Developing natural marine products for treating liver diseases.

In recent years, marine-derived bioactive compounds have gained increasing attention because of their higher biodiversity vs land-derived compounds. A number of marine-derived compounds are proven to improve lipid metabolism, modulate the gut microbiota, and possess anti-inflammatory, antioxidant, antibacterial, antiviral, and antitumor activities. With the increasing understanding of the molecular landscape underlying the pathogenesis of chronic liver diseases, interest has spiked in developing new therapeutic drugs and medicine food homology from marine sources for the prevention and treatment of liver diseases.

Serum amyloid A levels in patients with liver diseases.

BACKGROUND: Serum amyloid A (SAA) is an acute phase protein mainly synthesized by the liver. SAA induces inflammatory phenotype and promotes cell proliferation in activated hepatic stellate cells, the major scar forming cells in the liver. However, few studies have reported on the serum levels of SAA in human liver disease and its clinical significance in various liver diseases. AIM: To investigate the serum levels of SAA in patients with different liver diseases and analyze the factors associated with the alteration of SAA levels in chronic hepatitis B (CHB) patients. METHODS: Two hundred and seventy-eight patients with different liver diseases and 117 healthy controls were included in this study. The patients included 205 with CHB, 22 with active autoimmune liver disease (AILD), 21 with nonalcoholic steatohepatitis (NASH), 14 with drug-induced liver injury (DILI), and 16 with pyogenic liver abscess. Serum levels of SAA and other clinical parameters were collected for the analysis of the factors associated with SAA level. Mann-Whitney U test was used to compare the serum SAA levels of patients with various liver diseases with those of healthy controls. Bonferroni test was applied for post hoc comparisons to control the probability of type 1 error (alpha = 0.05/6 = 0.008). For statistical tests of other variables, P < 0.05 was considered statistically significant. Statistically significant factors determined by single factor analysis were further analyzed by binary multivariate logistic regression analysis. RESULTS: All patients with active liver diseases had higher serum SAA levels than healthy controls and the inactive CHB patients, with the highest SAA level found in patients with pyogenic liver abscess (398.4 ± 246.8 mg/L). Patients with active AILD (19.73 ± 24.81 mg/L) or DILI (8.036 ± 5.685 mg/L) showed higher SAA levels than those with active CHB (6.621 ± 6.776 mg/L) and NASH (6.624 ± 4.891 mg/L). Single (P < 0.001) and multivariate logistic regression analyses (P = 0.039) for the CHB patients suggested that patients with active CHB were associated with an SAA serum level higher than 6.4 mg/L. Serum levels of SAA and CRP (C-reactive protein) were positively correlated in patients with CHB (P < 0.001), pyogenic liver abscess (P = 0.045), and active AILD (P = 0.02). Serum levels of SAA (0.80-871.0 mg/L) had a broader fluctuation range than CRP (0.30-271.3 mg/L). CONCLUSION: Serum level of SAA is a sensitive biomarker for inflammatory activity of pyogenic liver abscess. It may also be a weak marker reflecting milder inflammatory status in the liver of patients with CHB and other active liver diseases.

Risk Factors for Hepatocellular Carcinoma in Cirrhotic Patients with Chronic Hepatitis B.

