Identification of matrine as a promising novel drug for hepatic steatosis and glucose intolerance with HSP72 as an upstream target

Bioprotective Role of Phytocompounds Against the Pathogenesis of Non-alcoholic Fatty Liver Disease to Non-alcoholic Steatohepatitis: Unravelling Underlying Molecular Mechanisms

Non-alcoholic fatty liver disease (NAFLD), with a global prevalence of 25%, continues to escalate, creating noteworthy concerns towards the global health burden. NAFLD causes triglycerides and free fatty acids to build up in the liver. The excessive fat build-up causes inflammation and damages the healthy hepatocytes, leading to non-alcoholic steatohepatitis (NASH). Dietary habits, obesity, insulin resistance, type 2 diabetes, and dyslipidemia influence NAFLD progression. The disease burden is complicated due to the paucity of therapeutic interventions. Obeticholic acid is the only approved therapeutic agent for NAFLD. With more scientific enterprise being directed towards the understanding of the underlying mechanisms of NAFLD, novel targets like lipid synthase, farnesoid X receptor signalling, peroxisome proliferator-activated receptors associated with inflammatory signalling, and hepatocellular injury have played a crucial role in the progression of NAFLD to NASH. Phytocompounds have shown promising results in modulating hepatic lipid metabolism and de novo lipogenesis, suggesting their possible role in managing NAFLD. This review discusses the ameliorative role of different classes of phytochemicals with molecular mechanisms in different cell lines and established animal models. These compounds may lead to the development of novel therapeutic strategies for NAFLD progression to NASH. This review also deliberates on phytomolecules undergoing clinical trials for effective management of NAFLD.

Enantioselective Synthesis of the 1,3-Dienyl-5-Alkyl-6-Oxy Motif: Method Development and Total Synthesis

The 1,3-dienyl-5-alkyl-6-oxy motif is widely found in various types of bioactive natural products. However, present synthesis is mainly non-asymmetric which relied upon different olefination or transition metal-catalyzed cross-coupling reactions using enantioenriched precursors. Herein, based upon a newly developed enantioselective α-alkylation of conjugated polyenoic acids, a variety of 1,3-dienyl-5-alkyl-6-oxy motif (with E-configured internal olefin) was generated as the corresponding α-adducts in a highly enantioselective and diastereoselective manner. Utilizing 1,3-dienyl-5-alkyl-6-oxy motif as key intermediates, we further demonstrated their synthetic potential by expedient total syntheses of three types of natural products (glutarimide antibiotics, α-pyrone polyketides and Lupin alkaloids) within 4-7 steps.

Sophoridine Counteracts Obesity via Src-Mediated Inhibition of VEGFR Expression and PI3K/AKT Phosphorylation

Sophoridine (SRP) is a natural quinolizidine alkaloid found in many traditional Chinese herbs, though its effect on adipose tissue is unclear. We improved serum lipid levels by administering SRP by gavage in high-fat diet (HFD)-fed C57BL/6 mice. After 11 weeks, SRP supplementation significantly reduced body weight gain and improved glucose homeostasis, while reducing subcutaneous fat and liver weight. SRP also inhibited cell proliferation and differentiation of 3T3-L1 cells. Proteomics analysis revealed that SRP inhibits adipocyte differentiation by interacting with Src, thereby suppressing vascular endothelial growth factor receptor 2 (VEGFR2) expression and PI3K/AKT phosphorylation. This study provides an empirical basis for the treatment of obesity with small molecules.

The role of heat shock proteins (HSPs) in type 2 diabetes mellitus pathophysiology

Type 2 diabetes mellitus (T2DM) is a metabolic disorder characterized by sustained hyperglycemia caused by impaired insulin signaling and secretion. Metabolic stress, caused by an inappropriate diet, is one of the major hallmarks provoking inflammation, endoplasmic reticulum (ER) stress, and mitochondrial dysfunction. Heat shock proteins (HSPs) are a group of highly conserved proteins that have a crucial role in chaperoning damaged and misfolded proteins to avoid disruption of cellular homeostasis under stress conditions. To do this, HSPs interact with diverse intra-and extracellular pathways among which are the insulin signaling, insulin secretion, and apoptosis pathways. Therefore, HSP dysfunction, e.g. HSP70, may lead to disruption of the pathways responsible for insulin secretion and uptake. Consistently, the altered expression of other HSPs and genetic polymorphisms in HSP-producing genes in diabetic subjects has made HSPs hot research in T2DM. This paper provides a comprehensive overview of the role of different HSPs in T2DM pathogenesis, affected cellular pathways, and the potential therapeutic strategies targeting HSPs in T2DM.

Matrine alleviates oxidative stress and ferroptosis in severe acute pancreatitis-induced acute lung injury by activating the UCP2/SIRT3/PGC1α pathway

Acute lung injury (ALI) is one of the most serious complications of severe acute pancreatitis (SAP). Matrine is well known for its powerful antioxidant and antiapoptotic properties, although its specific mechanism of action in SAP-ALI is unknown. In this study, we examined the effects of matrine on SAP-associated ALIand the specific signaling pathways implicated in SAP-induced ALI, such as oxidative stress, the UCP2-SIRT3-PGC1α pathway, and ferroptosis. The administration of caerulein and lipopolysaccharide (LPS) to UCP2-knockout (UCP2^-/-) and wild-type (WT) mice that were pretreated with matrine resulted in pancreatic and lung injury. Changes in reactive oxygen species (ROS) levels, inflammation, and ferroptosis in BEAS-2B and MLE-12 cells were measured following knockdown or overexpression and LPS treatment. Matrine inhibited excessive ferroptosis and ROS production by activating the UCP2/SIRT3/PGC1α pathway while reducing histological damage, edema, myeloperoxidase activity and proinflammatory cytokine expression in the lung. UCP2 knockout decreased the anti-inflammatory properties of matrine and reduced the therapeutic effects of matrine on ROS accumulation and ferroptosis hyperactivation. LPS-induced ROS production and ferroptosis activation in BEAS-2B cells and MLE-12 cells were further enhanced by knockdown of UCP2, but this effect was rescued by UCP2 overexpression. This study demonstrated that matrine reduced inflammation, oxidative stress, and excessive ferroptosis in lung tissue during SAP by activating the UCP2/SIRT3/PGC1α pathway, demonstrating its therapeutic potential in SAP-ALI.

