Inhibitory effects of armepavine against hepatic fibrosis in rats

Ethnomedicine, phytochemistry, and pharmacological activities of Uvaria chamae P. Beauv.: A comprehensive review

The use of medicinal plants as food and medicine has been a common practice in the world, especially in tropical African countries. One such plant in West Africa is Uvaria chamae, also known as Bush banana, renowned for its diverse ethnomedicinal applications and, more recently, for its pharmacological activities attributed to a rich array of phytochemical constituents. Various parts of the plant have been traditionally employed for the treatment of diverse health issues such as digestive disorders, fever, dysmenorrhea, cancer, wound healing, and many more. To unravel the bioactive compounds responsible for these medicinal properties, a comprehensive phytochemical analysis has been undertaken. Notable isolates include chamanetin, dichamanetin, uvaretin, and uvarinol from different parts of the plant. The pharmacological evaluation of these compounds has revealed significant anticancer and antimicrobial properties. Therefore, this review provides a thorough examination of the phytochemicals derived from Uvaria chamae, detailing their associated pharmacological activities both in vitro and in vivo. The review emphasizes the potential of Uvaria chamae as a valuable source of lead compounds for cancer chemotherapy and antimicrobial drug discovery.

Antihepatofibrotic effect of Guizhifuling pill on carbon tetrachloride-induced liver fibrosis in mice

OBJECTIVE

To evaluate the protective effects and the underlying mechanism of Guizhifuling pill (, GZFL) on carbon tetrachloride (CCl)-induced hepatic fibrosis in mice.

METHODS

Male ICR mice by intraperitoneally administered with 20% CCl (mixed 1∶4 in soybean oil) to induce liver fibrosis. Mice that underwent CCl were orally with GZFL. Using hematoxylin and eosin and Masson staining to examine the pathological changes in liver tissue. Serum biochemical parameters, antioxidant enzyme activity and proinflammatory cytokines was assessed. Nuclear factor-kappaB (NF-κB) pathway and nuclear factor-erythroid 2-related factor 2 (Nrf2) family members were evaluated by Western blotting.

RESULTS

Our findings indicated that GZFL could effectively suppress the progression of liver fibrosis in mice, which was determined based on the improvement in liver function and reduction of collagen deposition. GZFL treatment also decreased the level of cytokines and increased the activity of antioxidant enzymes in liver tissue. Moreover, GZFL exerted anti-inflammatory and antioxidant effects through regulating the Nrf2-mediated antioxidant system and inhibiting the NF-κB pathway.

CONCLUSIONS

GZFL may prevent the progression of liver fibrosis by regulating the Nrf2/ heme oxygenase-1 and NF-κB signaling pathways, thereby highlighting its role in the management of liver fibrosis.

The importance of natural chalcones in ischemic organ damage: Comprehensive and bioinformatic analysis review

Over the last few decades, extensive research has been conducted, yielding a detailed account of thousands of newly discovered compounds of natural origin and their biological activities, all of which have the potential to be used for a wide range of therapeutic purposes. There are multiple research papers denoting the central objective of chalcones, which have been shown to have therapeutic potential against various forms of ischemia. The various aspects of chalcones are discussed in this review regarding molecular mechanisms involved in the promising anti-ischemic potential of these chalcones. The main mechanisms involved in these protective effects are Nrf2/Akt activation and NF-κB/TLR4 suppression. Furthermore, in-silico studies were carried out to discover the probable binding of these chalcones to Keap-1 (an inhibitor of Nrf2), Akt, NF-κB, and TLR4 protein molecules. Besides, network pharmacology analysis was conducted to predict the interacting partners of these signals. The obtained results indicated that Nrf2, Akt, NF-κB, and TLR4 are involved in the beneficial anti-ischemic actions of chalcones. Conclusively, the present findings show that chalcones as anti-ischemic agents have a valid rationale. The discussed studies will provide a comprehensive viewpoint on chalcones and can help to optimize their effects in different ischemia. PRACTICAL APPLICATIONS: Ischemic organ damage is an unavoidable pathological condition with a high worldwide incidence. According to the current research progress, natural chalcones have been proved to treat and/or prevent various types of ischemic organ damage by alleviating oxidative stress, inflammation, and apoptosis by different molecular mechanisms. This article displays the comprehensive research progress and the molecular basis of ischemic organ damage pathophysiology and introduces natural chalcones' mechanism in the ischemic organ condition.

