Protective effects of emodin and astragalus polysaccharides on chronic hepatic injury in rats:

Isolation and purification of polysaccharides from Bupleurum marginatum Wall.ex DC and their anti-liver fibrosis activities

Bupleurum marginatum Wall.ex DC [Apiaceae] (BM)is widely grown in southwestern China, and the whole plant is used as Traditional Chinese Medicine (TCM). Polysaccharides are main natural products in lots of TCM and have been studied for their effects of reducing oxidative stress, anti-inflammation and immune regulation. Herein, we investigated the extraction techniques of Bupleurum marginatum Wall.ex DC polysaccharides (BMP), the identification of their key components, and their ability to inhibit liver fibrosis in both cellular and animal models. Component identification indicated that monosaccharides in BMP mainly consisted of glucose, galactose, mannose, rhamnose, arabinose, and xylose. In vivo analysis revealed that BMP provided significant protective effects on N-Nitroso dimethylamine (NDMA)-induced liver fibrosis rats through reducing hepatomegaly, reducing tissue inflammation, and reducing collagen deposition. BMP also improved the hepatobiliary system and liver metabolism in accord to reduce the serum levels of ALT, AST, ALP, r-GT, and TBIL. In addition, BMP could reduce the level of inflammation and fibrosis through inhibition of IL-1β and TGF-β1. Cellular studies showed that the BMP could provide therapeutic effects on lipopolysaccharide (LPS)-induced cellular fibrosis model, and could reduce the level of inflammation and fibrosis by decreasing the level of TGF-β1, IL-1β, and TNF-α. Our study demonstrated that BMP may provide a new therapy strategy of liver injury and liver fibrosis.

Biosynthesis and Pharmacological Activities of Flavonoids, Triterpene Saponins and Polysaccharides Derived from Astragalus membranaceus

Astragalus membranaceus (A. membranaceus), a well-known traditional herbal medicine, has been widely used in ailments for more than 2000 years. The main bioactive compounds including flavonoids, triterpene saponins and polysaccharides obtained from A. membranaceus have shown a wide range of biological activities and pharmacological effects. These bioactive compounds have a significant role in protecting the liver, immunomodulation, anticancer, antidiabetic, antiviral, antiinflammatory, antioxidant and anti-cardiovascular activities. The flavonoids are initially synthesized through the phenylpropanoid pathway, followed by catalysis with corresponding enzymes, while the triterpenoid saponins, especially astragalosides, are synthesized through the universal upstream pathways of mevalonate (MVA) and methylerythritol phosphate (MEP), and the downstream pathway of triterpenoid skeleton formation and modification. Moreover, the Astragalus polysaccharide (APS) possesses multiple pharmacological activities. In this review, we comprehensively discussed the biosynthesis pathway of flavonoids and triterpenoid saponins, and the structural features of polysaccharides in A. membranaceus. We further systematically summarized the pharmacological effects of bioactive ingredients in A. membranaceus, which laid the foundation for the development of clinical candidate agents. Finally, we proposed potential strategies of heterologous biosynthesis to improve the industrialized production and sustainable supply of natural products with pharmacological activities from A. membranaceus, thereby providing an important guide for their future development trend.

Astragalus Mongholicus: A review of its anti-fibrosis properties

Background: Fibrosis-related diseases (FRD) include cerebral fibrosis, pulmonary fibrosis, cardiac fibrosis, liver fibrosis, renal fibrosis, peritoneal fibrosis, etc. The effects of fibrosis can be severe, resulting in organ dysfunction, functional decline, and even organ failure, which can cause serious health problems.

Aim: Currently, there is no effective modern medicine for anti-fibrosis in the clinics; however, Chinese medicine has a certain beneficial effect on treating such diseases. Astragalus Mongholicus (AM) has rich medicinal value, and its anti-fibrosis effect has been recently investigated. In recent years, more and more experimental studies have been conducted on the intervention of astragaloside IV (AS-IV), astragalus polysaccharide (APS), astragalus flavone, cycloastragalus alcohol, astragalus water extract and other pharmacological components in fibrosis-related diseases, attracting the interest of researchers. We aim to provide ideas for future research by summarizing recent research advances of AM in treating fibrosis-related diseases.

Methods: A literature search was conducted from the core collections of electronic databases such as Baidu Literature, Sciencen.com, Google Scholar, PubMed, and Science Direct using the above keywords and the pharmacological and phytochemical details of the plant.

Results: AM can be used to intervene in fibrosis-disease progression by regulating inflammation, oxidative stress, the immune system, and metabolism.

Conclusion: AS-IV, APS, and astragalus flavone were studied and discussed in detail. These components have high potential anti-fibrosis activity. Overall, this review aims to gain insight into the AM’s role in treating fibro-related diseases.

2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucopyranoside enhances the hepatotoxicity of emodin in vitro and in vivo

Herb-induced liver injury results from the interplay between the herb and host with the herbal components serving as the major origin for hepatotoxicity. Although Polygoni Multiflori Radix (PMR) has been frequently reported to induce liver injury, contributions of its major components such as emodin, emodin-8-O-β-D-glucopyranoside, physcion and 2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucopyranoside (TSG) towards its hepatotoxicity have not been clearly identified. Our initial cytotoxicity screenings of the major PMR components using rat hepatocytes identified emodin as the most toxic. Subsequently, the bile acid homeostasis-related mechanisms of emodin and its combination treatment with TSG in PMR-associated liver injury were explored in sandwich-cultured rat hepatocytes (SCRH) and verified in rats. In SCRH, emodin was found to be able to induce total bile acid accumulation in a dose-dependent manner. In both SCRH and rats, the presence of TSG significantly enhanced the hepatotoxicity of emodin via i) increasing its hepatic exposure by inhibiting its glucuronidation mediated metabolism; ii) enhancing its disruption on bile acid homeostasis through amplifying its inhibition on bile acid efflux transporters and its up-regulation on bile acids synthesis enzymes; iii) enhancing its apoptosis. Our study for the first time demonstrated the critical role of the combination treatment with emodin and TSG in PMR-induced liver injury.