Matrine Attenuates Lung Injury by Modulating Macrophage Polarization and Suppressing Apoptosis

INTRODUCTION

Persistent lung inflammation is a characteristic of sepsis-induced lung injury. Matrine, the active ingredient from Sophora flavescens, has exhibited anti-inflammatory activities. This study investigated the effects of prophylactic administration of matrine on macrophage polarization, apoptosis, and tissue injury in a cecal ligation and puncture (CLP)-induced murine lung injury model.

METHODS

Mice were randomly allocated into four groups: Sham, CLP, Sham + Matrine, and CLP + Matrine. Lung tissues were collected at 24 h post-CLP. Histopathology and immunofluorescence analysis were performed to evaluate lung injury and macrophage infiltration in the lung, respectively. Caspase-3 activities, TUNEL staining, and anti-apoptotic proteins were examined to assess apoptosis. To determine the mechanism of action of matrine, protein levels of Sirtuin 1 (SIRT1), nuclear factor κB (NF-κB), p53 and the messenger RNA levels of p53-mediated proapoptotic genes were examined to elucidate the associated signaling pathways.

RESULTS

Histopathological evaluation showed that matrine prophylaxis attenuated sepsis-induced lung injury. Matrine prophylaxis attenuated sepsis-induced infiltration of the total population of macrophages in the lung. Matrine inhibited M1 macrophage infiltration, but increased M2 macrophage infiltration, thus resulting in a decrease in the proportion of M1 to M2 macrophages in septic lung. Sepsis-induced lung injury was associated with apoptotic cell death as evidenced by increases in caspase-3 activity, TUNEL-positive cells, and decreases in antiapoptotic proteins, all of which were reversed by matrine prophylaxis. Matrine restored sepsis-induced downregulation of SIRT1 and deacetylation of NF-κB p65 subunit and p53, thus inactivating NF-κB pathway and suppressing p53-induced proapoptotic pathway in septic lung.

CONCLUSIONS

In summary, this study demonstrated that matrine exhibited pro-M2 macrophage polarization and antiapoptotic effects in sepsis-induced lung injury, which might be, at least partly, due to the modulation of SIRT1/NF-κB and SIRT1/p53 pathways.

Heat Therapy Can Improve Hepatic Mitochondrial Function and Glucose Control

This review proposes the novel hypothesis that heat can be used as an alternative therapy to exercise to improve hepatic mitochondrial function and glucose regulation in patients with nonalcoholic fatty liver disease. Although exercise has proven benefits in treating nonalcoholic fatty liver disease, barriers to exercise in the majority of patients necessitate an alternative method of treatment.

Efficacy of Cyanotis tuberosa (Roxb.) Schult. &Schult. f. root tubers' active fraction as anti-diabetic, antihyperlipidemic and antioxidant in Streptozotocin-induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Cyanotis tuberosa (Roxb.) Schult. &Schult.f. is traditionally used as ethnomedicine for curing several ailments like diabetes, liver problems, ulcers, etc. OBJECTIVE: The present study was designed to evaluate the anti-diabetic potential of Cyanotis tuberosa root tubers (CTRT)in Streptozotocin (STZ) induced diabetic rats.

MATERIALS AND METHODS

Anti-hyperglycemic activity of hexane extract of CTRT was investigated in diabetic rats. Silica gel chromatography was used to fractionate the hexane extract and the fraction's antihyperglycemic activity was checked in diabetic rats. Effects of long-term (30 days) treatment with an active fraction (CTAF) were evaluated in diabetic rats for 30 days by measurement of body weights, glycemic control, insulin levels, HbA1c, and serum and tissue lipid profiles. Lipid peroxide levels and antioxidant status were measured in the liver and kidney. Hepatic and Renal functional markers were also measured. Phytochemical characterization of CTAF was carried out by LC-ESI-MS/MS analysis.

RESULTS

Hexane extract of CTRT at a dose of 750 mg/kg b.w produced significant antihyperglycemic activity in diabetic rats whereas CTAF has produced maximum antihyperglycemic activity at the dose of 75 mg/kg b.w. Following long-term treatment with CTAF in diabetic rats, significant improvement in glycemic control, (HbA1c) along with decreased insulin resistance (HOMA-IR), increase in body weights, and plasma insulin were observed. Also, CTAF ameliorated the serum and tissue lipid profiles. In addition, CTAF suppressed lipid peroxidation and restored the activities of antioxidant enzymes in the liver and kidney to normal levels. Further, CTAF reversed the liver and kidney functional markers to normalcy. LC-ESI-MS/MS analysis revealed the presence of 7 different phytoconstituents.

CONCLUSION

This study confirmed that CTAF exerts antidiabetic effects in diabetic rats by improving insulin secretion, glycemic control, and restoring functional activities of the liver and kidney. Our results suggest that root tubers of Cyanotis tuberosa can be used as a complementary or alternative agent for the treatment of diabetes mellitus.

Matrine counteracts obesity in mice via inducing adipose thermogenesis by activating HSF1/PGC-1α axis

Promoting energy expenditure is known to curb obesity and can be exploited for its treatment. Our previous study has demonstrated that activation of HSF1/PGC-1α axis efficiently induced mitochondrial biogenesis and adaptive oxidation and thus ameliorating lipid accumulation, however, whether it can be a therapeutic approach for metabolic disorders treatment needs explored. Here, a high-efficient and specific HSF1/PGC-1α activator screening system was established and the natural clinical liver-protecting agent matrine was identified as a robust HSF1/PGC-1α activator. Matrine treatment efficiently induced mitogenesis and thermogenic program in primary mouse adipose stem cell derived adipocytes by enriching HSF1 to the promoter of Pgc-1α. Deficiency of PGC-1α in adipocytes diminished the browning induction ability of matrine. Oral administration of matrine to the obese mice induced by high fat and high cholesterol diet increased energy expenditure and corrected the degeneration of thermogenesis in brown adipose tissue (BAT). Also, matrine treatment markedly induced the transformation of brown-like adipocytes in subcutaneous white adipose tissue (sWAT) via a mechanism of HSF1/PGC-1α, thereby attenuating obesity and myriads of metabolic disorders. This led to an improvement in adaptive thermogenesis to cold stimuli. These findings are of great significance in understanding the regulation mechanisms of the HSF1/PGC-1α axis in thermogenesis and providing a novel therapeutic approach for obesity treatment. Matrine may have potential therapeutic implications for the treatment of obesity in clinics.

