Capsaicin suppresses liver fat accumulation in high-fat diet-induced NAFLD mice

Mitigating Metabolic Dysfunction-associated Steatotic Liver Disease (MASLD): The Role of Bioactive Phytoconstituents in Indian Culinary Spices

PURPOSE OF REVIEW

The term metabolic dysfunction-associated steatotic liver disease (MASLD) refers to a group of progressive steatotic liver conditions that include metabolic dysfunction-associated steatohepatitis (MASH), which has varying degrees of liver fibrosis and may advance to cirrhosis, and independent hepatic steatosis. MASLD has a complex underlying mechanism, with patients exhibiting diverse causes and phases of the disease. India has a pool prevalence of MASLD of 38.6% in adults. In 2023, the term NAFLD has been redefined and changed to MASLD. Currently, there are no drugs approved by the FDA for the treatment of MASLD. This study investigates the potential of bioactive phytoconstituents present in spices as a therapeutic approach for MASLD. Moreover, it offers comprehensive data on several pre-clinical studies of bioactive phytoconstituents derived from spices that primarily focus on treating obesity-associated MASLD.

RECENT FINDINGS

Spices include a high amount of bioactive chemicals and several research have indicated their diverse pharmacological activities. Bioactive phytoconstituents from common Indian spices like cinnamic acid, eugenol, curcumin, allicin, 6-gingerols, capsaicin, piperine, eucalyptol, trigonelline, and linalool have been reported to exhibit anti-MASLD effects both in-vivo and in-vitro. Bioactive phytoconstituents from different culinary species of India have shown promising potential against MASLD in pre-clinical status. Further clinical studies on a large scale would be beneficial for paving the path to the development of a new drug which is the need of time.

Drug Advances in NAFLD: Individual and Combination Treatment Strategies of Natural Products and Small-Synthetic-Molecule Drugs

Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease and is closely associated with metabolic diseases such as obesity, type 2 diabetes mellitus (T2DM), and metabolic syndrome. However, effective treatment strategies for NAFLD are still lacking. In recent years, progress has been made in understanding the pathogenesis of NAFLD, identifying multiple therapeutic targets and providing new directions for drug development. This review summarizes the recent advances in the treatment of NAFLD, focusing on the mechanisms of action of natural products, small-synthetic-molecule drugs, and combination therapy strategies. This review aims to provide new insights and strategies in treating NAFLD.

Oxymatrine relieves non-alcoholic fatty liver disease by promoting sirtuin 1/adenosine 5'-monophosphate-activated protein kinase pathway and peroxisome proliferator activated receptor alpha-mediated hepatic fatty acid oxidation

Non-alcoholic fatty liver disease (NAFLD) is a liver disease without approved treatment. Oxymatrine (OMT) has protective effects in various liver diseases. We aimed to investigate the roles and mechanisms of OMT in NAFLD. NAFLD models were established using high-fat and high-sucrose diet-fed rats and oleic acid (OA)-stimulated hepatocytes, respectively. Then, OMT was used to treat the NAFLD models, with metformin as a positive control. Liver damage, lipid accumulation and hepatic lipid profile of NAFLD rats were assessed. Peroxisome proliferator activated receptor alpha (PPARα), sirtuin 1 (Sirt1)/adenosine 5'-monophosphate-activated protein kinase (AMPK) pathway- and fatty acid oxidation (acyl-CoA oxidase 1 and carnitine palmitoyltransferase 1A)-associated proteins were measured both in vivo and in vitro. Furthermore, hepatocytes were transfected with si-Sirt1 and oe-PPARα to verify the mechanisms of OMT in NAFLD. NAFLD rats supplemented with OMT displayed reduced liver damage and lipid accumulation. After OMT intervention, the liver lipid profile of NAFLD rats was changed greatly, most of the top differentially expressed lipid metabolites were triglyceride, moreover, diacylglycerol content was decreased in NAFLD rats. OMT activated the Sirt1/AMPK pathway and PPARα, and upregulated acyl-CoA oxidase 1 and carnitine palmitoyltransferase 1A expressions in NAFLD models. In vitro, OMT enhanced viability, and improved lipid accumulation in OA-stimulated hepatocytes. However, the protective functions of OMT in OA-exposed hepatocytes were offset by Sirt1 knockdown, while PPARα overexpression further counteracted the effects of Sirt1 knockdown. OMT could relieve NAFLD by promoting Sirt1/AMPK pathway- and PPARα-mediated hepatic fatty acid oxidation, indicating that OMT is a potential approach for NAFLD treatment.

