Capsaicin Inhibits Dimethylnitrosamine-Induced Hepatic Fibrosis by Inhibiting the TGF-β1/Smad Pathway via Peroxisome Proliferator-Activated Receptor Gamma Activation

Anti-stromal nanotherapeutics for hepatocellular carcinoma

Hepatocellular carcinoma (HCC), the most commonly diagnosed primary liver cancer, has become a leading cause of cancer-related death worldwide. Accumulating evidence confirms that the stromal constituents within the tumor microenvironment (TME) exacerbate HCC malignancy and set the barriers to current anti-HCC treatments. Recent developments of nano drug delivery system (NDDS) have facilitated the application of stroma-targeting therapeutics, disrupting the stromal TME in HCC. This review discusses the stromal activities in HCC development and therapy resistance. In addition, it addresses the delivery challenges of NDDS for stroma-targeting therapeutics (termed anti-stromal nanotherapeutics in this review), and provides recent advances in anti-stromal nanotherapeutics for safe, effective, and specific HCC therapy.

Epigenetic modification in liver fibrosis: Promising therapeutic direction with significant challenges ahead

Liver fibrosis, characterized by scar tissue formation, can ultimately result in liver failure. It's a major cause of morbidity and mortality globally, often associated with chronic liver diseases like hepatitis or alcoholic and non-alcoholic fatty liver diseases. However, current treatment options are limited, highlighting the urgent need for the development of new therapies. As a reversible regulatory mechanism, epigenetic modification is implicated in many biological processes, including liver fibrosis. Exploring the epigenetic mechanisms involved in liver fibrosis could provide valuable insights into developing new treatments for chronic liver diseases, although the current evidence is still controversial. This review provides a comprehensive summary of the regulatory mechanisms and critical targets of epigenetic modifications, including DNA methylation, histone modification, and RNA modification, in liver fibrotic diseases. The potential cooperation of different epigenetic modifications in promoting fibrogenesis was also highlighted. Finally, available agonists or inhibitors regulating these epigenetic mechanisms and their potential application in preventing liver fibrosis were discussed. In summary, elucidating specific druggable epigenetic targets and developing more selective and specific candidate medicines may represent a promising approach with bright prospects for the treatment of chronic liver diseases.

Nano-biomaterial Fibrinogen/P(LLA-CL) for prevention of intrauterine adhesion and restoration of fertility

Endometrial damage resulting from surgical procedures is a significant cause of intrauterine adhesion, thin endometrium, and subsequent miscarriage and infertility. Unfortunately, there is currently no effective clinical solution to promote endometrial regeneration after severe injury. In this study, we combined fibrinogen (Fg) and P(LLA-CL) by electrostatic spinning to form a stable nano-biomaterial Fg/P(LLA-CL), which can promote endometrial regeneration. After inducing physical injury to rat endometrium, we found that Fg/P(LLA-CL) membranes placed in the uterine cavities increased endometrial thickness and the number of glands after injury, while reducing the area of endometrial fibrosis. In addition, Fg/P(LLA-CL) increased neovascularization and decreased COL1A1 deposition. The expression of TGF-β1, a cytokine that promotes fibrosis, was down-regulated in the early stage of injury. Finally, fertility assays confirmed that Fg/P(LLA-CL) improved the pregnancy rate in rats with endometrial injury, and its safety was verified by blood tests and pathological examination of heart, liver, spleen, lung, and kidney. Therefore, Fg/P(LLA-CL) shows great potential as a safe and nontoxic biomaterial for endometrial regeneration, ultimately improving pregnancy outcomes in patients with intrauterine adhesion.

Regulation of miRNA-155-5p ameliorates NETosis in pulmonary fibrosis rat model via inhibiting its target cytokines IL-1β, TNF-α and TGF-β1

Idiopathic pulmonary fibrosis (IPF) is an age-related inflammatory disease with no cure up till now.It is accompanied by neutrophils infiltration as the main responders to inflammation and fibrosis. Importantly, neutrophils release neutrophil extracellular traps (NETs) through NETosis process. The function of microRNAs during inflammation became of great biological attention. Owing to microRNAs' central role in immune system, microRNA-155-5p (miR-155-5p) is intensely involved in the inflammatory response. Capsaicin (Cap) is a bioactive compound that exhibits antioxidative and anti-inflammatory functions. Recent studies have shown its role in regulation of certain microRNAs' expressions. Accordingly, the present study aims to investigate the effect of miR-155-5p regulation in suppressing NETs production via ameliorating its target inflammatory cytokines, IL-1ß, TNF-α and TGF-ß1, in bleomycin (BLM)-induced pulmonary fibrosis rat model treated by Cap. The obtained results demonstrated that miR-155-5p downregulation was associated with significant decrease in IL-1ß, TNF-α, TGF-β1, which consequently, reduced hydroxyproline (HYP), NETs activity markers as NE and PAD-4, and alleviated CTGF levels in lung tissues of animals treated by Cap. Furthermore, NETosis ultrastructure examination by transmission electron microscope (TEM), MPO immunohistochemical staining and histopathological studies confirmed an abolishment in NETs formation and an improvement in lung tissue architecture in Cap-treated rats. This study concluded that Cap quenched the inflammatory response through interrupting IL-1β, TNF-α and TGF-β1 pathway via modulating miR-155-5p expression. In addition, Cap was able to alleviate pulmonary NETosis markers by restraining NETs activity markers. These findings provide novel insight into the application of Cap-based treatment in ameliorating pulmonary damage in IPF.

BMP4 Regulates EMT to be Involved in non-Syndromic Cleft lip With or Without Palate

OBJECTIVE

In the previous study, we identified bone morphogenetic protein 4 (BMP4) responsible for non-syndromic cleft lip with or without cleft palate (NSCL/P). We aimed to elucidate the effects and mechanisms of BMP4 on epithelial-mesenchymal transition (EMT) through Smad1 signaling pathway to be involved in NSCL/P.

METHODS

The human oral epidermoid carcinoma cells (KBs) were transfected with plasmids or small interfering RNA (siRNA) to build the models. The migration of the cells was evaluated by transwell assay. Western blotting and quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) were used to detect the expressions of BMP4, E-cadherin, N-cadherin, EMT-related transcription factors snal1 and snal2, matrix metalloproteinase 2 (MMP2), MMP9, Smad1, and phosphorylated Smad1.

RESULTS

In the overexpression group, the migration number of cells was increased significantly. The protein expression of E-cadherin was decreased significantly, while the protein expression level of the N-cadherin was increased significantly. The protein and mRNA expressions of MMP2, MMP9, snal1, and snal2 were significantly higher. The expression level of Smad1 was not significantly changed, while the phosphorylation of Smad1 was significantly increased. In the BMP4-siRNA group, the migrating number cells was significantly decreased. The protein expression of E-cadherin was increased significantly, while the expression of N-cadherin was significantly decreased. The protein and mRNA expressions of MMP2, MMP9, snal1, and snal2 were significantly lower than that of the control group. The expressions of Smad1 and phosphorylation of Smad1 were not significantly changed.

CONCLUSIONS

BMP4 enhances cell migration and promotes cell EMT through Smad1 signaling pathway. Abnormal BMP4 mediates migration and EMT through other relevant signaling pathways resulting in NSCL/P. The study provides new insight into the mechanisms of NSCL/P associated with BMP4.n.

Capsaicin and 1,25-Dihydroxyvitamin D3 Glycoside: Effects on the Reproductive Performance of Hyper-Prolific Sows

This study evaluated the effect of a natural source of vitamin D3 [1,25-(OH)2D3] and capsaicin (CAP) in the dietary supplementation of sows in the final phase (85-114 days) of gestation (Gest) and lactation (Lact) on the reproductive performance of the sows and health of piglets through two experiments (Exp I and II). In Exp I, 120 sows were subjected to four treatments: T1-control (without [1,25-(OH)2D3] and supplemental CAP); T2-3.5 µg 1,25-(OH)2D3/Gest/day and 7.0 µg Vit 1,25-(OH)2D3/Lact/day; T3-7.0 µg CAP/Gest/day and 14.0 µg CAP/Lact/day; T4-1.75 µg Vit 1,25-(OH)2D3 + 3.5 µg CAP/Gest/day and 3.5 µg 1,25-(OH)2D3 + 7.0 µg CAP/Lact/day. In Exp II, 200 sows were randomly blocked, factorial 2 × 2 (without or with Vit 1,25-(OH)2D3 and without or with CAP): T1-control (without Vit 1,25-(OH)2D3 and CAP); T2-3.5 µg Vit 1,25-(OH)2D3/Gest/day and 7.0 µg Vit 1,25-(OH)2D3/Lact/day; T3-7.0 µg CAP/Gest/day and 14.0 µg CAP/Lact/day; T4-3.5 µg Vit 1,25-(OH)2D3 + 7 µg CAP/Gest/day; and 7.0 µg Vit 1,25-(OH)2D3 + 14.0 µg CAP/Lact/day. The duration of delivery (3:48 vs. 4:57 h) and the percentage of stillbirths (5.37% vs. 7.61%) were improved (p < 0.05) in the group that received Vit 1,25-(OH)2D3 (Exp II) compared to the control group. Moreover, the dystocia rate decreased (p < 0.05) in Exp II, which received Vit 1,25-(OH)2D3 (4.21 vs. 27.63%), and in Exp I, which received the combination of Vit 1,25-(OH)2D3 + CAP (12 vs. 40%) compared to the respective control groups. Colostrum production was greater (p < 0.05) in sows that received Vit 1,25-(OH)2D3 supplementation compared to the control group, consequently resulting in higher colostrum intake (p < 0.05) of the piglets (330 vs. 258 g/piglet). The additives reduced the incidence of diarrhea (p < 0.05) in piglets (Exp I and II). Thus, the use of additives improved the reproductive performance of sows and contributed to litter growth.

