Inhibitory effects of the herbal medicine Sho-saiko-to (TJ-9) on cell proliferation and procollagen gene expressions in cultured rat hepatic stellate cells

Herbal medicine Inchin-ko-to (TJ-135) prevents liver fibrosis and enzyme-altered lesions in rat liver cirrhosis induced by a choline-deficient L-amino acid-defined diet

BACKGROUND/AIMS

The herbal medicine Inchin-ko-to (TJ-135), extract power from three herbs, has recently been reported possessing anti-apoptotic activity. The aim of this study was to investigate whether TJ-135 has any influence on the development of preneoplastic lesions as well as liver fibrosis.

METHODS

The effects of the TJ-135 were examined using the choline-deficient L-amino acid-defined diet-induced liver fibrosis model. In addition, the effect of TJ-135 on mitogen-activated protein (MAP) kinase, type III procollagen mRNA expression and the medium N-terminal procollagen III propeptide (PIIINP) concentration in a hepatic stellate cell line (LI90) were examined.

RESULTS

TJ-135 prevented fibrosis in a dose-dependent manner up to 1.5% (w/w). TJ-135 also reduced the expression of type III procollagen mRNA in the liver, as well as the number of activated stellate cells. Furthermore, TJ-135 reduced the area of preneoplastic lesions in the liver. With LI90 cells, TJ-135 reduced MAP kinase (ERK and JNK but not P38) activities resulting in reduced type III procollagen mRNA and PIIINP concentrations in the medium in a dose-dependent manner.

CONCLUSIONS

These results indicate that although TJ-135 has anti-apoptotic activity, TJ-135 does not increase preneoplastic lesions but significantly reduces liver fibrosis through the inhibition of stellate cell activation without a reduction of hepatocyte cell death.

L-cysteine administration prevents liver fibrosis by suppressing hepatic stellate cell proliferation and activation

Recent studies showed that the function of some amino acids is not only nutritional but also pharmacological. However, the effects of amino acids on liver fibrosis and hepatic stellate cell (HSC) remain unclear. In this research, as a result of screening of amino acids using liver fibrosis induced by DMN administration, L-cysteine was selected as a suppressor of liver fibrosis. Furthermore, the number of activated HSCs, which increased in the fibrotic liver after DMN administration, was decreased in L-cysteine-fed rats. Treatment of freshly isolated HSCs with L-cysteine resulted in inhibition of the increase in smooth muscle alpha-actin (alphaSMA) expression by HSCs and BrdU incorporation into the activated HSCs. These findings suggest that L-cysteine is effective against liver fibrosis. The mechanism of inhibition of fibrosis in the liver is surmized to be direct inhibition of activated HSC proliferation and HSC transformation by L-cysteine.

Effect of Oxymatrine on experimental liver fibrosis

AIM: To study the effect of Oxymatrine on liver fibrosis in immunogenic liver fibrosis rat model.

METHODS: Rat liver fibrosis model was induced by human serum albumin (HSA), 60 Wistar rats were randomly divided into 5 groups, control group without any treatment, liver fibrosis model group, oxymatrine preventive group, oxymatrine therapeutic group, and cochicine therapeutic group. The pathological changes of liver were observed by HE and Von-Gieson staining. The expressions of mRNA and proteins of collagen I/III in liver were determined by in situ hybridization and immunohistochemistry.

RESULTS: The liver fibrosis degree and level of mRNA and proteins of collagen I/III in the liver were significantly reduced in the decreasing order in oxymatrine preventive group, oxymatrine therapeutic group, and cochicine therapeutic group.

CONCLUSION: Oxymatrine may inhibit hepatic inflammation and hepatic synthesis of collagen I/III, and thus prevent and inhibit hepatic fibrosis.

Gadolinium chloride reverses dimethylnitrosamine (DMN)-induced rat liver fibrosis with increased matrix metalloproteinases (MMPs) of Kupffer cells

The aim of this study was to investigate whether matrix metalloproteinases (MMP-13, 9) of Kupffer cells induced by gadolinium chloride (GdCl(3)) treatment can reverse dimethylnitrosamine (DMN)-induced liver fibrosis (in vivo) and the effect of GdCl(3) on MAP kinase activity (in vitro). Male Wistar rats 6 weeks of age received DMN (10 mg/kg) three successive days a week for 4 weeks. Then two groups of rats (n = 6 each) were treated twice weekly with either GdCl(3) (7 mg/kg) or saline solution intravenously for the next 4 weeks. Animals were sacrificed to estimate the degree of liver fibrosis. Isolated Kuppfer cells were treated with GdCl(3) and the expressions of MMPs, MAP kinase activity (ERK, SAPK/JNK, P38) as well as apoptosis were also examined. Rats that received DMN for 4 weeks followed by GdCl(3) injection for 4 weeks showed an reduced liver hydroxyproline content compared to rats treated with DEN followed by saline (277 +/- 22 VS 348 +/- 34 microg/g, n = 6 each, P < 0.01). There were significantly increased MMP-13 mRNA levels in GdCl(3)-treated rats. However, no significant change was observed in procollagen type I mRNA levels. Isolated Kuppfer cells treated with GdCl(3) showed increased MAP kinase activity, especially P38 pathway as well as MMP-13, 9 mRNA and type I collagen-degrading activity leading to apoptosis. SB203580, inhibitor of P38 pathway diminished these activation and prevented apoptosis. These results suggest that Kuppfer cells can reverse liver fibrosis via the expression of MMPs mainly through P38 pathway.

