells during liver fibrosis.

Dietary lecithin protects against cholestatic liver disease in cholic acid-fed Abcb4- deficient mice

Mutations in multidrug resistance 3 gene (MDR3 or ABCB4) underlie progressive familial intrahepatic cholestasis type 3 (PFIC3), a severe pediatric liver disease progressing to cirrhosis. Abcb4-/- mice exhibit slowly developing hepatic lesions that can be accelerated by feeding a cholic acid (CA)-supplemented diet. We investigated the beneficial effects of a soybean lecithin (L)-supplemented diet in this model of liver disease. Abcb4-/- mice and wild-type (WT) controls were divided in four groups by the diet they were fed: control (C) diet, L-supplemented diet, CA-supplemented diet, and L- and CA-supplemented (L+CA) diet. After 2 wk on these regimens, liver enzymes and bilirubin were measured in serum with bile flow, total bile acids, and cholesterol (CHOL) and phospholipid (PL) concentrations in bile. Ductular hyperplasia, portal fibroblastic cell proliferation, myofibroblast activation, and hepatic fibrosis were quantified on liver sections. Abcb4-/- mice fed the C diet exhibited mild liver damage. CA produced very high elevations of serum liver enzymes and bilirubin with significant bile duct proliferation, peribiliary fibroblast activation, and fibrosis. The L-supplemented diet dramatically mitigated the hepatic damage in CA-supplemented diet animals. We conclude that L is protective against liver disease in Abcb4-/- mice and suggest that it could offer potential benefit in PFIC3.

Treatment of patients with non-alcoholic fatty liver disease: current views and perspectives

Non-alcoholic fatty liver disease is considered a component of the metabolic syndrome associated with obesity. Problems still exist concerning non-alcoholic fatty liver disease patients in clinical practice, for example: (a) how to diagnose non-alcoholic fatty liver disease and its type; (b) how to select patients candidate to treatment; (c) how to treat selected patients. Non-alcoholic fatty liver disease includes steatosis and non-alcoholic steatohepatitis, but only non-alcoholic steatohepatitis evolves into cirrhosis and the absolute risk of mortality for non-alcoholic fatty liver disease is low. As yet, no tools, other than liver biopsy, are available to differentiate the various types of non-alcoholic fatty liver disease. Many drugs are, currently, under study to treat non-alcoholic fatty liver disease, even if well-performed trials are until necessary to define the best treatment. At the moment, the entity of the problem and the characteristics of patients frequently put the physician, in clinical practice, to choose the therapeutic approach arbitrarily which is considered more effective for each individual patient. Probably the future will consider the possibility of treating non-alcoholic fatty liver disease with more than one drug, by considering the various aspects and degree of this syndrome. Actually each physician should select the individual treatment on the basis of his/her knowledge and experience, by never forgetting the old saying 'primum non nocere'. However, the epidemiological entity of the problem, the characteristics of the patients, generally young, the frequent lack of clinical evidence of involvement of the liver, are all the factors that require vast well-performed clinical trials in order to define the best therapeutic approach for each individual patient.

Oral acute toxicity of polyenylphosphatidylcholine (PPC) in rats

Endogen phospholipids play a major role in determining the structure and nature of cell membranes. A deficiency of phospholipids in cellular membranes makes it almost impossible for the cell membrane to perform its function as a selective barrier between what passes in and out of the cell. Polyenylphosphatidylcholine chemical structure corresponds to that of endogen phospholipids, but it possesses functional superiority because of its content of unsaturated fatty acids. Polyenylphosphatidylcholine integrates in the cell membrane and organelle systems while becoming their constitutive elements. A healthy cell membrane leads to healthy cells and then healthy tissue and then to healthy organs or body systems and finally, healthy bodies and minds. For a long time, polyenylphosphatidylcholine in combination with vitamins has been used in the treatment of numerous health problems such as liver diseases, dyslipoproteinaemias and different intoxications with consequent liver failure. The main aim of toxicology studies is evaluation of the toxic potential and risks of human exposition to the substance. According to the Organization for Economic Cooperation and Development (OECD) acute oral toxicity refers to those adverse effects occurring following oral administration of a single dose of a substance or multiple doses given within 24 hours. LD50 (median lethal dose), oral, is a statistically derived single dose of a substance that can be expected to cause death in 50 per cent of animals when administered by the oral route. Our acute toxicity study was performed on albino Wistar rats. Animals were randomised in three experimental and one control group, each of 5 males and 5 females. Study was based on the administration of a single oral dose of the test substance (polyenylphosphatidylcholine) to each experimental animal. There were three dose-levels of the test substance: 300, 500 and 1000 mg/kg. Test substance administration day was the first day of the observation period that lasted 14 days. Control animals were given milk vehicle. At the end of the study, no statistically significant differences between experimental and control animals were observed concerning the recorded parameters: body weight, respiratory rate, tremor, faeces and phonation quality, indicating the absence of the test substance acute toxicity.