Medicinal plants used against hepatic disorders in Bangladesh: A comprehensive review

ETHNOPHARMACOLOGICAL RELEVANCE

Liver disease is a major cause of illness and death worldwide which accounts for approximately 2 million deaths per year worldwide, 1 million due to complications of cirrhosis and 1 million due to viral hepatitis and hepatocellular carcinoma. That's why it is seeking the researchers' attention to find out the effective treatment strategies. Phytochemicals from natural resources are the main leads for the development of noble hepatoprotective drugs. The majority of the natural sources whose active compounds are currently employed actually have an ethnomedical use. Ethnopharmacological research is essential for the development of these bioactive compounds. These studies not only provide scientific evidence on medicinal plants utilized for particular therapeutic purposes, but they also ensure cultural heritage preservation. Plenty of experimental studies have been well-documented that the ethnomedicinal plants are of therapeutics' interest for the advanced pharmacological intervention in terms of hepatic disorders.

AIM OF THE STUDY

This study summarizes the processes of hepatotoxicity induced by various toxins and explores identified hepatoprotective plants and their phytoconstituents, which can guide the extraction of novel phytochemical constituents from plants to treat liver injury. This review aimed to summarize the hepatoprotective activity of Bangladeshi medicinal plants where the bioactive compounds may be leads for the drug discovery in future.

MATERIALS AND METHODS

Literature searches in electronic databases, such as Web of Science, Science Direct, SpringerLink, PubMed, Google Scholar, Semantic Scholar, Scopus, BanglaJOL, and so on, were performed using the keywords 'Bangladesh', 'ethnomedicinal plants', 'Hepatoprotective agents' as for primary searches, and secondary search terms were used as follows, either alone or in combination: traditional medicine, medicinal plants, folk medicine, liver, hepatitis, therapeutic uses, and anti-inflammatory. Besides, several books, including the book entitled "Medicinal plants of Bangladesh: chemical constituents and uses" authored by Abdul Ghani, were carefully considered, which contained pharmacological properties and phytoconstituents of many medicinal plants growing and traditionally available in Bangladesh. Among them, the most promising plant species with their latest therapeutic effects against hepatic disorders were deeply considered in this review.

RESULTS

The results of this study revealed that in most cases, therapy using plant extracts stabilized altered hepatic biochemical markers induced by hepatotoxins. Initially, we investigated 32 plant species for hepatoprotective activity, however after extensive literature searching; we observed that 20 plants offer good pharmacological evidence of hepatoprotective function. Consequently, most bioactive compounds derived from the herbs including berberine, thymoquinone, andrographolide, ursolic acid, luteolin, naringenin, genistein, quercetin, troxerutin, morin, epigallocatechin-3-gallate, chlorogenic acid, emodin, curcumin, resveratrol, capsaicin, ellagic acid, etc. are appeared to be effective against hepatic disorders.

CONCLUSIONS

Flavonoids, phenolic acids, monoterpenoids, diterpenoids, triterpenoids, alkaloids, chromenes, capsaicinoids, curcuminoids, and anthraquinones are among the phytoconstituents were appraised to have hepatoprotective activities. All the actions displayed by these ethnomedicinal plants could make them serve as leads in the formulation of drugs with higher efficacy to treat hepatic disorders.

Unravelling the Protective Effects of Emodin Against Cyclophosphamide Induced Gonadotoxicity in Male Wistar Rats

Background

Over the past few decades, cyclophosphamide (CP) has been extensively used as a broad-spectrum alkylating agent for the treatment of various cancers and solid tumors. However, the therapeutic actions on CP are not limited to only cancer cells, as it simultaneously exerts significant toxicities on healthy cells through the instigation of oxidative stress and oxidative damages. CP induced testicular toxicity is associated with impaired spermatogenesis, reduced sperm functionality, reproductive hormone and testicular weight. This study was aimed at unravelling the protective effects of emodin (EMD) on testicular toxicity following CP treatment.

Methods

Twenty-four male Wistar rats were allotted into 4 groups as normal control group (NCG), CP control group (CPCG), EMD25+CP (25 mg/kg in 5% tween 80) and EMD50+CP groups (50 mg/kg in 5% tween 80). EMD was orally administered for 35 consecutive days, while four doses of CP (100 mg/kg/week) were administered intraperitoneally from the second to fifth week of treatment. Thereafter, the animals were sacrificed and histopathological examination of the testes as well as serum/testicular biochemical assays were conducted.

Results

The results revealed that CP significantly impeded sperm function parameters including sperm count, viability and motility as well as decreased reproductive hormones (testosterone, LH and FSH) levels. In addition, CP enhanced testicular oxidative stress and proinflammatory markers (MDA, IL-6 and TNF-α), while simultaneously decreasing testicular antioxidant enzymes (GSH, GPx, SOD and CAT). Evidence of marked histopathological alterations was also observed in the H&E stained testicular tissues of CP treated rats. EMD significantly prevented these CP induced negative effects.