Complete biosynthesis of the bisbenzylisoquinoline alkaloids guattegaumerine and berbamunine in yeast

This work demonstrates microbial biosynthesis of bisbenzylisoquinoline (bisBIA) alkaloids. We show that several didomain epimerases can function in yeast to epimerize the nonnative substrate N-methylcoclaurine, an essential step in bisBIA biosynthesis. The N-methylcoclaurine epimerase activity was increased 10-fold by combining individual reductase and oxidase domains from different plant species. Strain engineering and optimization of media and growth conditions increased the bisBIA titer over 10,000-fold. We show that strains can be engineered to primarily produce one bisBIA product by selection of the cytochrome P450 variant that couples the monomer BIA subunits. We then leverage our bisBIA biosynthetic strain as a platform for the screening of other plant enzymes to produce two additional plant natural products de novo in a heterologous host.

Benzylisoquinoline alkaloids (BIAs) are a diverse class of medicinal plant natural products. Nearly 500 dimeric bisbenzylisoquinoline alkaloids (bisBIAs), produced by the coupling of two BIA monomers, have been characterized and display a range of pharmacological properties, including anti-inflammatory, antitumor, and antiarrhythmic activities. In recent years, microbial platforms have been engineered to produce several classes of BIAs, which are rare or difficult to obtain from natural plant hosts, including protoberberines, morphinans, and phthalideisoquinolines. However, the heterologous biosyntheses of bisBIAs have thus far been largely unexplored. Here, we describe the engineering of yeast strains that produce the Type I bisBIAs guattegaumerine and berbamunine de novo. Through strain engineering, protein engineering, and optimization of growth conditions, a 10,000-fold improvement in the production of guattegaumerine, the major bisBIA pathway product, was observed. By replacing the cytochrome P450 used in the final coupling reaction with a chimeric variant, the product profile was inverted to instead produce solely berbamunine. Our highest titer engineered yeast strains produced 108 and 25 mg/L of guattegaumerine and berbamunine, respectively. Finally, the inclusion of two additional putative BIA biosynthesis enzymes, SiCNMT2 and NnOMT5, into our bisBIA biosynthetic strains enabled the production of two derivatives of bisBIA pathway intermediates de novo: magnocurarine and armepavine. The de novo heterologous biosyntheses of bisBIAs presented here provide the foundation for the production of additional medicinal bisBIAs in yeast.

Determination of armepavine in mouse blood by UPLC-MS/MS and its application to pharmacokinetic study

The purpose of this study was to develop an ultra-performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) method to determine armepavine in mouse blood. Nuciferine was used as internal standard. Chromatographic separation was performed on a UPLC BEH (2.1 × 50 mm, 1.7 μm) column with a gradient elution of acetonitrile and 10 mmol/L ammonium acetate solution (containing 0.1% formic acid). The quantitative analysis was conducted in multiple reaction monitoring mode with m/z 314.1 → 106.9 for armepavine and m/z 296.2 → 265.1 for nuciferine. Calibration curves were linear (r > 0.995) over the concentration range 1-1000 ng/mL in mouse blood with a lowest limit of quantitation of 1 ng/mL. The intra- and inter-day precisions of armepavine in mouse were < 13.5 and 10.8%, respectively. The accuracy ranged between 86.8 and 103.3%. Meanwhile, the average recovery was >70.7% and the matrix effect was within the range 109.5-113.7%. All of the obtained data confirmed the satisfactory sensitivity and selectivity of the developed method which was then successfully applied to evaluate the pharmacokinetic behavior of armepavine in mouse for the first time. The bioavailability of armepavine in mouse was calculated to be 11.3%.

