Effects of sho-saiko-to extract on fibrosis and regeneration of the liver in rats

A comprehensive review of bupleuri radix and its bioactive components： with a major focus on treating chronic liver diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Bupleuri Radix (BR) has been recognized as an essential herbal medicine for relieving liver depression for thousands of years. Contemporary research has provided compelling evidence of its pharmacological effects, including anti-inflammatory, immunomodulatory, metabolic regulation, and anticancer properties, positioning it as a promising treatment option for various liver diseases. Hepatitis, steatohepatitis, cirrhosis, and liver cancer are among the prevalent and impactful liver diseases worldwide. However, there remains a lack of comprehensive systematic reviews that explore the prescription, bio-active components, and underlying mechanisms of BR in treating liver diseases.

AIM OF THE REVIEW

To summarize the BR classical Chinese medical prescription and ingredients in treating liver diseases and their mechanisms to inform reference for further development and research.

MATERIALS AND METHODS

Literature in the last three decades of BR and its classical Chinese medical prescription and ingredients were collated and summarized by searching PubMed, Wiley, Springer, Google Scholar, Web of Science, CNKI, etc. RESULTS: BR and its classical prescriptions, such as Xiao Chai Hu decoction, Da Chai Hu decoction, Si Ni San, and Chai Hu Shu Gan San, have been utilized for centuries as effective therapies for liver diseases, including hepatitis, steatohepatitis, cirrhosis, and liver cancer. BR is a rich source of active ingredients, such as saikosaponins, polysaccharides, flavonoids, sterols, organic acids, and so on. These bioactive compounds exhibit a wide range of beneficial effects, including anti-inflammatory, antioxidant, immunomodulatory, and lipid metabolism regulation. However, it is important to acknowledge that BR and its constituents can also possess hepatotoxicity, which is associated with cytochrome P450 (CYP450) enzymes and oxidative stress. Therefore, caution should be exercised when using BR in therapeutic applications to ensure the safe and appropriate utilization of its potential benefits while minimizing any potential risks.

CONCLUSIONS

To sum up, BR, its compounds, and its based traditional Chinese medicine are effective in liver diseases through multiple targets, multiple pathways, and multiple effects. Advances in pharmacological and toxicological investigations of BR and its bio-active components in the future will provide further contributions to the discovery of novel therapeutics for liver diseases.

Therapeutic effect of Soshiho-tang, a traditional herbal formula, on liver fibrosis or cirrhosis in animal models: a systematic review and meta-analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Liver fibrosis has been recognized as a major lesion of the liver that leads to liver cirrhosis at the end stage. Soshiho-tang (SST) has been used to improve liver fibrosis/cirrhosis by ameliorating fibrosis-specific markers. This study aimed to assess the efficacy of SST on liver fibrosis/cirrhosis through a systematic review of the literature and meta-analysis using animal models.

MATERIALS AND METHODS

Studies of SST treatment in liver fibrosis/cirrhosis-induced animal models were searched by electronic data bases. The quality of the studies included was assessed and the efficacy of SST was evaluated based on markers from liver tissues and serum.

RESULTS

Among the 838 studies identified in the literature search, 20 studies that met the inclusion criteria were included in the analysis. SST significantly reduced the elevated levels of fibrosis markers, such as the degree of fibrosis, hydroxyproline, hyaluronic acid, transforming growth factor-β1, and procollagen III in liver tissues, and aspartate aminotransferase, alanine aminotransferase, procollagen III, tissue inhibitor of metalloproteinase-1, and type IV collagen in the serum.

CONCLUSIONS

SST was effective in decreasing pathologically increased markers in animal models of liver fibrosis/cirrhosis. A larger-scale of animals, well-designed animal study is expected to improve the methodological quality, heterogeneity, and potential biases of the meta-analysis.

Sho-saiko-to, a traditional herbal medicine, regulates gene expression and biological function by way of microRNAs in primary mouse hepatocytes

BACKGROUND

Sho-saiko-to (SST) (also known as so-shi-ho-tang or xiao-chai-hu-tang) has been widely prescribed for chronic liver diseases in traditional Oriental medicine. Despite the substantial amount of clinical evidence for SST, its molecular mechanism has not been clearly identified at a genome-wide level.