Role of the mTOR-autophagy-ER stress pathway in high fructose-induced metabolic-associated fatty liver disease

Metabolic-associated fatty liver disease (MAFLD) is the most common metabolic disease with a global prevalence of 25%. While MAFLD is serious and incurable at the later stage, it can be controlled or reversed at the early stage of hepatosteatosis originating from unhealthy diets. Recent laboratory evidence implicates a critical role of the mammalian target of rapamycin (mTOR)-autophagy signaling pathway in the pathogenesis of MAFLD induced by a high-fructose diet mimicking the overconsumption of sugar in humans. This review discusses the possible molecular mechanisms of mTOR-autophagy-endoplasmic reticulum (ER) stress in MAFLD. Based on careful analysis of recent studies, we suggest possible new therapeutic concepts or targets that can be explored for the discovery of new anti-MAFLD drugs.

GADD45β stabilized by direct interaction with HSP72 ameliorates insulin resistance and lipid accumulation

Growth arrest and DNA damage-inducible 45β (GADD45β) belongs to the GADD45 family which is small acidic proteins in response to cellular stress. GADD45β has already been reported to have excellent capabilities against cancer, innate immunity and neurological diseases. However, there is little information regard GADD45β and non-alcoholic fatty liver disease (NAFLD). In the current work, we found that the expression of GADD45β was markedly decreased in the livers of NAFLD patients via analyzing Gene Expression Omnibus (GEO) dataset and in mouse model through detecting its mRNA in high-fat-high-fructose diet (HFHFr)-fed mice. Moreover, the results from in vivo experiment demonstrated that overexpression of GADD45β by AAV8-mediated gene transfer in HFHFr-fed mouse model could reduce the level of serum and hepatic triglyceride (TG), and alleviate insulin resistance. Subsequently, by combining immunoprecipitation (IP) and mass spectrometry, we identified that HSP72 directly interacted with GADD45β to prevent GADD45β from being degraded by the proteasome pathway. Finally, the benefits of GADD45β in regulating key factors of TG synthesis and insulin signaling pathway were abolished after HSP72 knockdown. In conclusion, GADD45β stabilized by the interaction with HSP72 could alleviate the NAFLD-related pathologies, suggested it might be a potential target for the treatment of NAFLD.

Exposure to cigarette smoke precipitates simple hepatosteatosis to NASH in high-fat diet fed mice by inducing oxidative stress

Consumption of diet rich in fat and cigarette smoking (CS) are independent risk factors of non-alcoholic steatohepatitis (NASH), and they often occur together in some populations. The present study investigated the mechanisms of high-fat diet (HFD) and CS, individually and in combination, on the pathogenesis of NASH in mice. C57BL/6 male mice were subjected to either a low-fat chow (CH) or HFD with or without mainstream CS-exposure (4 cigarettes/day, 5 days/ week for 14 weeks). HFD alone caused hepatosteatosis (2.5-fold increase in TG content) and a significant increase in 3-nitrotyrisine (by ∼40-fold) but without an indication of liver injury, inflammation or fibrosis. CS alone in CH-fed mice increased in Tnfα expression and macrophage infiltration by 2-fold and relatively less increase in 3-nitrotyrosine (18-fold). Combination of HFD and CS precipitated hepatosteatosis to NASH reflected by exacerbated makers of liver inflammation and fibrosis which were associated with much severe liver oxidative stress (90-fold increase in 3-nitrotyrisine along with 6-fold increase in carbonylated proteins and 56% increase in lipid oxidations). Further studies were performed to administer the antioxidant tempol to CS exposed HFD mice and the results showed that the inhibition of liver oxidative stress prevented inflammatory and fibrotic changes in liver despite persisting hepatosteatosis. Our findings suggest that oxidative stress is a key mechanism underlying CS-promoted progression of simple hepatosteatosis to NASH. Targeting hepatic oxidative stress may be a viable strategy in halting the progression of metabolic associated fatty liver disease.

Modern computational intelligence based drug repurposing for diabetes epidemic

BACKGROUND AND AIM

Objectives are to explore recent advances in discovery of new antidiabetic agents using repurposing strategies and to discuss modern technologies used for drug repurposing highlighting diabetic specific web portal.

METHODS

Recent literature were studied and analyzed from various sources such as Scopus, PubMed, and IEEE Xplore databases.

RESULTS

Drugs like Niclosamideethanolamine, Methazolamide, Diacerein, Berberine, Clobetasol, etc. with possibility of repurposing to curb diabetes can be potential late-stage clinical candidates, providing access to information on pharmacology, formulation, and probable toxicity if any.

CONCLUSIONS

With collaboration of artificial intelligence (AI) with pharmacology, the efficiency of drug repurposing can improve significantly.

Activation of heat shock response improves biomarkers of NAFLD in patients with metabolic diseases

Nonalcoholic fatty liver disease (NAFLD) is often accompanied by metabolic disorders such as metabolic syndrome and type 2 diabetes (T2DM). Heat shock response (HSR) is one of the most important homeostatic abilities but is deteriorated by chronic metabolic insults. Heat shock (HS) with an appropriate mild electrical stimulation (MES) activates HSR and improves metabolic abnormalities including insulin resistance, hyperglycemia and inflammation in metabolic disorders. To analyze the effects of HS + MES treatment on NAFLD biomarkers, three cohorts including healthy men (two times/week, n = 10), patients with metabolic syndrome (four times/week, n = 40), and patients with T2DM (n = 100; four times/week (n = 40) and two, four, seven times/week (n = 20 each)) treated with HS + MES were retrospectively analyzed. The healthy subjects showed no significant alterations in NAFLD biomarkers after the treatment. In patients with metabolic syndrome, many of the NAFLD steatosis markers, including fatty liver index, NAFLD-liver fat score, liver/spleen ratio and hepatic steatosis index and NAFLD fibrosis marker, aspartate aminotransferase/alanine aminotransferase (AST/ALT) ratio, were improved upon the treatment. In patients with T2DM, all investigated NAFLD steatosis markers were improved and NAFLD fibrosis markers such as the AST/ALT ratio, fibrosis-4 index and NAFLD-fibrosis score were improved upon the treatment. Thus, HS + MES, a physical intervention, may become a novel treatment strategy for NAFLD as well as metabolic disorders.