CD36 in liver diseases

Cluster of differentiation 36 (CD36) is a transmembrane glycoprotein with the ability to bind to multiple ligands and perform diverse functions. Through the recognition of long-chain fatty acids, proteins containing thrombospondin structural homology repeat domains such as thrombospondin-1, and molecules with molecular structures consistent with danger- or pathogen-associated molecular patterns, CD36 participates in various physiological and pathological processes of the body. CD36 is widely expressed in various cell types, including hepatocytes and KCs in the liver, where it plays a pivotal role in lipid metabolism, inflammation, and oxidative stress. Accumulating evidence suggests that CD36 plays a complex role in the development of nonalcoholic simple fatty liver disease and NASH and contributes to the pathogenesis of inflammatory liver injury, hepatitis B/hepatitis C, liver fibrosis, and liver cancer. This review summarizes the current understanding of the structural properties, expression patterns, and functional mechanisms of CD36 in the context of liver pathophysiology. Furthermore, the potential of CD36 as a therapeutic target for the prevention and treatment of liver diseases is highlighted.

Capsaicin and Quercitrin Maintained Lipid Homeostasis of Hyperlipidemic Mice: Serum Metabolomics and Signaling Pathways

Capsaicin and quercitrin have proved to be two major ingredients in fresh chili pepper. However, the effect of these two compounds on hyperlipidemia and the related molecular mechanisms were still unclear. This work was performed to examine the hypolipidemic capacity of capsaicin and quercitrin as well as the related signaling pathways. Hyperlipidemia was induced in mice by feeding them with a high-fat diet for 4 weeks. Both capsaicin and quercitrin were beneficial to inhibit a rise in fasting glucose, total cholesterol, total triglycerides, low-density lipoprotein cholesterol, and total bile acids and to lift the level of high-density lipoprotein cholesterol in the serum. The optimal lipid-lowering data were achieved in the capsaicin and quercitrin/3:1 group. Supplementation with capsaicin and quercitrin both singly and together in the feed caused a significant influence on the metabolite profiles of mouse serum. The signaling pathway for the hypolipidemic effect of capsaicin and quercitrin was related to the down-regulation of epidermal growth factor receptor (EGFR) but the up-regulation of phosphatidylin-ositol-3-kinase (PI3K), protein kinase Bb(Akt), farnesoid X receptor 1 (FXR1), and cholesterol 7α-hydroxylase (CYP7A1). This study confirmed the jointly hypolipidemic effect of capsaicin and quercitrin, which would benefit the valorization of chili pepper resources.

The use of capsicum oleoresin microparticles to mitigate hepatic damage and metabolic disorders induced by obesity

Capsicum oleoresin has potential health benefits, particularly against obesity markers. Due to its high pungency, few studies have been done to explore the intake of this ingredient. The objective of this study was to use the Capsicum oleoresin (CO) microencapsulated into a high-fat diet to evaluate its metabolic effect on mice. Two formulation containing 15 % solids were prepared: the first (F1) with 5% CO and 95% emulsifier, and the second (F2) with 2.5% corn oil, 2.5% CO, and 95% emulsifier. These formulation were atomized in a spray dryer. Ultra-Performance Liquid Chromatography determined the capsaicin content for both formulations. Mice were divided into two groups: lean control (normocaloric AIN diet, n = 10) and high fat (HF diet: hypercaloric, n = 30), which were subdivided into three subgroups: HF control diet (n = 10); diet F1: HF + 20 % CO oleoresin microparticles (n = 10); and diet F2: HF + 20 % CO microparticles containing corn oil (n = 10). The animals treated with the microparticles showed lower glucose levels than the HF control. Mice fed with HF-containing CO microparticles had cholesterol blood levels similar to that of the lean group and lower (<100 mg/dL) than that of the HF control group (150 mg/dL). Capsicum oleoresin microparticles added to high-fat diets promoted lower weight gain and protected the liver against hepatic steatosis. Leptin levels for mice fed with HF diet plus CO microparticles averaged between 2 and 5 ng/ml, whereas the fat control group developed leptin resistance. Capsicum microparticles evidenced a protective effect against dyslipidemia compared to the fat control group, which suggests their use as a potential ingredient for the control of obesity.

