Timosaponin A3 induces hepatotoxicity in rats through inducing oxidative stress and down-regulating bile acid transporters

The role of botanical triterpenoids and steroids in bile acid metabolism, transport, and signaling: Pharmacological and toxicological implications

Bile acids (BAs) are synthesized by the host liver from cholesterol and are delivered to the intestine, where they undergo further metabolism by gut microbes and circulate between the liver and intestines through various transporters. They serve to emulsify dietary lipids and act as signaling molecules, regulating the host's metabolism and immune homeostasis through specific receptors. Therefore, disruptions in BA metabolism, transport, and signaling are closely associated with cholestasis, metabolic disorders, autoimmune diseases, and others. Botanical triterpenoids and steroids share structural similarities with BAs, and they have been found to modulate BA metabolism, transport, and signaling, potentially exerting pharmacological or toxicological effects. Here, we have updated the research progress on BA, with a particular emphasis on new-found microbial BAs. Additionally, the latest advancements in targeting BA metabolism and signaling for disease treatment are highlighted. Subsequently, the roles of botanical triterpenoids in BA metabolism, transport, and signaling are examined, analyzing their potential pharmacological, toxicological, or drug interaction effects through these mechanisms. Finally, a research paradigm is proposed that utilizes the gut microbiota as a link to interpret the role of these important natural products in BA signaling.

Anti-tumor effect and mechanisms of Timosaponin AIII across diverse cancer progression

Timosaponin AIII (TAIII), a steroidal saponin derived from Anemarrhena asphodeloides Bunge, has gained attention for its versatile therapeutic properties. While well-established for its anti-inflammatory, antidepressant, and anticoagulant properties, emerging research highlights its potent anti-tumor capabilities. This review synthesizes recent findings on the intricate mechanisms and diverse functions of TAIII in cancer therapy, elucidating its impact on various tumor cells, encompassing the effects of TAIII on critical aspects of cancer progression, including metastasis, apoptosis, and autophagy. Additionally, the shared features of TAIII-induced anti-tumor activities, the factors contributing to the multifaceted anti-cancer activities of TAIII, and an exploration of the advantages and disadvantages associated with the regulation of multiple anti-tumor pathways by TAIII are discussed. Furthermore, the detailed regulation of signaling pathways is delineated and tailored to specific cancer types, providing a comprehensive overview of the potential development of TAIII as a promising anti-tumor agent.

Nourishing Yin traditional Chinese medicine: potential role in the prevention and treatment of type 2 diabetes

Type 2 diabetes mellitus (T2DM), a common and frequently occurring disease in contemporary society, has become a global health threat. However, current mainstream methods of prevention and treatment, mainly including oral hypoglycemic drugs and insulin injections, do not fundamentally block the progression of T2DM. Therefore, it is imperative to find new ways to prevent and treat diabetes. Traditional Chinese medicine is characterized by multiple components, pathways, and targets with mild and long-lasting effects. Pharmacological studies have shown that nourishing yin traditional Chinese medicine (NYTCM) can play a positive role in the treatment of T2DM by regulating pathways such as the phosphatidylinositol 3-kinase/serine-threonine kinase, mitogen-activated protein kinase, nuclear factor-kappa B, and other pathways to stimulate insulin secretion, protect and repair pancreatic β cells, alleviate insulin resistance, ameliorate disordered glucose and lipid metabolism, mitigate oxidative stress, inhibit inflammatory responses, and regulate the intestinal flora. The pharmacologic activity, mechanisms, safety, and toxicity of NYTCM in the treatment of T2DM are also reviewed in this manuscript.

The Potential Role of Timosaponin-AIII in Cancer Prevention and Treatment

Cancer, as one of the leading causes of death worldwide, has challenged current chemotherapy drugs. Considering that treatments are expensive, alongside the resistance of tumor cells to anticancer drugs, the development of alternative medicines is necessary. Anemarrhena asphodeloides Bunge, a recognized and well-known medicinal plant for more than two thousand years, has demonstrated its effectiveness against cancer. Timosaponin-AIII (TSAIII), as a bioactive steroid saponin isolated from A. asphodeloides, has shown multiple pharmacological activities and has been developed as an anticancer agent. However, the molecular mechanisms of TSAIII in protecting against cancer development are still unclear. In this review article, we provide a comprehensive discussion on the anticancer effects of TSAIII, including proliferation inhibition, cell cycle arrest, apoptosis induction, autophagy mediation, migration and invasion suppression, anti-angiogenesis, anti-inflammation, and antioxidant effects. The pharmacokinetic profiles of TSAII are also discussed. TSAIII exhibits efficacy against cancer development. However, hydrophobicity and low bioavailability may limit the application of TSAIII. Effective delivery systems, particularly those with tissue/cell-targeted properties, can also significantly improve the anticancer effects of TSAIII.