Microbiome analysis reveals gut microbiota alteration in mice with the effect of matrine

Mounting evidence revealed the negative effects of abuse of antibiotic including the induction of decreased immunity and dysbacteriosis. Matrine displayed multiple beneficial effects such as anti-inflammatory, antiviral and antibacterial, but studies of its influence on gut microbiota are still insufficient to report. Here, the present study was conducted to investigate the influence of matrine on the gut microbiota of mice and amoxicillin was used as a positive control. A total of 21 cecal samples were obtained from seven groups for high-throughput sequencing analysis based on V3-V4 variable region of 16S rRNA genes. Results revealed that the diversity and abundance of gut microbiota in mice gradually decreased with the increase of the concentration of amoxicillin, whereas matrine administration did not effect the intestinal microbial community structure. Additionally, amoxicillin and matrine supplementation also caused significant changes in the relative abundance of some intestinal bacteria. Specifically, the ratio of Klebsiella and Corynebacterium_1, Bacteroides and Parasutterella in the amoxicillin treated-group were increased as compared to the control group, whereas Muribaculaceae_unclassified, Alistipes and Lactobacillus were significantly decreased. Conversely, matrine administration significantly increased the proportion of beneficial bacteria such as Ruminiclostridium_9, Lachnospiraceae_NK4A136_group and Ruminococcaceae_unclassified. In conclusion, amoxicillin administration could change the microbial community composition and structure by increasing the proportion of pathogenic to beneficial bacteria, whereas matrine could increase the number of beneficial bacteria. Moreover, this study provides a theoretical basis for finding alternatives to antibiotics to decrease bacterial resistance and intestinal flora imbalance.

Matrine attenuates pathological cardiac fibrosis via RPS5/p38 in mice

Pathological cardiac fibrosis is a common feature in multiple cardiovascular diseases that contributes to the occurrence of heart failure and life-threatening arrhythmias. Our previous study demonstrated that matrine could attenuate doxorubicin-induced oxidative stress and cardiomyocyte apoptosis. In this study, we investigated the effect of matrine on cardiac fibrosis. Mice received aortic banding (AB) operation or continuous injection of isoprenaline (ISO) to generate pathological cardiac fibrosis and then were exposed to matrine lavage (200 mg·kg-1·d-1) or an equal volume of vehicle as the control. We found that matrine lavage significantly attenuated AB or ISO-induced fibrotic remodeling and cardiac dysfunction. We also showed that matrine (200 μmol/L) significantly inhibited the proliferation, migration, collagen production, and phenotypic transdifferentiation of cardiac fibroblasts. Mechanistically, matrine suppressed p38 activation in vivo and in vitro, and overexpression of constitutively active p38 completely abolished the protective effects of matrine. We also demonstrated that ribosomal protein S5 (RPS5) upregulation was responsible for matrine-mediated inhibition on p38 and fibrogenesis. More importantly, matrine was capable of ameliorating preexisting cardiac fibrosis in mice. In conclusion, matrine treatment attenuates cardiac fibrosis by regulating RPS5/p38 signaling in mice, and it might be a promising therapeutic agent for treating pathological cardiac fibrosis.

Matrine, as a CaSR agonist promotes intestinal GLP-1 secretion and improves insulin resistance in diabetes mellitus

BACKGROUND

Matrine (Mat), a bitter tastes compounds of derived from leguminosae such as Sophora flavescens and S. subprostrata, commonly used to improve obesity and diabetes.

PURPOSE

Our study to demonstrate bitter substances can stimulate the Bitter taste receptors (TAS2Rs) or Calcium-sensing receptor (CaSR) to stimulate the secretion of GLP-1 to promote blood glucose regulation.

METHODS

The diabetic mice and intestinal secretory cell model were established to evaluate the Mat on glucose metabolism, intestinal insulin secretion and GLP-1 secretion related substances. To clarify the mechanism of Mat in regulating GLP-1 secretion by immunofluorescence, calcium labeling, siRNA, and molecular docking.

RESULTS

The results showed that Mat could significantly improve glucose metabolism and increased insulin and GLP-1 secretion in diabetic mice and increased trisphosphate inositol (IP3) levels by affecting the expression of phospholipase C β2 (PLCβ2) and promote an increase in intracellular Ca2+ levels in STC-1 cells to subsequently stimulate the secretion of GLP-1. Knockdown of the bitter taste receptors mTas2r108, mTas2r137, and mTas2r138 in STC-1 cells by siRNA did could not affect the role of Mat in regulating GLP-1. However, the secretion of GLP-1 by Mat could be significantly inhibited by administration of a CaSR inhibitor or siRNA CaSR. Molecular docking analysis showed that Mat could embed CaSR protein and bind to the original ligand of the egg white at the same amino acid site to play the role of an agonist.

CONCLUSION

Matrine is a typical bitter alkaloid could be used as an agonist of CaSR to stimulate the secretion of GLP-1 in the intestine, and it may be used as a potential drug for diabetes treatment.

Research progress in use of traditional Chinese medicine monomer for treatment of non-alcoholic fatty liver disease

With the improvement of people's living standards and the change of eating habits, non-alcoholic fatty liver disease (NAFLD) has gradually become one of the most common chronic liver diseases in the world. However, there are no effective drugs for the treatment of NAFLD. Therefore, it is urgent to find safe, efficient, and economical anti-NAFLD drugs. Compared with western medicines that possess fast lipid-lowering effect, traditional Chinese medicines (TCM) have attracted increasing attention for the treatment of NAFLD due to their unique advantages such as multi-targets and multi-channel mechanisms of action. TCM monomers have been proved to treat NAFLD through regulating various pathways, including inflammation, lipid production, insulin sensitivity, mitochondrial dysfunction, autophagy, and intestinal microbiota. In particular, peroxisome proliferator-activated receptor α (PPAR-α), sterol regulatory element-binding protein 1c (SREBP-1c), nuclear transcription factor kappa (NF-κB), phosphoinositide 3-kinase (PI3K), sirtuin1 (SIRT1), AMP-activated protein kinase (AMPK), p53 and nuclear factor erythroid 2-related factor 2 (Nrf2) are considered as important molecular targets for ameliorating NAFLD by TCM monomers. Therefore, by searching PubMed, Web of Science and SciFinder databases, this paper updates and summarizes the experimental and clinical evidence of TCM monomers for the treatment of NAFLD in the past six years (2015-2020), thus providing thoughts and prospects for further exploring the pathogenesis of NAFLD and TCM monomer therapies.

