Modulation of thioacetamide-induced hepatic inflammations, angiogenesis and fibrosis by andrographolide in mice

Gut microbiota-mediated C-sulfonate metabolism impairs the bioavailability and anti-cholestatic efficacy of andrographolide

Cholestatic liver injury results from the accumulation of toxic bile acids in the liver, presenting a therapeutic challenge with no effective treatment available to date. Andrographolide (AP) has exhibited potential as a treatment for cholestatic liver disease. However, its limited oral bioavailability poses a significant obstacle to harnessing its potent therapeutic properties and restricts its clinical utility. This limitation is potentially attributed to the involvement of gut microbiota in AP metabolism. In our study, employing pseudo-germ-free, germ-free and strain colonization animal models, along with 16S rRNA and shotgun metagenomic sequencing analysis, we elucidate the pivotal role played by gut microbiota in the C-sulfonate metabolism of AP, a process profoundly affecting its bioavailability and anti-cholestatic efficacy. Subsequent investigations pinpoint a specific enzyme, adenosine-5'-phosphosulfate (APS) reductase, predominantly produced by Desulfovibrio piger, which catalyzes the reduction of SO42- to HSO3-. HSO3- subsequently interacts with AP, targeting its C=C unsaturated double bond, resulting in the formation of the C-sulfonate metabolite, 14-deoxy-12(R)-sulfo andrographolide (APM). Inhibition of APS reductase leads to a notable enhancement in AP bioavailability and anti-cholestatic efficacy. Furthermore, employing RNA sequencing analysis and farnesoid X receptor (FXR) knockout mice, our findings suggest that AP may exert its anti-cholestatic effects by activating the FXR pathway to promote bile acid efflux. In summary, our study unveils the significant involvement of gut microbiota in the C-sulfonate metabolism of AP and highlights the potential benefits of inhibiting APS reductase to enhance its therapeutic effects. These discoveries provide valuable insights into enhancing the clinical applicability of AP as a promising treatment for cholestatic liver injury.

Andrographolide attenuated MCT-induced HSOS via regulating NRF2-initiated mitochondrial biogenesis and antioxidant response

Hepatic sinusoidal obstruction syndrome (HSOS) is a death-dealing liver disease with a fatality rate of up to 67%. In the study present, we explored the efficacy of andrographolide (Andro), a diterpene lactone from Andrographis Herba, in ameliorating the monocrotaline (MCT)-induced HSOS and the underlying mechanism. The alleviation of Andro on MCT-induced rats HSOS was proved by biochemical index detection, electron microscope observation, and liver histological evaluation. Detection of hepatic ATP content, mitochondrial DNA (mtDNA) copy number, and protein expression of nuclear respiratory factor-1 (NRF1) and peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PPARGC1A) demonstrated that Andro strengthened mitochondrial biogenesis in livers from MCT-treated rats. Chromatin immunoprecipitation assay exhibited that Andro enhanced the occupation of nuclear factor erythroid 2-related factor 2 (NFE2L2, also known as NRF2) in the promoter regions of both PPARGC1A and NRF1. Andro also activated the NRF2-dependent anti-oxidative response and alleviated liver oxidative injury. In Nrf2 knock-out mice, MCT induced more severe liver damage, and Andro showed no alleviation in it. Furthermore, the Andro-activated mitochondrial biogenesis and anti-oxidative response were reduced in Nrf2 knock-out mice. Contrastingly, knocking out Kelch-like ECH-associated protein 1 (Keap1), a NRF2 repressor, reduced MCT-induced liver damage. Results from co-immunoprecipitation, molecular docking analysis, biotin-Andro pull-down, cellular thermal shift assay, and surface plasmon resonance assay showed that Andro hindered the NRF2-KEAP1 interaction via directly binding to KEAP1. In conclusion, our results revealed that NRF2-dependent liver mitochondrial biogenesis and anti-oxidative response were essential for the Andro-provided alleviation of the MCT-induced HSOS. Graphical Headlights: 1. Andro alleviated MCT-induced HSOS via activating antioxidative response and promoting mitochondrial biogenesis. 2. Andro-activated antioxidative response and mitochondrial biogenesis were NRF2-dependent. 3. Andro activated NRF2 via binding to KEAP1.

A Reappraisal of the Antiviral Properties of and Immune Regulation through Dietary Phytochemicals

In the present era of the COVID-19 pandemic, viral infections remain a major cause of morbidity and mortality worldwide. In this day and age, viral infections are rampant and spreading rapidly. Among the most aggressive viral infections are ebola, AIDS (acquired immunodeficiency syndrome), influenza, and SARS (severe acute respiratory syndrome). Even though there are few treatment options for viral diseases, most of the antiviral therapies are ineffective owing to frequent mutations, the development of more aggressive strains, drug resistance, and possible side effects. Traditionally, herbal remedies have been used by healers, including for dietary and medicinal purposes. Many clinical and scientific studies have demonstrated the therapeutic potential of plant-derived natural compounds. Because of unsafe practices like blood transfusions and organ transplants from infected patients, medical supply contamination. Our antiviral therapies cannot achieve sterile immunity, and we have yet to find a cure for these pernicious infections. Herbs have been shown to improve therapeutic efficacy against a wide variety of viral diseases because of their high concentration of immunomodulatory phytochemicals (both immunoinhibitory and anti-inflammatory). Combined with biotechnology, this folk medicine system can lead to the development of novel antiviral drugs and therapies. In this Review, we will summarize some selected bioactive compounds with probable mechanisms of their antiviral actions, focusing on the immunological axis of these compounds.