Discovery of orally effective and safe GPR40 agonists by incorporating a chiral, rigid and polar sulfoxide into β-position to the carboxylic acid

GPR40 is primarily expressed in pancreatic islet β-cells, and its activation by endogenous ligands of medium to long-chain free fatty acids or synthetic agonists is clinically proved to improve glycemic control by stimulating glucose-dependent insulin secretion. However, most of the reported agonists are highly lipophilic, which might cause lipotoxicity and the off-target effects in CNS. Particularly, the withdrawal of TAK-875 from clinical trials phase III due to liver toxicity concern threw doubt over the long-term safety of targeting GPR40. Improving the efficacy and the selectivity, thus enlarging the therapeutic window would provide an alternative to develop safe GPR40-targeted therapeutics. Herein, by employing an innovative "three-in-one" pharmacophore drug design strategy, the optimal structural features for GPR40 agonist was integrated into one functional group of sulfoxide, which was incorporated into the β-position of the propanoic acid core pharmacophore. As a result, the conformational constraint, polarity as well as chirality endowed by the sulfoxide significantly enhanced the efficacy, selectivity and ADMET properties of the novel (S)- 2-(phenylsulfinyl)acetic acid-based GPR40 agonists. The lead compounds (S)-4a and (S)-4s exhibited robust plasma glucose-lowering effects and insulinotropic action during an oral glucose tolerance test in C57/BL6 mice, excellent pharmacokinetic profile and little hepatobiliary transporter inhibition, marginal cell toxicities against human primary hepatocyte at 100 μM.

Mechanism of Phellodendron and Anemarrhena Drug Pair on the Treatment of Liver Cancer Based on Network Pharmacology and Bioinformatics

Background

This study aims to explore the key targets and signaling pathways of the traditional Chinese medicine Phellodendron and Anemarrhena drug pair (PADP) for the treatment of liver cancer.

Methods

Firstly, bioinformatics technology was used to analyze GSE62232 gene chip to obtain the differential genes of liver cancer. A network pharmacology technology was used to find the active components of PADP and their targets. Secondly, the differential genes were imported into STRING database to draw a PPI network, and network topology structure map combined with Cytoscape software. And the R language was used to identify differential gene targets and pathways through GO and KEGG pathway enrichment analysis. In addition, AutoDock Vina was used for molecular docking of core targets and core compounds. Moreover, GEPIA online analysis tool was used to perform survival analysis of the core target genes. Finally, RT-PCR was used to verify the changes of key target genes. CCK−8 assay was performed to detect cell proliferation. Flow cytometry was performed to detect the cell cycle and apoptotic. Transwell invasion assay was performed to detect cell invasion.

Results

Firstly, a total of 21,654 genes were obtained. After screening, 1019 differential genes were obtained, including 614 down-regulated genes and 405 up-regulated genes. Furthermore, after screening by ADME standards, 52 active ingredients were obtained, of which 37 were Phellodendron and 15 were Anemarrhena. And a total of 36 differential genes have been identified, including 13 up-regulated genes and 23 down-regulated genes. Moreover, through enrichment analysis, we found that PADP may treat liver cancer through multiple channels and multiple pathways including the p53 signaling pathway, IL-17 signaling pathway, TNF signaling pathway, Toll-like receptor signaling pathway and so on. Secondly, the molecular docking results showed that there was certain affinity between the core compounds and core target genes. In addition, GEPIA online analysis showed that ESR1, AR, CCNB1, CDK1, AKR1C3 and CCNA2 might become potential target genes for the survival and prognosis of PADP for the treatment of liver cancer. Finally, it was found that PADP could up regulate genes ESR1 and AR, down regulate genes CCNB1, CDK1, AKR1C3, and CCNA2. PADP could promote the apoptosis of liver cancer cells, shorten the cell cycle, and inhibit the proliferation and invasion of liver cancer cells.

Conclusion

PADP may treat liver cancer through multiple targets, multiple channels, and multiple pathways, thereby suppressing cancer cells and improving the living quality of patients.

Liver injury associated with acute pancreatitis: The current status of clinical evaluation and involved mechanisms

Acute pancreatitis (AP) is a very common acute disease, and the mortality rate of severe AP (SAP) is between 15% and 35%. The main causes of death are multiple organ dysfunction syndrome and infections. The mortality rate of patients with SAP related to liver failure is as high as 83%, and approximately 5% of the SAP patients have fulminant liver failure. Liver function is closely related to the progression and prognosis of AP. In this review, we aim to elaborate on the clinical manifestations and mechanism of liver injury in patients with AP.