Herbal remedies for liver fibrosis: A review on the mode of action of fifty herbs

Liver fibrosis is a dynamic pathological condition which can be slowed down in its initial phases. Without proper clinical management of fibrosis, progressive liver damage may lead to cirrhosis and ultimately to liver failure or primary liver cancer, which are irreversible conditions. Therefore, in order to cure fibrotic damage to liver, its early stages should be the centre of attention. In this context, some supplements and ‘complementary and alternative medicine (CAM)’ deserve specific mention, because of their already recognized natural way of healing and long lasting curative effects. Moreover, CAM display negligible side effects and hence it is gaining worldwide importance in clinical practices. In particular, herbal medicines are now replacing synthetic pharmaceuticals and looked upon as the sources of novel bioactive substances. To develop satisfactory herbal combinations for treating liver fibrosis, phytoproducts need to be systematically evaluated for their potency as anti-fibrotic, anti-hepatotoxic and antioxidant agents. More importantly, the identified herb/agent should have the remarkable tendency to stimulate hepatocytes regeneration. The present review is a systematic account of at least fifty medicinal herbs and their products which in experimental models have demonstrated antifibrotic activity and thus, most likely candidates to offer therapeutic protection to liver. Nevertheless, much additional work is still needed to explore molecular pathways to discover potential applications of these medicines so as to open up new vistas in biomedical research.

Possible Involvement of Hepatitis B Virus Infection of Hepatocytes in the Attenuation of Apoptosis in Hepatic Stellate Cells

Background

The induction of apoptosis in hepatic stellate cells (HSCs) is a promising therapeutic strategy against hepatitis B virus (HBV)-related hepatic fibrosis. The underlying mechanisms of apoptosis in HSCs, however, are unknown under consideration of HBV infection. In this study, the effects of HBV on apoptosis and endoplasmic reticulum (ER) stress signaling in HSCs were examined.

Methods

The effects of conditioned media (CM) from HepG2.2.15 on apoptosis induced by the proteasome inhibitor MG132 in LX-2 and HHSteC were studied in regard to c-Jun. In combination with c-Fos, c-Jun forms the AP-1 early response transcription factor, leading to AP-1 activation, signal transduction, endoplasmic reticulum (ER) stress and apoptosis.

Results

In LX-2 cells, MG132 treatment was associated with the phosphorylation of c-Jun, activation of AP-1 and apoptosis. However, in the presence of CM from HepG2.2.15, these phenomena were attenuated. In HHSteC cells, similar results were observed. HBV genomic DNA is not involved in the process of HSC apoptosis. It is possible that HBeAg has an inhibitory effect on MG132-induced apoptosis in LX-2. We also observed the upregulation of several ER stress-associated genes, such as cAMP responsive element binding protein 3-like 3, inhibin-beta A and solute carrier family 17-member 2, in the presence of CM from HepG2.2.15, or CM from PXB cells infected with HBV.

Conclusions

HBV inhibits the activation of c-Jun/AP-1 in HSCs, contributing to the attenuation of apoptosis and resulting in hepatic fibrosis. HBV also up-regulated several ER stress genes associated with cell growth and fibrosis. These mechanistic insights might shed new light on a treatment strategy for HBV-associated hepatic fibrosis.