Low glycemic index potato biscuits alleviate physio-histological damage and gut dysbiosis in rats with type-2 diabetes mellitus induced by high-sugar and high-fat diet and streptozotocin

Type 2 diabetes mellitus (T2DM) is the most common type of diabetes globally and poses a major concern for human health. This study aimed to investigate the effects on T2DM of low-glycemic index (GI) potato biscuits with oat bran and inulin as functional additives. T2DM was induced in rats by streptozotocin (STZ) and a high-sugar and high-fat diet. The alleviation of T2DM by low-GI potato biscuits at different doses was evaluated based on the analysis of glycolipid levels, histological observations, inflammatory markers and gut microbiota structure. Compared to wheat biscuits, low-GI potato biscuits resulted in lower postprandial blood glucose levels. After eight weeks of intervention, fasting blood sugar levels were 16.9% lower in T2DM rats fed high-dose low-GI potato biscuits than in untreated T2DM rats. Moreover, the intervention with low-GI potato biscuits significantly alleviated T2DM-induced pathological damage, glucose and lipid metabolic disorders, and inflammation by reversing the levels of total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, transforming growth factor-β, interleukin-1β, interleukin-6 and tumor necrosis factor-α. Moreover, the levels of short-chain fatty acids and gut microbiota structure in T2DM rats were significantly reversed. The abundance of beneficial bacteria (e.g., Bifidobacterium, Lachnoclostridium, Roseburia) in the gut of T2DM rats was significantly increased whereas the abundance of Escherichia-Shigella and Desulfovibrio decreased. The present study revealed that low-GI potato biscuits alleviated damages caused by high-sugar and high-fat diet- and STZ-induced T2DM in rats, as well as reversed disturbances in the gut microbiota. Thus, low-GI potato biscuits are potentially beneficial to T2DM patients.

Matrix metalloproteinases induce extracellular matrix degradation through various pathways to alleviate hepatic fibrosis

Liver fibrosis is the common consequence of various chronic liver injuries and is mainly characterized by the imbalance between the production and degradation of extracellular matrix, which leads to the accumulation of interstitial collagen and other matrix components. Matrix metalloproteinases (MMPs) and their specific inhibitors, that is, tissue inhibitors of metalloproteinases (TIMPs), play a crucial role in collagen synthesis and lysis. Previous in vivo and in vitro studies of our laboratory found repressing extracellular matrix (ECM) accumulation by restoring the balance between MMPs and TIMPs can alleviate liver fibrosis. We conducted a review of articles published in PubMed and Science Direct in the last decade until February 1, 2023, which were searched for using these words "MMPs/TIMPs" and "Hepatic Fibrosis." Through a literature review, this article reviews the experimental studies of liver fibrosis based on MMPs/TIMPs, summarizes the components that may exert an anti-liver fibrosis effect by affecting the expression or activity of MMPs/TIMPs, and attempts to clarify the mechanism of MMPs/TIMPs in regulating collagen homeostasis, so as to provide support for the development of anti-liver fibrosis drugs. We found the MMP-TIMP-ECM interaction can result in better understanding of the pathogenesis and progression of hepatic fibrosis from a different angle, and targeting this interaction may be a promising therapeutic strategy for hepatic fibrosis. Additionally, we summarized and analyzed the drugs that have been found to reduce liver fibrosis by changing the ratio of MMPs/TIMPs, including medicine natural products.

A review of edible plant-derived natural compounds for the therapy of liver fibrosis

Liver fibrosis has a high incidence worldwide and is the common pathological basis of many chronic liver diseases. Liver fibrosis is caused by the excessive deposition of extracellular matrix and concomitant collagen accumulation in livers and can lead to the development of liver cirrhosis and even liver cancer. A large number of studies have provided evidence that liver fibrosis can be blocked or even reversed by appropriate medical interventions. However, the antifibrosis drugs with ideal clinical efficacy are still insufficient. The edible plant-derived natural compounds have been reported to exert effective antifibrotic effects with few side-effects, representing a kind of promising source for the treatment of liver fibrosis. In this article, we reviewed the current progress of the natural compounds derived from dietary plants in the treatment of liver fibrosis, including phenolic compounds (capsaicin, chlorogenic acid, curcumin, ellagic acid, epigallocatechin-3-gallate, resveratrol, sinapic acid, syringic acid, vanillic acid and vitamin E), flavonoid compounds (genistein, hesperidin, hesperetin, naringenin, naringin and quercetin), sulfur-containing compounds (S-allylcysteine, ergothioneine, lipoic acid and sulforaphane) and other compounds (betaine, caffeine, cucurbitacin B, lycopene, α-mangostin, γ-mangostin, ursolic acid, vitamin C and yangonin). The pharmacological effects and related mechanisms of these compounds in in-vivo and in-vitro models of liver fibrosis are focused.

Nitro Capsaicin Suppressed Microglial Activation and TNF-α-Induced Brain Microvascular Endothelial Cell Damage

Chronically activated microglia and brain vascular damage are major causes of neuroinflammation. The aim of this study was to determine the anti-inflammatory effects of nitro capsaicin, a newly modified capsaicin with less irritating characteristics, against microglial activation and brain microvascular endothelial cell damage. Using the SIMA9 microglia cell line, we found that nitro capsaicin reduced nitric oxide (NO) production in LPS-activated microglia better than its parent compound, capsaicin. Nitro capsaicin also decreased the expression of proinflammatory cytokines (TNF-α, IL-1β, and IL-6) and enhanced the levels of anti-inflammatory factors, IL-4 and IL-10, both at the mRNA and protein levels. In the TNF-α-induced vascular damage model, nitro capsaicin decreased expression and secretion of the proinflammatory cytokines IL-1β and IL-6. Phosphorylated NF-κB p65, a key transcription factor that stimulates the signaling of inflammatory pathways, was also reduced in the presence of nitro capsaicin, suggesting that the anti-inflammatory effects of nitro capsaicin were created through reducing NF-κB activation. Together, we concluded that nitro capsaicin has the potential to be further developed as an anti-neuroinflammatory agent.

Therapeutic Response of Multifunctional Lipid and Micelle Formulation in Hepatocellular Carcinoma

Hepatic stellate cells (HSCs), as an important part of the tumor microenvironment (TME), could be activated by tumor cells as cancer-associated fibroblasts (CAFs), thereby promoting the production of extracellular matrix (ECM) and favoring the development of tumors. Therefore, blocking the "CAFs-ECM" axis is a promising pathway to improve antitumor efficacy. Based on this, we developed a multifunctional nanosized delivery system composed of hyaluronic acid-modified pH-sensitive liposomes (CTHLs) and glycyrrheic acid-modified nanomicelles (DGNs), which combines the advantages of targeted delivery, pH-sensitivity, and deep drug penetration. To mimic actual TME, a novel HSCs+BEL-7402 cocultured cell model and a m-HSCs+H22 coimplanted mice model were established. As expected, CTHLs and DGNs could target CAFs and tumor cells, respectively, and promote the drug penetration and retention in tumor regions. Notably, CTHLs+DGNs not only exhibited a superior antitumor effect in three-level tumor-bearing mice but also presented excellent antimetastasis efficiency in lung-metastatic mice. The antitumor mechanism revealed that the lipid&micelle mixed formulations effectively inhibited the activation of CAFs, reduced the deposition of ECM, and reversed the epithelial-mesenchymal transition (EMT) of tumor cells. In brief, the nanosized delivery system composed of CTHLs and DGNs could effectively improve the therapeutic effect of liver cancer by blocking the "CAFs-ECM" axis, which has a good clinical application prospect.

The Enteric Glia and Its Modulation by the Endocannabinoid System, a New Target for Cannabinoid-Based Nutraceuticals?