Conclusion

This study provides a basis for the potential use of EMD in counteracting chemotherapy induced testicular toxicity. The results further suggest that EMD testicular protective effects in CP-treated rats may be mediated through its modulatory role on oxidative stress and inflammation.

Emodin - A natural anthraquinone derivative with diverse pharmacological activities

Emodin (1,3,8-trihydroxy-6-methyl-anthraquinone) is a natural anthraquinone derivative that is present in numerous globally renowned herbal medicines. It is recognised as a protein tyrosine kinase inhibitor and as an anticancer drug, active against various tumour cells, including lung, breast, liver, and ovarian cancer cells. Recently, its role in combination chemotherapy with various allopathic medicines, to minimize their toxicity and to enhance their efficacy, has been studied. The use of emodin in these therapies is gaining popularity, due to fewer associated side effects compared with standard anticancer drugs. Emodin has a broad therapeutic window, and in addition to its antineoplastic activity, it displays anti-ulcer, anti-inflammatory, hepatoprotective, neuroprotective, antimicrobial, muscle relaxant, immunosuppressive and antifibrotic activities, in both in vitro and in vivo models. Although reviews on the anticancer activity of emodin have been published, none coherently unite all the pharmacological properties of emodin, particularly the anti-oxidant, antimicrobial, antidiabetic, immunosuppressive and hepatoprotective activities of the compound. Hence, in this review, all of the available data regarding the pharmacological properties of emodin are explored, with particular emphasis on the modes of action of the molecule. In addition, the manuscript details the occurrence, biosynthesis and chemical synthesis of the compound, as well as its toxic effects on biotic systems.

Overview of Pharmacokinetics and Liver Toxicities of Radix Polygoni Multiflori

Radix Polygoni Multiflori (RPM), a traditional Chinese medicine, has been used as a tonic and an anti-aging remedy for centuries. However, its safe and effective application in clinical practice could be hindered by its liver injury potential and lack of investigations on its hepatotoxicity mechanism. Our current review aims to provide a comprehensive overview and a critical assessment of the absorption, distribution, metabolism, excretion of RPM, and their relationships with its induced liver injury. Based on the well-reported intrinsic liver toxicity of emodin, one of the major components in RPM, it is concluded that its plasma and liver concentrations could attribute to RPM induced liver injury via metabolic enzymes alteration, hepatocyte apoptosis, bile acids homeostasis disruption, and inflammatory damage. Co-administered 2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucopyranoside in RPM and other drugs/herbs could further aggravate the hepatotoxicity of emodin via enhancing its absorption and inhibiting its metabolism. To ensure the safe clinical use of RPM, a better understanding of the toxicokinetics and effect of its co-occurring components or other co-administered drugs/herbs on the pharmacokinetics of emodin is warranted.

The effect of emodin on liver disease -- comprehensive advances in molecular mechanisms

Liver injury could be caused by a variety of causes, including alcohol, drug poisoning, autoimmune overreaction, etc. In the period of liver injury, hepatic stellate cells (HSCs) will be activated and produce excessive extracellular matrix (ECM). If injury cannot be suppressed, liver injury will develop into fibrosis, even cirrhosis and liver cancer. It is reported that some monomer components extracted from traditional Chinese medicine have better effects on protecting liver. Emodin, an anthraquinone compound extracted from the traditional Chinese medicine RHEI RADIX ET RHIZOMA, has anti-inflammatory, antioxidant, liver protection and anti-cancer effects, and can prevent liver injury induced by a variety of factors. By searching literatures related to the liver protection of emodin in PUBMED, SINOMED, EBM and CNKI databases, it was found that emodin could inhibit the production and promote the secretion of bile acids, and have a protective effect on intrahepatic cholestasis. Also, emodin reduce collagen synthesis and anti-hepatic fibrosis by inhibiting oxidative stress, TGF-β/Smad pathway and HSCs proliferation, and promoting apoptosis of HSCs. Emodin can also regulate lipid metabolism and regulate the synthesis and oxidation of lipids and cholesterol to protect the nonalcoholic fatty liver. Besides, emodin can induce the apoptosis of hepatocellular carcinoma cells by acting on the death receptor pathway and mitochondrial apoptosis pathway, thus inhibiting the development of hepatocellular carcinoma. Moreover, emodin can modulate immunity and improve immune rejection in liver transplantation animals. In conclusion, emodin has a good effect on liver protection, but further experimental data are needed to verify it.

Hepatoprotection and hepatotoxicity of Chinese herb Rhubarb (Dahuang): How to properly control the "General (Jiang Jun)" in Chinese medical herb

Chinese herb Rhubarb (Dahuang), one of the most widely used traditional Chinese medicine in clinical application for over a thousand years and known as the "General (Jiang Jun)" in Chinese medical herb, currently used clinically for long-term treatment of gastrointestinal diseases and chronic liver diseases. Through previous researches, it has been identified that Rhubarb possessed a good hepatoprotective effect, which primarily protected liver from oxidation, fibrosis and cirrhosis, liver failure, hepatocellular carcinoma and various types of hepatitis. Meanwhile, it has been recently reported that long-term administration of Rhubarb preparation may undertake the risk of liver damage, which has aroused worldwide doubts about the safety of Rhubarb. Therefore, how to correctly understand the "two-way" effect of Rhubarb on liver protection and liver toxicity provides a basis for scientific evaluation of Rhubarb's efficacy on liver and side effects, as well as guiding clinical rational drug use. In this review, the mechanisms of Rhubarb how to play a role in hepatoprotection and why it causes hepatotoxic potential will be elaborated in detail and critically. In addition, some positive clinical guidances are also advised on how to reduce its hepatotoxicity in medical treatment.