Promising Therapeutic Treatments for Cardiac Fibrosis: Herbal Plants and Their Extracts

Cardiac fibrosis is closely associated with multiple heart diseases, which are a prominent health issue in the global world. Neurohormones and cytokines play indispensable roles in cardiac fibrosis. Many signaling pathways participate in cardiac fibrosis as well. Cardiac fibrosis is due to impaired degradation of collagen and impaired fibroblast activation, and collagen accumulation results in increasing heart stiffness and inharmonious activity, leading to structure alterations and finally cardiac function decline. Herbal plants have been applied in traditional medicines for thousands of years. Because of their naturality, they have attracted much attention for use in resisting cardiac fibrosis in recent years. This review sheds light on several extracts from herbal plants, which are promising therapeutics for reversing cardiac fibrosis.

The role of Andrographolide in the prevention and treatment of liver diseases

BACKGROUND

The presence or absence of damage to the liver organ is crucial to a person's health. Nutritional disorders, alcohol consumption, and drug abuse are the main causes of liver disease. Liver transplantation is the last irrevocable option for liver disease and has become a serious economic burden worldwide. Andrographolide (AP) is one of the main active ingredients of Herba Andrographitis. It has several biological activities and has been reported to have protective and therapeutic effects against liver diseases. Earlier literature has been written on AP's role in treating inflammation and other diseases, and there has not been a systematic review on liver diseases. This review is dedicated to sorting out the research results of AP against liver diseases. Pharmacokinetics, toxicity, and nanotechnology to improve bioavailability are discussed. Finally, an outlook and assessment of its future are provided.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. PubMed and web of Science databases were used to search all relevant literature on AP for liver disease up to 2022.

RESULTS

Studies have shown that AP plays an important role in different liver disease phenotypes, mainly through anti-inflammatory and antioxidant activities. AP regulates HO-1 and inhibits hepatitis virus replication. It affects the NF-κB pathway, downregulates inflammatory factors such as IL-1β, IL-6, and TNF-α, and reduces liver damage. In preventing liver fibrosis, AP inhibits angiogenesis and activation of hepatic stellate cells and reduces oxidative stress involved in the Nrf2 and TGF-β1/Smad pathways. In addition, AP impedes the development of liver cancer by promoting apoptosis and autonomous phagocytosis in a cell-dependent way. Interestingly, miRNAs are involved in the therapeutic process of liver cancer and hepatic fibrosis. The poor solubility of AP limits the development of dosage forms. Therefore, the advent of nanoformulations has improved bioavailability. Although the effect of AP is dose- and time-dependent, the magnitude of its toxicity is not negligible. Some clinical trials have shown that AP has mild side effects.

CONCLUSIONS

AP, as an effective natural product, has a good effect on the liver disease through multiple pathways and targets. However, the dose reaches a certain level, leading to its toxicity and side effects. For better clinical application of AP, high-quality clinical and toxic intervention mechanisms are needed to validate current studies. In addition, modulation of miRNA-mediated hepatocellular carcinoma and liver fibrosis and synergistic action with drugs may be the future focus of AP. In conclusion, AP can be regarded as an important candidate for treating different liver diseases in the future.

Andrographolide suppresses breast cancer progression by modulating tumor-associated macrophage polarization through the Wnt/β-catenin pathway

Andrographolide(ADE) has been demonstrated to inhibit tumor growth through direct cytotoxicity on tumor cells. However, its potential activity on tumor microenvironment (TME) remains unclear. Tumor-associated macrophages (TAMs), composed mainly of M2 macrophages, are the key cells that create an immunosuppressive TME by secretion of cytokines, thus enhancing tumor progression. Re-polarized subpopulations of macrophages may represent vital new therapeutic alternatives. Our previous studies showed that ADE possessed anti-metastasis and anoikis-sensitization effects. Here, we demonstrated that ADE significantly suppressed M2-like polarization and enhanced M1-like polarization of macrophages. Moreover, ADE inhibited the migration of M2 and tube formation in HUVECs under M2 stimulation. In vivo studies showed that ADE restrained the growth of MDA-MB-231 and HCC1806 human breast tumor xenografts and 4T-1 mammary gland tumors through TAMs. Wnt5a/β-catenin pathway and MMPs were particularly associated with ADE's regulatory mechanisms to M2 according to RNA-seq and bioinformatics analysis. Moreover， western blot also verified the expressions of these proteins were declined with ADE exposure. Among the cytokines released by M2, PDGF-AA and CCL2 were reduced. Our current findings for the first time elucidated that ADE could modulate macrophage polarization and function through Wnt5a signaling pathway, thereby playing its role in inhibition of triple-negative breast cancer.