Targeting lipid droplets and lipid droplet-associated proteins: a new perspective on natural compounds against metabolic diseases

BACKGROUND

Lipid droplet (LD) is a metabolically active organelle, which changes dynamically with the metabolic state and energy requirements of cells. Proteins that either insert into the LD phospholipid monolayer or are present in the cytoplasm, playing a crucial role in lipid homeostasis and signaling regulation, are known as LD-associated proteins.

METHODS

The keywords "lipid droplets" and "metabolic diseases" were used to obtain literature on LD metabolism and pathological mechanism. After searching databases including Scopus, OVID, Web of Science, and PubMed from 2013 to 2024 using terms like "lipid droplets", "lipid droplet-associated proteins", "fatty liver disease", "diabetes", "diabetic kidney disease", "obesity", "atherosclerosis", "hyperlipidemia", "natural drug monomers" and "natural compounds", the most common natural compounds were identified in about 954 articles. Eventually, a total of 91 studies of 10 natural compounds reporting in vitro or in vivo studies were refined and summarized.

RESULTS

The most frequently used natural compounds include Berberine, Mangostin, Capsaicin, Caffeine, Genistein, Epigallocatechin-3-gallate, Chlorogenic acid, Betaine, Ginsenoside, Resveratrol. These natural compounds interact with LD-associated proteins and help ameliorate abnormal LDs in various metabolic diseases.

CONCLUSION

Natural compounds involved in the regulation of LDs and LD-associated proteins hold promise for treating metabolic diseases. Further research into these interactions may lead to new therapeutic applications.

Capsaicin: a spicy way in liver disease

The incidence of liver disease continues to rise, encompassing a spectrum from simple steatosis or non-alcoholic fatty liver disease (NAFLD) to non-alcoholic steatohepatitis (NASH), cirrhosis and liver cancer. Dietary habits in individuals with liver disease may significantly impact the treatment and prevention of these conditions. This article examines the role of chili peppers, a common dietary component, in this context, focusing on capsaicin, the active ingredient in chili peppers. Capsaicin is an agonist of the transient receptor potential vanilloid subfamily 1 (TRPV1) and has been shown to exert protective effects on liver diseases, including liver injury, NAFLD, liver fibrosis and liver cancer. These protective effects are attributed to capsaicin's anti-oxidant, anti-inflammatory, anti-steatosis and anti-fibrosis effects. This article reviewed the different molecular mechanisms of the protective effect of capsaicin on liver diseases.

Innovative treatments for obesity and NAFLD: A bibliometric study on antioxidants, herbs, phytochemicals, and natural compounds

The increasing scientific interest in antioxidants and naturally derived compounds as potential remedies for obesity and non-alcoholic fatty liver disease (NAFLD) has led to extensive research. The objective of this bibliometric analysis is to present an updated perspective on the topic of antioxidants, herbs, phytochemicals, and natural compounds, in the control of obesity and NAFLD, to identify new areas for future research. Publications from the years 2012-2022 were retrieved using the Scopus database. The research trends were analyzed using the Biblioshiny and VOSviewer tools. The field has seen a significant increase in research activity, as indicated by an annual growth rate of 10 % in the number of published manuscripts. China, Korea, and the USA emerged as the most prominent contributors in this specific field, supported by their notable volumes of publications and citations. The density analysis revealed that the most frequently occurring authors' keywords related to herbal species are, in rank order, Camelia sinensis, Momordica charantia, Curcuma longa, Ilex paraguariensis, Panax ginseng, Moringa oleifera, Garcinia cambogia, Garcinia mangostana, Zingiber officinale, and Cinnamomum verum. In the group of antioxidants, phytochemicals, and natural compounds, the top 10 were resveratrol, curcumin, quercetin, vitamin E, alpha-lipoic acid, vitamin C, chlorogenic acid, lycopene, fucoxanthin, and berberine. The co-occurrence analysis unveiled significant themes and potential trends, including a notable interest in the impact of herbal species, antioxidants, phytochemicals, and natural compounds on obesity and NAFLD through the modulation of the gut microbiome. Another recurring theme that arises, is the ongoing investigation of molecular targets that demonstrate anti-adipogenesis properties. The analysis presented in this study provides valuable insights for researchers investigating the efficacy of antioxidants, herbs, phytochemicals, and natural compounds in addressing obesity and NAFLD. Through the use of bibliometric methods, the study offers a comprehensive overview. Furthermore, the findings of this analysis can serve as a foundation for future research in this specific domain.