Oxidative stress in viral and alcoholic hepatitis

Liver damage ranges from acute hepatitis to hepatocellular carcinoma, through apoptosis, necrosis, inflammation, immune response, fibrosis, ischemia, altered gene expression and regeneration, all processes that involve hepatocyte, Kupffer, stellate, and endothelial cells. Reactive oxygen and nitrogen species (ROS, RNS) play a crucial role in the induction and in the progression of liver disease, independently from its etiology. They are involved in the transcription and activation of a large series of cytokines and growth factors that, in turn, can contribute to further production of ROS and RNS. The main sources of free radicals are represented by hepatocyte mitochondria and cytochrome p450 enzymes, by endotoxin-activated macrophages (Kupffer cells), and by neutrophils. The consequent alteration of cellular redox state is potentiated by the correlated decrease of antioxidant and energetic reserves. Indices of free radical-mediated damage, such as the increase of malondialdehyde, 4-hydroxynonenal, protein-adducts, peroxynitrite, nitrotyrosine, etc., and/or decrease of glutathione, vitamin E, vitamin C, selenium, etc., have been documented in patients with viral or alcoholic liver disease. These markers may contribute to the monitoring the degree of liver damage, the response to antiviral therapies and to the design of new therapeutic strategies. In fact, increasing attention is now paid to a possible "redox gene therapy." By enhancing the antioxidant ability of hepatocytes, through transgene vectors, one could counteract oxidative/nitrosative stress and, in this way, contribute to blocking the progression of liver disease.

Semi-quantitative analysis of cytokine mRNA expression induced by the herbal medicine Sho-saiko-to (TJ-9) using a Gel Doc system

The RT-PCR method was employed to determine the cytokine mRNA expression of human peripheral lymphocytes induced by the Japanese herbal medicine Sho-saiko-to (TJ-9). The results showed that the mRNA expression of IL-12, IL-1beta, IL-10, TNF-alpha, G-CSF, and IFN-gamma increased after 6 hr in culture. This is the first reported finding that TJ-9 is an IFN-gamma inducer. Next, cytokine mRNA expression was semi-quantitatively measured using the Gel Doc system with a CCD camera and then statistically analyzed in order to determine which component of TJ-9 was the true cytokine inducer. The results showed that the scutellaria root is the main component inducing the cytokines, while the glycyrrhiza root is the secondary component. When the cytokine concentrations in the supernatants of cell cultures were measured by ELISA, the levels of IL-12, IL-1beta, IL-10, TNF-alpha, and G-CSF reflected mRNA expression levels in the cell fraction. However, the level of IFN-gamma was below the detectable limit. The effects of various reagents on many different kinds of cytokine mRNA expression could be analyzed objectively in a short time using the Gel Doc system. Many important findings could be demonstrated by this simple, easy, sensitive, and cheap method. After the clinical significance of cytokine analysis is confirmed, this method may become a useful clinical examination tool.

Antifibrotic effect of the herbal medicine Saiko-keishi-to (TJ-10) on chronic pancreatitis in the WBN/Kob rat

Chronic pancreatitis is characterized by fibrosis. We reported an anti-inflammatory effect of the herbal medicine Saiko-keishi-to (TJ-10) on chronic pancreatitis. This study aimed to elucidate the antifibrotic effect of TJ-10. Four-week-old male WBN/Kob rats were fed a special pellet diet (MB-3) with or without TJ-10 (80 mg/100 g body weight) for 20 weeks. Pancreata were histopathologically examined at every 4 weeks, and the expression of fibrosis-related factors such as transforming growth factor beta1 (TGF-beta1), fibronectin (FN), alpha-smooth muscle actin (alpha-SMA), and type III collagen was analyzed. In untreated WBN/Kob rats, chronic pancreatitis developed at 12 weeks and progressed with marked fibrosis at 16 weeks, and the expression of TGF-beta1 and FN peaked at 12 weeks. However, in the TJ-10-treated rats, the rate of pancreatic fibrosis and the expression of TGF-beta1, FN, alpha-SMA, and type III collagen at 12 and 16 weeks decreased significantly compared to those in the untreated rats. These results suggest that TJ-10 inhibits the pancreatic fibrosis by the suppression of TGF-beta1 expression.