AIMS: To investigate the clinical and genetic risk factors associated with hepatocellular carcinoma (HCC) in cirrhotic patients with chronic hepatitis B (CHB). METHODS: Nine hundred forty-nine Chinese Han patients with CHB were studied, including noncirrhotic patients without HCC (N = 234), cirrhotic patients without (N = 281) and with HCC (N = 434). Patients were genotyped for 10 candidate single nucleotide polymorphisms (SNPs) by the polymerase chain reaction (PCR)-ligase detection reaction (LDR) method. RESULTS: By multivariate logistic regression analysis adjusted for Child-Pugh scores, noneffective antiviral treatment, drinking history, family history of HCC, and age ≥50 years old were associated with HCC risk (odds ratio [OR] = 5.923, 2.456, 2.241, 1.955, respectively). Sixty-two of 170 cirrhotic patients who achieved sustained virological suppression by antiviral treatment developed HCC, with fatty liver disease, family history of HCC, and family history of hepatitis B virus (HBV) infection as the risk factors (OR = 11.646, 3.339, 2.537, respectively). The SNPs associated with HCC risk in patients with cirrhosis and CHB were rs11536889 in TLR4 and rs2853744 in SPP1. Polymorphisms of TLR4 rs2149356, AP3S2 rs2290351, STXBP5L rs2169302, MLEC rs7976497, and SOCS3 rs4969168 were associated with HCC risk in specific stratified analyses with gender, age, and drinking history in the cirrhotic patients. CONCLUSIONS: Inadequate antiviral treatment, family history of HCC, drinking history, and age ≥50 years old are risk factors for HCC. Sustained suppression of HBV does not eliminate the risk of HCC. Specific host genetic factors may impact HCC development in Han Chinese cirrhotic patients with CHB, including SNPs in TLR4, SPP1, AP3S2, STXBP5L, MLEC, and SOCS3, which warrant further validation in additional cohorts.

Antiviral therapies for hepatitis B virus-related hepatocellular carcinoma.

Chronic hepatitis B virus (HBV) infection is a critical risk factor for the carcinogenesis and progression of hepatocellular carcinoma (HCC). It promotes HCC development by inducing liver fibrogenesis, genetic and epigenetic alterations, and the expression of active viral-coded proteins. Effective antiviral treatments inhibit the replication of HBV, reduce serum viral load and accelerate hepatitis B e antigen serum conversion. Timely initiation of antiviral treatment is not only essential for preventing the incidence of HCC in chronic hepatitis B patients, but also important for reducing HBV reactivation, improving liver function, reducing or delaying HCC recurrence, and prolonging overall survival of HBV-related HCC patients after curative and palliative therapies. The selection of antiviral drugs, monitoring of indicators such as HBV DNA and hepatitis B surface antigen, and timely rescue treatment when necessary, are essential in antiviral therapies for HBV-related HCC.

[Effects of cordyceps acid and cordycepin on the inflammatory and fibrogenic response of hepatic stellate cells].

OBJECTIVE: To investigate the effects of cordyceps acid and cordycepin on the inflammatory phenotype and fibrogenic property of hepatic stellate cells (HSCs). METHODS: An immortalized mouse HSC line (JS1) was stimulated with lippolysaccharide (LPS; 100 ng/ml) to induce an inflammatory response with or without co-administration of cordyceps acid or cordycepin in various concentrations (10, 50, or 200 mumol/L). Effects of the treatments on the chemokine monocyte chemotactic protein-1 (MCP-1) mRNA expression in the cells and the protein secretion in the cell culture supernatants were determined by reverse transcription and real-time quantitative PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. In addition, JS1 cells were treated with transforming growth factor-b1 (TGFb1; 10 ng/ml) to induce a fibrogenic response with or without co-administration of cordyceps acid or cordycepin in various concentrations (10, 50, or 200 mumol/L). Effects on the expression of fibrogenic proteins including collagen type I and a-smooth muscle actin (a-SMA), were investigated by Western blot. RESULTS: High-concentration (200 mumol/L) treatments of both cordyceps acid and cordycepin significantly inhibited the LPS-induced up-regulation of MCP-1 transcription and secretion (mRNA: 2.07 +/- 0.29 vs. 3.35 +/- 0.26, t = 15.90 and 1.15 +/- 0.23 vs. 4.17 +/- 0.61, t = 8.93; protein: 1.88 +/- 0.06 vs. 2.33 +/- 0.06, t = 10.39 and 1.47 +/- 0.25 vs. 1.97 +/- 0.04, t = 4.60; all P less than 0.05). All concentrations of cordyceps acid and cordycepin inhibited the TGFb1-induced up-regulation of collagen type I and a-SMA protein expression. However, the effects were more robust with the 200 mumol/L concentrations (P less than 0.05). CONCLUSION: Cordyceps acid and cordycepin ameliorate the LPS-induced inflammatory phenotype and TGFb1-induced fibrogenic response of cultured HSCs. These effects may contribute significantly to the drugs' therapeutic mechanisms to inhibit and resolve liver fibrosis.