METHODS

By using a microarray, we analyzed the temporal changes of messenger RNA (mRNA) and microRNA expression in primary mouse hepatocytes after SST treatment. The pattern of genes regulated by SST was identified by using time-series microarray analysis. The biological function of genes was measured by pathway analysis. For the identification of the exact targets of the microRNAs, a permutation-based correlation method was implemented in which the temporal expression of mRNAs and microRNAs were integrated. The similarity of the promoter structure between temporally regulated genes was measured by analyzing the transcription factor binding sites in the promoter region.

RESULTS

The SST-regulated gene expression had two major patterns: (1) a temporally up-regulated pattern (463 genes) and (2) a temporally down-regulated pattern (177 genes). The integration of the genes and microRNA demonstrated that 155 genes could be the targets of microRNAs from the temporally up-regulated pattern and 19 genes could be the targets of microRNAs from the temporally down-regulated pattern. The temporally up-regulated pattern by SST was associated with signaling pathways such as the cell cycle pathway, whereas the temporally down-regulated pattern included drug metabolism-related pathways and immune-related pathways. All these pathways could be possibly associated with liver regenerative activity of SST. Genes targeted by microRNA were moreover associated with different biological pathways from the genes not targeted by microRNA. An analysis of promoter similarity indicated that co-expressed genes after SST treatment were clustered into subgroups, depending on the temporal expression patterns.

CONCLUSIONS

We are the first to identify that SST regulates temporal gene expression by way of microRNA. MicroRNA targets and non-microRNA targets moreover have different biological roles. This functional segregation by microRNA would be critical for the elucidation of the molecular activities of SST.

Therapeutic effects of the oriental herbal medicine Sho-saiko-to on liver cirrhosis and carcinoma

The traditional Chinese herbal medicine Sho-saiko-to is a mixture of seven herbal preparations that has long been used in the treatment of chronic liver disease. Various clinical trials have shown that Sho-saiko-to protects against the development of hepatocellular carcinoma in cirrhotic patients. However, the mechanism by which Sho-saiko-to protects hepatocytes against hepatic fibrosis and carcinoma is not yet known. Basic science studies have demonstrated that Sho-saiko-to reduces hepatocyte necrosis and enhances liver function. Sho-saiko-to significantly inhibits hepatic fibrosis by inhibiting the activation of stellate cells, the major producers of collagen in the liver, as well as by inhibiting hepatic lipid peroxidation, promoting matrix degradation, and suppressing extracellular matrix (ECM) accumulation. Furthermore, clinical trials have shown that Sho-saiko-to lowers the rate of hepatocellular carcinoma (HCC) development in patients with cirrhosis and increases the survival of patients with HCC. Unfortunately, some case reports have shown the side effects of Sho-saiko-to. Most of the side effects were interstitial pneumonia and acute respiratory failure induced by Sho-saiko-to in Japan. As a result of analyzing these case reports, the incidence and risk are increased by co-administration of interferon, duration of medication, and, high in an elderly population. This review discusses the properties of Sho-saiko-to with regards to the treatment of chronic liver diseases and suggests the side effects of Sho-saiko-to.

Chinese medicines as a resource for liver fibrosis treatment

Liver fibrosis is a condition of abnormal proliferation of connective tissue due to various types of chronic liver injury often caused by viral infection and chemicals. Effective therapies against liver fibrosis are still limited. In this review, we focus on research on Chinese medicines against liver fibrosis in three categories, namely pure compounds, composite formulae and combination treatment using single compounds with composite formulae or conventional medicines. Action mechanisms of the anti-fibrosis Chinese medicines, clinical application, herbal adverse events and quality control are also reviewed. Evidence indicates that some Chinese medicines are clinically effective on liver fibrosis. Strict quality control such as research to identify and monitor the manufacturing of Chinese medicines enables reliable pharmacological, clinical and in-depth mechanism studies. Further experiments and clinical trials should be carried out on the platforms that conform to international standards.