Perspectives on the mechanism of pyroptosis after intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a highly harmful neurological disorder with high rates of mortality, disability, and recurrence. However, effective therapies are not currently available. Secondary immune injury and cell death are the leading causes of brain injury and a poor prognosis. Pyroptosis is a recently discovered form of programmed cell death that differs from apoptosis and necrosis and is mediated by gasdermin proteins. Pyroptosis is caused by multiple pathways that eventually form pores in the cell membrane, facilitating the release of inflammatory substances and causing the cell to rupture and die. Pyroptosis occurs in neurons, glial cells, and endothelial cells after ICH. Furthermore, pyroptosis causes cell death and releases inflammatory factors such as interleukin (IL)-1β and IL-18, leading to a secondary immune-inflammatory response and further brain damage. The NOD-like receptor protein 3 (NLRP3)/caspase-1/gasdermin D (GSDMD) pathway plays the most critical role in pyroptosis after ICH. Pyroptosis can be inhibited by directly targeting NLRP3 or its upstream molecules, or directly interfering with caspase-1 expression and GSDMD formation, thus significantly improving the prognosis of ICH. The present review discusses key pathological pathways and regulatory mechanisms of pyroptosis after ICH and suggests possible intervention strategies to mitigate pyroptosis and brain dysfunction after ICH.

Phytochemical profiling and anti-fibrotic activities of Plumbago indica L. and Plumbago auriculata Lam. in thioacetamide-induced liver fibrosis in rats

This study aimed at investigating the chemical composition and the hepatoprotective activities of Plumbago indica L. and P. auriculata Lam. LC-MS/MS analyses for the hydroalcoholic extracts of the aerial parts of the two Plumbago species allowed the tentative identification of thirty and twenty-five compounds from P. indica and P. auriculata, respectively. The biochemical and histopathological alterations associated with thioacetamide (TAA)-induced liver fibrosis in rats were evaluated in vivo where rats received the two extracts at three different dose levels (100, 200 and 400 mg/kg p.o, daily) for 15 consecutive days with induction of hepatotoxicity by TAA (200 mg/kg/day, i.p.) at 14th and 15th days. Results of the present study showed a significant restoration in liver function biomarkers viz. alanine transaminase (ALT), aspartate transaminase (AST), gamma glutamyl transferase and total bilirubin. The liver homogenates exhibited increased levels of antioxidant biomarkers: reduced glutathione (GSH) and catalase (CAT), accompanied with decline in malondialdehyde (MDA). Furthermore, treated groups exhibited a significant suppression in liver inflammatory cytokines: tumor necrosis factor-α (TNF-α) and interlukin-6 (IL-6), and fibrotic biomarker: alpha smooth muscle relaxant. Histopathological examination of the liver showed normality of hepatocytes. Noteworthy, P. indica extract showed better hepatoprotective activity than P. auriculata, particularly at 200 mg/kg. To sum up, all these results indicated the hepatoprotective properties of both extracts, as well as their antifibrotic effect was evidenced by reduction in hepatic collagen deposition. However, additional experiments are required to isolate their individual secondary metabolites, assess the toxicity of the extracts and explore the involved mechanism of action.

Acute and Subacute Toxicity Assessment of Andrographolide-2-hydroxypropyl-β-cyclodextrin Complex via Oral and Inhalation Route of Administration in Sprague-Dawley Rats

Objective

Acute and subacute toxicity analysis of AND-2-HyP-β-CYD complex was conducted in Sprague-Dawley (SD) rats following oral and inhalation routes of administration.

Methods and Results

Single dose acute toxicity was carried out at 2000 mg/kg of AND-2-HyP-β-CYD complex, while the doses of 200, 400, and 666 mg/kg were administered, over a period of 28 days under repeated dose oral toxicity study. Hence, LD50 (lethal dose) was found to be >2000 mg/kg in addition to NOAEL (no observed adverse effect level) of 666 mg/kg. Correspondingly, single dose acute inhalation toxicity of AND-2-HyP-β-CYD complex was carried out at 5 mg/L/4 h/day and subacute inhalation toxicity at 0.5, 1, and 1.66 mg/L/4 h/day over a period of 28 days. The NOAEL and LOAEL (lowest observed adverse effect level) were estimated to be 0.5 mg/L/4 h/day and 1 mg/L/4 h/day, respectively.

Conclusion

The findings of the present study would further be useful in assessing and utilizing the medicinal and therapeutic benefits of AND-2-HyP-β-CYD complex.

Advances in ameliorating inflammatory diseases and cancers by andrographolide: Pharmacokinetics, pharmacodynamics, and perspective

Andrographolide, a well-known natural lactone having a range of pharmacological actions in traditional Chinese medicine. It has long been used to cure a variety of ailments. In this review, we cover the pharmacokinetics and pharmacological activity of andrographolide which supports its further clinical application in cancers and inflammatory diseases. Growing evidence shows a good therapeutic effect in inflammatory diseases, including liver diseases, joint diseases, respiratory system diseases, nervous system diseases, heart diseases, inflammatory bowel diseases, and inflammatory skin diseases. As a result, the effects of andrographolide on immune cells and the processes that underpin them are discussed. The preclinical use of andrographolide to different organs in response to malignancies such as colorectal, liver, gastric, breast, prostate, lung, and oral cancers has also been reviewed. In addition, several clinical trials of andrographolide in inflammatory diseases and cancers have been summarized. This review highlights recent advances in ameliorating inflammatory diseases as well as cancers by andrographolide and its analogs, providing a new perspective for subsequent research of this traditional natural product.