Single cell Raman spectroscopy to identify different stages of proliferating human hepatocytes for cell therapy

Background

Cell therapy provides hope for treatment of advanced liver failure. Proliferating human hepatocytes (ProliHHs) were derived from primary human hepatocytes (PHH) and as potential alternative for cell therapy in liver diseases. Due to the continuous decline of mature hepatic genes and increase of progenitor like genes during ProliHHs expanding, it is challenge to monitor the critical changes of the whole process. Raman microspectroscopy is a noninvasive, label free analytical technique with high sensitivity capacity. In this study, we evaluated the potential and feasibility to identify ProliHHs from PHH with Raman spectroscopy.

Methods

Raman spectra were collected at least 600 single spectrum for PHH and ProliHHs at different stages (Passage 1 to Passage 4). Linear discriminant analysis and a two-layer machine learning model were used to analyze the Raman spectroscopy data. Significant differences in Raman bands were validated by the associated conventional kits.

Results

Linear discriminant analysis successfully classified ProliHHs at different stages and PHH. A two-layer machine learning model was established and the overall accuracy was at 84.6%. Significant differences in Raman bands have been found within different ProliHHs cell groups, especially changes at 1003 cm⁻¹, 1206 cm⁻¹ and 1440 cm⁻¹. These changes were linked with reactive oxygen species, hydroxyproline and triglyceride levels in ProliHHs, and the hypothesis were consistent with the corresponding assay results.

Conclusions

In brief, Raman spectroscopy was successfully employed to identify different stages of ProliHHs during dedifferentiation process. The approach can simultaneously trace multiple changes of cellular components from somatic cells to progenitor cells.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02619-9.

Dihydro-stilbene gigantol relieves CCl4-induced hepatic oxidative stress and inflammation in mice via inhibiting C5b-9 formation in the liver

In general, anti-inflammatory treatment is considered for multiple liver diseases despite the etiology. But current drugs for alleviating liver inflammation have defects, making it necessary to develop more potent and safer drugs for liver injury. In this study, we screened a series of (dihydro-)stilbene or (dihydro-)phenanthrene derivatives extracted from Pholidota chinensis for their potential biological activities. Among 31 compounds, the dihydro-stilbene gigantol exerted most potent protective effects on human hepatocytes against lithocholic acid toxicity, and exhibited solid antioxidative and anti-inflammatory effect in vitro. In mice with CCl₄-induced acute liver injury, pre-administration of gigantol (10, 20, 40 mg· kg^-1· d^-1, po, for 7 days) dose-dependently decreased serum transaminase levels and improved pathological changes in liver tissues. The elevated lipid peroxidation and inflammatory responses in the livers were also significantly alleviated by gigantol. The pharmacokinetic studies showed that gigantol was highly concentrated in the mouse livers, which consisted with its efficacy in preventing liver injury. Using a label-free quantitative proteomic analysis we revealed that gigantol mainly regulated the immune system process in liver tissues of CCl₄-treated mice, and the complement and coagulation cascades was the predominant pathway; gigantol markedly inhibited the expression of complement component C9, which was a key component for the formation of terminal complement complex (TCC) C5b-9. These results were validated by immunohistochemistry (IHC) or real time-PCR. Confocal microscopy analysis showed that gigantol significantly inhibited the vascular deposition of TCC in the liver. In conclusion, we demonstrate for the first time that oral administration of gigantol potently relieves liver oxidative stress and inflammation, possibly via a novel mechanism of inhibiting the C5b-9 formation in the liver.

Triterpenoid Saponin AG8 from Ardisia gigantifolia stapf. Induces Triple Negative Breast Cancer Cells Apoptosis through Oxidative Stress Pathway

Triple-negative breast cancers (TNBCs) are associated with poor patient survival because of the absence of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expressions. Our previous studies have shown that the triterpenoid saponin AG8 from Ardisia gigantifolia stapf. inhibits the proliferation of MDA-MB-231 cells. In this study, the effects of AG8 were further analyzed in different TNBC cell types: MDA-MB-231, BT-549, and MDA-MB-157 cells. AG8 inhibited the viability of MDA-MB-231, BT-549, and MDA-MB-157 cells in a dose-dependent manner and showed stronger cytotoxicity to African American (AA) and mesenchymal (M) subtypes than Caucasian (CA) and mesenchymal stem-like (MSL) subtypes, respectively. AG8 impaired the uptake of MitoTracker Red CMXRos by the mitochondria of TNBC cells in a dose-dependent manner, and this was recovered by N-acetyl-l-cysteine (NAC). AG8 affected GSH, SOD, and MDA levels of TNBC cells, but different TNBC subtypes had different sensitivities to AG8 and NAC. In addition, we found that AG8 increased the Bax/Bcl-2 ratio and the levels of cytoplasmic cytochrome c and significantly decreased phosphorylation of ERK and AKT in BT549 and MDA-MB-157 cells. AG8 elicited its anticancer effects through ROS generation, ERK and AKT activation, and by triggering mitochondrial apoptotic pathways in TNBC cells. AG8 had selective cytotoxic effects against the AA and M TNBC subtypes and markedly induced MDA-MB-157 (AA subtype) cell apoptosis through pathways that were not associated with ROS, which was different from the other two subtypes. The underlying mechanisms should be further investigated.