Capsaicin: Emerging Pharmacological and Therapeutic Insights

Capsaicin, the most prominent pungent compound of chilli peppers, has been used in traditional medicine systems for centuries; it already has a number of established clinical and industrial applications. Capsaicin is known to act through the TRPV1 receptor, which exists in various tissues; capsaicin is hepatically metabolised, having a half-life correlated with the method of application. Research on various applications of capsaicin in different formulations is still ongoing. Thus, local capsaicin applications have a pronounced anti-inflammatory effect, while systemic applications have a multitude of different effects because their increased lipophilic character ensures their augmented bioavailability. Furthermore, various teams have documented capsaicin's anti-cancer effects, proven both in vivo and in vitro designs. A notable constraint in the therapeutic effects of capsaicin is its increased toxicity, especially in sensitive tissues. Regarding the traditional applications of capsaicin, apart from all the effects recorded as medicinal effects, the application of capsaicin in acupuncture points has been demonstrated to be effective and the combination of acupuncture and capsaicin warrants further research. Finally, capsaicin has demonstrated antimicrobial effects, which can supplement its anti-inflammatory and anti-carcinogenic actions.

Kimchi attenuates endoplasmic reticulum stress-induced hepatic steatosis in HepG2 cells and C57BL/6N mice

Kimchi is a traditional fermented food that contains abundant nutrients and functional ingredients with various health benefits. We previously reported that kimchi active components suppress hepatic steatosis caused by endoplasmic reticulum (ER) stress in vitro and in vivo. Therefore, we assessed the effect of kimchi on the inhibition of hepatic steatosis caused by ER stress in HepG2 cells and C57BL/6N mice to verify the hypothesis that kimchi may potentially inhibit nonalcoholic fatty liver disease. We investigated the effect of kimchi on cell viability and triglyceride concentrations in cells and on lipid profile, lipid accumulation, and expression of related genes in cells and mice with hepatic steatosis. A mechanistic study was also performed using the liver X receptor α agonist T0901317 and the AMP-activated protein kinase agonist AICAR. Kimchi was noncytotoxic and effectively reduced triglyceride concentrations and suppressed hepatic steatosis-related gene expression in cells and mice. Additionally, kimchi recovered weight loss, lowered the serum and liver tissue lipid profiles, suppressed lipid accumulation, and reduced the effects of T0901317 and AICAR on lipogenic gene expression in tunicamycin-treated mice. Our results highlight that kimchi could prevent hepatic steatosis caused by ER stress in cells and mice.

Regulation Mechanism and Potential Value of Active Substances in Spices in Alcohol-Liver-Intestine Axis Health

Excessive alcohol intake will aggravate the health risk between the liver and intestine and affect the multi-directional information exchange of metabolites between host cells and microbial communities. Because of the side effects of clinical drugs, people tend to explore the intervention value of natural drugs on diseases. As a flavor substance, spices have been proven to have medicinal value, but they are still rare in treating hepatointestinal diseases caused by alcohol. This paper summarized the metabolic transformation of alcohol in the liver and intestine and summarized the potential value of various perfume active substances in improving liver and intestine diseases caused by alcohol. It is also found that bioactive substances in spices can exert antioxidant activity in the liver and intestine environment and reduce the oxidative stress caused by diseases. These substances can interfere with fatty acid synthesis, promote sugar and lipid metabolism, and reduce liver injury caused by steatosis. They can effectively regulate the balance of intestinal flora, promote the production of SCFAs, and restore the intestinal microenvironment.

Hepatoprotection of capsaicin in alcoholic and non-alcoholic fatty liver diseases

Alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD) are common causes of chronic liver disease that share the range of steatosis, steatohepatitis, fibrosis, cirrhosis, and finally, hepatocellular carcinoma. They are identified by the dysregulation of disease-specific signalling pathways and unique microRNAs. Capsaicin is an active ingredient of chilli pepper that acts as an agonist of transient receptor potential vanilloid subfamily 1. It seems that the protective role of capsaicin against NAFLD and ALD is linked to its anti-steatotic, antioxidant, anti-inflammatory, and anti-fibrotic effects. Capsaicin-induced inhibiting metabolic syndrome and gut dysbiosis and increasing bile acids production are also involved in its anti-NAFLD role. This review summarises the different molecular mechanisms underlying the protective role of capsaicin against NAFLD and ALD. More experimental studies are needed to clarify the effects of capsaicin on the expression of genes involved in hepatic lipid metabolism and hepatocytes apoptosis in NAFLD and ALD.