Andrographolide and its derivatives: Current achievements and future perspectives

Natural product andrographolide isolated from the plant Andrographis paniculata shows a plethora of biological activities, including anti-tumor, anti-bacterial, anti-inflammation, anti-virus, anti-fibrosis, anti-obesity, immunomodulatory and hypoglycemic activities. Based on extensive chemical structural modifications, a series of andrographolide derivatives with improved bioavailability and druggability has been developed. Moreover, greater understanding of their mechanisms of action at the molecular and cellular level has been thoroughly investigated. In this review, we give an outlook for the therapeutical potential of andrographolide and its derivatives in diverse diseases and highlighted the drug design, pharmacokinetic and mechanistic studies for the past ten years, together with a brief overview of the pharmacological effects. Notably, we focused to provide a critical enlightenment of the area of andrographolide and its derivatives with the intent of indicating the future perspectives, challenges and limitations. We believe that this review paper will benefit drug discovery where andrographolide was used as a template, shed light on the identification of drug targets for andrographolide and its analogs, as well as increase our knowledge for using them for therapeutic application, including the treatment for various forms of cancers.

A Computational Approach Identified Andrographolide as a Potential Drug for Suppressing COVID-19-Induced Cytokine Storm

BACKGROUND

The newly identified betacoronavirus SARS-CoV-2 is the causative pathogen of the coronavirus disease of 2019 (COVID-19) that killed more than 3.5 million people till now. The cytokine storm induced in severe COVID-19 patients causes hyper-inflammation, is the primary reason for respiratory and multi-organ failure and fatality. This work uses a rational computational strategy to identify the existing drug molecules to target host pathways to reduce the cytokine storm.

RESULTS

We used a "host response signature network" consist of 36 genes induced by SARS-CoV-2 infection and associated with cytokine storm. In order to attenuate the cytokine storm, potential drug molecules were searched against "host response signature network". Our study identified that drug molecule andrographolide, naturally present in a medicinal plant Andrographis paniculata, has the potential to bind with crucial proteins to block the TNF-induced NFkB1 signaling pathway responsible for cytokine storm in COVID-19 patients. The molecular docking method showed the binding of andrographolide with TNF and covalent binding with NFkB1 proteins of the TNF signaling pathway.

CONCLUSION

We used a rational computational approach to repurpose existing drugs targeting host immunomodulating pathways. Our study suggests that andrographolide could bind with TNF and NFkB1 proteins, block TNF-induced cytokine storm in COVID-19 patients, and warrant further experimental validation.

Phytochemical add-on therapy to DMARDs therapy in rheumatoid arthritis: In vitro and in vivo bases, clinical evidence and future trends

The use of biologically active compounds derived from plants i.e. phytochemicals, have been known for ages for their pharmacological activities in the treatment of autoimmune disorders like rheumatoid arthritis (RA). Besides enormous scientific evidence, the therapeutic potential of phytochemicals is often undervalued. The treatment in RA involves the use of synthetic and biological disease modifying anti-rheumatic drugs (DMARDs). However, the long-term treatment in RA is associated with the risk of gastrointestinal, liver, pulmonary and renal toxicities and serious infections including latent tuberculosis, pneumococcus influenza, herpes zoster and hepatitis. These adverse effects sometimes lead to discontinuation of the therapy. A relatively new vision based on the combination of DMARDs with phytochemicals exhibiting anti-inflammatory, anti-arthritic, anti-oxidant, hepatoprotective and nephroprotective properties for the treatment of RA has achieved substantial importance in the last decade. From this perspective, the present review focuses on the combination of DMARDs (primarily MTX) with phytochemicals that have shown synergistic therapeutic effects while decreasing the toxic repercussions of current RA therapy. The review covers recent evidences of such combination studies that have shown promising results both in experimental arthritic models and clinical arthritis. Few of the combinations including resveratrol, sinomenine, coenzyme Q10 exhibited considerable interest because of their efficacy as an adjuvant to the MTX/standard DMARDs therapy in clinical trials. Besides giving an overview of such combination studies the review also critically discusses the limitations with the use of phytochemicals (e.g. solubility, permeability and bioavailability) compromising their clinical application. Additionally, it stresses upon the need of novel delivery systems and pharmaceutical technologies to increase the therapeutic efficacy of the combination therapy. Overall, the review unveils the potential of phytochemicals in combination with DMARDs with increased tolerability and superior efficacy in further refining the future of the RA therapy.