[HMGB1-mediated activation of TLR4 signaling in hepatic stellate cells].

To determine the potential of the high mobility group box-1 protein 1 (HMGB1) to activate Toll-like receptor 4 (TLR4) signaling in hepatic stellate cells (HSCs) and investigate the subsequent transition of HSC towards the inflammatory phenotype. Three immortalized mouse HSC cell lines, wild-type (JS1), TLR4-/- (JS2) and MyD88-/- (JS3), were subcultured in plates and divided into groups of normal control (untreated), postive control (lipopolysaccaride, LPS treatment), and experimental (HMGB1 treatment). All groups were transfected with luciferase reporter plasmids carrying responsive elements for either the nuclear factor-kappa B (NF-kB) or activator protein-1 AP-1 transcription factors. Following stimulation with normal saline, LPS (100 ng/mL) or HMGB1 (100 ng/mL), the activation of NF-kB or AP-1 was detected by a dual-luciferase reporter assay system. The induction of monocyte chemotactic protein-1 (MCP-1) transcription was determined by measuring the mRNA levels using real time quantitative reverse transcription PCR (qRT-PCR). The secreted protein levels of MCP-1 were determined by enzyme-linked immunosorbent assay (ELISA) of the culture supernatants. Activation of NF-kB- and AP-1-responsive reporters was significantly up-regulated in JS1 cells treated with HMGB1 or LPS, and the activation was coincident with markedly up-regulated transcription and secretion of MCP-1. However, HMGB1 and LPS treatment produced no responsive of the NF-kB and AP-1 reporters, and no increase in expression or secretion of MCP-1, in JS2 or JS3 cells. As an endogeous ligand of TLR4, HMGB1 may activate TLR4 signaling and the TLR4-mediated inflammatory response of HSC.

[Polymorphism of ornithine decarboxylase antizyme inhibitor 1 gene is associated with liver cirrhosis in Chinese hepatitis B patients].

A cirrhosis risk score (CRS) comprised of single nucleotide polymorphisms (SNPs) in seven genes that predicts the risk of cirrhosis in Caucasian hepatitis C has been reported. The present study was to evaluate the association of 11 separate but related SNPs and the CRS with cirrhosis risk in Chinese hepatitis B patients. A total of 563 Chinese subjects with persistent HBV infection (349 with evident liver cirrhosis and 214 without cirrhosis clinically or pathologically) were studied. The candidate SNPs were detected with a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) method. The allele frequency and genotype distribution of each polymorphism as well as the CRS value within the cirrhosis and non-cirrhosis subjects were compared. The rs2679757 polymorphism of the antizyme inhibitor 1 (AZIN1) gene was associated with the risk of cirrhosis (x2 = 6.79, P = 0.03, odds ratio for GG+AG versus AA = 1.63, 95% confidence interval = 1.13-2.35). A gene variant (rs886277) in the transient receptor potential cation channel subfamily M, member 5 gene (TRPM5) was associated with liver cirrhosis, but did not reach statistical significance (x2 = 5.77, P = 0.06). Two SNPs (rs4986791, rs62522600) are not polymorphic in Chinese. Genotype frequencies of other SNPs were not different between the cirrhosis and non-cirrhosis groups. The overall CRS values were not different between the cirrhotic and non-cirrhotic groups (median value 0.57 versus 0.62, Z = -1.05, P = 0.29). SNP rs2679757 in the AZIN1 gene is associated with the risk of HBV-related liver cirrhosis in Chinese. The CRS for Caucasian population has limited applicability for predicting liver cirrhosis in Chinese hepatitis B patients. SNPs associated with cirrhosis prognosis in hepatitis B patients and liver diseases with other etiologies warrant further clinical validation.

[The role of HO-CO system in the hemodynamic disturbance of cirrhotic rats].