Alpha-Mangosteen lessens high-fat/high-glucose diet and low-dose streptozotocin induced-hepatic manifestations in the insulin resistance rat model

CONTEXT

α-Mangosteen (α-MG) attenuates insulin resistance (IR). However, it is still unknown whether α-MG could alleviate hepatic manifestations in IR rats.

OBJECTIVE

To investigate the effect of α-MG on alleviating hepatic manifestations in IR rats through AMP-activated protein kinase (AMPK) and sterol-regulatory element-binding protein-1 (SREBP-1) pathway.

MATERIALS AND METHODS

IR was induced by exposing male Sprague-Dawley rats (180-200 g) to high-fat/high-glucose diet and low-dose injection of streptozotocin (HF/HG/STZ), then treated with α-MG at a dose of 100 or 200 mg/kg/day for 8 weeks. At the end of the study (11 weeks), serum and liver were harvested for biochemical analysis, and the activity of AMPK, SREBP-1c, acetyl-CoA carboxylase (ACC), tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, insulin receptor substrate (IRS)-1, Bax and liver histopathology were analyzed.

RESULTS

α-MG at both doses significantly lowered ALT, AST, triglyceride, and cholesterol total by 16.5, 15.7, 38, and 36%, respectively. These beneficial effects of α-MG are associated with the downregulation of the IR-induced inflammation in the liver. Furthermore, α-MG, at both doses, activated AMPK by 24-29 times and reduced SREBP-1c by 44-50% as well as ACC expression by 19-31% similar to metformin. All treatment groups showed liver histopathology improvement regarding fat deposition in the liver.

CONCLUSIONS

Based on the findings demonstrated, α-MG protected against HF/HG/STZ-induced hepatic manifestations of the IR rats, at least in part via the modulation of the AMPK/SREBP-1c/ACC pathway and it could be a potential drug candidate to prevent IR-induced hepatic manifestations.

Dietary Intake of Capsaicin and Its Association with Markers of Body Adiposity and Fatty Liver in a Mexican Adult Population of Tijuana

Background: Capsaicin (CAP) is the main chemical component responsible for the pungency (burning pain) of the chili plant (capsicum spp.), whose metabolic functions include energy balance and fatty acid oxidation. The aim of this study is to analyze the association of dietary capsaicin consumption with markers of adiposity and fatty liver in a Mexican adult population. Methods: This cross-sectional/analytical study recruited 221 subjects aged 18 to 65 years who were resident in the city of Tijuana, Baja California, Mexico. The daily CAP intake was analyzed through a validated chili/CAP consumption questionnaire. Anthropometric and biochemical measurements were performed following standardized protocols. Adjusted Pearson's correlations were applied to analyze the association of CAP with adiposity and fatty liver markers. Results: In this study, the daily average consumption of CAP was 152.44 mg. The dietary CAP consumption positively correlated with BMI (r = 0.179, p = 0.003), hip circumference (r = 0.176, p = 0.004) and body adiposity index (r = 0.181, p = 0.001. Likewise, the daily CAP intake positively correlated with hepatic steatosis index (r = 0.158, p = 0.004), fatty liver index (r = 0.141, p = 0.003) and lactate dehydrogenase (r = 0.194, p = 0.016) after statistical settings. Conclusions: The results of this study suggest positive associations between dietary CAP consumption and the markers of body adiposity and fatty liver in a Mexican adult population.

Effects of Foods of Mesoamerican Origin in Adipose Tissue and Liver-Related Metabolism

Adipose tissue and liver metabolism play a key role in maintaining body homeostasis; therefore, their impairment conduces a pathological state. Nowadays, occidental lifestyle is a common etiological issue among a variety of chronic diseases, while diet is a unique strategy to prevent obesity and liver metabolism impairment and is a powerful player in the treatment of metabolic-related diseases. Mesoamerican foods are rich in bioactive molecules that enhance and improve adipose tissue and liver performance and represent a prophylactic and therapeutic alternative for disorders related to the loss of homeostasis in the metabolism of these two important tissues.