Metabolism of alcohol

Most tissues of the body contain enzymes capable of ethanol oxidation or nonoxidative metabolism, but significant activity occurs only in the liver and, to a lesser extent, in the stomach. Hence, medical consequences are predominant in these organs. In the liver, ethanol oxidation generates an excess of reducing equivalents, primarily as NADH, causing hepatotoxicity. An additional system, containing cytochromes P-450 inducible by chronic alcohol feeding, was demonstrated in liver microsomes and found to be a major cause of hepatotoxicity.

Alcoholic fatty liver: its pathogenesis and mechanism of progression to inflammation and fibrosis

Liver disease in the alcoholic is due not only to malnutrition but also to ethanol's hepatotoxicity linked to its metabolism by means of the alcohol dehydrogenase and cytochrome P450 2E1 (CYP2E1) pathways and the resulting production of toxic acetaldehyde. In addition, alcohol dehydrogenase-mediated ethanol metabolism generates the reduced form of nicotinamide adenine dinucleotide (NADH), which promotes steatosis by stimulating the synthesis of fatty acids and opposing their oxidation. Steatosis is also promoted by excess dietary lipids and can be attenuated by their replacement with medium-chain triglycerides. Through reduction of pyruvate, elevated NADH also increases lactate, which stimulates collagen synthesis in myofibroblasts. Furthermore, CYP2E1 activity is inducible by its substrates, not only ethanol but also fatty acids. Their excess and metabolism by means of this pathway generate release of free radicals, which cause oxidative stress, with peroxidation of lipids and membrane damage, including altered enzyme activities. Products of lipid peroxidation such as 4-hydroxynonenal stimulate collagen generation and fibrosis, which are further increased through diminished feedback inhibition of collagen synthesis because acetaldehyde forms adducts with the carboxyl-terminal propeptide of procollagen in hepatic stellate cells. Acetaldehyde is also toxic to the mitochondria, and it aggravates their oxidative stress by binding to reduced glutathione and promoting its leakage. Oxidative stress and associated cellular injury promote inflammation, which is aggravated by increased production of the proinflammatory cytokine tumor necrosis factor-alpha in the Kupffer cells. These are activated by induction of their CYP2E1 as well as by endotoxin. The endotoxin-stimulated tumor necrosis factor-alpha release is decreased by dilinoleoylphosphatidylcholine, the active phosphatidylcholine (PC) species of polyenylphosphatidylcholine (PPC). Moreover, defense mechanisms provided by peroxisome proliferator-activated receptor alpha and omega fatty acid oxidation are readily overwhelmed, particularly in female rats and also in women who have low hepatic induction of fatty acid-binding protein (L-FABPc). Accordingly, the intracellular concentration of free fatty acids may become high enough to injure membranes, thereby contributing to necrosis, inflammation, and progression to fibrosis and cirrhosis. Eventually, hepatic S-adenosylmethionine and PCs become depleted in the alcoholic, with impairment of their multiple cellular functions, which can be restored by PC replenishment. Thus, prevention and therapy opposing the development of steatosis and its progression to more severe injury can be achieved by a multifactorial approach: control of alcohol consumption, avoidance of obesity and of excess dietary long-chain fatty acids, or their replacement with medium-chain fatty acids, and replenishment of S-adenosylmethionine and PCs by using PPC. Progress in the understanding of the pathogenesis of alcoholic fatty liver and its progression to inflammation and fibrosis has resulted in prospects for their better prevention and treatment.

Metabolic, antioxidant, nutraceutical, probiotic, and herbal therapies relating to the management of hepatobiliary disorders

Many nutraceuticals, conditionally essential nutrients, and botanical extracts have been proposed as useful in the management of liver disease. The most studied of these are addressed in terms of proposed mechanisms of action, benefits, hazards, and safe dosing recommendations allowed by current information. While this is an area of soft science, it is important to keep an open and tolerant mind, considering that many major treatment discoveries were in fact serendipitous accidents.

II. Veterans Affairs Cooperative Study of polyenylphosphatidylcholine in alcoholic liver disease

BACKGROUND

Polyenylphosphatidylcholine (PPC) has been shown to prevent alcoholic cirrhosis in animals. Our aims were to determine the effectiveness of PPC in preventing or reversing liver fibrosis in heavy drinkers and to assess the extent of liver injury associated with the reduced drinking achieved in these patients.