Pharmacology and toxicology of Bupleurum root-containing Kampo medicines in clinical use

Kampo (Japanese traditional herbal) medicines have been produced by combining multiple crude drugs, almost all of plant origin but with some of animal or mineral origin, and contain a great many substances. Their effect is a combination of the various interactions of the constituent substances, whether they are enhancing, synergistic or suppressive. Kampo medicine has an overall effect that is different from the combined effects of individual crude drugs, and several side effects such as anorexia, slight fever and nausea have been reported in the treatment of certain disorders and disease states with Kampo medicines. Among 210 medical formulations used in Japan, some relevant information on the clinical uses, pharmacology and toxicology of six manufactured Kampo medical formulations, Shosaikoto, Daisaikoto, Saikokeishito, Hochuekkito, Saibokuto and Saireito, containing Bupleurum root are reviewed. Studies of some potential interactions between Kampo medicine and western drugs are also considered.

The hepatoprotective effect of Bupleurum kaoi, an endemic plant to Taiwan, against dimethylnitrosamine-induced hepatic fibrosis in rats

In the present study, three materials extracted or isolated from the roots of B. kaoi, an endemic plant to Taiwan, were used to be examined the hepatoprotective effect against dimethylnitrosamine (DMN)-induced hepatic fibrosis in rats, they were water extract (BKW), polysaccharide-enriched fractions (BKP) and saponin-enriched fractions (BKS). After treated with DMN for 4 weeks, the levels of aminotrasferases (GOT, GPT) were significantly elevated in serum, and the levels of total protein (TP) and albumin were significantly decreased in serum and liver homogenates. Furthermore, the collagen contents were significantly elevated in liver homogenates and corresponded to the hepatofibrotic pathological examination. As the results showed, treated with groups of BKW, BKP, BKS markedly reduced GOT, GPT levels in rats serum. In addition, treated with groups of BKW, BKP, BKS markedly raised TP levels in rats serum and liver homogenates. Furthermore, treated with groups of BKW, BKP markedly raised albumin levels in rats serum and liver homogenates. Treated with groups of BKW, BKP, BKS markedly raised interferon-gamma (IFN-gamma) levels in rats serum, where only BKS and silymarin markedly raised interkeukin-10 (IL-10) levels in rats serum compared to that of DMN treated rats. None of test materials of B. kaoi except silymarin reduced the malondialdehyde (MDA) levels, but BKW, BKP markedly raised hepatic glutathione (GSH) levels to reveal the activity of anti-lipid peroxidation. Otherwise, treated with groups of BKW, BKP, BKS significantly reduced collagen contents in rats liver homogenates. In conclusion, B. kaoi demonstrated the anti-inflammatory and anti-fibrotic activities followed by anti-oxidant activity of enhanced GSH production, enhanced the liver cell regeneration and concerned with regulations of INF-gamma and IL-10. The ability of hepatoprotective and anti-fibrotic activities of B. kaoi are higher than B. chinense, a Bupleuri Radix imported from China to Taiwan.

Separation and isolation methods for analysis of the active principles of Sho-saiko-to (SST) oriental medicine

Sho-saiko-to (SST) was introduced into Japan as an oriental classical medicine from China approximately 1500 years ago, and it is currently the most representative Kampo medicine (traditional Japanese medicine). SST is manufactured in Japan as an ethical drug on a modern industrial scale in which the quality of ingredients is standardized with Good Manufacturing Practices (GMP) regulation. SST is widely used for the treatment of chronic hepatitis. Experimental and clinical studies including multi-center, placebo-controlled, double-blind studies have demonstrated the various pharmacological effects of SST. SST is prepared from the hot water extraction of seven raw materials, therefore many kinds of constituents are included. Three-dimensional (3D) HPLC analysis is useful for obtaining many kinds of constituents, especially low molecular ultraviolet (UV) quenching compounds, contained in SST as well as its fractions. Fingerprint pattern provided by 3D HPLC analysis makes possible to identify the overall-viewing of SST. Databases of UV spectra of the components of medicinal herbs obtained by reversed-phase (RP) HPLC using a photodiode array (PDA) and fingerprint patterns of crude drugs made by 3D HPLC analysis facilitate the identification, analysis and quality of herbal drugs. Studies using both PDA HPLC and an amino acid analysis with a fluorometric detector have found that SST contains fifteen major low molecular compounds (i.e. baicalin, wogonin-7-O-glucuronide, liquiritin, their three aglycons, liquiritin apioside, glycyrrhizin, saikosaponin b1, saikosaponin b2, ginsenoside Rg1, ginsenoside Rb1, (6)-gingerol, (6)-shogaol and arginine). These compounds have various pharmacological actions, and are assumed to be responsible, at least partly, for the pharmacological effects of SST. Although there have only been a few investigations on high molecular compounds with pharmacological actions contained in SST, several kinds of polysaccharides have been isolated from constituent herbs of SST. This review paper summarizes analytical methods of separation, isolation and identification of compounds with biological activities from SST, which is a mixture drug of medicinal herbs. Accordingly, this paper would not focus on methods of separation, isolation and analysis of particular compounds from each constituent herb of SST.