Antimicrobial Properties of Capsaicin: Available Data and Future Research Perspectives

Capsaicin is a phytochemical derived from plants of the genus Capsicum and subject of intensive phytochemical research due to its numerous physiological and therapeutical effects, including its important antimicrobial properties. Depending on the concentration and the strain of the bacterium, capsaicin can exert either bacteriostatic or even bactericidal effects against a wide range of both Gram-positive and Gram-negative bacteria, while in certain cases it can reduce their pathogenicity by a variety of mechanisms such as mitigating the release of toxins or inhibiting biofilm formation. Likewise, capsaicin has been shown to be effective against fungal pathogens, particularly Candida spp., where it once again interferes with biofilm formation. The parasites Toxoplasma gondi and Trypanosoma cruzi have been found to be susceptible to the action of this compound too while there are also viruses whose invasiveness is significantly dampened by it. Among the most encouraging findings are the prospects for future development, especially using new formulations and drug delivery mechanisms. Finally, the influence of capsaicin in somatostatin and substance P secretion and action, offers an interesting array of possibilities given that these physiologically secreted compounds modulate inflammation and immune response to a significant extent.

Rhynchophylline relieves nonalcoholic fatty liver disease by activating lipase and increasing energy metabolism

Hepatic fat metabolism may be altered in the context of overnutrition and obesity, often resulting in the accumulation of triglycerides in hepatocytes and leading to nonalcoholic fatty liver disease (NAFLD). Natural plant alkaloids have demonstrated great potential for the prevention and treatment of NAFLD. However, the role of rhynchophylline (RHY) in lipid metabolism is not clear. We explored the role of RHY in lipid metabolism in cells treated with oleic and palmitic acids to mimic high-fat diet (HFD) conditions. RHY attenuated oleic and palmitic acid-induced increases in triglyceride accumulation in HepG2, AML12, and LMH cells. RHY also increased energy metabolism and reduced oxidative stress. We further investigated the effect of RHY on hepatic lipid metabolism in mice fed an HFD including 40 mg/kg RHY. RHY alleviated hepatic steatosis, reduced fat deposition, promoted energy metabolism, and improved glucose metabolism. We investigated the mechanism responsible for this activity by docking with key proteins of lipid metabolism disorders using Discovery Studio software, which showed that RHY interacted well with lipases. Finally, we found that adding RHY promoted lipase activity and lipolysis. In conclusion, RHY ameliorated HFD-induced NAFLD and its complications by increasing lipase activity.

Endoplasmic reticulum stress inhibition ameliorated WFS1 expression alterations and reduced pancreatic islets' insulin secretion induced by high-fat diet in rats

Endoplasmic reticulum (ER) stress is involved in the development of glucose homeostasis impairment. When ER stress occurs, the unfolded protein response (UPR) is activated to cope with it. One of the UPR components is WFS1 (Wolfram syndrome 1), which plays important roles in ER homeostasis and pancreatic islets glucose-stimulated insulin secretion (GSIS). Accordingly and considering that feeding high-fat food has a major contribution in metabolic disorders, this study aimed to investigate the possible involvement of pancreatic ER stress in glucose metabolism impairment induced by feeding high-fat diet (HFD) in male rats. After weaning, the rats were divided into six groups, and fed on normal diet and HFD for 20 weeks, then 4-phenyl butyric acid (4-PBA, an ER stress inhibitor) was administered. Subsequently, in all groups, after performing glucose tolerance test, the animals were dissected and their pancreases were removed to extract ER, islets isolation and assessment of GSIS. Moreover, the pancreatic ER stress [binding of immunoglobulin protein (BIP) and enhancer-binding protein homologous protein (CHOP)] and oxidative stress [malondialdehyde (MDA), glutathione (GSH) and catalase] biomarkers as well as WFS1 expression level were evaluated. HFD decreased pancreatic WFS1 protein and GSH levels, and enhanced pancreatic catalase activity, MDA content, BIP and CHOP protein and mRNA levels as well as Wfs1 mRNA amount. Accordingly, it increased BIP, CHOP and WFS1 protein levels in the extracted ER of pancreas. In addition, the HFD caused glucose intolerance, and decreased the islets' GSIS and insulin content. However, 4-PBA administration restored the alterations. It seems that, HFD consumption through inducing pancreatic ER stress, altered WFS1 expression levels, reduced the islets' GSIS and insulin content and finally impaired glucose homeostasis.

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.