The enteric nervous system (ENS) is a part of the autonomic nervous system that intrinsically innervates the gastrointestinal (GI) tract. Whereas enteric neurons have been deeply studied, the enteric glial cells (EGCs) have received less attention. However, these are immune-competent cells that contribute to the maintenance of the GI tract homeostasis through supporting epithelial integrity, providing neuroprotection, and influencing the GI motor function and sensation. The endogenous cannabinoid system (ECS) includes endogenous classical cannabinoids (anandamide, 2-arachidonoylglycerol), cannabinoid-like ligands (oleoylethanolamide (OEA) and palmitoylethanolamide (PEA)), enzymes involved in their metabolism (FAAH, MAGL, COX-2) and classical (CB1 and CB2) and non-classical (TRPV1, GPR55, PPAR) receptors. The ECS participates in many processes crucial for the proper functioning of the GI tract, in which the EGCs are involved. Thus, the modulation of the EGCs through the ECS might be beneficial to treat some dysfunctions of the GI tract. This review explores the role of EGCs and ECS on the GI tract functions and dysfunctions, and the current knowledge about how EGCs may be modulated by the ECS components, as possible new targets for cannabinoids and cannabinoid-like molecules, particularly those with potential nutraceutical use.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) shows therapeutic effect on dimethylnitrosamine (DMN)-induced liver fibrosis in rats

This study was undertaken to investigate the inhibitory effects of granulocyte-macrophage colony-stimulating factor (GM-CSF) on dimethylnitrosamine (DMN)-induced liver fibrosis in rats. Liver fibrosis was induced in Sprague-Dawley rats by injecting DMN intraperitoneally (at 10 mg/kg of body weight) daily for three consecutive days per week for 4 weeks. To investigate the effect of GM-CSF on disease onset, GM-CSF (50 μg/kg of body weight) was co-treated with DMN for 2 consecutive days per week for 4 weeks (4-week groups). To observe the effect of GM-CSF on the progression of liver fibrosis, GM-CSF was post-treated alone at 5–8 weeks after the 4 weeks of DMN injection (8-week groups). We found that DMN administration for 4 weeks produced molecular and pathological manifestations of liver fibrosis, that is, it increased the expressions of collagen type I, alpha-smooth muscle actin (α-SMA), and transforming growth factor-β1 (TGF-β1), and decreased peroxisome proliferator-activated receptor gamma (PPAR-γ) expression. In addition, elevated serum levels of aspartate aminotransferase (AST), total bilirubin level (TBIL), and decreased albumin level (ALB) were observed. In both the 4-week and 8-week groups, GM-CSF clearly improved the pathological liver conditions in the gross and histological observations, and significantly recovered DMN-induced increases in AST and TBIL and decreases in ALB serum levels to normal. GM-CSF also significantly decreased DMN-induced increases in collagen type I, α-SMA, and TGF-β1 and increased DMN-induced decreases in PPAR-γ expression. In the DMN groups, survival decreased continuously for 8 weeks after DMN treatment for the first 4 weeks. GM-CSF showed a survival benefit when co-treated for the first 4 weeks but a marginal effect when post-treated for 5–8 weeks. In conclusion, co-treatment of GM-CSF showed therapeutic effects on DMN-induced liver fibrosis and survival rates in rats, while post-treatment efficiently blocked liver fibrosis.

Traditional Chinese medicine: An important source for discovering candidate agents against hepatic fibrosis

Hepatic fibrosis (HF) refers to the pathophysiological process of connective tissue dysplasia in the liver caused by various pathogenic factors. Nowadays, HF is becoming a severe threat to the health of human being. However, the drugs available for treating HF are limited. Currently, increasing natural agents derived from traditional Chinese medicines (TCMs) have been found to be beneficial for HF. A systemic literature search was conducted from PubMed, GeenMedical, Sci-Hub, CNKI, Google Scholar and Baidu Scholar, with the keywords of “traditional Chinese medicine,” “herbal medicine,” “natural agents,” “liver diseases,” and “hepatic fibrosis.” So far, more than 76 natural monomers have been isolated and identified from the TCMs with inhibitory effect on HF, including alkaloids, flavones, quinones, terpenoids, saponins, phenylpropanoids, and polysaccharides, etc. The anti-hepatic fibrosis effects of these compounds include hepatoprotection, inhibition of hepatic stellate cells (HSC) activation, regulation of extracellular matrix (ECM) synthesis & secretion, regulation of autophagy, and antioxidant & anti-inflammation, etc. Natural compounds and extracts from TCMs are promising agents for the prevention and treatment of HF, and this review would be of great significance to development of novel drugs for treating HF.

Peroxisome proliferator-activated receptor gamma as a therapeutic target for hepatocellular carcinoma: Experimental and clinical scenarios

Hepatocellular carcinoma (HCC) is the most common type of liver cancer worldwide. Viral hepatitis is a significant risk factor for HCC, although metabolic syndrome and diabetes are more frequently associated with the HCC. With increasing prevalence, there is expected to be > 1 million cases annually by 2025. Therefore, there is an urgent need to establish potential therapeutic targets to cure this disease. Peroxisome-proliferator-activated receptor gamma (PPARγ) is a ligand-activated transcription factor that plays a crucial role in the patho-physiology of HCC. Many synthetic agonists of PPARγ suppress HCC in experimental studies and clinical trials. These synthetic agonists have shown promising results by inducing cell cycle arrest and apoptosis in HCC cells and preventing the invasion and metastasis of HCC. However, some synthetic agonists also pose severe side effects in addition to their therapeutic efficacy. Thus natural PPARγ agonists can be an alternative to exploit this potential target for HCC treatment. In this review, the regulatory role of PPARγ in the pathogenesis of HCC is elucidated. Furthermore, the experimental and clinical scenario of both synthetic and natural PPARγ agonists against HCC is discussed. Most of the available literature advocates PPARγ as a potential therapeutic target for the treatment of HCC.

Effect of capsaicin on the feed intake and immunoglobin concentration of sows, and performance of piglets

Capsaicin is a recognized alkaloid that can be used as a flavoring and palatability agent. These effects can increase feed intake in lactating sows during farrowing, especially under thermal stress conditions, and provide antioxidant and immunostimulant activities. The objective of this work was to find out the effects of a capsaicin-based product on the feed intake of sows, immunomodulation, and repercussions on litter performance and the control of piglet diarrhea conditions. A total of 132 pregnant sows and lactating sows and their respective litters were divided into 66 sows each and submitted to one of two possible treatments: a capsaicin-free diet (control group) or capsaicin per meal/day. Capsaicin was mixed with gestation and lactation diets in the proportion of 98.6 g of feed and 1.4 g of capsaicin/kg feed, with the dose administered "on top" of 100 g per treatment day on the first feeding. The sows were treated between 90 days of gestation and 21 days of lactation. Backfat thickness, feed intake during farrowing, colostrum production, IgG colostrum concentration, sow reproductive performance, piglet performance, and diarrhea were evaluated. Compared to the sows in the control group, those that received capsaicin had higher feed intake (+ 0.69 kg/day during lactation, P = 0.008), higher levels of IgG in colostrum (185.75 versus 153.80 mg/mL, P = 0.04), an 11.2% higher litter weight gain, with individual piglet weight gains greater than 5.24% (P = 0.045), and an effective reduction in the frequency of piglet diarrhea on the 10th and 17th days of age (P = 0.013 and P = 0.001, respectively). Capsaicin is an additive with potential effects on the sow's performance, with positive influences on the health and growth of suckling piglets.

Tanshinone IIA regulates the TGF‑β1/Smad signaling pathway to ameliorate non‑alcoholic steatohepatitis‑related fibrosis

Tanshinone IIA (TIIA) is a major component extracted from the traditional herbal medicine Salvia miltiorrhiza and has been indicated to play a role in the treatment of organ fibrosis. However, the evidence supporting its antifibrotic effect is insufficient and the underlying mechanism is unclear. To investigate the therapeutic effect of TIIA on non-alcoholic steatohepatitis-related fibrosis (NASH-F), the present study used a methionine choline deficiency diet to induce NASH-F in rats, and explored the effect of TIIA on the transforming growth factor-β1 (TGF-β1)/Smad signaling pathway. Wistar rats were randomly divided into control, NASH-F and TIIA groups. After 8 weeks of treatment, the levels of serum markers associated with liver function and fibrosis were measured, liver fat vacuoles and inflammation were assessed by haematoxylin and eosin staining, and liver fibrosis was assessed by Masson's trichrome staining. TGF-β1, Smad2, Smad3, Smad7 and α-smooth muscle actin (α-SMA) mRNA expression, and TGF-β1, Smad2/3, phosphorylated (p)-Smad2/3, Smad7 and α-SMA protein levels were determined. The results revealed that TIIA could remarkably ameliorate liver fat vacuoles and inflammation in NASH-F rats, and could decrease the levels of serum aspartate aminotransferase, alanine aminotransferase, total bilirubin, total bile acid, hyaluronic acid, type Ⅳ collagen, laminin and type III collagen, while increasing the levels of total cholesterol and triglycerides; however, this was not statistically significance. TIIA markedly suppressed the increased TGF-β1, Smad2, Smad3 and α-SMA mRNA expression levels observed in the liver of NASH-F rats, while it increased the mRNA expression level of Smad7. Similarly, TIIA suppressed the increased TGF-β1, p-Smad2/3 and α-SMA protein levels observed in the liver of NASH-F rats, while it increased the protein expression level of Smad7 in vitro and in vivo. TIIA had no significant cytotoxic effect at 10, 20, 40 and 80 µmol/l on human LX-2 cell. In conclusion, the findings of the present study indicated that TIIA alleviated NASH-F by regulating the TGF-β1/Smad signaling pathway. TIIA may be a useful tool in the prevention and treatment of NASH-F.