Heat Treatment Improves Hepatic Mitochondrial Respiratory Efficiency via Mitochondrial Remodeling

Nonacholic fatty liver disease, or hepatic steatosis, is the most common liver disorder affecting the western world and currently has no pharmacologic cure. Thus, many investigations have focused on alternative strategies to treat or prevent hepatic steatosis. Our laboratory has shown that chronic heat treatment (HT) mitigates glucose intolerance, insulin resistance, and hepatic steatosis in rodent models of obesity. Here, we investigate the direct bioenergetic mechanism(s) surrounding the metabolic effects of HT on hepatic mitochondria. Utilizing mitochondrial proteomics and respiratory function assays, we show that one bout of acute HT (42°C for 20 min) in male C57Bl/6J mice (n = 6/group) triggers a hepatic mitochondrial heat shock response resulting in acute reductions in respiratory capacity, degradation of key mitochondrial enzymes, and induction of mitophagy via mitochondrial ubiquitination. We also show that chronic bouts of HT and recurrent activation of the heat shock response enhances mitochondrial quality and respiratory function via compensatory adaptations in mitochondrial organization, gene expression, and transport even during 4 weeks of high-fat feeding (n = 6/group). Finally, utilizing a liver-specific heat shock protein 72 (HSP72) knockout model, we are the first to show that HSP72, a protein putatively driving the HT metabolic response, does not play a significant role in the hepatic mitochondrial adaptation to acute or chronic HT. However, HSP72 is required for the reductions in blood glucose observed with chronic HT. Our data are the first to suggest that chronic HT (1) improves hepatic mitochondrial respiratory efficiency via mitochondrial remodeling and (2) reduces blood glucose in a hepatic HSP72-dependent manner.

Are Heat Shock Proteins an Important Link between Type 2 Diabetes and Alzheimer Disease?

Type 2 diabetes (T2D) and Alzheimer’s disease (AD) are growing in prevalence worldwide. The development of T2D increases the risk of AD disease, while AD patients can show glucose imbalance due to an increased insulin resistance. T2D and AD share similar pathological features and underlying mechanisms, including the deposition of amyloidogenic peptides in pancreatic islets (i.e., islet amyloid polypeptide; IAPP) and brain (β-Amyloid; Aβ). Both IAPP and Aβ can undergo misfolding and aggregation and accumulate in the extracellular space of their respective tissues of origin. As a main response to protein misfolding, there is evidence of the role of heat shock proteins (HSPs) in moderating T2D and AD. HSPs play a pivotal role in cell homeostasis by providing cytoprotection during acute and chronic metabolic stresses. In T2D and AD, intracellular HSP (iHSP) levels are reduced, potentially due to the ability of the cell to export HSPs to the extracellular space (eHSP). The increase in eHSPs can contribute to oxidative damage and is associated with various pro-inflammatory pathways in T2D and AD. Here, we review the role of HSP in moderating T2D and AD, as well as propose that these chaperone proteins are an important link in the relationship between T2D and AD.

A Systematic Review of the Pharmacology, Toxicology and Pharmacokinetics of Matrine

Matrine (MT) is a naturally occurring alkaloid and an bioactive component of Chinese herbs, such as Sophora flavescens and Radix Sophorae tonkinensis. Emerging evidence suggests that MT possesses anti-cancer, anti-inflammatory, anti-oxidant, antiviral, antimicrobial, anti-fibrotic, anti-allergic, antinociceptive, hepatoprotective, cardioprotective, and neuroprotective properties. These pharmacological properties form the foundation for its application in the treatment of various diseases, such as multiple types of cancers, hepatitis, skin diseases, allergic asthma, diabetic cardiomyopathy, pain, Alzheimer's disease (AD), Parkinson's disease (PD), and central nervous system (CNS) inflammation. However, an increasing number of published studies indicate that MT has serious adverse effects, the most obvious being liver toxicity and neurotoxicity, which are major factors limiting its clinical use. Pharmacokinetic studies have shown that MT has low oral bioavailability and short half-life in vivo. This review summarizes the latest advances in research on the pharmacology, toxicology, and pharmacokinetics of MT, with a focus on its biological properties and mechanism of action. The review provides insight into the future of research on traditional Chinese medicine.

Oxymatrine ameliorates imiquimod-induced psoriasis pruritus and inflammation through inhibiting heat shock protein 90 and heat shock protein 60 expression in keratinocytes

In this work, we aimed to investigate whether oxymatrine exerts its anti-pruritic and anti-inflammatory efficacy in the imiquimod-induced psoriasis mice and the related mechanism. We established the psoriasis model by applying the imiquimod ointment topically and oxymatrine was injected intraperitoneally as the treatment. The behavior and skin morphology results indicated that oxymatrine inhibits imiquimod-induced pruritus alleviating keratinization of skin and inflammatory infiltration. Moreover, we examined the expression of various indicators and found heat shock protein (HSP) 90 and 60 upregulated in model group, which were reversed in oxymatrine treated groups. Molecular docking and the studies in vivo confirmed that HSP90 and HSP60 participate in the inhibitory effect of oxymatrine on the phenotypes of psoriasis mice. Mechanically, immunofluorescence staining demonstrated that oxymatrine-induced downregulation of HSP90 and HSP60 was mainly in keratinocytes. In vitro results showed that oxymatrine decreases the expression of HSP90 and HSP60 upregulated by TNF-α and IFN-γ in HaCaTs cells and the siRNA mediated HSP90 and HSP60 silencing reverses inflammation inhibited by oxymatrine. Taken together, these results indicate that oxymatrine relieves psoriasis pruritic and inflammation by inhibiting the expression of HSP90 and HSP60 in keratinocytes through MAPK signaling pathway.

Hyperthermia-induced changes in liver physiology and metabolism: a rationale for hyperthermic machine perfusion

Liver transplantation is the standard treatment for end-stage liver disease. However, due to the ongoing disparity between supply and demand for optimal donor organs, there is increasing usage of extended criteria donor organs, including steatotic liver grafts. To mitigate the increased risks associated with extended criteria donor livers, ex situ oxygenated machine perfusion (MP) has received increasing attention in recent years as an emerging platform for dynamic preservation, reconditioning, and viability assessment to increase organ utilization. MP can be applied at different temperatures. During hypothermic MP (4-12°C), liver metabolism is reduced, while oxygenation restores the intracellular levels of adenosine triphosphate. The liver is quickly "recharged" to support metabolism when at normothermia (35-37°C) and to ameliorate the detrimental effects of ischemia/reperfusion injury during transplantation. During normothermia, MP can be applied to assess hepatocellular and cholangiocellular viability. MP at hyperthermic (>38°C) temperatures (HyMP), however, remains relatively understudied. The liver is an important component in the regulation of core body temperature and, as such, displays significant physiological and metabolic changes in response to different temperatures. Hyperthermia may promote vasodilation, increase aerobic metabolism and induce production of protective molecules such as heat shock proteins. Therefore, HyMP could provide an attractive reconditioning strategy for steatotic livers. In this review, we describe current literature on the physiological and metabolic effects of the liver at hyperthermia for human, rodents, and pigs and provide a rationale for using therapeutic HyMP during isolated liver machine perfusion to recondition extended criteria donor livers, including steatotic livers, before transplantation.