METHODS

This randomized, prospective, double-blind, placebo-controlled clinical trial was conducted in 20 Veterans Affairs Medical Centers with 789 patients (97% male; mean age, 48.8 years) averaging 16 drinks per day (1 drink = 14 g of alcohol) for 19 years. A baseline liver biopsy confirmed the presence of perivenular or septal fibrosis or incomplete cirrhosis. They were randomly assigned either PPC or placebo. Liver biopsy was repeated at 24 months, and the main outcome measure was the stage of fibrosis compared with baseline. Progression was defined as advancing to a more severe stage.

RESULTS

The 2-year biopsy was completed in 412 patients. PPC did not differ significantly from placebo in its effect on the main outcome. Alcohol intake was unexpectedly reduced in both groups to approximately 2.5 drinks per day. With this intake, 21.4% advanced at least one stage (22.8% of PPC patients and 20.0% of placebo patients). The hepatitis C virus-positive subgroup exhibited accelerated progression. Improvement in transaminases and bilirubin favoring PPC was seen at some time points in other subgroups (hepatitis C virus-positive drinkers or heavy drinkers).

CONCLUSIONS

PPC treatment for 2 years did not affect progression of liver fibrosis. A trend in favor of PPC was seen for transaminases and bilirubin (in subgroups). One of five patients progressed even at moderate levels of drinking, and thus health benefits commonly associated with moderate drinking do not necessarily extend to individuals in the early stages of alcoholic liver disease.

New concepts of the pathogenesis of alcoholic liver disease lead to novel treatments

Activation of methionine to S-adenosylmethionine is depressed in alcoholics. Its repletion opposes alcoholic liver cirrhosis in baboons, decreases mortality in cirrhotic patients, and opposes oxidative stress resulting from cytochrome P4502E1 (CYP2E1) induction by alcohol, ketones, and fatty acids. Their excess causes alcoholic and nonalcoholic steatohepatitis. CYP2E1 is also induced in Kupffer cells, promoting their activation and release of inflammatory cytokines, including tumor necrosis factor (TNF)-alpha. The TNF-alpha inhibitor pentoxifylline decreased mortality from alcoholic hepatitis. Polyenylphosphatidylcholine (PPC), an antioxidant phosphatidylcholine mixture extracted from soybeans, 50% of which consists of the highly bioavailable dilinoleoylphosphatidylcholine, restores phospholipids of the damaged membranes and reactivates their enzymes, including phosphatidylethanolamine methyltransferase, needed for phospholipid regeneration. In baboons, PPC prevented cirrhosis by stimulating collagenase and by opposing lipid peroxidation, which produces the fibrogenic hydroxynonenal. PPC was beneficial in patients with alcoholic hepatitis, and it opposed fibrosis in heavy drinkers and decreased aminotransferases in patients with hepatitis C. The antioxidant silymarin also successfully opposed alcoholic cirrhosis in baboons and in some but not all clinical trials; this effect also pertains to a-tocopherol. The anti-inflammatory corticosteroids and colchicine yielded mixed results. Finally, replacing long-chain with medium-chain triglycerides opposed the fatty liver experimentally and clinically.

Treatment of Lower Eyelid Fat Pads Using Phosphatidylcholine: Clinical Trial and Review

BACKGROUND

Injectable phosphatidylcholine, a lecithin-derived phospholipid, has been previously demonstrated to improve the appearance of infraorbital fat pad herniation. Current use internationally has led to a significant interest in this novel substance.

OBJECTIVE

To evaluate the efficacy and safety of injectable phosphatidylcholine, we conducted an open-label study for the treatment of infraorbital fat pad herniation.

METHODS

Patients received 0.4-mL phosphatidylcholine (50 mg/mL) injections within infraorbital fat pads every 2 weeks. Patient and physician grading of fat herniation, side effects, digital photographs, and a follow-up questionnaire was recorded.

RESULTS

Ten of the 13 enrolled patients had three to five treatments. Improvements in fat herniation were reported in 80% and 70% of patients as graded by the physician and patients, respectively. Sixty percent of patients assessed their improvement as equal or greater than 5 points (on a 10-point fat herniation scale); however, the physician judged 40% of patients improving to this degree. Little or no response was seen in three patients. Side effects included burning, erythema, and swelling at the injection site. At follow-up averaging 9 months, 50% of patients reported persistence of benefit, 20% experienced some fading, and 30% were the nonresponders.

CONCLUSIONS

Injectable phosphatidylcholine is a novel treatment for infraorbital fat herniation that may benefit some patients who are considering blepharoplasty. Larger studies evaluating long-term safety and efficacy of phosphatidylcholine for cosmetic purposes are warranted.

Protective effect of polyunsaturated phosphatidylcholine on liver damage induced by biliary obstruction in rats

BACKGROUND/PURPOSE

Persistent inflammatory response secondary to congenital or acquired biliary choleastasis plays an important role in the pathophysiology of hepatic tissue damage. The polyunsaturated fatty acids (PUFA) have been shown to suppress the inflammatory reactions in vivo and in vitro. PUFA has been shown also to protect against various types of experimental liver damage in animal models and isolated hepatocytes. Therefore, the aim of this study was to investigate the protective effect of PUFA administration on liver damage using the rat chronic biliary obstruction model.