Pharmacological Activity, Pharmacokinetics, and Toxicity of Timosaponin AIII, a Natural Product Isolated From Anemarrhena asphodeloides Bunge: A Review

Anemarrhena asphodeloides Bunge is a famous Chinese Materia Medica and has been used in traditional Chinese medicine for more than two thousand years. Steroidal saponins are important active components isolated from A. asphodeloides Bunge. Among which, the accumulation of numerous experimental studies involved in Timosaponin AIII (Timo AIII) draws our attention in the recent decades. In this review, we searched all the scientific literatures using the key word "timosaponin AIII" in the PubMed database update to March 2020. We comprehensively summarized the pharmacological activity, pharmacokinetics, and toxicity of Timo AIII. We found that Timo AIII presents multiple-pharmacological activities, such as anti-cancer, anti-neuronal disorders, anti-inflammation, anti-coagulant, and so on. And the anti-cancer effect of Timo AIII in various cancers, especially hepatocellular cancer and breast cancer, is supposed as its most potential activity. The anti-inflammatory activity of Timo AIII is also beneficial to many diseases. Moreover, VEGFR, X-linked inhibitor of apoptosis protein (XIAP), B-cell-specific Moloney murine leukemia virus integration site 1 (BMI1), thromboxane (Tx) A2 receptor, mTOR, NF-κB, COX-2, MMPs, acetylcholinesterase (AChE), and so on are identified as the crucial pharmacological targets of Timo AIII. Furthermore, the hepatotoxicity of Timo AIII was most concerned, and the pharmacokinetics and toxicity of Timo AIII need further studies in diverse animal models. In conclusion, Timo AIII is potent as a compound or leading compound for further drug development while still needs in-depth studies.

Antiangiogenesis effect of timosaponin AIII on HUVECs in vitro and zebrafish embryos in vivo

Timosaponin AIII (Timo AIII) is a natural steroidal saponin isolated from the traditional Chinese herb Anemarrhena asphodeloides Bge with proved effectiveness in the treatment of numerous cancers. However, whether Timo AIII suppresses tumor angiogenesis remains unclear. In the present study, we investigated the antiangiogenesis effects of Timo AIII and the underlying mechanisms in human umbilical vein endothelial cells (HUVECs) in vitro and zebrafish embryos in vivo. We showed that treatment with Timo AIII (0.5-2 µM) partially disrupted the intersegmental vessels (ISVs) and subintestinal vessels (SIVs) growth in transgenic zebrafish Tg(fli-1a: EGFP)y1. Timo AIII (0.5-4 µM) dose-dependently inhibited VEGF-induced proliferation, migration, invasion, and tube formation of HUVECs, but these inhibitory effects were not due to its cytotoxicity. We further demonstrated that Timo AIII treatment significantly suppressed the expression of VEGF receptor (VEGFR) and the phosphorylation of Akt, MEK1/2, and ERK1/2 in HUVECs. Timo AIII treatment also significantly inhibited VEGF-triggered phosphorylation of VEGFR2, Akt, and ERK1/2 in HUVECs. Moreover, we conducted RNA-Seq and analyzed the transcriptome changes in both HUVECs and zebrafish embryos following Timo AIII treatment. The coexpression network analysis results showed that various biological processes and signaling pathways were enriched including angiogenesis, cell motility, cell adhesion, protein serine/threonine kinase activity, transmembrane signaling receptor activity, growth factor activity, etc., which was consistent with the antiangiogenesis effects of Timo AIII in HUVECs and zebrafish embryos. We conclude that the antiangiogenesis effect of Timo AIII is mediated through VEGF/PI3K/Akt/MAPK signaling cascade; Timo AIII potentially exerts antiangiogenesis effect in cancer treatment.