Targeting metabolic syndrome with phytochemicals: Focus on the role of molecular chaperones and hormesis in drug discovery

Adaptive cellular stress response confers stress tolerance against inflammatory and metabolic disorders. In response to metabolic stress, the key mediator of cellular adaptation and tolerance is a class of molecules called the molecular chaperones (MCs). MCs are highly conserved molecules that play critical role in maintaining protein stability and functionality. Hormesis in this context is a unique adaptation mechanism where a low dose of a stressor (which is toxic at high dose) confers a stress-resistant adaptive cellular phenotype. Hormesis can be observed at different level of biological organization at various measurable endpoints. The MCs are believed to play a key role in adaptation during hormesis. Several phytochemicals are known for their hormetic response and are called phytochemical hormetins. The role of phytochemical-mediated hormesis on the adaptive cellular processes is proposed as a potential therapeutic approach to target inflammation associated with metabolic syndrome. However, the screening of phytochemical hormetins would require a paradigm shift in the methods currently used in drug discovery.

Matrine: A Promising Natural Product With Various Pharmacological Activities

Matrine is an alkaloid isolated from the traditional Chinese medicine Sophora flavescens Aiton. At present, a large number of studies have proved that matrine has an anticancer effect can inhibit cancer cell proliferation, arrest cell cycle, induce apoptosis, and inhibit cancer cell metastasis. It also has the effect of reversing anticancer drug resistance and reducing the toxicity of anticancer drugs. In addition, studies have reported that matrine has a therapeutic effect on Alzheimer's syndrome, encephalomyelitis, asthma, myocardial ischemia, rheumatoid arthritis, osteoporosis, and the like, and its mechanism is mainly related to the inhibition of inflammatory response and apoptosis. Its treatable disease spectrum spans multiple systems such as the nervous system, circulatory system, and immune system. The antidisease effect and mechanism of matrine are diverse, so it has high research value. This review summarizes recent studies on the pharmacological mechanism of matrine, with a view to providing reference for subsequent research.

Characterization of the Therapeutic Profile of Albiflorin for the Metabolic Syndrome

Albiflorin (AF) is a small molecule (MW 481) isolated from Paeoniae radix, a plant used as a remedy for various conditions with pathogenesis shared by metabolic diseases. Reported here is our characterization of its therapeutic profiles in three mouse models with distinctive pathological features of metabolic syndrome (MetS). Our results firstly showed that AF alleviated high fat (HF) induced obesity and associated glucose intolerance, suggesting its therapeutic efficacy for MetS. In the type 2 diabetes (T2D) model induced by a combination of HF and low doses of streptozotocin, AF lowered hyperglycaemia and improved insulin-stimulated glucose disposal. In the non-alcoholic steatohepatitis-like model resulting from a HF and high cholesterol (HF-HC) diet, AF reversed the increased liver triglyceride and cholesterol, plasma aspartate aminotransferase, and liver TNFα mRNA levels. Consistent with its effect in promoting glucose disposal in HF-fed mice, AF stimulated glucose uptake and GLUT4 translocation to the plasma membrane in L6 myotubes. However, these effects were unlikely to be associated with activation of insulin, AMPK, ER, or cellular stress signalling cascades. Further studies revealed that AF increased the whole-body energy expenditure and physical activity. Taken together, our findings indicate that AF exerts a therapeutic potential for MetS and related diseases possibly by promoting physical activity associated whole-body energy expenditure and glucose uptake in muscle. These effects are possibly mediated by a new mechanism distinct from other therapeutics derived from Chinese medicine.

Bouchardatine analogue alleviates non-alcoholic hepatic fatty liver disease/non-alcoholic steatohepatitis in high-fat fed mice by inhibiting ATP synthase activity

BACKGROUND AND PURPOSE

Non-alcoholic hepatic fatty liver disease (NAFLD) is a manifestation of the metabolic syndrome in the liver and non-alcoholic steatohepatitis (NASH) represents its advanced stage. R17 derived from bouchardatine, shows benefits in the metabolic syndrome, but has not been tested in the liver. The present study examined the pharmacological effects of R17 in a model of NAFLD/NASH and its mode of action.

EXPERIMENTAL APPROACH

The effects of R17 were examined in mice fed a high-fat (HF) diet to induce the pathological characteristics of NAFLD/NASH and in cultures of HuH7 cells. We used histological and immunohistochemical techniques along with western blotting and siRNA. Generation of ROS and apoptosis were measured.

KEY RESULTS

Administration of R17 (20 mg·kg^-1 , i.p. every other day) for 5 weeks reversed HF-induced hepatic triglyceride content, inflammation (inflammatory cytokines and macrophage numbers), injury (hepatocyte ballooning and apoptosis, plasma levels of alanine aminotransferase and aspartate aminotransferase), and fibrogenesis (collagen deposition and mRNA expression of fibrosis markers). In cultured cells, R17 reduced cell steatosis from both lipogenesis and fatty acid influx. The attenuated inflammation and cell injury were associated with inhibition of both endoplasmic reticulum (ER) stress and oxidative stress. Notably, R17 activated the liver kinase B1-AMP-activated protein kinase (AMPK) pathway by inhibiting activity of ATP synthase, rather than direct stimulation of AMPK.

CONCLUSION AND IMPLICATIONS

R17 has therapeutic potential for NAFLD/NASH. Its mode of action involves the elimination of ER and oxidative stresses, possibly via activating the LKB1-AMPK axis by inhibiting the activity of ATP synthase.