METHODS

Swiss albino rats of either sex were divided into 4 groups as follows: control group (group 1, 10 rats); rats with sham operation and treated with saline group 2, 10 rats); rats with biliary obstruction (group 3, 15 rats); and polyunsaturated phophatidylcholine (PPC)-treated rats with biliary obstruction (Group 4, 15 rats). Biliary obstruction was induced by double ligation and division of the common bile duct. PUFA treatment was started 2 weeks later from biliary obstruction in doses of 50 mg/d per rat and continued for 2 weeks. All animals were killed after 4 weeks of common bile duct ligation or sham operation. Liver damage and cholestasis were determined by biochemical and histologic examinations.

RESULTS

The data showed a decrease in plasma bilirubin level (both conjugated and unconjugated) and liver enzyme levels (AST, ALT, AP, GGT, 5'-NT) in group 4, when compared with group 3 (P <.05). Tissue levels of malondialdehyde (MDA) in group 4 was 20.00 +/- 2.93 compared with that in group 3, 27.12 +/- 2.96 (P <.05). Administration of PUFA to the biliary obstructed rats resulted in inhibition of collagen accumulation (P <.05) and ductal proliferation (P <.05).

CONCLUSIONS

PUFA reduced liver damage, ductular proliferation, and fibrosis in biliary obstructed rats. These effects suggest that it might be a useful agent to preserve liver function in patients with biliary obstruction such as biliary atresia.

DLPC decreases TGF-beta1-induced collagen mRNA by inhibiting p38 MAPK in hepatic stellate cells

Dilinoleoylphosphatidylcholine (DLPC), the active component of polyenylphosphatidylcholine extracted from soybeans, decreases collagen accumulation induced by TGF-beta1 in cultured hepatic stellate cells (HSCs). Because DLPC exerts antioxidant effects and TGF-beta1 generates oxidative stress, we evaluated whether the antifibrogenic effect of DLPC is linked to its antioxidant action. In passage 1 culture of rat HSCs, TGF-beta1 induced a concentration-dependent increase in procollagen-alpha(1)(I) mRNA levels and enhanced intracellular H(2)O(2) and superoxide anion formation and lipid peroxidation but decreased GSH levels. These changes were prevented by DLPC. Upregulation of collagen mRNA by TGF-beta1 was likewise inhibited by catalase and p38 MAPK inhibitor SB-203580, suggesting involvement of H(2)O(2) and p38 MAPK signaling in this process. TGF-beta1 or addition of H(2)O(2) to HSCs activated p38 MAPK with a rise in procollagen mRNA level; these changes were blocked by catalase and SB-203580 and likewise by DLPC. alpha-Smooth muscle actin abundance in HSCs was not altered by TGF-beta1 treatment (with or without DLPC), indicating that downregulation of procollagen mRNA by DLPC was not due to alteration in HSC activation. These results demonstrate that DLPC prevents TGF-beta1-induced increase in collagen mRNA by inhibiting generation of oxidative stress and associated H(2)O(2)-dependent p38 MAPK activation, which explains its antifibrogenic effect. DLPC, an innocuous phospholipid, may be considered for prevention and treatment of liver fibrosis.

Developing strategies for liver fibrosis treatment

Liver fibrosis represents a major worldwide healthcare burden. Current therapy is limited to removing the causal agent. This approach is successful in some diseases; particularly haemochromatosis and chronic viral hepatitis. However, for many patients treatment is not possible, while other patients present to medical attention at an advanced stage of fibrosis. There is therefore a great need for novel therapies for liver fibrosis. The hepatic stellate cell has been recognised to be responsible for most of the excess extracellular matrix observed in chronic liver fibrosis. The detailed understanding of hepatic stellate cell biology has allowed the rational design of novel antifibrotic therapies. This review describes for the general reader the novel emerging therapies for liver fibrosis.