Expression and functions of transient receptor potential channels in liver diseases

Liver diseases constitute a major healthcare burden globally, including acute hepatic injury resulted from acetaminophen overdose, ischemia-reperfusion or hepatotropic viral infection and chronic hepatitis, alcoholic liver disease (ALD), non-alcoholic fatty liver disease (NAFLD) and hepatocellular carcinoma (HCC). Attainable treatment strategies for most liver diseases remain inadequate, highlighting the importance of substantial pathogenesis. The transient receptor potential (TRP) channels represent a versatile signalling mechanism regulating fundamental physiological processes in the liver. It is not surprising that liver diseases become a newly explored field to enrich our knowledge of TRP channels. Here, we discuss recent findings revealing TRP functions across the fundamental pathological course from early hepatocellular injury caused by various insults, to inflammation, subsequent fibrosis and hepatoma. We also explore expression levels of TRPs in liver tissues of ALD, NAFLD and HCC patients from Gene Expression Omnibus (GEO) or The Cancer Genome Atlas (TCGA) database and survival analysis estimated by Kaplan-Meier Plotter. At last, we address the therapeutical potential and challenges by pharmacologically targeting TRPs to treat liver diseases. The aim is to provide a better understanding of the implications of TRP channels in liver diseases, contributing to the discovery of novel therapeutic targets and efficient drugs.

Red Pepper Seeds Inhibit Hepatic Lipid Accumulation by Inducing Autophagy via AMPK Activation

Although the red pepper and its seeds have been studied for metabolic diseases, the effects and potential mechanisms of red pepper seed extract (RPS) on hepatic lipid accumulation are not yet completely understood. This study aimed to evaluate the inhibitory effect of RPS on hepatic lipid accumulation via autophagy. C57BL/6 mice were fed a high-fat diet (HFD) or a HFD supplemented with RPS. RPS treatment inhibited hepatic lipid accumulation by suppressing lipogenesis, inducing hepatic autophagic flux, and activating AMPK in HFD-fed mice. To investigate the effect of RPS on an oleic acid (OA)-induced hepatic steatosis cell model, HepG2 cells were incubated in a high-glucose medium and OA, followed by RPS treatment. RPS treatment decreased OA-induced lipid accumulation and reduced the expression of lipogenesis-associated proteins. Autophagic flux dramatically increased in the RPS-treated group. RPS phosphorylated AMPK in a dose-dependent manner, thereby dephosphorylated mTOR. Autophagy inhibition with 3-methyladenine (3-MA) antagonized RPS-induced suppression of lipogenesis-related protein expressions. Moreover, the knockdown of endogenous AMPK also antagonized the RPS-induced regulation of lipid accumulation and autophagy. Our findings provide new insights into the beneficial effects of RPS on hepatic lipid accumulation through the AMPK-dependent autophagy-mediated downregulation of lipogenesis.

Capsaicin for Weight Control: “Exercise in a Pill” (or Just Another Fad)?

Medical management of obesity represents a large unmet clinical need. Animal experiments suggest a therapeutic potential for dietary capsaicin, the pungent ingredient in hot chili peppers, to lose weight. This is an attractive theory since capsaicin has been a culinary staple for thousands of years and is generally deemed safe when consumed in hedonically acceptable, restaurant-like doses. This review critically evaluates the available experimental and clinical evidence for and against capsaicin as a weight control agent and comes to the conclusion that capsaicin is not a magic “exercise in a pill”, although there is emerging evidence that it may help restore a healthy gut microbiota.

Capsaicin Attenuates Oleic Acid-Induced Lipid Accumulation via the Regulation of Circadian Clock Genes in HepG2 Cells

As the major component in red chili peppers, capsaicin is useful in the prevention of lipid metabolism disorders. In this study, the attenuation effect of capsaicin on oleic acid (OA)-induced lipid accumulation in HepG2 cells was evaluated with respect to circadian clock gene expressions. Lipid profiles, including triacylglycerols, total cholesterols, high-density lipoproteins, low-density lipoproteins, and aspartate aminotransferase content, were measured using enzymatic assay kits. The mitochondrial membrane potential, cellular redox status, and lipid droplet morphology were also determined using different assay kits and staining methods. The mRNA and protein expressions of core circadian clock genes and major lipometabolism-related factors were assessed using RT-qPCR and western blotting. Results showed that 50 μM capsaicin alleviated the circadian desynchrony and inhibited OA-induced ROS overproduction (from 166.44 ± 12.63% to 119.90 ± 5.43%) and mitochondrial dysfunction (from 0.60 ± 0.08 to 0.83 ± 0.09, represented by the red/green fluorescence ratio) in HepG2 cells. The amelioration effect of capsaicin on OA-induced lipid accumulation was weakened after Bmal1-knockdown, demonstrating that the rhythmic expression of the circadian clock gene is involved in the regulation process of capsaicin in lipid metabolism.