Resource, chemical structure and activity of natural polysaccharides against alcoholic liver damages

Many natural polysaccharides from bio-resources hold advantages of multi-functions, high efficiency, non-toxicity or low side effect, and have strong potentials in protection against alcoholic liver damages. This review summarized the bio-resources, chemical and structural characteristics of natural polysaccharides with potentials in inhibition against alcoholic liver damages, and also emphasized knowledge on correlations between their chemical structure and function. Approximately 95 species were confirmed in generation of hepatoprotective polysaccharides. Products as crude polysaccharides originated from 17 species were sum up despite the indetermination of their accurate structure. Additional four polysaccharides were described for their known chemical structures. Possible roles of hepatoprotective polysaccharides were provided with evidence on antioxidant promotion, lipids regulation, apoptosis inhibition and anti-inflammation, as well as confirmations in immune enhancement, iron removal and anti-fibrosis when currently treated against the alcoholic liver damages. To sum up, this overview could serve to guide development and utilization of natural hepatoprotective polysaccharides.

Astragalus polysaccharides alleviate tilmicosin-induced toxicity in rats by inhibiting oxidative damage and modulating the expressions of HSP70, NF-kB and Nrf2/HO-1 pathway

The present study evaluated the toxic effects of Tilmicosin (TIL) on adult rats. The rats received a single subcutaneous injection of TIL at different doses (10, 25, 50, 75 and 100 mg/kg bw). TIL altered the biochemical parameters including liver and kidney function markers, glucose level and lipid profile as well as resulted in histopathological lesions in liver and adrenal glands mostly in rats exposed to 75 and 100 mg/kg bw. Then the role of Astragalus polysaccharide (APS) at 100 and 200 mg/kg bw, in modulating the toxic effects induced by high dose of TIL was evaluated. Single injection of TIL at a dose of 75 mg/kg bw was found to increase the activity of ALT, AST and ALP enzymes, induce the generation of reactive oxygen species (ROS) and decrease the total antioxidant capacity (TAC). TIL upregulated the hepatic mRNA expression of heat shock protein 70 (HSP70) and nuclear factor kappa B (NF-kB) while blocked the Nrf2/HO-1 mediated response. These changes were also associated with increasing tumer necrosis factor-alpha (TNF-α), interlukin1-beta (IL-1β) and nitric oxide levels. On the other hand, the results indicate that APS has a beneficial role particularly at high level in alleviating the stress and the hepatotoxic effects elicited by TIL injection in rats.

Inactivation of Kupffer Cells by Selenizing Astragalus Polysaccharides Prevents CCl4-Induced Hepatocellular Necrosis in the Male Wistar Rat

Selenizing astragalus polysaccharides-3 (sAPS₃) was prepared by nitric acid-sodium selenite method. The effects of sAPS₃ on carbon tetrachloride (CCl₄) induced hepatocellular necrosis, and its underlying mechanisms were studied in male Wistar rats. Hepatic damage was induced by intraperitoneal injection of CCl₄ twice a week, for 3 weeks. Meanwhile, the rats in addition to CCl₄ were also exposed to sodium selenite (SS), astragalus polysaccharides (APS), SS + APS or sAPS₃, in parallel by oral gavage once a day for 3 weeks. At the end of 3 weeks, blood and liver tissue were taken. Serum was collected to test the levels of alanine aminotransferase, aspartate aminotransferase and antioxidant status parameters. Liver tissue was collected for histopathological examination and determination of messenger RNA (mRNA) expression levels of CD68, TNF-α, IL-1β and ATG7 followed by the measurements of CD68, IL-1β and LC3II by immunohistochemistry assay (IHC), or TNF-α by immunofluorescence assay (IFA). The results showed that sAPS₃ effectively ameliorated CCl₄ induced hepatocellular necrosis and inflammation and significantly decreased the levels of aspartate aminotransferase, alanine aminotransferase, malondialdehyde and the expression levels of Kupffer cells (KCs)-specific biomarker CD68 and proinflammatory cytokines produced by activated KCs such as IL-1β and TNF-α (P < 0.01). While increasing the levels of total antioxidant capacity, glutathione, glutathione peroxidase and superoxide dismutase (P < 0.05) and reduced the expression levels of a key regulator of autophagy in KCs ATG7 or LC3II (P < 0.05). These findings indicate that sAPS₃ could ameliorate CCl₄-induced hepatocellular necrosis by inactivation of Kupffer cells and its activity may be superior to the application of selenium, APS or combination of selenium with APS.

Preliminary study on Emodin alleviating alpha-naphthylisothiocyanate-induced intrahepatic cholestasis by regulation of liver farnesoid X receptor pathway

The aim of this study is to investigate Emodin on alleviating intrahepatic cholestasis by regulation of liver farnesoid X receptor (FXR) pathway. Cell and animal models of intrahepatic cholestatis were established. Biochemical tests and histomorphology were performed. The messenger RNA (mRNA) and protein expression of FXR, small heterodimer partner (SHP), uridine diphosphate glucuronosyltransferase 2 family polypeptide B4 (UGT2B4), and bile salt export pump (BSEP) was detected. As a result, compared with the model group, the serum levels of biochemical test were significantly lower in the Emodin group (P <0.01). The histopathological changes were remitted significantly by Emodin treatment. In the model group, the mRNA and protein expression of FXR, SHP, UGT2B4, and BSEP was significantly lower than in the normal group in cell models (P <0.05). With Emodin intervention, the expression of FXR, SHP, UGT2B4, and BSEP was notably increased (P <0.05). In conclusion, Emodin plays a protective role in intrahepatic cholestasis by promoting FXR signal pathways.