Capsaicin ameliorates renal fibrosis by inhibiting TGF-β1-Smad2/3 signaling

BACKGROUND AND PURPOSE

Chronic kidney disease (CKD), characterized by renal fibrosis, is a global refractory disease with few effective therapeutic strategies. It has been reported that capsaicin exerts many pharmacological effects including liver and cardiac fibrosis. However, whether capsaicin plays a therapeutic role in renal fibrosis remains unclear.

METHODS

We investigated antifibrotic effects of capsaicin in two mouse renal fibrosis models as follows: C57BL/6J mice were subjected to unilateral ureteral obstruction (UUO) and fed with an adenine-rich diet. We uncovered and verified the mechanisms of capsaicin in human proximal tubular epithelial cells (HK2). We mainly used histochemistry, immunohistochemistry and immunofluorescence staining, western blot assay, biochemical examination and other tools to examine the effects of capsaicin on renal fibrosis and the underlying mechanisms.

RESULTS

Capsaicin treatment significantly alleviated fibronectin and collagen depositions in the tubulointerstitium of the injured kidneys from UUO and adenine-fed mice. Meanwhile, capsaicin treatment obviously reduced α-SMA expression. Moreover, capsaicin treatment dramatically protected against the phenotypic alteration of tubular epithelial cells by increasing E-cadherin expression and decreasing vimentin expression during renal fibrosis. Mechanistically, capsaicin treatment effectively suppressed α-SMA and vimentin expressions but promoted E-cadherin expression in HK2 cells mainly through the inhibition of TGF-β1-Smad2/3 signaling.

CONCLUSION

Capsaicin significantly ameliorated renal fibrosis possibly by retarding the activation of myofibroblasts and protecting against the phenotypic alteration of tubular epithelial cells mainly through the inhibition of TGF-β1-Smad2/3 signaling. Thus, our findings may provide a new insight into the clinical application of capsaicin in renal fibrosis.

Recent Advances in Glycyrrhetinic Acid-Functionalized Biomaterials for Liver Cancer-Targeting Therapy

Liver cancer is one of the most common causes of cancer mortality worldwide. Chemotherapy and radiotherapy are the conventional therapies generally employed in patients with liver tumors. The major issue associated with the administration of chemotherapeutics is their high toxicity and lack of selectivity, leading to systemic toxicity that can be detrimental to the patient’s quality of life. An important approach to the development of original liver-targeted therapeutic products takes advantage of the employment of biologically active ligands able to bind specific receptors on the cytoplasmatic membranes of liver cells. In this perspective, glycyrrhetinic acid (GA), a pentacyclic triterpenoid present in roots and rhizomes of licorice, has been used as a ligand for targeting the liver due to the expression of GA receptors on the sinusoidal surface of mammalian hepatocytes, so it may be employed to modify drug delivery systems (DDSs) and obtain better liver or hepatocyte drug uptake and efficacy. In the current review, we focus on the most recent and interesting research advances in the development of GA-based hybrid compounds and DDSs developed for potential employment as efficacious therapeutic options for the treatment of hepatic cancer.

Zishen Qingre Tongluo Formula Improves Renal Fatty Acid Oxidation and Alleviated Fibrosis via the Regulation of the TGF-β1/Smad3 Signaling Pathway in Hyperuricemic Nephrology Rats

Hyperuricemia, an independent risk factor for ensuing chronic kidney disease (CKD), contributed to tubulointerstitial fibrosis and insufficiency of renal fatty acid oxidation. Many studies have shown that renal fatty acid oxidation dysfunction is related to the TGF-β1/Smad3 signaling pathway. We experimented the effects of Zishen Qingre Tongluo Formula (ZQTF) on the adenine/yeast-induced HN rats and uric acid-induced renal mouse tubular epithelial cells (mTECs), determined whether this effect was related to the TGF-β1/Smad3 signaling pathway, and further investigated the relationship between this effect and renal fatty acid oxidation. Rats were given intraperitoneally with adenine (100 mg/kg) and feed chow with 10% yeast for 18 days and then received ZQTF (12.04 g/kg/day) via intragastric gavage for eight weeks. The TGF-β1/Smad3 signaling pathway and renal fatty acid oxidation protein were detected by using western blotting, real-time PCR, and immunohistochemistry staining. mTECs induced by UA were used to investigate the relationship between the TGF-β1/Smad3 signaling pathway and renal fatty acid oxidation. After treatment with ZQTF, levels of UA, 24 h UTP, BUN, and Scr were significantly decreased and histologic injuries were visibly ameliorated in HN rats. Western blotting, real-time PCR, and immunohistochemistry staining revealed that PGC-1α, PPARγ, and PPARα significantly increased, and fibronectin, collagen 1, and P-Smad3 significantly decreased in HN rats and UA-induced mTECs after ZQTF treatment. SIS3 (a specific inhibitor of Smad3) treatment significantly increased the expressions of PGC-1α, PPARγ, and PPARα and decreased the expressions of fibronectin, collagen 1, and P-Smad3 in UA-induced mTECs. Our study demonstrated that ZQTF exhibited renoprotective effects by promoting renal fatty acid oxidation via the regulation of the TGF-β1/Smad3 signaling pathway. Thus, the present results indicated that ZQTF was a novel antifibrotic strategy for hyperuricemic nephropathy.

Signaling Targets Related to Antiobesity Effects of Capsaicin: A Scoping Review

The search for new antiobesogenic agents is increasing because of the current obesity pandemic. Capsaicin (Caps), an exogenous agonist of the vanilloid receptor of transient potential type 1 (TRPV1), has shown promising results in the treatment of obesity. This scoping review aims to verify the pathways mediating the effects of Caps in obesity and the different methods adopted to identify these pathways. The search was carried out using data from the EMBASE, MEDLINE (PubMed), Web of Science, and SCOPUS databases. Studies considered eligible evaluated the mechanisms of action of Caps in obesity models or cell types involved in obesity. Nine studies were included and 100% (n = 6) of the in vivo studies showed a high risk of bias. Of the 9 studies, 66.6% (n = 6) administered Caps orally in the diet and 55.5% (n = 5) used a concentration of Caps of 0.01% in the diet. In vitro, the most tested concentration was 1 μM (88.9%; n = 8). Capsazepine was the antagonist chosen by 66.6% (n = 6) of the studies. Seven studies (77.8%) linked the antiobesogenic effects of Caps to TRPV1 activation and 3 (33.3%) indicated peroxisome proliferator-activated receptor (PPAR) involvement as an upstream connection to TRPV1, rather than a direct metabolic target of Caps. The main secondary effects of Caps were lower weight gain (33.3%; n = 3) or loss (22.2%; n = 2), greater improvement in lipid profile (33.3%; n = 3), lower white adipocyte adipogenesis (33.3%; n = 3), browning process activation (44.4%; n = 4), and higher brown adipocyte activity (33.3%; n = 3) compared with those of the control treatment. Some studies have shown that PPAR agonists modulate TRPV1 activity, and no study has evaluated the simultaneous antagonism of these 2 receptors. Consequently, further studies are necessary to elucidate the role of each of these signaling molecules in the antiobesogenic effects of Caps.

Natural Ingredients from Medicine Food Homology as Chemopreventive Reagents against Type 2 Diabetes Mellitus by Modulating Gut Microbiota Homoeostasis

Type 2 diabetes mellitus (T2DM) is a noteworthy worldwide public health problem. It represents a complex metabolic disorder, mainly characterized as hyperglycemia and lipid dysfunction. The gut microbiota dysbiosis has been proposed to play a role in the development of diabetes. Recently, there has been considerable interest in the use of medicine food homology (MFH) and functional food herbs (FF) to ameliorate diabetes and lead to a natural and healthy life. Hence, this review compiles some reports and findings to demonstrate that the practical use of the MFH/FF can modulate the homoeostasis of gut microbiota, thereby ameliorating the development of T2DM. The results provided useful data to support further investigation of the functional basis and application of MFH/FF to treat T2DM through maintaining intestinal homeostasis.