Effect of Anoectochilus formosanus on fibrosis and regeneration of the liver in rats

1. The present study examined the effects of an aqueous extract of Anoectochilus formosanus (AFE) on both hepatic fibrosis and regeneration in rats. 2. Fibrosis was induced by intraperitoneal injection of dimethylnitrosamine (DMN) for 3 consecutive days per week for 4 weeks. 3. In DMN-treated rats, liver cirrhosis-associated complications, such as liver atrophy, low concentrations of serum albumin and the accumulation of hepatic collagen, were observed. The AFE protected the liver against DMN-induced fibrosis, as determined by morphological and biochemical observations. 4. In addition, AFE was administered to two-thirds hepatectomized normal and DMN-injured rats. Three and 5 days after hepatectomy, AFE increased the extent of liver weight regeneration and the number of S-phase cells in DMN-injured rats, but not in normal rats. 5. These results show that AFE seems to be useful in the repair of liver injury, improvement of fibrotic changes and promotion of liver regeneration.

A Korean herbal medicine, Panax notoginseng, prevents liver fibrosis and hepatic microvascular dysfunction in rats

We assessed the prevention of hepatic fibrogenesis by water-extract of Panax notoginseng Buck F.H. Chen. (Arialiaceae) root (PNS) in Long-Evans rats with cinnamon coat color (LEC rats). LEC rats were divided into three groups A, fed on a basal diet (BD); B, fed on BD plus 1% PNS; and C), fed on BD plus 0.005% lycopene as a control. All rats were sacrificed at 26 weeks of age. The percentage of the total area involved by fibrosis was 1.46 +/- 0.47 in group A, 0.83 +/- 0.10 in B (P=0.0030, B vs A) and 0.91 +/- 0.45 in C (P=0.0035, C vs. A). The percentage of the total area that was stained for alpha-SMA was 0.56 +/- 0.34 in group A, 0.15 +/- 0.02 in B (P=0.0016, B vs. A and 0.11 +/- 0.01 in C (P=0.0025, C vs. A. In group B, malondialdehyde (MDA) in the liver was lower than in group C (P=0.007). In group C, the concentration of iron in the liver was lower than in group A (P=0.0053). Thus, PNS suppressed fibrogenesis through reduced generation of lipid peroxides. The mechanisms of this preventive effect of fibrogenesis with PNS were suggested to inhibit the stellate cell activity. Second objective of this study was to determine whether PNS affects hepatic microvascular dysfunction elicited by gut ischemia and reperfusion (I/R), since gut I/R causes hepatic microvascular dysfunction, and to investigate the role of nitric oxide (NO). Male Wistar rats were exposed to 30 min of gut ischemia followed by 60 min of reperfusion. Intravital microscopy was used to monitor the number of non-perfused sinusoids (NPS). In another set of experiments, PNS (1 g/kg per day intragastrically) was administered to rats for 7 days. In some experiments, dexamethasone (ST) (2 mg/kg per day intravenously) was administered. In control rats, gut I/R elicited increases in the number of NPS, and plasma TNF-alpha and ALT activities, and these changes were mitigated by the pretreatment with PNS. Pretreatment with an NO synthase inhibitor diminished the protective effects of PNS on the increase in NPS and plasma TNF-alpha levels, but not its effect on the increase in plasma ALT activities. Pretreatment with PNS increased plasma nitrite/nitrate levels. The responses caused by gut I/R were attenuated by the pretreatment with ST. Pretreatment with an NO synthase inhibitor did not affect the effect of ST. These results suggest that PNS attenuates the gut I/R-induced hepatic microvascular dysfunction and inflammatory responses such as TNF-alpha production in the early phase via enhancement of NO production, and sequential hepatocellular damage via its anti-inflammatory effect.