Effect of Oenanthe Javanica Extract on Antioxidant Enzyme in the Rat Liver

Background:

Oenanthe javanica (O. javanica) has been known to have high antioxidant properties via scavenging reactive oxygen species. We examined the effect of O. javanica extract (OJE) on antioxidant enzymes in the rat liver.

Methods:

We examined the effect of the OJE on copper, zinc-superoxide dismutase (SOD1), manganese superoxide dismutase (SOD2), catalase (CAT), and glutathione peroxidase (GPx) in the rat liver using immunohistochemistry and western blot analysis. Sprague-Dawley rats were randomly assigned to three groups; (1) normal diet fed group (normal-group), (2) diet containing ascorbic acid (AA)-fed group (AA-group) as a positive control, (3) diet containing OJE-fed group (OJE-group).

Results:

In this study, no histopathological finding in the rat liver was found in all the experimental groups. Numbers of SOD1, SOD2, CAT, and GPx immunoreactive cells and their protein levels were significantly increased in the AA-fed group compared with those in the normal-group. On the other hand, in the OJE-group, numbers of SOD1, SOD2, CAT, and GPx immunoreactive cells in the liver were significantly increased by about 190%, 478%, 685%, and 346%, respectively, compared with those in the AA-group. In addition, protein levels of SOD1, SOD2, CAT, and GPx in the OJE-group were also significantly much higher than those in the AA-group.

Conclusion:

OJE significantly increased expressions of SOD1 and SOD2, CAT, and GPx in the liver cells of the rat, and these suggests that significant enhancements of endogenous enzymatic antioxidants by OJE might be a legitimate strategy for decreasing oxidative stresses in the liver.

An experimental study on providing a scientific evidence for seven-time alcohol-steaming of Rhei Rhizoma when clinically used

Background

Rhei Rhizoma (RR) has been widely used as laxative and processed to alter its therapeutic actions or reduce its side effects. In this study, we evaluated experimentally the clinical application guideline that RR should be alcohol-steamed seven times before being used in elderly patients, as described in Dongeuibogam, the most famous book on Korean traditional medicine.

Methods

Unprocessed RR (RR-U) was soaked in rice wine, steamed and then fully dried (RR-P1). The process was repeated four (RR-P4) or seven times (RR-P7). Reversed-phase high-performance liquid chromatography was used to determine the RR-U, RR-P1, RR-P4 and RR-P7 (RRs) constituents. To evaluate the effect of RRs on liver toxicity, human hepatoma cells (HepG2) were treated with RRs at 100 μg/mL for 4 h and then cell viabilities were measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. To confirm the effects in vivo, 5-week-old male Sprague–Dawley rats were treated with RRs at 3 g/kg/day for 21 days. Body weight and serum biochemical parameters were measured and liver histology was assessed.

Results

The levels of sennosides decreased in processed RRs in an iteration-dependent manner, while the emodin level was unaffected. In HepG2 cells, cell viability was reduced with RR-U, while the toxicity decreased according to the number of processing cycles. The changes in body weight, relative liver weight and liver enzymes of RR-U-treated rats were reduced in processed RRs-treated rats. Histopathological analysis indicated swelling and cholestasis improved following seven times alcohol-steaming cycles.

Conclusions

These results provide experimental evidence that RR-P7 almost completely reduces RR hepatotoxicity.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-015-0922-y) contains supplementary material, which is available to authorized users.

Inflammatory stress potentiates emodin-induced liver injury in rats

Herbal medicines containing emodin, widely used for the treatment of hepatitis in clinic, have been reported with hepatotoxicity in individuals. A modest inflammatory stress potentiating liver injury has been linked to the idiosyncratic drug-induced liver injury (IDILI). In this study, we investigated the hypothesis that lipopolysaccharide (LPS) interacts with emodin could synergize to cause liver injury in rats. Emodin (ranging from 20, 40, to 80 mg/kg), which is in the range of liver protection, was administered to rats, before LPS (2.8 mg/kg) or saline vehicle treatment. The biochemical tests showed that non-toxic dosage of LPS coupled with emodin caused significant increases of plasma ALT and AST activities as compared to emodin alone treated groups (P < 0.05). In addition, with LPS or emodin alone could not induce any changes in ALT and AST activity, as compared with the control group (0.5% CMC-Na treatment). Meanwhile, the plasma proinflammatory cytokines, TNF-α, IL-1β, and IL-6 increased significantly in the emodin/LPS groups compared to either emodin groups or the LPS (P < 0.05). Histological analysis showed that liver damage was only found in emodin/LPS cotreatmented rat livers samples. These results indicate that non-toxic dosage of LPS potentiates the hepatotoxicity of emodin. This discovery raises the possibility that emodin and herbal medicines containing it may induce liver injury in the inflammatory stress even in their therapeutic dosages.