Sho-saiko-to: Japanese herbal medicine for protection against hepatic fibrosis and carcinoma

Herbal medicines, which have been used in China for thousands of years, are now being manufactured in Japan, in standardized form in terms of quality and quantities of ingredients. The Chinese herbal medicine Sho-saiko-to is a mixture of seven herbal preparations, which is widely administered in Japan to patients with chronic hepatitis and cirrhosis. In a prospective study, this herbal medicine was found to play a chemopreventive role in the development of hepatocellular carcinoma in cirrhotic patients. However, little is known about the mechanism by which Sho-saiko-to protects against hepatic fibrosis and carcinoma. Several laboratories, including ours, have clearly demonstrated the preventive and therapeutic effects of Sho-saiko-to on experimental hepatic fibrosis, as well as its inhibitory effect on the activation of hepatic stellate cells, which are the major types of collagen-producing cells. We provided evidence that Sho-saiko-to functions as a potent anti-fibrosuppressant via the inhibition of oxidative stress in hepatocytes and hepatic stellate cells and that its active components are baicalin and baicalein. In addition, Sho-saiko-to has anti-carcinogenic properties in that it inhibits chemical hepatocarcinogenesis in animals, acts as a biological response modifier and suppresses the proliferation of hepatoma cells by inducing apoptosis and arrests the cell cycle. Among the active components of Sho-saiko-to, baicalin, baicalein and saikosaponin-a have the ability to inhibit cell proliferation. It should be noted that baicalin and baicalein are flavonoids with chemical structures very similar to silybinin, which shows anti-fibrogenic activities. This may provide valuable information on the search for novel anti-fibrogenic agents.

Enhanced interstitial collagenase (matrix metalloproteinase-13) production of Kupffer cell by gadolinium chloride prevents pig serum-induced rat liver fibrosis

Hepatic fibrosis results from an imbalance between fibrogenesis and fibrolysis in the liver. It remains uninvestigated whether Kupffer cells produce matrix metalloproteinase-13 (MMP-13), which mainly hydrolyzes extracellular matrix (ECM). We sought to determine the role of Kupffer cells in fibrogenesis/fibrolysis. In vivo, we used the rat model of pig serum-induced liver fibrosis. A subset was treated with gadolinium chloride (GdCl(3)), which specifically acts on Kupffer cells. Administration of GdCl(3) remarkably decreased the hydroxyproline content of the liver and increased the expression of MMP-13 mRNA in the liver without a difference in procollagen type I and tissue inhibitors of metalloproteinase-1 (TIMP-1) mRNA expression on Northern blot analysis with the elimination of ED2-positive cells. In vitro, addition of GdCl(3) to isolated Kupffer cells showed increased type I collagen-degrading activity in a dose-dependent manner as well as MMP-13 mRNA expression on Northern blot analysis. It is concluded that Kupffer cells are a major source of MMP-13 and modulation of Kupffer cells by GdCl(3) prevents liver fibrosis with increased expression of MMP-13 mRNA and protein, whereas procollagen type I and TIMP-1 mRNA, which encode two major effectors of fibrogenesis, were unchanged. This is the first report showing that Kupffer cells produce interstitial collagenase (MMP-13) resulting in the reduction of ECM. This discovery may provide new insights into therapy for hepatic fibrosis.

Strong antiproliferative effects of baicalein in cultured rat hepatic stellate cells

Recently, antifibrogenetic effects of Sho-saiko-to, a traditional herbal medicine in Japan, have been shown in experimental hepatic fibrosis, and flavonoids in Sho-saiko-to are suspected as active ingredients. Thus, we evaluated the effects of baicalein, a major flavonoid in Sho-saiko-to, on proliferation and protein synthesis in cultured rat hepatic stellate cells. Baicalein decreased [3H]thymidine incorporation in cells stimulated with platelet-derived growth factor-B subunit homodimer (PDGF-BB) in a concentration-dependent manner (approximate ED50<10 microM, P<0.0001), and the decrease observed with 10 microM baicalein was greater than those observed with 5 microM retinol or 500 microM 3-isobutyl-1-methylxanthine (IBMX). Baicalein consistently decreased [3H]thymidine incorporation and cell number in cells stimulated with fetal calf serum (ED50<10 microM, P<0.0001), and moderately suppressed [3H]leucine and [3H]proline incorporation (P<0.0001). These results demonstrate the strong antiproliferative effect of baicalein in hepatic stellate cells, showing the possibility of baicalein as an antifibrogenetic drug for hepatic fibrosis.