Dilinoleoylphosphatidylcholine prevents transforming growth factor-beta1-mediated collagen accumulation in cultured rat hepatic stellate cells

Polyenylphosphatidylcholine (PPC), a mixture of polyunsaturated phosphatidylcholines, protects against alcoholic and nonalcoholic liver fibrosis in baboons and rats, respectively. In this study, we assessed the antifibrogenic action of dilinoleoylphosphatidylcholine (DLPC), the main phosphatidylcholine species of PPC, against transforming growth factor-beta1-mediated expression of alpha1(I) procollagen, tissue inhibitor of metallopreoteinase-1 (TIMP-1) and matrix metalloproteinase-13 (MMP-13) in cultured rat hepatic stellate cells (HSCs). In primary culture-activated HSCs, TGF-beta1 up-regulated the alpha1(I) procollagen mRNA level with a concomitant increase in type I collagen accumulation in culture media. Whereas TIMP-1 mRNA levels and TIMP-1 accumulation in media were also increased by TGF-beta1, MMP-13 mRNA expression and MMP-13 concentration in media were not altered. DLPC fully blocked TGF-beta1-induced increase in alpha1(I) procollagen mRNA expression and decreased collagen accumulation in media. Whereas TIMP-1 mRNA level and TIMP-1 accumulation in media were decreased by DLPC, MMP-13 mRNA expression and MMP-13 concentration in media were not changed by this treatment. Palmitoyl-linoleoylphosphatidylcholine (PLPC), the second most abundant component of PPC, had no effect on the concentrations of collagen, TIMP-1, and MMP-13 in HSC culture. We conclude that DLPC prevents TGF-beta1-mediated HSC fibrogenesis through down-regulation of alpha1(I) procollagen and TIMP-1 mRNA expression. The latter effect leads to a decreased accumulation of TIMP-1 that, in the presence of unchanged MMP-13 mRNA expression and MMP-13 concentration, results in a larger ratio of MMP-13/TIMP-1 concentrations in the culture media, favoring collagen degradation and lesser collagen accumulation. This effect of DLPC may explain, at least in part, the antifibrogenic action of PPC against alcoholic and other fibrotic disorders of the liver.

Alcoholic liver injury: pathogenesis and therapy in 2001

Much progress has been made in the understanding of the pathogenesis of alcoholic liver disease, resulting in improvement of prevention and promising prospects for even more effective treatments. It continues to be important to replenish nutritional deficiencies when present but it is crucial to recognize that, because of the alcohol-induced disease process, some of the nutritional requirements change. For instance, methionine, one of the essential amino acids for humans, must be activated to SAMe but, in severe liver disease, the activity of the corresponding enzyme is depressed. Therefore, the resulting deficiencies and associated pathology can be attenuated by the administration of SAMe, but not by methionine. Similarly, phosphatidylethanolamine methyltransferase (PEMT) activity, which is important for hepatic phosphatidylcholine (PC) synthesis, is also depressed in alcoholic liver disease, therefore calling for administration of the products of the reaction. It might also be beneficial to add other compounds to such therapeutic regiment. Since free radical generation by the ethanol-induced CYP2E1 plays a key role in the oxidative stress, inhibitors of this enzyme have great promise. Several have been investigated experimentally and PPC is particularly interesting because of its innocuity. In view of the striking negative interaction between alcoholic liver injury and hepatitis C, an antiviral agent is eagerly awaited that, unlike Interferon, is not contraindicated in the alcoholic. Anti-inflammatory agents are also required. In addition to down-regulators of cytokines and end toxic are being considered. Finally, since excess drinking is the crux of the issue, anticraving agents should be incorporated in any contemplated therapeutic cocktail, in view of the recent promising results obtained with some of these agents such as naltrexone and acamprosate.

Signaling for ethanol-induced apoptosis and repair in vitro

OBJECTIVES

To evaluate whether caspases are involved in ethanol (EtOH)-induced apoptosis and if polyenylphosphatidylcholine (PPC) affects apoptosis, in vitro in Hep G2 cells.

METHODS

Cells were treated with 100 mmol/L EtOH for 24 h and with 2 doses of 100 mmol/L EtOH (1/24 h) in the presence of absence of 20 mmol/L of PPC or 50 micromol/L caspase 3 inhibitor (IDN). Cells were analyzed for apoptosis by transmission electron microscopy (TEM) 6000 cells/treatment, DNA fragmentation by ELISA and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (T dt-mediated d-UTP) nick-end-labeling, TUNEL.

RESULTS

100 mmol/L dose of EtOH resulted in 22 +/- 2.5% (p < 0.001) apoptosis (vs. control). Two consecutive doses of 100 mmol/L EtOH for 24 h each caused 36 +/- 3.0% (p < 0.001 vs. control and p < 0.05 vs. one dose). PPC significantly reduced apoptosis (vs. non exposed to PPC): 100 mmol/L -12 +/- 1.5% (p < 0.05) and 2 x 10(-)(0) mmol/L -20 +/- 2.0% (p < 0.001). Pretreatment with 50 micromol caspase inhibitor reduced EtOH-induced apoptosis in a similar proportion.

CONCLUSIONS

PPC downregulates EtOH-apoptosis by a mechanism similar to caspase inhibition.