Apoptosis of Dalton's lymphoma due to in vivo treatment with emodin is associated with modulations of hydrogen peroxide metabolizing antioxidant enzymes

The evolving concept of pro-oxidative mechanism-based antitumor activity of emodin (1,3,8-trihydroxy-6-methyl anthraquinone), derived mainly from in vitro studies, needs to be defined for in vivo tumor models. The present article describes apoptosis and regression of Dalton's lymphoma (DL) in mice by emodin vis a vis modulations of hydrogen peroxide (H2O2) metabolizing antioxidant enzymes in the tumor cells in vivo. A non-toxic dose (40 mg/kg bw) of emodin, given intraperitoneally to the DL bearing mice daily up to 12th post DL transplantation day, caused a significant decline (P < 0.05) in the number of viable DL cells and could significantly increase life span of the DL mice (P < 0.01). A significant decline in Bcl2/Bax ratio consistent with the release of mitochondrial cytochrome c release in DL cells from emodin-treated DL mice suggested that emodin could induce mitochondrial pathway of apoptosis in the DL cells in vivo. Apoptosis of DL cells by emodin was further confirmed by the appearance of smaller DNA fragments on DNA ladder analysis. Over activation of both, the Cu-Zn-superoxide dismutases (SOD1) and Mn-SOD (SOD2), has been found correlated with the tumor suppression. Emodin caused significant increases in the expression and activity of SOD1 and SOD2 in the DL cells. H2O2 produced by SODs is degraded by catalase and glutathione peroxidase in the cells. Both these enzymes were observed to be declined significantly with a concomitant increment in H2O2 concentration (P < 0.01) in the DL cells from emodin-treated DL mice. It is concluded that emodin is able to induce mitochondrial pathway of apoptosis in the DL cells in vivo via reciprocal modulations of H2O2 producing and degrading antioxidant enzymes.

Two xanthones from Swertia punicea with hepatoprotective activities in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Swertia punicea Hemsl. (Gentianaceae) is more commonly known as "Ganyan-cao" and used mainly as a traditional Chinese folk medicine for the treatment of acute bilious hepatitis, cholecystitis, fever, intoxification and jaundice.

MATERIALS AND METHODS

The active hepatoprotective constituents of Swertia punicea were purified using various column chromatography techniques. The structures of two isolated compounds were determined on the basis of spectroscopic data interpretation such as NMR analysis. The hepatoprotective activities of isolated compounds were evaluated by using hepatotoxicity in vitro and dimethylnitrosamine-induced rat hepatic fibrosis in vivo, respectively.

RESULTS

Two xanthones, 1, 7-dihydroxy-3, 4, 8-trimethoxyxanthone (1) and bellidifolin (2) were isolated from the stems of Swertia punicea. The compounds 1 and 2 exhibited notable hepatoprotective activities against carbon tetrachloride (CCl4) -induced HepG2 cell damage, and effectively alleviated the levels of aspartate transaminase (AST), lactate dehydrogenase (LDH), superoxide dismutase (SOD) and malonic dialdehyde (MDA) induced by CCl₄ in a concentration-dependent manner. Co-treatment with compound 2 significantly increased the cell viability compared with N-acetyl-p-aminophenol (APAP) treatment. Compound 2 also alleviated APAP-induced hepatotoxicity by increasing glutathione (GSH) content and decreasing hydroxyl free radical (·OH) levels and reactive oxygen specises (ROS) production. In addition, the protective effect of compound 1 significantly alleviated DMN-induced liver inflammation and fibrosis. Oral administration of compound 1 recovered the reduction of albumin (ALB) and reversed the elevation of serum alanine transaminase (ALT), AST and total bilirubin (TBIL) in dimethylnitrosamine (DMN)-induced fibrotic rats. Severe oxidative stress induced in fibrotic rats was evidenced by a 1.5-fold elevation in MDA and a fall in the SOD activity, and treatment with compound 1 protected against these adverse effects. Recovery of rat liver tissue against DMN-induced hepatocellular necrosis, inflammatory changes and hepatic fibrosis by compound 1 is also confirmed by H&E and Masson stained histopathological evaluation of liver tissue.

CONCLUSION

Two xanthones from Swertia punicea exhibited hepatoprotective activities in vitro (compounds 1 and 2) and in vivo (compound 1), respectively.

Structural features and biological activities of the polysaccharides from Astragalus membranaceus

Recently, a great deal of interest has been developed to isolate and investigate novel bioactive components with health benefit effects from natural resources. The dried root of Astragalus membranaceus, one of the most popular health-promoting herbal medicines, has been used historically as an immunomodulating agent for the treatment of common cold, diarrhea, fatigue and anorexia for more than 2000 years. Modern phytochemistry and pharmacological experiments have proved that polysaccharide is one of the major active ingredients in the root of A. membranaceus with various important bioactivities, such as immunomodulation, antioxidant, antitumor, anti-diabetes, antiviral, hepatoprotection, anti-inflammation, anti-atherosclerosis, hematopoiesis and neuroprotection. The aim of the present review is to summarize previous and current references and give a comprehensive summary regarding the structural features and biological activities of A. membranaceus polysaccharides in order to provide new insight for further development of these macromolecules.

Emodin prevents ethanol-induced developmental anomalies in cultured mouse fetus through multiple activities

BACKGROUND

Maternal alcohol ingestion on pregnant period causes fetal alcohol syndrome including psychological and behavioral problems, and developmental abnormality. In this study, we investigated the effect of emodin, an active anthraquinone component found in the roots and bark of the genus Rhamnus (Buckthorn), on ethanol-induced teratogenesis during embryonic organogenesis.