Sodium Acetate Inhibit TGF-β1-Induced Activation of Hepatic Stellate Cells by Restoring AMPK or c-Jun Signaling

Short-chain fatty acids (SCFAs) are crucial gut microbial metabolites that play a major role in the occurrence and development of hepatic fibrosis (HF). However, the effect of SCFAs on hepatic stellate cells (HSCs), the major pro-fibrogenic cells, is yet undefined. In this study, the effects of three major SCFAs (acetate, propionate, and butyrate) were assessed on the activation of HSCs. LX2 cells were activated with TGF-β1 and treated with sodium acetate (NaA), sodium propionate (NaP), or sodium butyrate (NaB). SCFA treatment significantly reduced the protein levels of α-SMA and the phosphorylation of Smad2 and decreased the mRNA expression of Acta2/Col1a1/Fn in cells compared to the TGF-β1 treatment. Among the three SCFAs, NaA revealed the best efficacy at alleviating TGF-β1-induced LX2 cell activation. Additionally, acetate accumulated in the cells, and G protein-coupled receptor (GPR) 43 silencing did not have any impact on the inhibition of LX2 cell activation by NaA. These findings indicated that NaA enters into the cells to inhibit LX2 cell activation independent of GPR43. The results of phosphokinase array kit and Western blot indicated that NaA increased the AMP-activated protein kinase (AMPK) activation and reduced the phosphorylation of c-Jun in cultured LX2 cells, and siRNA-peroxisome proliferator-activated receptor (PPAR) -γ abolished the inhibitory effects of NaA against TGF-β1-induced LX2 cell activation. In conclusion, this study showed that NaA inhibited LX2 cell activation by activating the AMPK/PPARγ and blocking the c-Jun signaling pathways. Thus, SCFAs might represent a novel and viable approach for alleviating HF.

microRNA-199a downregulation alleviates hyperuricemic nephropathy via the PPARγ/β-catenin axis

Hyperuricemia always develops into hyperuricemic nephropathy (HN). The role of microRNA (miR) in HN is less studied. We aimed to discuss the role of miR-199a in HN. The expression of miR-199a and PPARγ in renal tissues of HN rats was detected. The targeting relation between miR-199a and PPARγ was verified. The contents of SCr, UA, BUN, and mALB, renal injury-relevant biomarkers were detected, and the pathological changes of renal tissue and renal interstitial fibrosis were observed by histological staining. After miR-199a and PPARγ knockdown, the contents of SCr, BUN, and mALB and renal interstitial fibrosis were estimated. Collectively, overexpression of miR-199a aggravated the renal injury in HN rats. By contrast, inhibition of miR-199a weakened renal injury, as evidenced by decreased contents of SCr, UA, BUN, and mALB, and mitigated renal interstitial fibrosis. miR-199a targeted PPARγ. Silencing of PPARγ upregulated the levels of downstream genes of β-catenin and the contents of SCr, UA, BUN, and mALB and deteriorated renal interstitial fibrosis. Moreover, the silencing of PPARγ blocked the alleviative effects of miR-199a inhibitor on the renal injury. Overall, miR-199a targets PPARγ and activates the β-catenin pathway, thus aggravating HN, which might provide a future target for the treatment of HN.

Roles of nuclear receptors in hepatic stellate cells

Introduction: Hepatic stellate cells (HSCs) are essential for physiological homeostasis of the liver extracellular matrix (ECM). Excessive transdifferentiation of HSC from a quiescent to an activated phenotype contributes to disrupt this balance and can lead to liver fibrosis. Accumulating evidence has suggested that nuclear receptors (NRs) are involved in the regulation of HSC activation, proliferation, and function. Therefore, these NRs may be therapeutic targets to balance ECM homeostasis and inhibit HSC activation in liver fibrosis.Areas covered: In this review, the authors summarized the recent progress in the understanding of the regulatory role of NRs in HSCs and their potential as drug targets in liver fibrosis.Expert opinion: NRs are still potential therapy targets for inhibiting HSCs activation and liver fibrosis. However, the development of NRs agonists or antagonists to inhibit HSCs requires fully consideration of systemic effects.

Peroxisome Proliferator-Activated Receptor-Gamma (PPAR-ɣ): Molecular Effects and Its Importance as a Novel Therapeutic Target for Cerebral Ischemic Injury

Cerebral ischemic injury is a leading cause of death and long-term disability throughout the world. Peroxisome proliferator-activated receptor gamma (PPAR-ɣ) is a ligand-activated nuclear transcription factor that is a member of the PPAR family. PPAR-ɣ has been shown in several in vitro and in vivo models to prevent post-ischemic inflammation and neuronal damage by negatively controlling the expression of genes modulated by cerebral ischemic injury, indicating a neuroprotective effect during cerebral ischemic injury. A extensive literature review of PubMed, Medline, Bentham, Scopus, and EMBASE (Elsevier) databases was carried out to understand the nature of the extensive work done on the mechanistic role of Peroxisome proliferator activated receptor gamma and its modulation in Cerebral ischemic injury. PPAR-ɣ can interact with specific DNA response elements to control gene transcription and expression when triggered by its ligand. It regulates lipid metabolism, improves insulin sensitivity, modulates antitumor mechanisms, reduces oxidative stress, and inhibits inflammation. This review article provides insights on the current state of research into the neuroprotective effects of PPAR-ɣ in cerebral ischemic injury, as well as the cellular and molecular mechanisms by which these effects are modulated, such as inhibition of inflammation, reduction of oxidative stress, suppression of pro-apoptotic production, modulation of transcription factors, and restoration of injured tissue through neurogenesis and angiogenesis.

Eugenol and capsaicin exhibit anti-metastatic activity via modulating TGF-β signaling in gastric carcinoma

The transforming growth factor-β (TGF-β) signaling is considered to be a key player in gastric cancer metastasis, and the inhibition of the TGF-β/SMAD4 signaling pathway may be a novel strategy for therapeutic interventions in cancer. Here, the anti-metastatic activity of two phytochemicals, eugenol and capsaicin, has been studied, and their potential to antagonize TGF-β has been investigated in gastric cancer cells. Both the phytochemicals exhibited anti-metastatic activity by inhibiting the TGF-β signaling pathway independent of P21 or P53, with capsaicin proving to be more potent than eugenol. However, unlike eugenol, the inhibitory effect of capsaicin on the TGF-β signaling pathway and metastasis was found to be dependent on SMAD4, which was validated in SMAD4-knocked down AGS cell and SMAD4-null SW620 cell line. Furthermore, the use of recombinant TGF-β and TGF-β receptor inhibitor LY2109761 confirmed that the anti-metastatic activity of eugenol is partially and that of capsaicin is principally mediated through the TGF-β signaling pathway. Identifying phytochemicals with the potential to inhibit cancer metastasis by targeting the TGF-β signaling pathway has immense scope for developing a therapeutic strategy against cancer metastasis.

Combined anti-hepatocellular carcinoma therapy inhibit drug-resistance and metastasis via targeting "substance P-hepatic stellate cells-hepatocellular carcinoma" axis

Peripheral nerves have emerged as the important components in tumor microenvironment (TME), which could activate hepatic stellate cells (HSCs) by secreting substance P (SP), leading to hepatocellular carcinoma (HCC) invasion and metastasis. Herein, we proposed a novel anti-HCC concept of blocking "SP-HSCs-HCC" axis for omnidirectional inhibition of HCC development. To pursue this aim, the novel CAP/GA-sHA-DOX NPs were developed for targeted co-delivery of capsaicin (CAP) and doxorubicin (DOX) using glycyrrhetinic acid (GA) modified sulfated-HA (sHA) as nanocarriers. Among that, CAP could inhibit the activation of HSCs as an inhibitor of SP. Notably, to real mimic "SP-HSCs-HCC" axis for in vitro and in vivo evaluation, both "SP + LX-2+BEL-7402" co-cultured cell model and "SP + m-HSC + H22" co-implantation mice model were attempted for the first time. Furthermore, in vivo anti-HCC effects were performed in three different tumor-bearing models: subcutaneous implantation of H22 or "SP + m-HSC + H22", intravenous injection of H22 for lung metastasis, and orthotopic implantation of H22 for primary HCC. Our results showed that CAP/GA-sHA-DOX NPs could be efficiently taken up by tumor cells and activated HSCs (aHSCs) simultaneously, and effectively inhibit tumor drug-resistance and migration by blocking SP-induced HSCs activation. In addition, CAP/GA-sHA-DOX NPs exhibited low ECM deposition, less tumor angiogenesis, and superior in vivo anti-HCC effects. The anti-HCC mechanisms revealed that CAP/GA-sHA-DOX NPs could down-regulate the expression level of Vimentin and P-gp, reverse epithelial-mesenchymal transition (EMT) of tumor cells. In brief, the nano-sized combination therapy based on GA-sHA-DOX polymers could effectively inhibit drug-resistance and metastasis of HCC by blocking "SP-HSCs-HCC" axis, which provides a promising approach for cancer therapy.

Co-Delivery of Curcumin and Capsaicin by Dual-Targeting Liposomes for Inhibition of aHSC-Induced Drug Resistance and Metastasis

Recent research studies have shown that the low survival rate of liver cancer is due to drug resistance and metastasis. In the tumor microenvironment (TME), activated hepatic stellate cells (aHSCs) have been proven to favor the development of liver cancer. Hence, the combination therapy dual-targeting aHSCs and tumor cells might be an effective strategy for treatment of liver cancer. In this study, the novel multifunctional liposomes (CAPS-CUR/GA&Gal-Lip) were prepared for co-delivery of curcumin (CUR) and capsaicin (CAPS), in which glycyrrhetinic acid (GA) and galactose (Gal) were chosen as targeting ligands to modify the liposomes (Lip) for dual-targeting liver cancer. To mimic TME, a novel HSCs+HepG2 (human hepatoma cell line) cocultured model was established for the antitumor effect in vitro. The results showed that, compared to HepG2 cells alone, the cocultured model promoted drug resistance and migration by upregulating the expression of P-glycoprotein (P-gp) and Vimentin, which were effectively inhibited by CAPS-CUR/GA&Gal-Lip. The efficacy of the in vivo antitumor was evaluated by three mice models: subcutaneous H22 (mouse hepatoma cell line) tumor-bearing mice, H22+m-HSC (mouse hepatic stellate cell) tumor-bearing mice, and orthotopic H22 cells-bearing mice. The results showed that CAPS-CUR/GA&Gal-Lip exhibited lesser extracellular matrix (ECM) deposition, lesser tumor angiogenesis, and superior antitumor effect compared with the no- and/or Gal-modified Lip, which was attributed to the simultaneous blocking of the activation of HSCs and inhibition of the metastasis of tumor cells. The dual-targeting method using Lip is thus a potential strategy for liver cancer treatment.