To investigate the role of heme oxygenase(HO), a catalyzing enzyme of heme to produce CO, in modulation of systemic circulation in CCl4-induced cirrhotic rats. Saline(vehicle) and ZnPP were s.c. injected into the posterior necks of rats respectively and the rats were then anesthetized by pentobarbital sodium in four hours. Mean arterial pressure (MAP, kPa), heart rate (HR, b/min) and portal pressure (PP, cm/H2O) were measured by indwelling catheter. Plasma CO was determined by Chalmers method. Heme oxygenase acivity was determined by the rate of bilirubin formation. The cirrhotic rats showed significant hyperdynamic circulation indicated by decreased mean arterial pressure [MAP, (15.6+/-1.7) vs (18.9+/-0.9) kPa, t = 4.52, P less than 0.01] and increased portal pressure [PP, (16.7+/-0.8) vs (8.8+/-0.3) cm H2O, t = 23.10, P less than 0.01] as compared to normal control rats(NS). ZnPP could cause a significant increase in MAP [(17.3+/-1.5) vs (15.6+/-1.7) kPa, t = 2.18, P less than 0.05] and significant decrease in PP [(13.2+/-0.7) vs (16.7+/-0.8) cm H2O, t = 8.53, P less than 0.01] in cirrhotic rats. The cirrhotic group presented a significant increase in plasma CO [(18.0+/-1.9) vs (10.4+/-1.3)mumol/L, t = 8.42, P less than 0.01] and HO activity in the spleens [(11.1+/-0.9) vs (6.5+/-0.9) nmol bilirubin/mg protein/h, t = 9.28, P less than 0.01] and intestines [(2.5+/-0.1) vs. (1.3+/-0.2) nmol bilirubin/mg protein/h, t = 15.1, P less than 0.01]. ZnPP could cause significant decreases in plasma CO and HO activity in liver, spleen and intestine of both control and cirrhotic rats. HO-CO system activation may be an important reason for the hemodynamic disturbance of liver cirrhosis.

Antifibrotic activity of rofecoxib in vivo is associated with reduced portal hypertension in rats with carbon tetrachloride-induced liver injury.

BACKGROUND AND AIM: Upregulation of cyclooxygenase-2 (COX-2), an inducible enzyme that is actively involved in inflammation and wound healing, has been found in cirrhotic livers. The aim of this study was to investigate the effects of selective inhibition of COX-2 on the development of liver cirrhosis and portal hypertension in rats. METHODS: Liver cirrhosis was induced by carbon tetrachloride (CCl(4)) in Sprague-Dawley rats. Rofecoxib, a highly selective COX-2 inhibitor, was orally administered to rats at a dose of 10 mg/kg/day. Portal pressure was measured at 8 weeks post CCl(4) administration with the catheterization method followed by the harvesting of liver samples. Liver histopathology was analyzed with hematoxylin and eosin and Masson's trichrome staining. The activated, alpha smooth muscle actin (alpha-SMA) positive hepatic stellate cells (HSCs) and the protein levels of collagen types I, III, IV, as well as laminin and two fibrogenic mediators, vascular endothelial growth factor (VEGF) and connective tissue growth factor (CTGF) in the livers, were detected with immunohistochemical staining and western blot methods, respectively. The level of hepatic thromboxane B(2) (TXB(2)), a potent vasoconstrictive substance derived from COX, was measured with enzyme immunoassay. RESULTS: Oral administration of rofecoxib decreased portal pressure in rats that were treated with CCl(4) for 8 weeks. This was associated with a marked reduction in collagen accumulation and TXB(2) level in the rat livers. In addition, rofecoxib administration was found to reduce the number of activated HSCs and to downregulate hepatic protein levels of three detected types of collagen, laminin, VEGF and CTGF in CCl(4)-treated rats. CONCLUSIONS: COX-2 is involved in the fibrogenesis of livers and the formation of portal hypertension in CCl(4)-treated rats. Selective inhibition of COX-2 by rofecoxib reduces portal hypertension and this is associated with antifibrotic activity as well as a reduction of COX-2-derived vasoactive substance.

[Effects of RNAi on cyclooxygenase-2 expression and biologic activity of human rheumatoid arthritis synovial fibroblasts].