METHODS

We cultured mouse embryos on embryonic day 8.5 for 2 days with ethanol (5 μl/3 ml) and/or emodin (1×10(-5) and 1×10(-4) μg/ml) using a whole embryo culture system and then investigated the developmental evaluation, superoxide dismutase (SOD) activity, and expression patterns of cytoplasmic SOD (SOD1), mitochondrial SOD (SOD2), cytosolic glutathione peroxidase (cGPx), tumor necrosis factor-α (TNF-α), caspase 3, and hypoxia inducible factor 1α (HIF-1α).

RESULTS

Morphological parameters, including growth in yolk sac and fetal head, body length, and development of the central nervous system, circulation system, sensory organs, skeletal system, and limbs in embryos exposed to ethanol were significantly decreased compared to those of the normal control group, but co-treatment with emodin (1 × 10(-5) and 1 × 10(-4) μg/ml) significantly improved these parameters. Furthermore, the reduced levels of SOD activity, and SOD1, SOD2, cGPx, and HIF-1α and the increased gene levels of TNF-α and caspase-3 due to ethanol exposure were significantly restored by cotreatment with emodin. Birth Defects Res (Part B) 98:268-275, 2013. © 2013 Wiley Periodicals, Inc.

CONCLUSIONS

This study revealed that cotreatment with emodin significantly prevented teratogenesis induced by ethanol, not only by modulating hypoxia and antioxidant enzymes, but also by attenuating the enhanced levels of TNF-α and caspase 3 in cultured embryos. Therefore, emodin may be an effective preventive agent for ethanol-induced teratogenesis.

In vitro and in vivo hepatoprotective and antioxidant effects of Astragalus polysaccharides against carbon tetrachloride-induced hepatocyte damage in common carp (Cyprinus carpio)

The present study is aiming at evaluating the hepatoprotective and antioxidant effects of Astragalus polysaccharide (APS) on the carbon tetrachloride (CCl(4))-induced hepatocyte and liver injury in common carp in vitro and in vivo. In vitro, APS (200, 400 and 800 μg/ml) was added to the carp primary hepatocytes before (pre-treatment), after (post-treatment) and both before and after (pre- and post-treatment) the incubation of the hepatocytes with CCl(4) at 8 mM in the culture medium. APS at concentrations of 200, 400 and 800 μg/ml significantly improved cell viability and inhibited the elevation of glutamate pyruvate transaminase (GPT), glutamate oxalate transaminase (GOT), lactate dehydrogenase (LDH) and malondialdehyde (MDA) and significantly increased the reduced level of superoxide dismutase (SOD). In vivo administration of APS at the doses of 1.5 and 3 g/kg in the diet for 60 days prior to CCl(4) intoxication significantly reduced the elevated activities of GPT, GOT and LDH and increased the reduced levels of total protein and albumin in the serum; meanwhile, the reduced levels of SOD, glutathione and total antioxidant capacity (T-AOC) were markedly increased and the MDA formation was significantly inhibited in liver tissue. Overall results proved the hepatoprotective action of APS, which is likely related to its antioxidant activity. The results support the use of APS as a hepatoprotective and antioxidant agent in fish.

Inhibitory effect of Astragalus polysaccharides on lipopolysaccharide-induced TNF-a and IL-1β production in THP-1 cells

Astragalus polysaccharides (APS), one of main bioactive components in Astragalus membranaceus Bunge, has been reported to possess anti-inflammatory activities, but the molecular mechanisms behind this activity are largely unknown. This study aimed to investigate expression of inflammatory cytokines and the MAPK/NF-κB pathway in human THP-1 macrophages induced by lipopolysaccharide (LPS). The results showed that the concentrations of TNF-α and IL-1β released from LPS stimulated THP-1 cells increased significantly compared to control (p < 0.01). After treatment with APS, the TNF-α and IL-1β levels were significantly lower than those in the LPS group (p < 0.05). The mRNA expression of TNF-α and IL-1β were also inhibited. Mechanistic studies indicated that APS strongly suppressed NF-κB activation and down-regulated the phosphorylation of ERK and JNK, which are important signaling pathways involved in the production of TNF-α and IL-1β, demonstrating that APS could suppress the production of TNF-α and IL-1β by LPS stimulated macrophages by inhibiting NF-κB activation and ERK and JNK phosphorylation.

Emodin and [6]-gingerol lessen hypoxia-induced embryotoxicities in cultured mouse whole embryos via upregulation of hypoxia-inducible factor 1α and intracellular superoxide dismutases

Excess hypoxia during embryonic organogenesis leads to developmental abnormalities and postnatal deficits. To determine whether emodin and [6]-gingerol affects hypoxia-induced anomalies during embryonic organogenesis, we cultured embryonic day 8.5 mouse embryos under hypoxic conditions (5% O(2)) for 2 days with or without emodin (1 × 10(-8) μg/mL), [6]-gingerol (1 × 10(-9) μg/mL), and SOD mimetics MnTBAP (1 × 10(2) nM/mL) and then investigated the developmental changes and expression patterns of hypoxia-inducible factor 1α (HIF-1α), cytoplasmic superoxide dismutase (SOD1), and mitochondrial SOD (SOD2) in the embryos. Hypoxic conditions induced various developmental anomalies in the growth stages and remarkably low levels of HIF-1α, SOD1 and SOD2 mRNAs, and SOD activity in the embryos; however, these effects were significantly reversed by treatment with emodin, [6]-gingerol, and MnTBAP, respectively. Our findings indicate that antioxidants such as emodin, [6]-gingerol, and MnTBAP lessen hypoxia-induced embryotoxicities via upregulation of HIF-1α and intracellular SODs.