Separation and isolation methods for analysis of the active principles of Sho-saiko-to (SST) oriental medicine

Sho-saiko-to (SST) was introduced into Japan as an oriental classical medicine from China approximately 1500 years ago, and it is currently the most representative Kampo medicine (traditional Japanese medicine). SST is manufactured in Japan as an ethical drug on a modern industrial scale in which the quality of ingredients is standardized with Good Manufacturing Practices (GMP) regulation. SST is widely used for the treatment of chronic hepatitis. Experimental and clinical studies including multi-center, placebo-controlled, double-blind studies have demonstrated the various pharmacological effects of SST. SST is prepared from the hot water extraction of seven raw materials, therefore many kinds of constituents are included. Three-dimensional (3D) HPLC analysis is useful for obtaining many kinds of constituents, especially low molecular ultraviolet (UV) quenching compounds, contained in SST as well as its fractions. Fingerprint pattern provided by 3D HPLC analysis makes possible to identify the overall-viewing of SST. Databases of UV spectra of the components of medicinal herbs obtained by reversed-phase (RP) HPLC using a photodiode array (PDA) and fingerprint patterns of crude drugs made by 3D HPLC analysis facilitate the identification, analysis and quality of herbal drugs. Studies using both PDA HPLC and an amino acid analysis with a fluorometric detector have found that SST contains fifteen major low molecular compounds (i.e. baicalin, wogonin-7-O-glucuronide, liquiritin, their three aglycons, liquiritin apioside, glycyrrhizin, saikosaponin b1, saikosaponin b2, ginsenoside Rg1, ginsenoside Rb1, (6)-gingerol, (6)-shogaol and arginine). These compounds have various pharmacological actions, and are assumed to be responsible, at least partly, for the pharmacological effects of SST. Although there have only been a few investigations on high molecular compounds with pharmacological actions contained in SST, several kinds of polysaccharides have been isolated from constituent herbs of SST. This review paper summarizes analytical methods of separation, isolation and identification of compounds with biological activities from SST, which is a mixture drug of medicinal herbs. Accordingly, this paper would not focus on methods of separation, isolation and analysis of particular compounds from each constituent herb of SST.

Sho-saiko-to prevents liver fibrosis induced by bile duct ligation in rats

Hepatic fibrosis is an over-accumulation of extracellular matrix (ECM). It is a result of an imbalance between collagen synthesis and degradation. Matrix metalloproteinase (MMP) has degradative activity against collagen, but tissue inhibitors of metalloproteinase (TIMP) control the active forms of MMP by blocking the active site of MMP. In our study, we established the bile duct ligated model (BDL) in rats to evaluate anti-fibrotic potential of Chinese medicine sho-saiko-to (TJ-9). We assessed the drug's potential in inhibiting collagen accumulation, suppressing procollagen alpha1 types (I) and (III), and TIMP-1 mRNA expression. After administration of TJ-9, hyperbilirubinemia reduced approximately four-fold when compared with BDL-untreated group. TJ-9 also significantly reduced the collagen content and fibrogenic score, as well as downregulated elevated procollagen alpha1 types (I) and (III) and TIMP-1 mRNA level. Finally, we concluded that (1) TJ-9 significantly reduced cholestasis in rats with BDL, (2) TJ-9 markedly reduced the collagen content by 50%, and (3) TJ-9 exerted its antifibrogenic effect by downregulation of the mRNA expression of procollagen alpha1 types (I) and (III), and TIMP-1 in liver tissue.