Glucagon-like peptide-1 (GLP-1) improved diabetic lung fibrosis via AMPK and microRNA-27a (miR-27a)

Background

Extracellular matrix proliferation is an issue which leads to lung tissue damage in diabetes mellitus. Glucagon-like peptide-1 (GLP-1) analogues can improve the proliferation of extracellular matrix in diabetic pulmonary disease. In this study, we investigated the effect of GLP-1 on pulmonary fibrosis through the AMPK/microRNA-27a (miR-27a) pathway.

Methods

Human embryonic lung fibroblast (MRC-5) cells were cultured with a high-glucose medium, and were treated with miR-27a inhibitor, GLP-1 analogues, and AMPK inhibitor. Cell Counting Kit-8 (CCK-8) detected the proliferation of MRC-5 cells. The fibrosis-related genes were analyzed, including Col-IV, fibronectin, NF-κB p65, α-SMA, and TGF-β1. Bioinformatics and dual-luciferase reporter assays were used to identify the targets for miR-27a.

Results

Compared with the control group, the expression of miR-27a in the hyperglycemic group was significantly up-regulated (P<0.01) and the expression of peroxisome proliferator-activated receptor γ (PPARγ) significantly down-regulated (P<0.01). The expression of Col-IV, fibronectin, NF-κB p65, α-SMA and TGF-β1 increased significantly (P<0.01). The expression level of apoptosis factor caspase-3 decreased significantly (P<0.01). MiR-27a inhibitor could reverse the expression of these proteins. The effect of GLP-1 on miR-27a was time- and concentration-dependent. After pretreating MRC-5 cells via GLP-1, with or without compound C (AMPK inhibitor), the expression of miR-27a in the GLP-1 treated group was significantly lower than that in Vehicle group. The expression of miR-27a was increased after inhibition of the AMPK pathway. A predictive TargetScan algorithm showed that the PPARγ gene was a potential target of miR-27a. MiR-27a was also shown to target 3'-UTR of PPARγ.

Conclusions

MiR-27a plays an important regulatory role in diabetic pulmonary fibrosis. GLP-1 could down-regulate the expression level of miR-27a by activating AMPK. Furthermore, the target gene PPARγ was up-regulated, consequently improving extracellular matrix proliferation in MRC-5 cells.

Peroxisome proliferator-activated receptors in the pathogenesis and therapies of liver fibrosis

Liver fibrosis is a dynamic wound-healing process associated with the deposition of extracellular matrix produced by myofibroblasts. HSCs activation, inflammation, oxidative stress, steatosis and aging play critical roles in the progression of liver fibrosis, which is correlated with the regulation of the peroxisome proliferator-activated receptor (PPAR) pathway. As nuclear receptors, PPARs reduce inflammatory response, regulate lipid metabolism, and inhibit fibrogenesis in the liver associated with aging. Thus, PPAR ligands have been investigated as possible therapeutic agents. Mounting evidence indicated that some PPAR agonists could reverse steatohepatitis and liver fibrosis. Consequently, targeting PPARs might be a promising and novel therapeutic option against liver fibrosis. This review summarizes recent studies on the role of PPARs on the pathogenesis and treatment of liver fibrosis.

Capsaicin attenuates liver fibrosis by targeting Notch signaling to inhibit TNF-α secretion from M1 macrophages

BACKGROUND

Capsaicin is a chili pepper extract with multiple therapeutic properties including anti-liver fibrosis. However, the paucity of its underlying mechanisms limited its widely clinical application.

METHODS

In the present study, carbon tetrachloride (CCl₄) was used to induce liver fibrosis in mice, and transforming growth factorβ1 (TGFβ1) was used to mimic liver fibrosis in vitro. Flow cytometry was conducted to determine the expression of CD80. The inflammatory factors level was examined by ELISA, and gene expression was detected by real-time PCR and western blot.

RESULTS

Here, we show that capsaicin attenuates liver fibrosis progression by mediating macrophage inflammatory response. Capsaicin inhibited M1 polarization of macrophage by regulating Notch signaling leading to the reduced secretion of inflammatory cytokine TNF-α that correspondingly attenuates myofibroblasts regeneration and fibrosis formation of hepatocyte stellate cells (HSCs).

CONCLUSION

Taken together, capsaicin alleviates liver fibrosis by inactivation of Notch signaling and further inhibiting TNF-α secretion from M1 macrophage. Targeting TNF-α or Notch signaling in macrophage represents a promising strategy to combat liver fibrosis.

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.

Curcumin blunts epithelial-mesenchymal transition of hepatocytes to alleviate hepatic fibrosis through regulating oxidative stress and autophagy

The massive production and activation of myofibroblasts (MFB) is key to the development of liver fibrosis. In many studies, it has been proven that hepatocytes are an important part of MFB, and can be transformed into MFB through epithelial-mesenchymal transition (EMT) during hepatic fibrogenesis. In our previous study, we confirmed that curcumin inhibited EMT procession and differentiation of hepatocytes into MFB. In addition, in previous studies, it has been shown that autophagy plays an important role in the regulation of cellular EMT procession. In the current study, we showed that curcumin inhibited TGF-β/Smad signaling transmission by activating autophagy, thereby inhibiting EMT. The mechanism of degradative polyubiquitylation of Smad2 and Smad3 is likely through inhibiting tetratricopeptide repeat domain 3 (TTC3) and by inducing ubiquitylation and proteasomal degradation of Smad ubiquitination regulatory factor 2 (SMURF2), which on account of the increase of autophagy in hepatocytes. Curcumin inhibits levels of reactive oxygen species (ROS) and oxidative stress in hepatocytes by activating PPAR-α, and regulates upstream signaling pathways of autophagy AMPK and PI3K/AKT/mTOR, leading to an increase of the autophagic flow in hepatocytes. In this study, we confirm that curcumin effectively reduced the occurrence of EMT in hepatocytes and inhibited production of the extracellular matrix (ECM) by activating autophagy, which provides a potential novel therapeutic strategy for hepatic fibrosis.

Treatment with a PPAR-γ Agonist Protects Against Hyperuricemic Nephropathy in a Rat Model

Purpose

Hyperuricemia is an independent risk factor for renal damage and can promote the progression of chronic kidney disease (CKD). In the present study, we employ a rat model to investigate the effects of rosiglitazone (RGTZ), a peroxisome proliferator-activated receptor-gamma agonist, on the development of hyperuricemic nephropathy (HN), and we elucidate the mechanisms involved.

Methods

An HN rat model was established by oral administration of a mixture of adenine and potassium oxonate daily for 3 weeks. Twenty-four rats were divided into 4 groups: sham treatment, sham treatment plus RGTZ, HN, and HN treated with RGTZ.

Results

Administration of RGTZ effectively preserved renal function, decreased urine microalbumin, and inhibited interstitial fibrosis and macrophage infiltration in a rat HN model. RGTZ treatment also inhibited TGF-β and NF-κB pathway activation, decreased expression of fibronectin, collagen I, α-SMA, vimentin, MCP-1, RANTES, TNF-α, and IL-1β, and increased E-cadherin expression in the kidneys of HN rats. Furthermore, RGTZ treatment preserved expression of OAT1 and OAT3 in the kidney of HN rats.

Conclusion

RGTZ attenuates the progression of HN through inhibiting TGF-β signaling, suppressing epithelial-to-mesenchymal transition, reducing inflammation, and lowering serum uric acid levels by preserving expression of urate transporters.

Synthesis and anti-hepaticfibrosis of glycyrrhetinic acid derivatives with inhibiting COX-2

Many tests have shown cyclooxygenase-2 (COX-2) was closely related to the activation of hepatic stellate cells (HSCs), which further promoting the onset and development of hepatic fibrosis. According to these research findings, a series of glycyrrhetinic acid derivatives were designed and synthesized. Meanwhile, their anti-hepaticfibrotic activities were evaluated in vitro and in vivo. Firstly, in the tests of the cell models, all the compounds displayed anti-proliferative effect on the HSC-T6 activated by (transforming growth factor beta) TGF-β₁ (10 ng/mL). Among them, compounds 2 and 16 exhibited a stronger activity than the others, and their IC₅₀ values were 17.6 µM and 30.3 µM, respectively; both of them were low toxicity to normal HSC-T6 cells and WI38 cells, and they inhibited the activated HSC-T6 cells proliferation by promoting apoptosis and resting them at the G₀/G₁ phase. Secondly, compounds 2 and 16 displayed strong inhibitory effect on activation of HSCs; they not only inhibited the expression of α-SMA and Col1 in the activated HSC-T6 cells, but also decreased the levels of COX-2, TGF-β₁ and (reactive oxygen species) ROS in a concentration-dependent manner; they down-regulated the levels of three biomarkers in the process of test, but this decrease did not change linearly with the action time of compound. Thirdly, for the rats which induced with (carbontetrachloride) CCl₄, the symptoms of liver fibrosis in rats were significantly alleviated after successive administration the tested compound for 14d; the α-SMA level in liver tissue decreased in a concentration dependent manner; and the liver cell necrosis and the fat collagen fiber decreased significantly compared with the positive control group; furthermore, inflammatory infiltration was significantly lower than that of the control. This suggests the compounds possibly are candidates for hepatic fibrosis with promising application in clinic.