Protective effect of emodin against lipopolysaccharides-induced corneal injury in rats

OBJECTIVE

To investigate the effect of emodin on lipopolysaccharides (LPS)-induced corneal injury in rats.

METHODS

Three parallel incisions on the central surface of corneal epithelium were made and LPS was applied on them to induce corneal injury in Wistar rats. All rats were randomly divided into emodin group (n=40) and keratitis group (n=40). Rats in the emodin group received subconjunctival injection of emodin and rats in the keratitis group received its vehicle 30 minutes before LPS exposure. At different time points--1, 3, 6, 12, and 24 hours after LPS exposure, the symptoms of all rats were observed and the severity of their ocular inflammation was examined with a slit lamp microscope, then 8 rats in each group were killed through cervical dislocation and their eyes were enucleated and prepared to observe pathological changes of corneal tissue under a light microscope. The activation of nuclear factor-kappaB (NF-kappaB) under different conditions was determined by Western blot. Immunocytochemistry staining with an antibody against intercellular adhesion molecule-1 (ICAM-1) was performed to identify positive cells in corneal tissues.

RESULTS

The model of acute keratitis was successfully established in Wistar rats. LPS could induce a typical corneal inflammatory response, such as hyperemia, corneal edema and opacity, which were observed in model rats. Compared with keratitis group, both ocular behaviors and damages of the corneal structure were improved in emodin group. Furthermore, the activation of NF-kappaB and the expression of ICAM-1 induced by LPS were markedly inhibited in emodin group.

CONCLUSION

Emodin can inhibit the activation of NF-kappaB and the expression of ICAM-1 induced by LPS in corneas, protect against acute corneal injury, and improve symptoms in rats.

Acute toxicity and sub-chronic toxicity of steroidal saponins from Dioscorea zingiberensis C.H.Wright in rodents

ETHNOPHARMACOLOGICAL RELEVANCE

Steroidal saponins from Dioscorea zingiberensis are widely used in China for curing cardiovascular diseases. However, there was little toxicological information available on them.

AIM OF THE STUDY

The study evaluated potential toxicity of the steroidal saponins and analyzed the metabolites in rats.

MATERIALS AND METHODS

For the acute study, the steroidal saponins were administered to kunming mice in single doses of 112.5-9000 mg/kg given by gavage. General behavior adverse effects, mortality and liver histopathological changes were examined. For the sub-chronic toxicity study, Sprague-Dawley rats were gavaged at doses of 127.5, 255 and 510 mg/kg/day for 30 days, then examined the biochemical and hematological parameters. Metabolites in serum were analyzed by HPLC-MS.

RESULTS

The steroidal saponins caused dose-dependent general behavior adverse effects, mortality and liver histopathological changes in the acute toxicity study. In the sub-chronic toxicity study, 510 mg/kg/day of steroidal saponins increased total bilirubin (TBIL) in serum and decreased protein content in liver significantly. The metabolic process of TBIL in liver includes TBIL intaking, conjugated bilirubin forming, conjugated bilirubin excreting to biliary passage. Treatment with high dose of the steroidal saponins in vivo may lead to vacuolization of the cytoplasm of hepatocytes and canalicular cholestasis. In all doses used in the experiment, the steroidal saponins decreased aspartate aminotransferase (GOT), alanine aminotransferase (ALT) and alkaline phosphatase (AKP) in serum and increased reduced glutathione hormone (GSH), glutathione reductase (GR) and glutathione S-transferases (GST) in liver. Diosgenin was the main metabolite in serum.

CONCLUSIONS

The steroidal saponins did not show any sign of toxicity up to oral dose of 562.5mg/kg in mice. No significant changes of biochemical and hematological parameters in rats (except at 510 mg/kg/day), it was concluded that the steroidal saponins did not appear to have significant toxicity in their traditional uses.

Inhibitory effect of emodin and Astragalus polysaccharide on the replication of HBV

AIM: To evaluate the anti-viral effect of emodin plus Astragalus polysaccharide (APS) in hepatitis B virus (HBV) transgenic mice.

METHODS: Sixty HBV transgenic mice (HBV TGM) whose weight varied between 18 and 24 g were randomly divided into 3 groups, with 20 mice in each group. Group A was the normal control, where the mice were treated with physiological saline; group B was the positive control where the mice were treated with lamivudine solution (100 mL/kg per day). Group C was the experimental group where the mice were treated with physiological saline containing emodin and APS (57.59 mg/kg per day and 287.95 mg/kg per day, respectively). The mice were treated daily for 3 wk. After 1 wk recovery time, the mice were sacrificed and serum as well as liver tissues were collected for ELISA and histological examination.

RESULTS: After 21 d treatment, HBV DNA levels in group B and group C significantly declined when compared with group A (P < 0.05). However, a significant increase in HBV DNA content was observed in group B, whereas this phenomenon was not observed in group C. A reduction in the contents of HBsAg, HBeAg and HBcAg in the mice from group B and C was observed when compared with group A.

CONCLUSION: Emodin and APS have a weak but persistent inhibitory effect on HBV replication in vivo, which may function as a supplementary modality in the treatment of hepatitis B infection.