Hepatic, metabolic, and nutritional disorders of alcoholism: from pathogenesis to therapy

Much progress has been made in the understanding of the pathogenesis of alcoholic liver disease, resulting in an improvement in treatment. Nutritional deficiencies should be corrected when present but, because of the alcohol-induced disease process, some of the nutritional requirements change. For instance, methionine, one of the essential amino acids for humans, must be activated to S-adenosylmethionine (SAMe), but, in severe liver disease, the activity of the corresponding enzyme is depressed. Therefore, the resulting deficiencies and associated pathology can be attenuated by the administration of SAMe, but not by methionine. Similarly, phosphatidylethanolamine methyltransferase (PEMT) activity, which is important for hepatic phosphatidylcholine (PC) synthesis, is also depressed in alcoholic liver disease, therefore calling for the administration of the products of the reaction. Inasmuch as free radical generation by the ethanol-induced CYP2E1 plays a key role in the oxidative stress, inhibitors of this enzyme have great promise and PPC, which is presently being evaluated clinically, is particularly interesting because of its innocuity. In view of the striking negative interaction between alcoholic liver injury and hepatitis C, an antiviral agent is eagerly awaited that, unlike Interferon, is not contraindicated in the alcoholic. Antiinflamatory agents may also be useful. In addition to steroids, down-regulators of cytokines and endotoxin are being considered. Finally, anticraving agents such as naltrexone or acamprosate should be incorporated into any contemplated therapeutic cocktail.

Alcoholic liver disease: new insights in pathogenesis lead to new treatments

Much progress has been made in the understanding of the pathogenesis of alcoholic liver disease, resulting in improvement of prevention and therapy, with promising prospects for even more effective treatments. The most successful approaches that one can expect to evolve are those that deal with the fundamental cellular disturbances resulting from excessive alcohol consumption. Two pathologic concepts are emerging as particularly useful therapeutically. Whereas it continues to be important to replenish nutritional deficiencies, when present, it is crucial to recognize that because of the alcohol-induced disease process, some of the nutritional requirements change. This is exemplified by methionine, which normally is one of the essential amino acids for humans, but needs to be activated to S-adenosylmethionine (SAMe), a process impaired by the disease. Thus, SAMe rather than methionine is the compound that must be supplemented in the presence of significant liver disease. Indeed, SAMe was found to attenuate mitochondrial lesions in baboons, replenish glutathione, and significantly reduce mortality in patients with Child A or B cirrhosis. Similarly, polyenylphosphatidylcholine (PPC) corrects the ethanol-induced hepatic phospholipid depletion as well as the decreased phosphatidylethanolamine methyltransferase activity and opposes oxidative stress. It also deactivates hepatic stellate cells, whereas its dilinoleoyl species (DLPC) increases collagenase activity, resulting in prevention of ethanol-induced septal fibrosis and cirrhosis in the baboon. Clinical trials with PPC are ongoing in patients with alcoholic liver disease. Furthermore, enzymes useful for detoxification, such as CYP2E1, when excessively induced, become harmful and should be downregulated. PPC is one of the substances with anti-CYP2E1 properties that is now emerging. Another important aspect is the association of alcoholic liver disease with hepatitis C: a quarter of all patients with alcoholic liver disease also have markers of HCV infection, with an even higher incidence in some urban areas but, at present, no specific therapy is available since interferon is contraindicated in that population. However, in addition to antiviral medications, agents that oppose oxidative stress and fibrosis should also be tested for hepatitis C treatment since these two processes contribute much to the pathology and mortality associated with the virus. In addition to antioxidants (such as PPC, silymarin, alpha-tocopherol and selenium), anti-inflammatory medications (corticosteroids, colchicine, anticytokines) are also being tested as antifibrotics. Transplantation is now accepted treatment in alcoholics who have brought their alcoholism under control and who benefit from adequate social support but organ availability is still the major limiting factor and should be expanded more aggressively. Finally, abstinence from excessive drinking is always indicated; it is difficult to achieve but agents that oppose alcohol craving are becoming available and they should be used more extensively.

Dilinoleoylphosphatidylcholine selectively modulates lipopolysaccharide-induced Kupffer cell activation