A comprehensive review of natural products to fight liver fibrosis: Alkaloids, terpenoids, glycosides, coumarins and other compounds

The discovery of drugs to treat liver fibrosis has long been a challenge over the past decades due to its complicated pathogenesis. As a primary approach for drug development, natural products account for 30% of clinical drugs used for disease treatment. Therefore, natural products are increasingly important for their medicinal value in liver fibrosis therapy. In this part of the review, special focus is placed on the effect and mechanism of natural compounds, including alkaloids, terpenoids, glycosides, coumarins and others. A total of 36 kinds of natural compounds demonstrate significant antifibrotic effects in various liver fibrosis models in vivo and in hepatic stellate cells (HSCs) in vitro. Revealing the mechanism will provide further basis for clinical conversion, as well as accelerate drug discovery. The mechanism was further summarized with the finding of network regulation by several natural products, such as oxymatrine, paeoniflorin, ginsenoside Rg1 and taurine. Moreover, there are still improvements needed in investigating clinical efficacy, determining mechanisms, and combining applications, as well as semisynthesis and modification. Therefore, natural products area promising resource for agents that protect against liver fibrosis.

Combination of pomegranate extract and curcumin ameliorates thioacetamide-induced liver fibrosis in rats: impact on TGF-β/Smad3 and NF-κB signaling pathways

Protection against liver injury and its consequences is considered an essential issue to minimize the number of annual deaths caused by liver diseases. The present study was designed to evaluate the potential role of pomegranate extract (PE) and/or curcumin in the regression of thioacetamide (TAA)-induced liver fibrosis, focusing on their modulatory effects on Nrf2/HO-1, NF-κB, and TGF-β/Smad3 signaling pathways. Liver fibrosis was induced in male Wistar rats by intraperitoneal injection of TAA (100 mg/kg) three times a week, for 8 weeks. To assess the protective effects of PE and/or curcumin against TAA-induced liver fibrosis, rats were treated on a daily basis with oral doses of PE (200 mg/kg) and/or curcumin (200 mg/kg) for 8 weeks. The results indicated that PE and/or curcumin attenuated TAA-induced liver fibrogenesis, as evidenced by a significant improvement in the liver function tests (AST, ALT, ALP, and albumin), oxidative stress biomarkers (MDA, SOD, and GSH), and inflammatory biomarkers (NF-ĸB, TNF-α, IL-1β, iNOS, TGF-β, and MPO), compared to TAA group. Moreover, treatment with PE and/or curcumin exerted a significant upregulation of Nrf2/HO-1 gene expressions along with significant downregulation of NF-ĸB, TGF-β, and phospho-Smad3 protein expressions, as well as α-SMA and collagen-1 gene expressions. The histopathological examination has corroborated these findings. In conclusion, hepatoprotective activities of PE and/or curcumin could be linked to their abilities to modulate Nrf2/HO-1, NF-κB, and TGF-β/Smad3 signaling pathways. It is worth noting that the combination of PE and curcumin exerted superior hepatoprotective effects against TAA-induced liver fibrosis, as compared to monotherapy.

The anti-inflammatory and anti-fibrotic effects of tadalafil in thioacetamide-induced liver fibrosis in rats

Liver fibrosis is a health concern that leads to organ failure mediated via production of inflammatory cytokines and fibrotic biomarkers. This study aimed to explore the protective effect of tadalafil, a phosphodiesterase-5 inhibitor, against thioacetamide (TAA)-induced liver fibrosis. Fibrosis was induced by administration of TAA (200 mg/kg, i.p.) twice weekly for 6 weeks. Serum transaminases activities, liver inflammatory cytokines, fibrotic biomarkers, and liver histopathology were assessed. TAA induced marked histopathological changes in liver tissues coupled with elevations in serum transaminases activities. Furthermore, hepatic content of nitric oxide and tumor necrosis factor-alpha, interleukin-6, and interleukin-1 beta were elevated, together with a reduction of interleukin-10 in the liver. In addition, TAA increased hepatic contents of transforming growth factor-beta, hydroxyproline, alpha-smooth muscle actin, and gene expression of collagen-1. Pretreatment with tadalafil protected against TAA-induced liver fibrosis, in a dose-dependent manner, as proved by the alleviation of inflammatory and fibrotic biomarkers. The effects of tadalafil were comparable with that of silymarin, a natural antioxidant, and could be assigned to its anti-inflammatory and anti-fibrotic properties.

Overview of pharmacological activities of Andrographis paniculata and its major compound andrographolide

Andrographis paniculata (A. paniculata) is a medicinal plant traditionally used as anti-inflammation and anti-bacteria herb. Andrographolide, the major active component of A. paniculata, exhibits diverse pharmacological activities, including anti-inflammation, anti-cancer, anti-obesity, anti-diabetes, and other activities. In this article, we comprehensively review the therapeutic potential of A. paniculata and andrographolide focusing on the mechanisms of action and clinical application. We systemically discuss the structure-activity relationship of andrographolide and derivatives. Despite the various pharmacological activities and formula of A. paniculata and andrographolide, we propose further development of more structural derivatives of andrographolide with reduced toxicity and increased therapeutic efficacy is still needed for the clinical application of this ancient mighty herb and its major component.