Peroxisome proliferator-activated receptor γ inhibits hepatic stellate cell activation regulated by miR-942 in chronic hepatitis B liver fibrosis

AIMS

Liver fibrosis is a chronic liver disease characterized by hepatic stellate cell (HSC) activation. Peroxisome proliferator-activated receptor gamma (PPARγ) play an important role in HSC activation. This study aimed to investigate the role of PPARγ in the progression of human hepatic fibrosis and the mechanism by which microRNA-942 regulates HSC activation.

METHODS

70 chronic hepatitis B (CHB) patients liver tissues were used to assess PPARγ, α-SMA and miR-942 levels by immunoblot and real-time PCR. Human primary HSCs or LX2 cells were used to perform multiple molecular experiments based on the transfection of small interfering RNA (siRNA) or co-transfection of microRNA inhibitor. Site-directed mutagenesis and luciferase reporter assays were used to identify miR-942 targets. miR-942 expression and localization in hepatic fibrosis and co-localization between α-SMA were determined by fluorescence in situ hybridization (FISH).

KEY FINDINGS

The mRNA expression of PPARγ was decreased in activated HSCs and CHB patients with liver fibrosis, which was negatively correlated with F stage and α-SMA. miR-942 negatively regulates PPARγ expression via targeting the PPARγ 3'UTR. Inhibiting PPARγ promoted TGFβ1 induced HSC activation, and this effect was blocked after inhibiting the miR-942. Moreover, miR-942 was mainly expressed in fibrous septa and negatively correlated with PPARγ in liver fibrosis.

SIGNIFICANCE

PPARγ targeting by miR-942 and decreasing HSC activation in human hepatic fibrosis. Hence, regulating PPARγ may be a promising therapeutic strategy for hepatic fibrosis.

L-carnitine supplementation attenuates NAFLD progression and cardiac dysfunction in a mouse model fed with methionine and choline-deficient diet

Non-alcoholic fatty liver disease (NAFLD) is a common cause of chronic liver disorder. NAFLD, associated lipotoxicity, fibrosis, oxidative stress, and altered mitochondrial metabolism, is responsible for systemic inflammation, which contributes to organ dysfunction in extrahepatic tissues, including the heart. We investigated the ability of L-carnitine (LC) to oppose the pathogenic mechanisms underlying NAFLD progression and associated heart dysfunction, in a mouse model of methionine-choline-deficient diet (MCDD). Mice were divided into three groups: namely, the control group (CONTR) fed with a regular diet and two groups fed with MCDD for 6 weeks. In the last 3 weeks, one of the MCDD groups received LC (200 mg/kg each day) through drinking water (MCDD + LC). The hepatic lipid accumulation and oxidative stress decreased after LC supplementation, which also reduced hepatic fibrosis via modulation of α-smooth muscle actin (αSMA), peroxisome-activated receptor gamma (PPARγ), and nuclear factor kappa B (NfƙB) expression. LC ameliorated systemic inflammation, mitigated cardiac reactive oxygen species (ROS) production, and prevented fibrosis progression by acting on signal transducer and activator of transcription 3 (STAT3), extracellular signal-regulated kinase 1-2 (ERK1-2), and αSMA. This study confirms the existence of a relationship between fatty liver disease and cardiac abnormalities and highlights the role of LC in controlling liver oxidative stress, steatosis, fibrosis, and NAFLD-associated cardiac dysfunction.

Therapeutic potential of PPARγ natural agonists in liver diseases

Peroxisome proliferator‐activated receptor gamma (PPARγ) is a vital subtype of the PPAR family. The biological functions are complex and diverse. PPARγ plays a significant role in protecting the liver from inflammation, oxidation, fibrosis, fatty liver and tumours. Natural products are a promising pool for drug discovery, and enormous research effort has been invested in exploring the PPARγ‐activating potential of natural products. In this manuscript, we will review the research progress of PPARγ agonists from natural products in recent years and probe into the application potential and prospects of PPARγ natural agonists in the therapy of various liver diseases, including inflammation, hepatic fibrosis, non‐alcoholic fatty liver and liver cancer.

Platyconic Acid A, Platycodi Radix-Derived Saponin, Suppresses TGF-1-induced Activation of Hepatic Stellate Cells via Blocking SMAD and Activating the PPAR Signaling Pathway

Platycodi radix is a widely sold health food worldwide, which contains numerous phytochemicals that are beneficial to health. Previously, we reported that saponin from the roots of Platycodi radix-derived saponin inhibited toxicant-induced liver diseases. Nevertheless, the inhibitory effect of platyconic acid A (PA), the active component of Platycodi radix-derived saponin, on the anti-fibrotic activity involving the SMAD pathway remains unclear. We investigated the inhibitory effects of PA on TGF-β1-induced activation of hepatic stellate cells (HSCs). PA inhibited TGF-β1-enhanced cell proliferation, as well as expression of α-SMA and collagen Iα1 in HSC-T6 cells. PA suppressed TGF-β1-induced smad2/3 phosphorylation and smad binding elements 4 (SBE4) luciferase activity. Reversely, PA restored TGF-β1-reduced expression of smad7 and peroxisome proliferator-activated receptor (PPAR)γ. PA also repressed TGF-β1-induced phosphorylation of Akt and MAPKs. In summary, the results suggest that the inhibitory effect of PA on HSCs occurs through the blocking of SMAD-dependent and SMAD-independent pathways, leading to the suppression of α-SMA and collagen Iα1 expression.

Curcumin and capsaicin modulates LPS induced expression of COX-2, IL-6 and TGF-β in human peripheral blood mononuclear cells

The mechanism of action of treatment of either curcumin or capsaicin or in combination on LPS (Lipopolysaccharide) induced inflammatory gene expression in peripheral blood mononuclear cells (PBMCs) was investigated using RT-PCR and in silico docking methods. RT-PCR analysis has shown that the curcumin and capsaicin significantly reduced LPS induced over expression of COX-2, IL-6 and TGF-β in PBMCs. Whereas combined molecules demonstrated synergistic response on the reduction of COX-2, IL-6 and TGF-β over expression in LPS induced PBMCs as compared to individual molecules. Further, The docking of curcumin and capsaicin at the active pockets of COX-2, IL-6 and TGF-β has shown - 3.90, - 4.49 and - 5.61 kcal/mol binding energy for curcumin and - 3.80, - 4.78 and - 5.76 kcal/mol binding energy for capsaicin, while multiple ligand simultaneous docking (MLSD) of both molecules has shown higher binding energy of - 4.24, - 5.35 and - 5.83 kcal/mol respectively. This has demonstrated the efficacy of combined curcumin and capsaicin against the LPS induced expression of pro-inflammatory cytokines in PBMCs. These results attributed the coordinated positive modulation on biochemical and molecular cellular process by combined curcumin and capsaicin as compared to individual molecules.

Isorhamnetin Inhibits Liver Fibrosis by Reducing Autophagy and Inhibiting Extracellular Matrix Formation via the TGF-β1/Smad3 and TGF-β1/p38 MAPK Pathways

Objective

Liver fibrosis is a consequence of wound-healing responses to chronic liver insult and may progress to liver cirrhosis if not controlled. This study investigated the protection against liver fibrosis by isorhamnetin.

Methods

Mouse models of hepatic fibrosis were established by intraperitoneal injection of carbon tetrachloride (CCl₄) or bile duct ligation (BDL). Isorhamnetin 10 or 30 mg/kg was administered by gavage 5 days per week for 8 weeks in the CCl₄ model and for 2 weeks in the BDL model. Protein and mRNA expressions were assayed by western blotting, immunohistochemistry, and quantitative real-time polymerase chain reaction.

Results

Isorhamnetin significantly inhibited liver fibrosis in both models, inhibiting hepatic stellate cell (HSC) activation, extracellular matrix (ECM) deposition, and autophagy. The effects were associated with downregulation of transforming growth factor β1 (TGF-β1) mediation of Smad3 and p38 mitogen-activated protein kinase (MAPK) signaling pathways.

Conclusion

Isorhamnetin protected against liver fibrosis by reducing ECM formation and autophagy via inhibition of TGF-β1-mediated Smad3 and p38 MAPK signaling pathways.