Strategies to prevent and reverse liver fibrosis in humans and laboratory animals

Liver fibrosis results from chronic damage to the liver in conjunction with various pathways and is mediated by a complex microenvironment. Based on clinical observations, it is now evident that fibrosis is a dynamic, bidirectional process with an inherent capacity for recovery and remodeling. The major mechanisms involved in liver fibrosis include the repetitive injury of hepatocytes, the activation of the inflammatory response after injury stimulation, and the activation and proliferation of hepatic stellate cells (HSCs), which represents the major extracellular matrix (ECM)-producing cells, stimulated by hepatocyte injury and inflammation. The microenvironment in the liver is synergistically regulated abnormal ECM deposition, scar formation, angiogenesis, and fibrogenesis. Moreover, recent studies have clarified novel mechanism in fibrosis such as epigenetic regulation of HSCs, the leptin and PPARγ pathways, the coagulation system, and even autophagy. Uncovering the mechanisms of liver fibrogenesis provides a basis to develop potential therapies to reverse and treat the fibrotic response, thereby improving the outcomes of patients with chronic liver disease. Although both scientific and clinical challenges remain, emerging studies attempt to reveal the ideal anti-fibrotic drug that could be easily delivered to the liver with high specificity and low toxicity. This review highlights the mechanisms, including novel pathways underlying fibrogenesis that may be translated into preventive and treatment strategies, reviews both current and novel agents that target specific pathways or multiple targets, and discusses novel drug delivery systems such as nanotechnology that can be applied in the treatment of liver fibrosis. In addition, we also discuss some current treatment strategies that are being applied in animal models and in clinical trials.

Implication of the stereoisomers of ginsenoside derivatives in the antiproliferative effect of HSC-T6 cells

Two ginsenoside derivatives (9, 10) along with 10 known ginsenosides (1-8, 11, and 12) were isolated from BST204, which is a crude ginseng extract fermented by enzyme and acid hydrolysis. The two ginsenosides were determined as 12β,20(S),25-trihydroxydammara-3-O-β-D-glucopyranoside (9) and 12β,20(R),25-trihydroxydammara-3-O-β-D-glucopyranoside (10). Compounds 1-12 were categorized into stereoisomeric pairs differentiated by R- or S-configuration at C-20, the number or position of sugar residues at C-3 or C-6, and the type of derivative at C-21. Their structure-activity relationship was evaluated by the cell viability assay using HSC-T6 cells. Results showed that 20(S) (3 > 4, 7 > 8, and 9 > 10), a 2-hydroxy-2-methylbutyl moiety at C-21 (3, 7 > 9), and the number of sugar residues at C-3 (3 > 7) significantly affected the antiproliferative activity on HSC-T6 cells. The inhibition of the cell proliferation of compound 3 was assessed by annexin-V/PI staining analysis using flow cytometry.

Antifibrotic effects of triptolide on hepatic stellate cells and dimethylnitrosamine-intoxicated rats

Triptolide (C₃₈H₄₂O₆N₂, TP, a diterpene triepoxide derived from Tripterygium wilfordii Hook F.), is a potent immunosuppresive and antiinflammatory agent. The present study investigated whether TP exerted antihepatofibrotic effects in vitro and in vivo. A cell line of rat hepatic stellate cells (HSC-T6) was stimulated with tumor necrosis factor-α (TNF-α) or transforming growth factor (TGF)-β1. The inhibitory effects of TP on the nuclear factor-κB (NFκB) signaling cascade and fibrosis markers, including α-smooth muscle actin (α-SMA) and collagen, were assessed. An in vivo therapeutic study was conducted in dimethylnitrosamine (DMN)-treated rats. The rats were randomly assigned to one of three groups: control rats, DMN rats receiving vehicle only and DMN rats receiving TP (20 μg/kg). Treatment was given by gavage twice daily for 3 weeks starting 1 week after the start of DMN administration. TP (5-100 nM) concentration-dependently inhibited the NFκB transcriptional activity induced by TNF-α, lipopolysaccharide and phorbol 12-myristate 13-acetate in HSC-T6 cells. In addition, TP also suppressed TNF-α and TGF-β1-induced collagen deposition and α-SMA secretion in HSC-T6 cells. In vivo, TP treatment significantly reduced hepatic fibrosis scores, collagen contents, IL-6 and TNF-α levels, and the number of α-SMA and NFκB-positive cells in DMN rats. The results showed that TP exerted antifibrotic effects in both HSC-T6 cells and DMN rats.