Andrographolide derivative as STAT3 inhibitor that protects acute liver damage in mice

Sustained activation of the Janus kinase-signal transducers and activators of transcription (JAK-STAT) pathway contributed to the progression of cancer and liver diseases. STAT3 signaling inhibitor has been extensively investigated for pharmacological use. We synthesized a series of andrographolide derivatives, and characterized their activity against STAT3 signaling pathway both in vitro and in the CCl₄-induced acute liver damage mice model. Among these derivatives, compound 24 effectively inhibited phosphorylation and dimerization of STAT3 but not its DNA binding activity. Compound 24 significantly ameliorated carbon tetrachloride-induced acute liver damage in vivo without changing mice body weight. Treatment with 24 attenuated hepatic pathologic damage and promoted hepatic proliferation and activation of STAT3. Compound 24 inhibited elevated expression of α-smooth muscle actin and serum pro-inflammatory cytokines downstream of STAT3 but not those factors that are regulated by NF-κB or SMADs. In summary, our results suggest that compound 24 may serve as a potential therapeutic agent for the treatment of hepatic damage or a liver protection agent via regulating STAT3 activation.

Evaluation of the effect of andrographolide and methotrexate combined therapy in complete Freund's adjuvant induced arthritis with reduced hepatotoxicity

OBJECTIVE

Methotrexate is one of the most widely used disease-modifying anti-rheumatic drugs. The hepatotoxicity of methotrexate resulted in poor compliance with therapy. The current study was designed to analyse the combined therapy of andrographolide (AD) and methotrexate (MTX) for complete Freund's adjuvant (CFA)-induced arthritis, focusing on hepatoprotective effects, oxidative stress and arthritic-related cytokines.

METHOD

Wistar rats were injected with CFA into the right hind paw. Ten days post-CFA injection, the Wistar rats were administered with 1% CMC-Na solution, methotrexate (2 mg/kg/week), AD (50 mg/kg/d) and combined therapy for 35 days. The anti-arthritic effect was assessed by paw volume, X-ray and serum tumour necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1β levels. Serum samples were also analysed for glutamic oxaloacetic transaminases (GOT), serum glutamic pyruvic transaminase (GPT), alkaline phosphatase (AKP) and lactate dehydrogenase (LDH). Liver tissue samples were used to examine the cellular antioxidant defence activities using catalase activity (CAT) and GSH as well as GSH-Px and MDA. Histopathology analysis was conducted to evaluate liver damage.

RESULTS

AD treatment strengthened the anti-arthritic capacity of MTX. AD and MTX-combined therapy additively reduced the inflammatory symptoms in CFA rats. The combined therapy of AD and MTX showed hepatoprotective effect indicated by an improvement in the serum marker, possibly due to antioxidant action and confirmed by liver histopathological changes. Furthermore, the combined therapy significantly reduced serum TNF-α, IL-6 and IL-1β levels.

CONCLUSIONS

A combined therapy of AD and methotrexate significantly alleviated MTX-induced hepatocellular injury and strengthened the anti-arthritic effect. Further clinical studies should be done to further verify the possibility of combined its clinical usage.

Andrographolide Ameliorates Liver Fibrosis in Mice: Involvement of TLR4/NF-κB and TGF-β1/Smad2 Signaling Pathways

Liver fibrosis is characterized by activated hepatic stellate cells (HSC) and extracellular matrix accumulation. Blocking the activation of HSC and the inflammation response are two major effective therapeutic strategies for liver fibrosis. In addition to the long history of using andrographolide (Andro) for inflammatory disorders, we aimed at elucidating the pharmacological effects and potential mechanism of Andro on liver fibrosis. In this study, liver fibrosis was induced by carbon tetrachloride (CCl₄) and the mice were intraperitoneally injected with Andro for 6 weeks. HSC cell line (LX-2) and primary HSC were also treated with Andro in vitro. Treatment of CCl₄-induced mice with Andro decreased the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), Sirius red staining as well as the expression of α smooth muscle actin (α-SMA) and transforming growth factor- (TGF-) β1. Furthermore, the expression of Toll-like receptor (TLR)4 and NF-κB p50 was also inhibited by Andro. Additionally, in vitro data confirmed that Andro treatment not only attenuated the expression of profibrotic and proinflammatory factors but also blocked the TGF-β1/Smad2 and TLR4/NF-κB p50 pathways. These results demonstrate that Andro prevents liver inflammation and fibrosis, which is in correlation with the inhibition of the TGF-β1/Smad2 and TLR4/NF-κB p50 pathways, highlighting Andro as a potential therapeutic strategy for liver fibrosis.

Andrographolide, a diterpene lactone from Andrographis paniculata and its therapeutic promises in cancer

The diterpene lactone andrographolide, isolated from Andrographis paniculata, has been proven to possess several important protective biological activities, including antioxidant, anti-inflammatory, immunomodulatory, antiseptic, antimicrobial, cytotoxic, hypolipidemic, cardioprotective, hepatoprotective, and neuroprotective effects. In addition, it has been reported to play a therapeutic role in the treatment of major human diseases, such as Parkinson's disease, rheumatoid arthritis, and colitis. This systematic review aims to highlight andrographolide as a promising agent in cancer treatment. To this purpose, a number of databases were used to search for the cytotoxic/anticancer effects of andrographolide in pre-clinical and clinical studies. Among 1703 identified literature articles, 139 were included in this review; 109 were investigated as non-clinical, whereas 24, 3, and 3 were pre-clinical, clinical, and non-pre-clinical trials, respectively. Among the model systems, cultured cell lines appeared as the most frequently (79.14%) used, followed by in vivo models using rodents, among others. Furthermore, andrographolide was found to exert cytotoxic/anticancer effects on almost all types of cell lines with the underlying mechanisms involving oxidative stress, cell cycle arrest, anti-inflammatory and immune system mediated effects, apoptosis, necrosis, autophagy, inhibition of cell adhesion, proliferation, migration, invasion, anti-angiogenic activity, and other miscellaneous actions. After careful consideration of the relevant evidence, we suggest that andrographolide can be one of the potential agents in the treatment of cancer in the near future.