OBJECTIVE: To screen highly efficient small interfering RNA (siRNA) targeting human cyclooxygenase-2 (hCOX-2) mRNA on human rheumatoid arthritis synovial fibroblasts (RASF) and to further study the impact there on prostaglandin E2 (PGE2) and cytokines, such as interleukin-1beta (IL-1beta), interleukin-6 (IL-6), timorous necrosis factor-alpha (TNF-alpha), and vascular endothelial growth factor (VEGF). METHODS: 4 lines of COX-2 mRNA siRNA (1(#) - 4(#) siRNA) were designed and transfected into the fibroblasts from the synovial membrane of a patient with rheumatoid arthritis (RASF). Phorbol ester was added 4 hours later. A scrambled line (NC) group and a blank control (CTL) group were used. RT-PCR and Western blot ting were used to detect the mRNA and protein expression of COX-2 36 and 48 hours after transfection. The levels of PGE2, IL-1beta, IL-6, TNF-alpha, and VEGF were measured by ELISA. RESULTS: RT-PCR showed that the absorbance ratios of the positively interfering groups, NC, and 1(#) - 3(#) siRNA groups, to CTL group were 0.72, 0.3, 0.25, 0.4, and 0.04 respectively. The ratios of the positively interfering groups to CTL group were 1.04, 0.52, 0.39, 0.9, and 36 h after transfection and 1.05, 0.52, 0.51, 0.9, and 0.15 respectively 48 h after transfection. The levels of PGE2, IL-1beta, IL-6, TNF-alpha, and VEGF in the culture supernatant were lower in the 4(#) siRNA group than in other groups 24, 36, and 48 h after transfection. The death rates of RASF of all trial groups were within the range of 9% - 11% and there were not statistically significant differences between the CTL group and the siRNA groups or between the 4(#) siRNA and other siRNA groups. CONCLUSION: 4(#) siRNA effectively inhibits the expression of COX-2 mRNA and protein the level of PGE2, IL-1beta, IL-6, TNF-alpha, and VEGF in the clear supernatant of the 4(#) group is lowest.

Differential effects of selective and non-selective inhibition of nitric oxide synthase on the expression and activity of cyclooxygenase-2 during gastric ulcer healing.

Nitric oxide synthases (NOS) and cyclooxygenase-2 (COX-2) are important enzymes involved in ulcer healing but interactions between them have not been clearly defined. The aim of this study was to investigate the effects of selective or non-selective inhibition of NOS on the expression and activity of COX-2 during healing of acetic acid-induced gastric ulcers in rats. N-[3-(aminomethyl)benzyl] acetamidine (1400 W), a potent selective inhibitor of inducible nitric oxide synthase (iNOS), at a dose of 0.1 mg/kg/day, was found to reduce the ulcer sizes at day 3 and 7 post-ulcer induction. On the other hand, 15 mg/kg/day of NG-nitro-L-arginine methyl ester (L-NAME), a non-selective NOS inhibitor that suppresses both iNOS and endothelial nitric oxide synthase (eNOS), enlarged the ulcer sizes over the same time periods. The expression of COX-2 and COX activity, together with NF-kappaB activation in the ulcer tissues were down-regulated by L-NAME but not 1400 W. It is concluded that iNOS may contribute to ulcer formation while COX-2 and eNOS promote ulcer healing. eNOS enhances COX-2 expression possibly through the activation of NF-kappaB.

Worsening effect of partial sleep deprivation on indomethacin-induced gastric mucosal damage.

The present study was to investigate the roles of cyclooxygenase-1 and -2 (COX-1 and COX-2) and prostaglandin (PG) on gastric mucosal integrity of partially sleep deprived (PSD) rats. A slowly moving drum was used to induce PSD. The PG levels in the gastric mucosa of PSD rats, with or without indomethacin or rofecoxib treatment, were determined. Exogenous prostaglandin E (PGE) analog, misoprostol, was administered to PSD rats to investigate the modulating effect of PG in indomethacin-induced gastric damage. It was observed that COX-1 mRNA and protein were up-regulated in the gastric mucosa of PSD rats. Selective COX-2 inhibition by rofecoxib failed to decrease mucosal PGE2 levels nor to affect mucosal integrity in both PSD and sleep undisturbed rats. However, indomethacin, a COX-1 preferential non-selective COX inhibitor, significantly reduced mucosal PGE2 content and produced more severe mucosal damage in PSD rats than in the controls. The deleterious effect of indomethacin on gastric mucosal integrity of PSD rats was significantly attenuated with the administration of misoprostol. These results suggest that PSD enhances COX-1 biosynthesis of gastroprotective PGE2 as an adaptive response of the stomach to stress. The administration of non-selective COX inhibitors to subjects with chronic sleep deprivation may induce more gastric damages.