Metabolomics of Aurantio-Obtusin-Induced Hepatotoxicity in Rats for Discovery of Potential Biomarkers

Aurantio-obtusin is an anthraquinone derived from Cassia obtusifolia (cassiae semen). It is also used as a tool and a detection index for the identification of cassiae semen, as stipulated by the Chinese Pharmacopoeia. Anthraquinones, the main components in cassiae semen, have been reported to show hepatotoxicity. This study investigates the hepatotoxicity of aurantio-obtusin in male Sprague–Dawley rats. We randomly divided the animals into a blank control group and treated three test groups with different doses of aurantio-obtusin: Low dose (4 mg/kg), medium dose (40 mg/kg), and high dose (200 mg/kg). Each group was treated with aurantio-obtusin for 28 days, whereas the control group was administered an equal volume of 0.5% carboxymethyl cellulose sodium salt (CMC-Na) aqueous solution. Subsequently, we conducted biochemical, hematological, and pathological investigations and determined the weight of different organs. We used serum metabolomics to identify possible biomarkers related to hepatotoxicity. The low-dose group showed no significant liver injury, whereas the medium- and high-dose groups manifested obvious liver injury. Compared with the control group, the test groups showed an increase in alanine transaminase, aspartate transaminase, and alkaline phosphatase levels. The liver organ coefficient also significantly increased. Additionally, we found significant changes in the hematological indices. Metabolomics analysis showed that aurantio-obtusin induced 28 endogenous markers related to liver injury. Our data indicate that aurantio-obtusin induces hepatotoxicity in rat liver in a dose-dependent manner and is mediated by pathways involving bile acids, fatty acids, amino acids, and energy metabolism. In particular, changes in bile acid content during treatment with therapeutic agents containing aurantio-obtusin deserve increased attention.

Metabolism, pharmacokinetics, and hepatic disposition of xanthones and saponins on Zhimu treatments for exploratively interpreting the discrepancy between the herbal safety and timosaponin A3-induced hepatotoxicity

Timosaponin A3, a saponin in Zhimu, elicited hepatotoxicity via oxidative stress. However, the clinical medication of Zhimu has been historically regarded as safe, probably associated with the antioxidants it contains. However, the related information on the in vivo levels of timosaponin A3 and antioxidants remained unclear on Zhimu treatments. Therefore, a combination of the in vitro metabolism, including microbiota-mediated and liver-mediated metabolism, and in vivo pharmacokinetics and hepatic disposition, was conducted for three xanthones (neomangiferin, mangiferin, and norathyriol) and three saponins (timosaponin B2, timosaponin B3, and timosaponin A3) on Zhimu treatments. Consequently, following oral administration of Zhimu decoction to rats, those saponins and xanthones were all observed in the plasma with severe liver first-pass effect, where mangiferin was of the maximum exposure. Despite the ignorable content in the herb, timosaponin A3 elicited sizable hepatic exposure as the microbiota-mediated metabolite of saponins in Zhimu. The similar phenomenon also occurred to norathyriol, the microbiota-mediated metabolite of xanthones. However, the major prototypes in Zhimu were of limited hepatic exposure. We deduced the hepatic collection of norathyriol, maximum circulating levels of mangiferin, and timosaponin B2 and mangiferin interaction may directly or indirectly contribute to the whole anti-oxidation of Zhimu, and then resisted the timosaponin A3-induced hepatotoxicity. Thus, our study exploratively interpreted the discrepancy between herbal safety and timosaponin A3-induced hepatotoxicity. However, given the considerable levels and slow eliminated rate of timosaponin A3 in the liver, more attention should be paid to the safety on the continuous clinical medication of Zhimu in the future.

Molecular Mechanisms Involved in Oxidative Stress-Associated Liver Injury Induced by Chinese Herbal Medicine: An Experimental Evidence-Based Literature Review and Network Pharmacology Study

Oxidative stress, defined as a disequilibrium between pro-oxidants and antioxidants, can result in histopathological lesions with a broad spectrum, ranging from asymptomatic hepatitis to hepatocellular carcinoma in an orchestrated manner. Although cells are equipped with sophisticated strategies to maintain the redox biology under normal conditions, the abundance of redox-sensitive xenobiotics, such as medicinal ingredients originated from herbs or animals, can dramatically invoke oxidative stress. Growing evidence has documented that the hepatotoxicity can be triggered by traditional Chinese medicine (TCM) during treating various diseases. Meanwhile, TCM-dependent hepatic disorder represents a strong correlation with oxidative stress, especially the persistent accumulation of intracellular reactive oxygen species. Of note, since TCM-derived compounds with their modulated targets are greatly diversified among themselves, it is complicated to elaborate the potential pathological mechanism. In this regard, data mining approaches, including network pharmacology and bioinformatics enrichment analysis have been utilized to scientifically disclose the underlying pathogenesis. Herein, top 10 principal TCM-modulated targets for oxidative hepatotoxicity including superoxide dismutases (SOD), malondialdehyde (MDA), glutathione (GSH), reactive oxygen species (ROS), glutathione peroxidase (GPx), Bax, caspase-3, Bcl-2, nuclear factor (erythroid-derived 2)-like 2 (Nrf2), and nitric oxide (NO) have been identified. Furthermore, hepatic metabolic dysregulation may be the predominant pathological mechanism involved in TCM-induced hepatotoxic impairment.