Natural product andrographolide alleviated APAP-induced liver fibrosis by activating Nrf2 antioxidant pathway

As a well-known analgesic drug, acetaminophen (APAP) is commonly used to relieve pain for patients with chronic painful diseases. Our previous study has shown that long-term ingestion of APAP caused liver fibrosis in mice. This study further investigated the critical role of nuclear factor erythroid 2-related factor 2 (Nrf2) in regulating APAP-induced liver fibrosis in mice and the anti-fibrotic effect of natural compound andrographolide (Andro). Our results showed that hepatic collagen deposition and hepatic stellate cells (HSCs) activation induced by APAP were more serious in Nrf2 knock-out mice than in normal wild-type mice. Andro reduced HSCs activation in vitro, and also decreased hepatic collagen deposition and HSCs activation induced by APAP in mice. Andro alleviated liver oxidative stress injury induced by APAP in mice and reduced cellular formation of reactive oxygen species (ROS) in HSCs. Andro enhanced Nrf2 nuclear translocation and increased the expression of Nrf2 downstream antioxidant genes both in vitro and in vivo. Furthermore, the Andro-provided protection against APAP-induced liver fibrosis was diminished in Nrf2 knock-out mice. In summary, Nrf2 is critically involved in preventing liver fibrosis induced by long-term administration of APAP in mice, and Andro alleviates APAP-induced liver fibrosis by attenuating liver oxidative stress injury via inducing Nrf2 activation. This study points out the potential application of Andro in the treatment of liver fibrosis in clinic.

Attenuation of Innate Immunity by Andrographolide Derivatives Through NF-κB Signaling Pathway

Andrographolide derivatives or analogs exhibit potent anti-inflammatory effects in several disease models through NF-κB activity. In this study, we synthesized different andrographolide derivatives and investigated their effects on the toll-like receptor (TLR)-induced production of pro-inflammatory cytokines. Among these compounds, 3b, 5a, and 5b inhibited both TNF-α/NF-κB and TLR4/NF-κB signaling pathways. Treatment with compounds 3b, 5a, and 5b and their structural analogs, 3a and 6b, suppressed the expression of pro-inflammatory cytokines upon the activation of TLR3 and TLR4 ligands. Compounds 3b and 5a, but not 3a, 5b, or 6b, inhibited the nuclear translocation of the NF-κB p65 subunit. Treatment with compounds 3b, 5a, 3a, 5b, and 6b attenuated the phosphorylation of p65 and IκBα. Compounds 6b suppressed the expression of the NF-κB p65 subunit. However, these compounds, except for 5b, did not affect the TLR9-induced NF-κB-independent production of the pro-inflammatory cytokines, TNF-α, and IFN-β. Compound 3b potentially protected mice from LPS-induced acute pulmonary inflammation through the inhibition of p65 phosphorylation and the decrease of serum pro-inflammatory cytokines and chemokine. Our study revealed a functional structure–activity relationship between andrographolide derivatives and innate immunity. We identified compound 3b as a potent immune suppressive agent with the potential to protect acute pulmonary infection.

Is there a future for andrographolide to be an anti-inflammatory drug? Deciphering its major mechanisms of action

Andrographis paniculata has long been part of the traditional herbal medicine system in Asia and in Scandinavia. Andrographolide was isolated as a major bioactive constituent of A. paniculata in 1951, and since 1984, andrographolide and its analogs have been scrutinized with modern drug discovery approach for anti-inflammatory properties. With this accumulated wealth of pre-clinical data, it is imperative to review and consolidate different sources of information, to decipher the major anti-inflammatory mechanisms of action in inflammatory diseases, and to provide direction for future studies. Andrographolide and its analogs have been shown to provide anti-inflammatory benefits in a variety of inflammatory disease models. Among the diverse signaling pathways investigated, inhibition of NF-κB activity is the prevailing anti-inflammatory mechanism elicited by andrographolide. There is also increasing evidence supporting endogenous antioxidant defense enhancement by andrographolide through Nrf2 activation. However, the exact pathway leading to NF-κB and Nrf2 activation by andrographolide has yet to be elucidated. Validation and consensus on the major mechanistic actions of andrographolide in different inflammatory conditions are required before translating current findings into clinical settings. There are a few clinical trials conducted using andrographolide in fixed combination formulation which have shown anti-inflammatory benefits and good safety profile. A concerted effort is definitely needed to identify potent andrographolide lead compounds with improved pharmacokinetics and toxicological properties. Taken together, andrographolide and its analogs have great potential to be the next new class of anti-inflammatory agents, and more andrographolide molecules are likely moving towards clinical study stage in the near future.