Clerodendrum trichotomum extract improves metabolic derangements in high fructose diet-fed rats

Clerodendrum trichotomum has been reported to possess beneficial properties for human health, but its effects on metabolic syndrome have not been reported. In this study, we investigated the effect of C. trichotomum leaf extract (CT) on the metabolic derangements induced by a high-fructose (HF) diet. Sprague–Dawley rats were fed with a 46% carbohydrate diet (HC group), 60% high-fructose diet (HF group), or HF diet supplemented with CT (500 mg/kg of body weight/day, CT group) via drinking water for 16 weeks. Results showed that CT alleviated HF diet-induced insulin resistance, dyslipidemia, and hepatic steatosis In liver tissues, CT affected the signaling pathways of AMP-activated protein kinase, peroxisome proliferator-activated receptor α (PPARα), and sterol regulatory element binding protein 1. CT enriched the genes that were mainly involved in cytokine-cytokine receptor interaction, PPAR, PI3K-Akt signaling pathways, and fatty acid metabolism pathway. These results suggest that CT is a promising therapeutic against metabolic disorders.

Prokinetic effects of diatrizoate meglumine (Gastrografin®) in a zebrafish for opioid-induced constipation model

Constipation is a common disease that reduces life quality. Drugs of various mechanisms are being developed to resolve this affliction. Intestinal motility can be easily monitored in zebrafish, and so we selected this organism to develop a constipation model to measure drug-induced prokinetic effects. In this study, intestinal motility was monitored in zebrafish by tracking intestinal transit using fluorescence, after which an opioid-induced constipation model was established using loperamide. We then evaluated the prokinetic effect of diatrizoate meglumine (Gastrografin®), which has been empirically used to treat post-operative ileus or adhesive small bowel obstructions. Diatrizoate meglumine was effective in promoting bowel movements in an opioid-induced zebrafish constipation model and its prokinetic effect was associated with an increased expression of interstitial cells of Cajal (ICC) markers. Therefore, the loperamide-induced zebrafish constipation model developed herein is a promising tool to evaluate novel constipation therapies.

Modulating effects of capsaicin on glucose homeostasis and the underlying mechanism

Abnormal glucose homeostasis is linked to a variety of metabolic syndromes, such as insulin resistance, obesity, type-2 diabetes mellitus, hypertension and cardiovascular diseases. Maintenance of normal glucose homeostasis is important for the body to keep normal biological functions. As the major bioactive ingredient in chili peppers responsible for the pungent flavor, capsaicin has been reported to effectively improve glucose homeostasis with low cytotoxicity. In this review, the modulating effects of capsaicin on glucose homeostasis in cell models, animal models and human trials are summarized through both TRPV1 dependent and TRPV1 independent pathways. The relevant molecular mechanisms underlying its regulatory effects are also evaluated. Understanding the effects and mechanisms of capsaicin on glucose metabolism could provide theoretical evidence for its application in the food and pharmaceutical industries.

Rutin inhibits DRP1-mediated mitochondrial fission and prevents ethanol-induced hepatotoxicity in HepG2 cells and zebrafish

Excessive alcohol consumption causes the cellular and tissue damage. The toxic metabolites of ethanol are harmful to multiple organ systems, such as the central nervous system, skeletal muscles, and liver, and cause alcohol-induced diseases like cancer, as well as induce hepatotoxicity, and alcoholic myopathy. Alcohol exposure leads to a surge in hepatic alcohol metabolism and oxygen consumption, a decrease in hepatic ATP, and the rapid accumulation of lipid within hepatocytes. Several pathologies are closely linked to defective mitochondrial dynamics triggered by abnormal mitochondrial function and cellular homeostasis, raising the possibility that novel drugs targeting mitochondrial dynamics may have therapeutic potential in restoring cellular homeostasis in ethanol-induced hepatotoxicity. Rutin is a phytochemical polyphenol known to protect cells from cytotoxic chemicals. We investigated the effects of rutin on mitochondrial dynamics induced by ethanol. We found that rutin enhances mitochondrial dynamics by suppressing mitochondrial fission and restoring the balance of the mitochondrial dynamics. Mitochondrial elongation following rutin treatment of ethanol exposed cells was accompanied by reduced DRP1 expression. These data suggest that rutin plays an important role in remodeling of mitochondrial dynamics to alleviate hepatic steatosis and enhance mitochondrial function and cell viability.