Effects of armepavine against hepatic fibrosis induced by thioacetamide in rats

The aim of this study was to investigate if armepavine (Arm, C₁₉H₂₃O₃N) could exert inhibitory effects against hepatic fibrosis in rats. A cell line of rat hepatic stellate cells (HSC-T6) was stimulated with tumour necrosis factor-α (TNF-α) to evaluate the inhibitory effects of Arm. Rats were injected with thioacetamide (TAA; 300 mg/kg, intraperitoneally) thrice a week for 4 weeks to induce hepatic fibrosis, with Arm (3 or 10 mg/kg) given by gavage twice a day. Liver sections were taken for western blotting, fibrosis scoring and immunofluorescence staining. Arm (1-10 µm) concentration-dependently attenuated TNF-α-stimulated: (i) protein expressions of α-smooth muscle actin (α-SMA), collagen type I and angiopoietin-1; (ii) H₂O₂ production; and (iii) NF-κB, JunD and C/EBPß (cytidine-cytidine-adenosine-adenosine-thymidine (CCAAT)/enhancer binding protein-ß (EBPß)) nuclear translocations in HSC-T6 cells. In vivo Arm treatment significantly reduced plasma aspartate transaminase and alanine transaminase levels, hepatic α-SMA expression and collagen contents, and fibrosis scores of TAA-injected rats. Moreover, Arm treatment decreased α-SMA- and NF-κB-positive cells in immunohistochemical staining, and mRNA expression levels of IL-6, TGF-ß1, TIMP-1, col1α2, iNOS and ICAM-1 genes, but up-regulated the metallothionein gene in the livers of TAA-injected rats. Our results indicated that Arm exerted both in vitro and in vivo antifibrotic effects in rats, with inhibition of NF-κB, JunD and C/EBPß pathways.

Suppression of nitric oxide production from nasal fibroblasts by metabolized clarithromycin in vitro

Background

Low-dose and long-term administration of 14-membered macrolide antibiotics, so called macrolide therapy, has been reported to favorably modify the clinical conditions of chronic airway diseases. Since there is growing evidence that macrolide antibiotic-resistant bacteria's spreaders in the populations received macrolide therapy, it is strongly desired to develop macrolide antibiotics, which showed only anti-inflammatory action. The present study was designed to examine the influence of clarithromycin (CAM) and its metabolized materials, M-1, M-4 and M-5, on free radical generation from nasal polyp fibroblasts (NPFs) through the choice of nitric oxide (NO), which is one of important effector molecule in the development of airway inflammatory disease in vitro.

Methods

NPFs (5 × 10⁵ cells/ml) were stimulated with 1.0 μg/ml lipopolysaccharide (LPS) in the presence of agents for 24 hours. NO levels in culture supernatants were examined by the Griess method. We also examined the influence of agents on the phosphorylation of MAPKs, NF-κB activation, iNOS mRNA expression and iNOS production in NPFs cultured for 2, 4, 8, and 12 hours, respectively.

Results

The addition of CAM (> 0.4 μg/ml) and M-4 (> 0.04 μg/ml) could suppress NO production from NPFs after LPS stimulation through the suppression of iNOS mRNA expression and NF-κB activation. CAM and M-4 also suppressed phosphorylation of MAPKs, ERK and p38 MAPK, but not JNK, which are increased LPS stimulation. On the other hand, M-1 and M-5 could not inhibit the NO generation, even when 0.1 μg/ml of the agent was added to cell cultures.

Conclusion

The present results may suggest that M-4 will be a good candidate for the agent in the treatment of chronic airway inflammatory diseases, since M-4 did not have antimicribiological effects on gram positive and negative bacteria.