Andrographolide inhibits hypoxia-induced HIF-1α-driven endothelin 1 secretion by activating Nrf2/HO-1 and promoting the expression of prolyl hydroxylases 2/3 in human endothelial cells

Andrographolide, the main bioactive component of the medicinal plant Andrographis paniculata, has been shown to possess potent anti-inflammatory activity. Endothelin 1 (ET-1), a potent vasoconstrictor peptide produced by vascular endothelial cells, displays proinflammatory property. Hypoxia-inducible factor 1α (HIF-1α), the regulatory member of the transcription factor heterodimer HIF-1α/β, is one of the most important molecules that responds to hypoxia. Changes in cellular HIF-1α protein level are the result of altered gene transcription and protein stability, with the latter being dependent on prolyl hydroxylases (PHDs). In this study, inhibition of pro-inflammatory ET-1 expression and changes of HIF-1α gene transcription and protein stability under hypoxia by andrographolide in EA.hy926 endothelial-like cells were investigated. Hypoxic conditions were created using the hypoxia-mimetic agent CoCl_2. We found that hypoxia stimulated the production of reactive oxygen species (ROS), the expression of HIF-1α mRNA and protein, and the expression and secretion of ET-1. These effects, however, were attenuated by co-exposure to andrographolide, bilirubin, and RuCO. Silencing Nrf2 and heme oxygenase 1 (HO-1) reversed the inhibitory effects of andrographolide on hypxoia-induced HIF-1α mRNA and protein expression. Moreover, andrographolide increased the expression of prolyl hydroxylases (PHD) 2/3, which hydroxylate HIF-1α and promotes HIF-1α proteasome degradation, with an increase in HIF-1α hydroxylation was noted under hypoxia. Inhibition of p38 MAPK abrogated the hypoxia-induced increases in HIF-1α mRNA and protein expression as well as ET-1 mRNA expression and secretion. Taken together, these results suggest that andrographolide suppresses hypoxia-induced pro-inflammatory ET-1 expression by activating Nrf2/HO-1, inhibiting p38 MAPK signaling, and promoting PHD2/3 expression. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 918-930, 2017.

The Effects of Taoren-Honghua Herb Pair on Pathological Microvessel and Angiogenesis-Associated Signaling Pathway in Mice Model of CCl4-Induced Chronic Liver Disease

Chronic liver disease is one of the most common diseases that threaten human health. Effective treatment is still lacking in western medicine. Semen Persicae (Taoren) and Flos Carthami (Honghua) are known to relieve acute hepatic injury and inflammation, improve microcirculation, and reduce tissue fiber. The aim of our study is to investigate the potential mechanisms of Taoren-Honghua Herb Pair (THHP) in murine model of chronic liver disease caused by Carbon Tetrachloride (CCl4). Mice were randomly divided into seven groups: (1) blank, (2) model, (3) control (colchicine, 0.1 mg/kg), (4) THHP (5.53, 2.67, and 1.33 g/kg), and (5) Tao Hong Siwu Decoction (THSWD) (8.50 g/kg). Histological change and microvessels density were examined by microscopy. Hepatic function, serum fibrosis related factors, and hepatic vascular endothelial growth factor (VEGF) were measured with ELISA. VEGF, kinase insert domain-containing receptor (KDR), Flt-1, and Akt mRNA expression in hepatic tissue were determined with PCR. Tissues of Akt, pAkt, KDR, and Flt-1 were measured with western blotting. Data from this study showed that THHP improved hepatic function and restrained the hepatic inflammation and fibrosis. Its role in inhibiting pathological angiogenesis and hepatic fibrogenesis may be through affecting the angiogenesis-associated VEGF and its upstream and downstream signaling pathways.

Differential in vitro and in vivo anti-angiogenic activities of acetal and ketal andrographolide derivatives in HUVEC and zebrafish models

Acetal and ketal andrographolide derivatives presented differing anti-angiogenic activities when applied to in vitro and in vivo models, leading to different inhibitory outcomes.

Activity of andrographolide against chikungunya virus infection

Chikungunya virus (CHIKV) is a re-emerging mosquito-borne alphavirus that has recently engendered large epidemics around the world. There is no specific antiviral for treatment of patients infected with CHIKV, and development of compounds with significant anti-CHIKV activity that can be further developed to a practical therapy is urgently required. Andrographolide is derived from Andrographis paniculata, a herb traditionally used to treat a number of conditions including infections. This study sought to determine the potential of andrographolide as an inhibitor of CHIKV infection. Andrographolide showed good inhibition of CHIKV infection and reduced virus production by approximately 3log₁₀ with a 50% effective concentration (EC₅₀) of 77 μM without cytotoxicity. Time-of-addition and RNA transfection studies showed that andrographolide affected CHIKV replication and the activity of andrographolide was shown to be cell type independent. This study suggests that andrographolide has the potential to be developed further as an anti-CHIKV therapeutic agent.

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.