Polyenylphosphatidylcholine (PPC), a mixture of polyunsaturated phosphatidylcholines extracted from soybeans, protects against alcoholic and non-alcoholic liver injury. Because Kupffer cells mediate liver injury, we hypothesized that PPC may modulate their activation. The activation of Kupffer cells by lipopolysaccharide (LPS) leads to an enhanced production of cytokines. Among these, tumor necrosis factor-alpha(TNF-alpha) exerts mainly a hepatotoxic effect, whereas interleukin-1beta (IL-1beta) appears to be hepatoprotective. The present study evaluated whether dilinoleoylphosphatidylcholine (DLPC), the main component of PPC (40% to 52%), affects LPS-induced Kupffer cell activation in vitro. For comparison, palmitoyl-linoleoylphosphatidylcholine (PLPC), the other major component of PPC (23% to 24%), and distearoylphosphatidylcholine (DSPC), the saturated counterpart of DLPC, were also tested. Rat Kupffer cells were cultured in serum-free RPMI-1640 medium containing 10 micromol/L of either DLPC, PLPC, or DSPC in the presence or absence of LPS (1 microg/mL). After 20 hours in culture, the media were collected for cytokine measurements by enzyme-linked immunosorbent assays. LPS significantly stimulated TNF-alpha and IL-1beta production by 62% and 328%, respectively. Treatment of Kupffer cells with LPS plus DLPC decreased the production of TNF-alpha by 23% (12.17+/-1.83 pg/ng DNA vs 15.72 +/-2.74 pg/ng DNA, P < .05, n = 6) and increased that of IL-1beta by 17% (1.80 +/- 0.16 pg/ng DNA vs 1.54 +/- 0.08 pg/ng DNA, P< .05, n = 6). No effect of PLPC or DSPC on LPS-induced TNF-alpha or IL-1beta generation was observed, thereby illustrating the selective effect of DLPC in this process. Thus DLPC selectively modulates the LPS-induced activation of Kupffer cells by decreasing the production of the cytotoxic TNF-alpha while increasing that of the protective IL-1beta. This dual action of DLPC on cytokines may provide a mechanism for the protective effect against liver injury, but its significance still needs to be determined by in vivo studies.

Activation of pancreatic stellate cells in human and experimental pancreatic fibrosis

The mechanisms of pancreatic fibrosis are poorly understood. In the liver, stellate cells play an important role in fibrogenesis. Similar cells have recently been isolated from the pancreas and are termed pancreatic stellate cells. The aim of this study was to determine whether pancreatic stellate cell activation occurs during experimental and human pancreatic fibrosis. Pancreatic fibrosis was induced in rats (n = 24) by infusion of trinitrobenzene sulfonic acid (TNBS) into the pancreatic duct. Surgical specimens were obtained from patients with chronic pancreatitis (n = 6). Pancreatic fibrosis was assessed using the Sirius Red stain and immunohistochemistry for collagen type I. Pancreatic stellate cell activation was assessed by staining for alpha-smooth muscle actin (alphaSMA), desmin, and platelet-derived growth factor receptor type beta (PDGFRbeta). The relationship of fibrosis to stellate cell activation was studied by staining of serial sections for alphaSMA, desmin, PDGFRbeta, and collagen, and by dual-staining for alphaSMA plus either Sirius Red or in situ hybridization for procollagen alpha(1) (I) mRNA. The cellular source of TGFbeta was examined by immunohistochemistry. The histological appearances in the TNBS model resembled those found in human chronic pancreatitis. Areas of pancreatic fibrosis stained positively for Sirius Red and collagen type I. Sirius Red staining was associated with alphaSMA-positive cells. alphaSMA staining colocalized with procollagen alpha(1) (I) mRNA expression. In the rat model, desmin staining was associated with PDGFRbeta in areas of fibrosis. TGFbeta was maximal in acinar cells adjacent to areas of fibrosis and spindle cells within fibrotic bands. Pancreatic stellate cell activation is associated with fibrosis in both human pancreas and in an animal model. These cells appear to play an important role in pancreatic fibrogenesis.

Prevention and treatment of liver fibrosis based on pathogenesis

Multiple agents have been proposed for the prevention and treatment of fibrosis. S-adenosylmethionine was reported to oppose CCl4-induced fibrosis in the rat, to attenuate the consequences of the ethanol-induced oxidative stress, and to decrease mortality in cirrhotics. Anti-inflammatory medications and agents that interfere with collagen synthesis, such as inhibitors of prolyl-4-hydroxylase and antioxidants, are also being tested. In nonhuman primates, polyenylphosphatidylcholine (PPC), extracted from soybeans, protected against alcohol-induced fibrosis and cirrhosis and prevented the associated hepatic phosphatidylcholine (PC) depletion by increasing 18:2 containing PC species; it also attenuated the transformation of stellate cells into collagen-producing transitional cells. Furthermore, it increased collagen breakdown, as shown in cultured stellate cells enriched with PPC or pure dilinoleoyl PC, the main PC species present in the extract. Because PPC and dilinoleoyl PC promote the breakdown of collagen, there is reasonable hope that this treatment may be useful for the management of fibrosis of alcoholic, as well as nonalcoholic, etiologies and that it may affect not only the progression of the disease, but may also reverse pre-existing fibrosis, as demonstrated for CCl4-induced cirrhosis in the rat and as presently tested in an ongoing clinical trial.