Matrine attenuates oxidative stress and cardiomyocyte apoptosis in doxorubicin-induced cardiotoxicity via maintaining AMPKα/UCP2 pathway

Oxidative stress and cardiomyocyte apoptosis are involved in the pathogenesis of doxorubicin (DOX)-induced cardiotoxicity. Matrine is well-known for its powerful anti-oxidant and anti-apoptotic capacities. Our present study aimed to investigate the effect of matrine on DOX-induced cardiotoxicity and try to unearth the underlying mechanisms. Mice were exposed with DOX to generate DOX-induced cardiotoxicity or normal saline as control. H9C2 cells were used to verify the effect of matrine in vitro. DOX injection triggered increased generation of reactive oxygen species (ROS) and excessive cardiomyocyte apoptosis, which were significantly mitigated by matrine. Mechanistically, we found that matrine ameliorated DOX-induced uncoupling protein 2 (UCP2) downregulation, and UCP2 inhibition by genipin could blunt the protective effect of matrine on DOX-induced oxidative stress and cardiomyocyte apoptosis. Besides, 5'-AMP-activated protein kinase α2 (Ampkα2) deficiency inhibited matrine-mediated UCP2 preservation and abolished the beneficial effect of matrine in mice. Besides, we observed that matrine incubation alleviated DOX-induced H9C2 cells apoptosis and oxidative stress level via activating AMPKα/UCP2, which were blunted by either AMPKα or UCP2 inhibition with genetic or pharmacological methods. Matrine attenuated oxidative stress and cardiomyocyte apoptosis in DOX-induced cardiotoxicity via maintaining AMPKα/UCP2 pathway, and it might be a promising therapeutic agent for the treatment of DOX-induced cardiotoxicity.

Traditional Chinese medicine combined with hepatic targeted drug delivery systems: A new strategy for the treatment of liver diseases

Liver diseases are clinically common and present a substantial public health issue. Many of the currently available drugs for the treatment of liver diseases suffer from limitations that include low hepatic distribution, lack of target effects, poor in vivo stability and adverse effects on other organs. Consequently, conventional treatment of hepatic diseases is ineffective. TCM is commonly used in the treatment of liver diseases worldwide, particularly in China, and has advantages over conventional therapy. HTDDS can be designed to enhance clinical efficacy in the treatment of liver diseases. We have conducted an extensive review of 335 studies reported since 1964. These included about 166 references involving the treatment of liver diseases with TCM (covering active components of TCM, single TCM and Chinese medicine formulas), 169 reports on HTDDS and background studies on liver-related diseases. Here we review the long history of TCM in the treatment of liver diseases.We have also reviewed the status of studies on active components of TCM using nanotechnology-based targeted delivery systems to provide support for further research and development of TCM-based targeted preparations for the treatment of liver disease.

Matrine Protects Against MCD-Induced Development of NASH via Upregulating HSP72 and Downregulating mTOR in a Manner Distinctive From Metformin

The present study investigated the effects of matrine on non-alcoholic steatohepatitis (NASH) in mice induced by a methionine choline-deficient (MCD) diet and the mechanism involved. The study was performed in C57B/6J mice fed a MCD diet for 6 weeks to induce NASH with or without the treatment of matrine (100 mg/kg/day in diet). Metformin was used (250 mg/kg/day in diet) as a comparator for mechanistic investigation. Administration of matrine significantly reduced MCD-induced elevations in plasma ALT and AST but without changing body or liver fat content. Along with alleviating liver injury, matrine suppressed MCD-induced hepatic inflammation (indicated by TNFα, CD68, MCP-1, and NLRP3) and fibrosis (indicated by collagen 1, TGFβ, Smad3, and sirius-red staining). In comparison, metformin treatment did not show any clear sign of effects on these parameters indicative of NASH. Further examination of the liver showed that matrine treatment rescued the suppressed HSP72 (a chaperon protein against cytotoxicity) and blocked the induction of mTOR (a key protein in a stress pathway). In keeping with the lack of the improvement of the NASH features, metformin did not show any significant effect against MCD-induced changes in HSP72 and mTOR. Matrine protects against MCD-induced development of NASH which is refractory to metformin treatment. Its anti-NASH effects involve enhancing HSP72 and downregulating mTOR but do not rely on amelioration of hepatosteatosis.

Matrine reduces cigarette smoke-induced airway neutrophilic inflammation by enhancing neutrophil apoptosis

Chronic Obstructive Pulmonary Disease (COPD) is a major incurable global health burden and will become the third largest cause of death in the world by 2030. It is well established that an exaggerated inflammatory and oxidative stress response to cigarette smoke (CS) leads to, emphysema, small airway fibrosis, mucus hypersecretion, and progressive airflow limitation. Current treatments have limited efficacy in inhibiting chronic inflammation and consequently do not reverse the pathology that initiates and drives the long-term progression of disease. In particular, there are no effective therapeutics that target neutrophilic inflammation in COPD, which is known to cause tissue damage by degranulation of a suite of proteolytic enzymes including neutrophil elastase (NE). Matrine, an alkaloid compound extracted from Sophora flavescens Ait, has well known anti-inflammatory activity. Therefore, the aim of the present study was to investigate whether matrine could inhibit CS-induced lung inflammation in mice. Matrine significantly reduced CS-induced bronchoalveolar lavage fluid (BALF) neutrophilia and NE activity in mice. The reduction in BALF neutrophils in CS-exposed mice by matrine was not due to reductions in pro-neutrophil cytokines/chemokines, but rather matrine's ability to cause apoptosis of neutrophils, which we demonstrated ex vivo Thus, our data suggest that matrine has anti-inflammatory actions that could be of therapeutic potential in treating CS-induced lung inflammation observed in COPD.

Impact of hepatic HSP72 on insulin signaling

Heat shock protein 72 (HSP72) is a major inducible molecule in the heat shock response that enhances intracellular stress tolerance. Decreased expression of HSP72 is observed in type 2 diabetes, which may contribute to the development of insulin resistance and chronic inflammation. We used HSP72 knockout (HSP72-KO) mice to investigate the impact of HSP72 on glucose metabolism and endoplasmic reticulum (ER) stress, particularly in the liver. Under a high-fat diet (HFD) condition, HSP72-KO mice showed glucose intolerance, insulin resistance, impaired insulin secretion, and enhanced hepatic gluconeogenic activity. Furthermore, activity of the c-Jun NH₂-terminal kinase (JNK) was increased and insulin signaling suppressed in the liver. Liver-specific expression of HSP72 by lentivirus (lenti) in HFD-fed HSP72-KO mice ameliorated insulin resistance and hepatic gluconeogenic activity. Furthermore, increased adipocyte size and hepatic steatosis induced by the HFD were suppressed in HSP72-KO lenti-HSP72 mice. Increased JNK activity and ER stress upon HFD were suppressed in the liver as well as the white adipose tissue of HSP72-KO lenti-HSP72 mice. Thus, HSP72 KO caused a deterioration in glucose metabolism, hepatic gluconeogenic activity, and β-cell function. Moreover, liver-specific recovery of HSP72 restored glucose homeostasis. Therefore, hepatic HSP72 may play a critical role in the pathogenesis of type 2 diabetes.