Effect of Sho-saiko-to extract on hepatic inflammation and fibrosis in dimethylnitrosamine induced liver injury rats

Sho-saiko-to extract, a Chinese herbal medicine, is widely used for treatment of chronic hepatitis in Japan. However, it is not clear what conditions Sho-saiko-to extract improves hepatic inflammation and fibrosis. We therefore induced various stages of liver injury in model rats and administered Sho-saiko-to extract. We then evaluated the liver inflammation and liver fibrosis-improving effects of Sho-saiko-to extract. The liver injury model rats were produced by administration of various doses of dimethylnitrosamine (DMN) and Sho-saiko-to extract was administered to these rats. Then the liver inflammation and fibrosis-improving effects of Sho-saiko-to extract were evaluated according to L-asparate aminotransferase (AST), L-alanine aminotransferase (ALT), liver retinoid levels, levels of hydroxyproline, Transforming Growth Factor-beta (TGF-beta), and the liver fibrosis area. These indicators depended on the total doses of DMN. The ability of Sho-saiko-to extract to improve liver inflammation and fibrosis was limited to the following levels of the respective parameters: AST levels (234-264 U/l), ALT levels (208-232 U/l), TGF-beta levels (1102-1265 pg/g liver tissue), hydroxyproline levels (633-719 nmol/g liver tissue), and liver fibrosis area (9.7-10.6 times for normal rat). These findings suggested that Sho-saiko-to extract is effective in the treatment of liver inflammation and fibrosis up to a certain degree of severity, but it produces no improvement in more severe cases.

Effects of extract derived from Eriobotrya japonica on liver function improvement in rats

Eriobotrya japonica is considered a medicinal plant, and its leaves (Eriobotrya folia) have been used to treat skin diseases, as well as to relieve inflammation, pain, coughing, and sputa. In our evaluation of the pharmacological efficacy of the seed extracts, constituents of the seeds were found to contain the unsaturated fatty acids linolenic and linoleic acids and the sterol beta-sitosterol in the 70% EtOH and the MeOH extracts. The seed extracts were orally administered to rats with dimethylnitrosamine-induced hepatopathy, and blood L-asparate aminotransferase (AST) and L-alanine aminotransferase (ALT) levels, liver retinoid level, and hydroxyproline level were measured. Liver fibrosis rates calculated after Azan-Mallory staining and evaluation of the liver function-improving effects of extracts were showed that AST, ALT, and hydroxyproline levels and liver fibrosis rates were significantly lower, and retinoid levels were significantly higher in hepatopathic rats treated with 70% EtOH and MeOH extracts of the seed than in water-treated control rats. This suggests that the positive effect on liver function of the extracts varies depending on the extracting solvent used. 70% EtOH and MeOH extract of the seeds inhibited the development of liver fibrosis in hepatopathic rats, thus exhibiting potent improvement. The unsaturated linolenic and linoleic acids and the sterol beta-sitosterol contained in these extracts may also contribute to the improvement of liver function.

Hepatic fibrosis. Pathogenesis and principles of therapy

There has been great progress made in our understanding of the cellular mechanisms of hepatic fibrosis. The recognition that the hepatic stellate cell, (formerly know as lipocyte, Ito, or fat-storing cell), played a central role in the fibrotic response was key to our understanding. Stellate cells undergo a process known as activation, in response to any insult. Activation is a broad phenotypic response, characterized by distinct functional changes in proliferation, fibrogenesis, contractility, cytokine secretion, and matrix degradation. Insights gained into the molecular regulations of stellate cell activation may lead to new antifibrotic therapies, which may reduce morbidity and mortality in patients with chronic liver injury.

Effect of Sho-saiko-to extract on HGF and TGF-beta levels of intraorgans in liver-injured rats after partial hepatectomy

To examine the effects of Sho-saiko-to extract on liver regeneration, Sho-saiko-to extract (0.75%, 1.5% or 3%) was administered to 70% partial hepatectomized rats with dimethylnitrosamine-induced liver-injury. S phase cell number, liver retinoid levels, hepatocyte growth factor (HGF) and transforming growth factor-beta (TGF-beta) levels in each intraorgan were measured as indicators of liver regeneration. Three to seven days after hepatectomy, HGF and TGF-beta levels of the liver and spleen of the Sho-saiko-to extract groups were significantly different from the levels of the ordinary food group (P < 0.05-0.1). HGF levels in the Sho-saiko-to extract groups were approximately 1.3-1.8 times higher in the liver and approximately 1.8-2.1 times higher in the spleen compared with the levels found in the ordinary food group. TGF-beta levels in the Sho-saiko-to extract groups were approximately 0.38-0.47 times the level in the liver and 0.58-0.77 times the level in the spleen of the ordinary food group. There was no difference in HGF and TGF-beta levels of the kidney and lung between the Sho-saiko-to extract group and the ordinary food group. There was a significant and positive correlation between HGF level and S phase cell number in the liver (r = 0.826, P < 0.01). There was a significant and negative correlation between TGF-beta level and the retinoid level in the liver (r = -0.696, P < 0.01). In addition, the levels of the active constituents of Sho-saiko-to extract (glycyrrhetic acid, baicalin and baicalein) showed high values in the liver and spleen of partial hepatectomized rats, and increased from the third day after partial hepatectomy. These results show that Sho-saiko-to extract induces liver regeneration by increasing the production of HGF and suppressing the production of TGF-beta in the liver and spleen of partial hepatectomized rats. It was considered that the increase in the Sho-saiko-to extract active constituent levels in the liver and spleen greatly influences this action.