Antibody-modified liposomes for tumor-targeting delivery of timosaponin AIII

Introduction

Timosaponin AIII (TAIII), as a steroid saponin in Anemarrhena asphodeloides, has favorable potential as an antitumor candidate. However, its hydrophobicity and low bioavailability severely limit its in vivo antitumor efficacy.

Methods

To overcome this drawback, TAIII-loaded liposomes (LP) were prepared to improve TAIII solubility and extend its circulation time. Furthermore, anti-CD44 antibody-modified LP (CD44-LP) was prepared to enhance the therapeutic index of TAIII. The LP and CD44-LP were also characterized through their biological activity, target selective binding and uptake, and in vivo pharmacokinetics.

Results

Compared with free TAIII, both LP and CD44-LP possessed a desirable sustained-release profile in vitro, with ~14.2- and 10.7-fold longer TAIII half-life, respectively, and 1.7- and 1.9-fold larger area under the curve, respectively. LP and CD44-LP enhanced TAIII antitumor activity against HepG2 cells and in a xenograft mouse model without detectable toxicity. In particular, CD44-LP exhibited notably higher cytotoxicity than did LP, with a lower half-maximal inhibitory concentration (48 h). CD44-LP exhibited stronger tumor inhibition, and the tumor inhibitory effect was 1.3-fold that of LP. Furthermore, confocal laser scanning microscopy and in vivo near-infrared imaging of a xenograft mouse model revealed that compared with LP, CD44-LP could effectively enhance tumor accumulation.

Conclusion

Taken together, the results indicate that both CD44-LP and LP can considerably extend TAIII circulation time, increase tumor-targeted accumulation, and enhance antitumor activity. Thus, the anti-CD44 antibody-modified liposome is a promising candidate for treating CD44-positive cancer with considerable antitumor effects.

Acute toxicity, 28-day repeated-dose toxicity and toxicokinetic study of timosaponin BII in rats

Timosaponin BII (TBII), a major steroidal saponin isolated from Anemarrhena asphodeloides Bge., displays a variety of promising pharmacological activities, such as neuroprotection, enhancement of learning and memory, vascular protection and inhibition of platelet aggregation; therefore, it has been developed as a pharmaceutical for prevention or treatment of dementia. Given the safety concerns surrounding timosaponins and the absence of studies on the safety of TBII, the potential toxicity of TBII was evaluated in toxicity and toxicokinetic studies in rats. In the acute oral toxicity study, loose stools were observed in rats receiving 4000 mg/kg, and the symptoms recovered within 1 day. In the 28-day repeated-dose oral toxicity and toxicokinetic study, rats receiving 540 mg/kg showed loose stools and a slight deceleration of body weight growth in both sexes, and the females also showed a slight decrease in food consumption. Moreover, urinalysis indicated reversible treatment-related toxicity in rats receiving 540 mg/kg. The toxicokinetic study demonstrated a dose-dependent increase in systematic exposure to TBII after 28 successive days of oral treatment with TBII. The accumulation coefficients of TBII were 4.35, 1.70 and 1.81, respectively, in rats that received 60, 180 and 540 mg/kg. The no-observed-adverse-effect level (NOAEL) is proposed to be 180 mg/kg.

Antiinflammatory and Hepatoprotective Medicinal Herbs as Potential Substitutes for Bear Bile