Research progress on the anti-hepatic fibrosis action and mechanism of natural products

Hepatic fibrosis is the most common pathological feature of most chronic liver diseases, and its continuous deterioration gradually develops into liver cirrhosis and eventually leads to liver cancer. At present, there are many kinds of drugs used to treat liver fibrosis. However, Western drugs tend to only target single genes/proteins and induce many adverse reactions. Most of the mechanisms and active ingredients of traditional Chinese medicine (TCM) are not clear, and there is a lack of unified diagnosis and treatment standards. Natural products, which are characterized by structural diversity, low toxicity, and origination from a wide range of sources, have unique advantages and great potential in anti-liver fibrosis. This article summarizes the work done over the previous decade, on the active ingredients in natural products that are reported to have anti-hepatic fibrosis effects. The effective anti-hepatic fibrosis ingredients identified can be generally divided into flavonoids, saponins, polysaccharides and alkaloids. Mechanisms of anti-liver fibrosis include inhibition of liver inflammation, anti-lipid peroxidation injury, inhibition of the activation and proliferation of hepatic stellate cells (HSCs), modulation of the synthesis and secretion of pro-fibrosis factors, and regulation of the synthesis and degradation of the extracellular matrix (ECM). This review provides suggestions for the development of anti-hepatic fibrosis drugs.

Thermal processing food-related toxicants: a review

Heterocyclic aromatic amines, acrylamide, 5-hydroxymethylfurfural, furan, polycyclic aromatic hydrocarbons, nitrosamines, acrolein, chloropropanols and chloroesters are generated toxicants formed in some foodstuffs, mainly starchy and protein-rich food during thermal treatment such as frying, roasting and baking. The formation of these chemical compounds is associated with development of aromas, colors and flavors. One of the challenges facing the food industry today is to minimize these toxicants without adversely affecting the positive attributes of thermal processing. To achieve this objective, it is essential to have a detailed understanding of the mechanism of formation of these toxicants in processed foods. All reviewed toxicants in that paper are classified as probable, possible or potential human carcinogens and have been proven to be carcinogenic in animal studies. The purpose of that review is to summarize some of the most frequent occurring heat-generated food toxicants during conventional heating, their metabolism and carcinogenicity. Moreover, conventional and microwave heating were also compared as two different heat treatment methods, especially how they change food chemical composition and which thermal food toxicants are formed during specific method.

Renoprotective effect of Zhenwu decoction against renal fibrosis by regulation of oxidative damage and energy metabolism disorder

Zhenwu decoction (ZWD) is a promising traditional Chinese prescription against renal fibrosis, while its underlying mechanism remains unclear. Rat model of renal fibrosis were established and divided into control group, model group, ZWD treatment group and enalapril maleate treatment group. Metabolic profiles on serum samples from each group were acquired by using ultra performance liquid chromatography coupled with quadrupole time-of-flight high-resolution mass spectrometry. Metabolomics combined with molecular biology were comparatively conducted on samples of various groups. Fifteen potential biomarkers were identified and these biomarkers are mainly phospholipids and fatty acids. The results showed renal fibrosis was associated with oxidative damage and energy metabolism disorder. The results of histopathology, biochemistry and metabolomics demonstrated that ZWD exhibited an efficient renoprotective effect by alleviating oxidative stress, increasing energy metabolism and regulating fibrotic cytokines. This study provided scientific support for the research and development of new drugs from traditional Chinese medicine.

Hepatoprotective Principles and Other Chemical Constituents from the Mycelium of Phellinus linteus

In the dimethylnitrosamine (DMN)-induced hepatic fibrosis Wistar rat model, the mycelium extract of Phellinus linteus (PLE) (20 mg/Kg) displayed significant protection against hepatic fibrosis. The present investigation characterized eleven new ionone derivatives, phellinulins D–N (4–14), from the P. linteus mycelium extract and the relative stereochemical structures were constructed according to the spectroscopic and spectrometric analytical results. Some purified compounds were examined for their inhibitory effects on activated rat hepatic stellate cells (HSCs) and several isolates did exhibit significant protection. The results indicated that the mycelium of P. linteus could be explored as a hepatoprotective drug or healthy food candidate in the near future.

MicroRNA‑326 inhibits endometrial fibrosis by regulating TGF‑β1/Smad3 pathway in intrauterine adhesions

Intrauterine adhesion (IUA), characterized by endometrial fibrosis, may lead to infertility and recurrent pregnancy loss. At present, there is no ideal therapy for IUA. Recent findings have revealed that microRNAs (miRNAs) have a decisive role in the regulation of fibrosis. The aim of the present study was to investigate the molecular mechanism of miRNAs in endometrial fibrosis. The present study compared the expression profiles of miRNAs between endometrial tissues from patients with IUA and normal endometrial tissues using microarray analysis. Validation of miR‑326 level in endometrial tissues was performed using reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR). Subsequently, the effects of miR‑326 on fibrotic markers including α‑smooth muscle actin (α‑SMA), collagen type I α 1 chain (COL1A1), transforming growth factor‑β1 (TGF‑β1) and fibronectin (FN), were evaluated in endometrial tissues and endometrial stromal cells (ESCs) from patients with IUA. Additional bioinformatics analysis, luciferase reporter assays, RT‑qPCR and western blotting were performed to identify target genes. Additionally, the expression levels of TGF‑β1, p‑Smad3 and Smad3 were quantified to determine whether the anti‑fibrotic role of miR‑326 was associated with the activity of the TGF‑β1/Smad3 signaling pathway. The present study determined that miR‑326 was downregulated in endometrial tissues from patients with IUA and miR‑326 levels were inversely correlated with the expression of TGF‑β1, α‑SMA, COL1A1 and FN. Additional findings revealed that overexpression of miR‑326 inhibited endometrial fibrosis by downregulating these pro‑fibrotic genes. TGF‑β1, an important pro‑fibrogenic mediator, was identified as a direct target of miR‑326. Additionally, overexpression of miR‑326 blocked the activation of the TGF‑β1/SMAD family member 3 (Smad3) signaling pathway by suppressing the expression of TGF‑β1 in ESCs from patients with IUA. The findings of the present study indicated that miR‑326 inhibited endometrial fibrosis by suppressing the TGF‑β1/Smad3 signaling pathway, suggesting that miR‑326 may be a prognostic biomarker and therapeutic target for IUA.

Capsaicinoids improve consequences of physical activity

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Capsaicinoids (CAPs) are active compounds in Capsicum fruits.

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CAPs have anti-inflammatory and antioxidant properties.

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CAPs with regular exercise may enhance lipid metabolism.

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CAPs down-regulate muscle SREBP-1c, LXRs, ACLY, FAS in exercised rats.

The purpose of this study was to investigate the effects of capsaicinoids (CAPs) on lipid metabolism, inflammation, antioxidant status and the changes in gene products involved in these metabolic functions in exercised rats. A total of 28 male Wistar albino rats were randomly divided into four groups (n = 7) (i) No exercise and no CAPs, (ii) No exercise + CAPs (iii) Regular exercise, (iv) Regular exercise + CAPs. Rats were administered as 0.2 mg capsaicinoids from 10 mg/kg BW/day Capsimax^® daily for 8 weeks. A significant decrease in lactate and malondialdehyde (MDA) levels and increase in activities of antioxidant enzymes were observed in the combination of regular exercise and CAPs group (P < 0.0001). Regular exercise + CAPs treated rats had greater nuclear factor-E2-related factor-2 (Nrf2) and heme oxygenase-1 (HO-1) levels in muscle than regular exercise and no exercise rats (P < 0.001). Nevertheless, regular exercise + CAPs treated had lower nuclear factor kappa B (NF-κB) and IL-10 levels in muscle than regular exercise and control rats (P < 0.001). Muscle sterol regulatory element-binding protein 1c (SREBP-1c), liver X receptors (LXR), ATP citrate lyase (ACLY) and fatty acid synthase (FAS) levels in the regular exercise + CAPs group were lower than all groups (P < 0.05). However, muscle PPAR-γ level was higher in the regular exercise and CAPs alone than the no exercise rats. These results suggest CAPs with regular exercise may enhance lipid metabolism by regulation of gene products involved in lipid and antioxidant metabolism including SREBP-1c, PPAR-γ, and Nrf2 pathways in rats.

Research progress of capsaicin responses to various pharmacological challenges

Capsaicin, a well known vanilloid, has shown evidence of an ample variety of biological effects which make it the target of extensive research ever since its identification. In spite of the fact that capsaicin causes health hazards in quite a few ways, yet, the verity cannot be ignored that capsaicin has several therapeutic implications. In patients with hypersensitive bladders, vesical instillation of 1 mM capsaicin markedly improved urinary frequency and urge incontinence. Again, administration of capsaicin favors an augmentation in lipid mobilization and a decrease in adipose tissue mass. Topical capsaicin cream as well decreases postsurgical neuropathic pain and is preferred by patients over a placebo among other therapies. Several in vitro studies have revealed that capsaicin results in growth arrest in some transformed cell lines. Furthermore, capsaicin has been proven to be an undeniably exciting molecule and remains a valuable drug for alleviating pain and itch. It has been recognized that capsaicinoids are the most potential agonists of capsaicin receptor (TRPV1). However, vanilloids could exert the beneficial effects not only through the receptor-dependent pathway but also through the receptor-independent one. The involvement of serotonin, neuropeptide Substance P and somatostatin in the pharmacological actions of capsaicin has been expansively investigated. Better understanding of the established TRPV1 receptor mechanism as well as exploring other possible receptor mechanism may publicize other new clinical efficacies of capsaicin. Further, clinical studies are required in several of these conditions to establish the efficacy of capsaicin.