Cancer antigen 125: a sensitive marker of ascites in patients with liver cirrhosis

OBJECTIVE

Cancer antigen 125 (CA 125) is a high molecular mass glycoprotein, usually used for monitoring the course of epithelial ovarian cancer. Recently it has been shown that liver cirrhosis is associated with increased levels of CA 125, particularly in the presence of ascites. The aim of this study was to evaluate CA 125 as a marker for the detection of ascites in patients with chronic liver disease.

METHODS

A total of 170 patients were studied. All had ultrasound scanning for detection of ascites. Group I consisted of 123 patients with chronic liver disease without ascites; whereas group II consisted of 47 patients with chronic liver disease with ascites. CA 125 levels were measured in all patients and also simultaneously in the ascitic fluid of 31 patients from group II.

RESULTS

Of 47 patients, 46 (97.8%) of group II had elevated serum levels of CA 125 (mean 321 +/- 283 U/ml) as compared with only nine of 123 (7.3%) patients of group I [mean 13 +/- 15 U/ml]), p < 0.001. The mean CA 125 concentration in the ascitic fluid of 31 cirrhotic patients (group II) was 624 +/- 397 U/ml and was always higher than corresponding serum levels (p < 0.01). Serum CA 125 levels correlated with the amount of ascitic fluid (r = 0.78). A profound decrease in serum CA 125 concentration was noted 2-3 and 10 days after large volume paracentesis. CA 125 was more sensitive and preceded ultrasonography in detection of ascites in few cirrhotic patients.

CONCLUSIONS

CA 125 is a highly sensitive marker to detect ascites in patients with liver cirrhosis. This marker may be useful to detect small to moderate amounts of ascitic fluid in cirrhotic patients when physical examination is difficult or equivocal for ascites.

Dilinoleoylphosphatidylcholine decreases hepatic stellate cell activation

The prevention of cirrhosis in alcohol-fed baboons by the administration of a soybean extract-43% to 50% of which was dilinoleoyl-phosphatidylcholine (DLPC) and 24% of which was 1,palmitoyl 2,linoleoyl-phosphatidylcholine (PLPC)-was associated with a significant reduction in the number of stellate cells transformed to myofibroblast-like cells. To study whether these two major phospholipids affect the similar transformation that occurs by culturing stellate cells on uncoated plastic, we assessed their effects on proliferation (by (methyl-3H)-thymidine incorporation into DNA), expression of alpha-smooth muscle actin and type I procollagen (by densitometry of Western blots), and collagen synthesis (by incorporation of tritiated proline into collagenase-digestible proteins). These manifestations of stellate cell activation were decreased by 10 micromol/L DLPC but not by 10 micromol/L PLPC when compared with controls incubated either with 17 mmol/L ethanol (used as solvent for the phospholipids) or without addition. These agents did not affect cell viability, contamination with other cells, or the capacity of stellate cells to synthesize protein. Thus DLPC specifically decreases the in vitro activation of stellate cells, as judged by the decreases in proliferative activity, alpha-smooth muscle actin and procollagen I expressions, and collagen synthesis, whereas PLPC did not show such effects. alpha-Procollagen (type I) mRNA was not affected by DLPC, suggesting a post-translational effect. The reduction in the activation of hepatic stellate cells by DLPC may be responsible for, or at least contribute to, the prevention of fibrosis by the polyenylphosphatidylcholine mixture administered in vivo.

Polyenylphosphatidylcholine inhibits PDGF-induced proliferation in rat hepatic stellate cells

Polyenylphosphatidylcholine (PPC), a polyunsaturated phospholipid extract from soy beans, prevents the development of liver cirrhosis in animal models. Its mechanism of action is unknown. Based on the hypothesis that PPC might act by decreasing hepatic stellate cell proliferation, we studied the effect of PPC and its main components, dilinoleoylphosphatidylcholine (DLPC) and palmitoyl-linoleoylphosphatidylcholine (PLPC), on PDGF-induced stellate cell proliferation and intracellular signal transduction. Normal rat hepatic stellate cells in tissue culture were serumstarved, and incubated with 10ng/ml PDGF in the absence or presence of phospholipids. Cell proliferation was measured by 3H-thymidine incorporation. P44MAPK activation was determined by kinase assay, and AP-1 binding by electrophoretic mobility shift assay. PPC (200 ng/ml) significantly inhibited PDGF-induced proliferation (p < 0.05; ANOVA, n = 3) and antagonized PDGF-induced P44MAPK activation and AP-1 binding. This effect was mimicked by DLPC but not by PLPC. Neither DLPC nor PLPC prevented PDGF receptor activation. We conclude that PPC exerts a previously unrecognized effect on mitogen-induced stellate cell proliferation which may be mediated by DLPC. Inhibition of this cascade represents a potential mechanism for the inhibitory effect of PPC on hepatic fibrogenesis.