Practitioners of traditional Chinese medicine (TCM) commonly prescribe medicinal formulations relying on the purported synergism of a combination of plant species, sometimes incorporating animal parts and minerals. Bear bile, obtained from either wild or farmed bears, is a commonly used constituent of traditional medicine formulations. With several bear species now listed under Convention on International Trade in Endangered Species of Wild Fauna and Flora as threatened with extinction and with bear farming being actively campaigned against on ethical grounds, it is important to seek and promote alternatives to the use of bear bile as medicine. This chapter describes and evaluates the scientific data relating to the efficacy of bear bile and potential alternatives to its use, including the use of bile from other animal species, the use of synthetic chemical alternatives, and the use of herbal substitutes. Scientific studies have confirmed the efficacy of bear bile as an antiinflammatory and a hepatoprotective agent. Ursodeoxycholic acid (UDCA), the active component of bear bile is used in a synthetic form in Western medicine and can serve as an alternative to bear bile in the treatment and management of certain cholestatic liver conditions. In TCM practice, bile from domesticated animal species (such as cattle, chicken, and pig) has been used as a substitute for bear bile. Following evaluation of TCM literature and pharmacological/clinical data, the authors propose six plant species, either as single herbs or in combination, Gardenia jasminoides (zhī zi; ), Scutellaria baicalensis (huáng qín; ), Coptis chinensis (huáng lián, ), Phellodendron amurense (huáng băi; ), Andrographis paniculata (chuan xin lian; ), and Rheum palmatum (dà huang; ), two medicinal Kampo formulations, Orengedokuto, Dia-Orengedokuto (which originated from traditional Chinese herbal formula Huanglian Jiedu Tang, ), and two individual phytochemicals (berberine and andrographolide) as alternatives to bear bile. The proposed herbal alternatives are frequently found listed in traditional formulations also containing bear bile, usually with different therapeutic roles ascribed to them. The existing evidence base for the effectiveness of herbal alternatives is sufficiently strong for TCM practitioners and consumers to consider using these without the addition of bear bile. This consideration is driven by the imperative to protect populations of bears from overexploitation in the wild and when farmed. However, for the identified alternatives to be accepted by users, it is essential that researchers and TCM practitioners collaborate effectively to initiate consumer behavior change.

The involvement of multidrug and toxin extrusion protein 1 in the distribution and excretion of berberine

1. Berberine (BBR), an isoquinoline alkaloid, has demonstrated multiple clinical pharmacological actions. As a substrate of multiple transporters in the liver, BBR is rarely excreted into the bile but can be found in the urine. The purpose of the present study was to investigate the role of multidrug and toxin extrusion protein 1 (MATE1) in the transport of BBR in the liver and kidney. 2. Using human MATE1 (hMATE1)-transfected HEK293 cells, BBR was shown to be a substrate of hMATE1 (K_m = 4.28 ± 2.18 μM). In primary rat hepatocytes, pH-dependent uptake and efflux studies suggested that the transport of BBR was driven by the exchange of H⁺ and involved Mate1. In rats, we found that pyrimethamine (PYR), an inhibitor of Mate1, increased hepatic and renal distribution of BBR and decreased systematic excretion of BBR. 3. These findings indicated that BBR is a substrate of MATE1 and that hepatic and renal Mate1 promote excretion of BBR into bile and urine, respectively. In conclusion, Mate1 plays a key role in the distribution and excretion of BBR, and we speculate that drug-drug interactions (DDIs) caused by MATE1 may occur between BBR and other co-administered drugs.

Functional human induced hepatocytes (hiHeps) with bile acid synthesis and transport capacities: A novel in vitro cholestatic model

Drug-induced cholestasis is a leading cause of drug withdrawal. However, the use of primary human hepatocytes (PHHs), the gold standard for predicting cholestasis in vitro, is limited by their high cost and batch-to-batch variability. Mature hepatocyte characteristics have been observed in human induced hepatocytes (hiHeps) derived from human fibroblast transdifferentiation. Here, we evaluated whether hiHeps could biosynthesize and excrete bile acids (BAs) and their potential as PHH alternatives for cholestasis investigations. Quantitative real-time PCR (qRT-PCR) and western blotting indicated that hiHeps highly expressed BA synthases and functional transporters. Liquid chromatography tandem mass spectrometry (LC-MS/MS) showed that hiHeps produced normal intercellular unconjugated BAs but fewer conjugated BAs than human hepatocytes. When incubated with representative cholestatic agents, hiHeps exhibited sensitive drug-induced bile salt export pump (BSEP) dysfunction, and their response to cholestatic agent-mediated cytotoxicity correlated well with that of PHHs (r² = 0.8032). Deoxycholic acid (DCA)-induced hepatotoxicity in hiHeps was verified by elevated aspartate aminotransferase (AST) and γ-glutamyl-transferase (γ-GT) levels. Mitochondrial damage and cell death suggested DCA-induced toxicity in hiHeps, which were attenuated by hepatoprotective drugs, as in PHHs. For the first time, hiHeps were reported to biosynthesize and excrete BAs, which could facilitate predicting cholestatic hepatotoxicity and screening potential therapeutic drugs against cholestasis.

Inhibition of hepatic cytochrome P450 enzymes and sodium/bile acid cotransporter exacerbates leflunomide-induced hepatotoxicity

AIM

Leflunomide is an immunosuppressive agent marketed as a disease-modifying antirheumatic drug. But it causes severe side effects, including fatal hepatitis and liver failure. In this study we investigated the contributions of hepatic metabolism and transport of leflunomide and its major metabolite teriflunomide to leflunomide induced hepatotoxicity in vitro and in vivo.