Effects of Sho-saiko-to extract on liver fibrosis in relation to the changes in hydroxyproline and retinoid levels of the liver in rats

To examine the effects of Sho-saiko-to extract on liver fibrosis, the drug was administered to rats with dimethylnitrosamine-induced liver-injury at various doses. Hydroxyproline and retinoid levels in the liver were measured as indicators of liver function. In liver-injured rats, the hydroxyproline level in the liver (957+/- 154nmol g(-1)) was about 4.16-times that found in normal liver (230+/-11 nmol g(-1)), but administration of Sho-saiko-to extract (0.75%, 1.5% or 3%) reduced the hydroxyproline level significantly (554+/-58, 356+/-51, 374+/-66nmol g(-1), P<0.01). Single administration of the active constituents of Sho-saiko-to extract, glycyrrhizin, baicalin or baicalein, decreased the hydroxyproline level significantly compared with the ordinary food group (P < 0.05), but the decrease was smaller compared with the Sho-saiko-to extract group. The liver retinoid level was higher in the Sho-saiko-to extract group than the ordinary food group and the value increased dose-dependently. A significant negative correlation, r=-0.814 (P<0.001) was detected between the hydroxyproline level and retinoid level in the liver of liver-injured rats. Significant negative correlations, r =-0.728 (P < 0.001) and r= -0.873 (P < 0.001), were also detected between the liver hydroxyproline level and the liver concentrations of the active constituents (glycyrretic acid, baicalin and baicalein) in the liver-injured rats. From these findings, it was considered that the liver concentrations of hydroxyproline and retinoid as well as the active constituents were involved in the improvement of liver fibrosis in the liver-injured rats administered Sho-saiko-to extract. Administration of Sho-saiko-to extract inhibited collagen production while an increase in retinoid level inhibited activation of Ito cells leading to inhibition and prevention of liver 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.

Liver fibrogenesis and the role of hepatic stellate cells: new insights and prospects for therapy

Hepatic fibrosis is a wound-healing response to chronic liver injury, which if persistent leads to cirrhosis and liver failure. Exciting progress has been made in understanding the mechanisms of hepatic fibrosis. Major advances include: (i) characterization of the components of extracellular matrix (ECM) in normal and fibrotic liver; (ii) identification of hepatic stellate cells as the primary source of ECM in liver fibrosis; (iii) elucidation of key cytokines, their cellular sources, modes of regulation, and signalling pathways involved in liver fibrogenesis; (iv) characterization of key matrix proteases and their inhibitors; (v) identification of apoptotic mediators in stellate cells and exploration of their roles during the resolution of liver injury. These advances have helped delineate a more comprehensive picture of liver fibrosis in which the central event is the activation of stellate cells, a transformation from quiescent vitamin A-rich cells to proliferative, fibrogenic and contractile myofibroblasts. The progress in understanding fibrogenic mechanisms brings the development of effective therapies closer to reality. In the future, targeting of stellate cells and fibrogenic mediators will be a mainstay of antifibrotic therapy. Points of therapeutic intervention may include: (i) removing the injurious stimuli; (ii) suppressing hepatic inflammation; (iii) down-regulating stellate cell activation; and (iv) promoting matrix degradation. The future prospects for effective antifibrotic treatment are more promising than ever for the millions of patients with chronic liver disease worldwide.