Partial sleep deprivation compromises gastric mucosal integrity in rats.

The gastric mucosa is most susceptible to stress that has been shown to induce mucosal damage in humans and animals. This study aims to explore the underlying mechanisms of partial sleep deprivation, as a source of psychophysiological stress, on gastric functions and its effect on mucosal integrity. Sprague-Dawley rats were partially sleep deprived (PSD) for 7 or 14 days by housing inside slowly rotating drums. Gastric tissues and plasma were sampled at the end of the sleep deprivation periods and mucosal lesion scores were evaluated. Morphological examination was performed after Hematoxylin and Eosin staining. Plasma levels of noradrenaline, adrenaline, gastrin, histamine and somatostatin were determined with enzyme immunoassays. Gastric acidity was measured with acid-base titration in pylorus ligated rats. Gastric mucosal blood flow was evaluated with Laser Doppler Flowmetry. It was found that gastric lesions were induced in about 30%-50% of the PSD rats. Gastric acidity as well as plasma levels of noradrenaline, gastrin and histamine were elevated. Gastric mucosal blood flow and plasma somatostatin level were on the contrary reduced, especially in rats with PSD for 14 days. It is concluded that partial sleep deprivation compromises gastric mucosal integrity by increasing gastric acidity, plasma levels of noradrenaline, gastrin, histamine, and decreasing gastric mucosal blood flow. These results provided experimental evidence on the gastric damaging effects of PSD and it could be one of the risk factors contributing to gastric ulcer formation.

The healing effects of Centella extract and asiaticoside on acetic acid induced gastric ulcers in rats.

In this study, the healing effects of Centella asiatica water extract (CE) and asiaticoside (AC), an active constituent of CE, on acetic acid induced gastric ulcers (kissing ulcers) in rats were examined. CE was prepared from Centella asiatica dry plant and the concentration of AC in CE was quantitatively determined with the use of high performance liquid chromatography analysis. Different concentrations of CE and AC were orally administered to rats with kissing ulcers. They were found to reduce the size of the ulcers at day 3 and 7 in a dose-dependent manner, with a concomitant attenuation of myeloperoxidase activity at the ulcer tissues. Epithelial cell proliferation and angiogenesis were on the other hand promoted. The expression of basic fibroblast growth factor, an important angiogenic factor, was also upregulated in the ulcer tissues in rats treated with CE or AC. These results further suggest the potential use of Centella asiatica and its active ingredient as anti-gastric ulcers drugs.

Inhibitory effects of Centella asiatica water extract and asiaticoside on inducible nitric oxide synthase during gastric ulcer healing in rats.

In this study, the effects of Centella asiatica water extract (CE) and its active constituent, asiaticoside (AC), on the expression and activity of inducible nitric oxide synthase (iNOS) during gastric ulcer healing in rats were investigated. CE was prepared from Centella asiatica dry plant and the concentration of AC in CE was quantitatively determined with the use of high performance liquid chromatography analysis. Different concentrations of CE (0.10 g/kg and 0.25 g/kg) and AC (5 mg/kg and 10 mg/kg) were orally administered to rats with acetic acid-induced gastric ulcers. They were found to reduce the size of the ulcers at days 1, 3 and 7 after ulcer induction in a dose-dependent manner, with a concomitant attenuation of iNOS activity and protein expression at the ulcer tissues. The levels of nitrite and nitrate (NO(X)-), the stable end-products of nitric oxide (NO), in the gastric ulcer tissues were also decreased. N-[3-(aminomethyl)benzyl]acetamidine (1400W), a highly selective inhibitor of iNOS, was found to produce similar but more potent inhibition on iNOS activity at a dose of 0.1 mg/kg. These findings indicate that CE and AC have an anti-inflammatory property that is brought about by inhibition of NO synthesis and thus facilitates ulcer healing.