METHODS

The metabolism and toxicity of leflunomide and teriflunomide were evaluated in primary rat hepatocytes in vitro. Hepatic cytochrome P450 reductase null (HRN) mice were used to examine the PK profiling and hepatotoxicity of leflunomide in vivo. The expression and function of sodium/bile acid cotransporter (NTCP) were assessed in rat and human hepatocytes and NTCP-transfected HEK293 cells. After Male Sprague-Dawley (SD) rats were administered teriflunomide (1,6, 12 mg · kg(-1) · d(-1), ig) for 4 weeks, their blood samples were analyzed.

RESULTS

A nonspecific CYPs inhibitor aminobenzotriazole (ABT, 1 mmol/L) decreased the IC50 value of leflunomide in rat hepatocytes from 409 to 216 μmol/L, whereas another nonspecific CYPs inhibitor proadifen (SKF, 30 μmol/L) increased the cellular accumulation of leflunomide to 3.68-fold at 4 h. After oral dosing (15 mg/kg), the plasma exposure (AUC0-t) of leflunomide increased to 3-fold in HRN mice compared with wild type mice. Administration of leflunomide (25 mg·kg(-1) · d(-1)) for 7 d significantly increased serum ALT and AST levels in HRN mice; when the dose was increased to 50 mg·kg(-1) · d(-1), all HRN mice died on d 6. Teriflunomide significantly decreased the expression of NTCP in human hepatocytes, as well as the function of NTCP in rat hepatocytes and NTCP-transfected HEK293 cells. Four-week administration of teriflunomide significantly increased serum total bilirubin and direct bilirubin levels in female rats, but not in male rats.

CONCLUSION

Hepatic CYPs play a critical role in detoxification process of leflunomide, whereas the major metabolite teriflunomide suppresses the expression and function of NTCP, leading to potential cholestasis.

Mesenchymal stem cells: In vivo therapeutic application ameliorates carbon tetrachloride induced liver fibrosis in rats

BACKGROUND

Egypt has the highest prevalence of hepatitis C virus in the world with infection rate up to 60%, for which liver fibrosis or hepatic carcinoma is the final outcome. Stem cell therapy provides a new hope for hepatic repair instead of traditional treatment, liver transplantation, as it is safer, gives long term engraftment and avoid expensive immunosuppressive drugs and unexpected hazardous effects.

AIM

This work aimed at determining the therapeutic potential of mesenchymal stem cells (MSC) in hepatic repair as a new line of therapy for liver fibrosis.

METHODS

33 female albino rats were divided into three groups: Group I: 10 rats injected subcutaneously with olive oil, Group II: 13 rats injected with carbon tetrachloride (CCl4) and Group III: 10 rats injected with CCl4 then bone marrow derived MSC from male rats. Blood and liver tissue samples were taken from all rats for biochemical and histological study.

RESULTS

Liver functions for group II rats showed significant deterioration in response to CCl4 in addition to significant histological changes in liver lobules and portal areas. Those parameters tend to be normal in MSC-treated group. Group III rats revealed normalized liver function and histological picture. Meanwhile, most of the pathological lesions were still detected in rats of second group.

CONCLUSION

Undifferentiated MSCs have the ability to ameliorate CCl4 induced liver injury in albino rats in terms of liver functions and histological features. So, stem cell therapy can be considered clinically to offer a hope for patients suffering from liver fibrosis.

BSEP expression in liver tissue of hyperlipidemia rats

AIM: To investigate the expression of bile salt export pump (BSEP) in hepatic tissue in a rat model of hyperlipidemia.

METHODS: Sixty wistar rats were randomly divided into two groups (n = 30 for each): a control group that was fed an ordinary diet, and an experimental group fed a high fat diet. Cholesterol and bile acid levels were regularly monitored. Liver tissue samples were taken for detecting the gene expression of BSEP by reverse transcription polymerase chain reaction (RT-PCR) and the protein expression of BSEP by immunohistochemistry.

RESULTS: The levels of cholesterol and bile acid were significantly higher in the experimental group than in the control group. RT-PCR analysis showed that the expression of BSEP mRNA was significantly higher in the experimental group than in the control group. Immunohistochemistry analysis showed that in the experimental group, the positive expression rate of BSEP was 76.7%, significantly higher than that in the control group (12.5%).

CONCLUSION: The expression of Bsep increases significantly in rat hyperlipidemia, which suggests that we can develop drugs acting on BSEP to find new treatment methods and means for hyperlipidemia and related diseases.