Preconditioning lessens high fat induced metabolic syndrome along with markers of increased metabolic capacity in muscle and adipose tissue

Postnatal overconsumption of fat is believed to increase the susceptibility to metabolic disease in the later life. Here we examined whether prior exposure to high fat (HF) in the adulthood may also accelerate the development of metabolic disorders in mice. Adult mice (12 weeks) were pre-exposed to two episodes of an HF diet each for 2 weeks followed by 2 weeks of washout with a low-fat diet. The mice were then fed the same HF diet for 6 weeks. Unexpectedly, prior exposures to HF diet significantly alleviated body weight gain, visceral adiposity and glucose/insulin intolerance during the period of last HF feeding. These protective effects were evident without changing calorie intake and were specific for HF, but not high fructose (HFru) diet. Following the HF prior exposures was increases in plasma fibroblast growth factor 21 (FGF21), the expressions of phospho-AMP-activated protein kinase (pAMPK), mitochondrial complex II and the expression of uncoupling protein (UCP) 3 in muscle and UCP1 and Sirtuin 1 (SIRT1) in adipose tissue. However, in the liver there was no significant change in pAMPK, SIRT1 expression or the capacity of glucose production. These findings indicated that, instead of exacerbating metabolic conditions, prior exposures to HF diet lead to the preconditioning against subsequent overload of HF, possibly involving FGF21-associated enhancement of markers for metabolic capacity in muscle and adipose tissue. This paradoxical phenomenon may offer a unique paradigm to identify factors and explore dietary ingredients with beneficial effects for the control of the metabolic syndrome in humans.

Repurposing matrine for the treatment of hepatosteatosis and associated disorders in glucose homeostasis in mice

The present study investigated the efficacy of the hepatoprotective drug matrine (Mtr) for its new application for hepatosteatosis and associated disorders in glucose homeostasis. The study was performed in two nutritional models of hepatosteatosis in mice with various abnormal glucose homeostasis: (1) high-fructose diet (HFru) induced hepatosteatosis and glucose intolerance from hepatic, and (2) hepatosteatosis and hyperglycemia induced by high-fat (HF) diet in combination with low doses of streptozotocin (STZ). Administration of Mtr (100 mg/kg every day in diet for 4 weeks) abolished HFru-induced hepatosteatosis and glucose intolerance. These effects were associated with the inhibition of HFru-stimulated de novo lipogenesis (DNL) without altering hepatic fatty acid oxidation. Further investigation revealed that HFru-induced endoplasmic reticulum (ER) stress was inhibited, whereas heat-shock protein 72 (an inducible chaperon protein) was increased by Mtr. In a type 2 diabetic model induced by HF-STZ, Mtr reduced hepatosteatosis and improved attenuated hyperglycemia. The hepatoprotective drug Mtr may be repurposed for the treatment of hepatosteatosis and associated disorders in glucose homeostasis. The inhibition of ER stress associated DNL and fatty acid influx appears to play an important role in these metabolic effects.

Heat Shock Proteins as a Potential Therapeutic Target in the Treatment of Gestational Diabetes Mellitus: What We Know so Far

Gestational diabetes mellitus (GDM) is a complex condition that involves a variety of pathological mechanisms, including pancreatic β-cell failure, insulin resistance, and inflammation. There is an increasing body of literature suggesting that these interrelated phenomena may arise from the common mechanism of endoplasmic reticulum (ER) stress. Both obesity-associated nutrient excess and hyperglycemia disturb ER function in protein folding and transport. This results in the accumulation of polypeptides in the ER lumen and impairs insulin secretion and signaling. Exercise elicits metabolic adaptive responses, which may help to restore normal chaperone expression in insulin-resistant tissues. Pharmacological induction of chaperones, mimicking the metabolic effect of exercise, is a promising therapeutic tool for preventing GDM by maintaining the body's natural stress response. Metformin, a commonly used diabetes medication, has recently been identified as a modulator of ER-stress-associated inflammation. The results of recent studies suggest the potential use of chemical ER chaperones and antioxidant vitamins as therapeutic interventions that can prevent glucose-induced ER stress in GDM placentas. In this review, we discuss whether chaperones may significantly contribute to the pathogenesis of GDM, as well as whether they can be a potential therapeutic target in GDM treatment.

Heat shock protein 72 regulates hepatic lipid accumulation

Induction of the chaperone heat shock protein 72 (HSP72) through heat treatment (HT), exercise, or overexpression improves glucose tolerance and mitochondrial function in skeletal muscle. Less is known about HSP72 function in the liver where lipid accumulation can result in insulin resistance and nonalcoholic fatty liver disease (NAFLD). The purpose of this study was 1) to determine whether weekly in vivo HT induces hepatic HSP72 and improves glucose tolerance in rats fed a high-fat diet (HFD) and 2) to determine the ability of HSP72 to protect against lipid accumulation and mitochondrial dysfunction in primary hepatocytes. Male Wistar rats were fed an HFD for 15 wk and were given weekly HT (41°C, 20 min) or sham treatments (37°C, 20 min) for the final 7 wk. Glucose tolerance and insulin sensitivity were assessed, along with HSP72 induction and triglyceride storage, in the skeletal muscle and liver. The effect of an acute loss of HSP72 in primary hepatocytes was examined via siRNA. Weekly in vivo HT improved glucose tolerance, elevated muscle and hepatic HSP72 protein content, and reduced muscle triglyceride storage. In primary hepatocytes, mitochondrial morphology was changed, and fatty acid oxidation was reduced in small interfering HSP72 (siHSP72)-treated hepatocytes. Lipid accumulation following palmitate treatment was increased in siHSP72-treated hepatocytes. These data suggest that HT may improve systemic metabolism via induction of hepatic HSP72. Additionally, acute loss of HSP72 in primary hepatocytes impacts mitochondrial health as well as fat oxidation and storage. These findings suggest therapies targeting HSP72 in the liver may prevent NAFLD.

Skeletal muscle-specific overexpression of heat shock protein 72 improves skeletal muscle insulin-stimulated glucose uptake but does not alter whole body metabolism

AIMS

The induction of heat shock protein 72 (Hsp72) via heating, genetic manipulation or pharmacological activation is metabolically protective in the setting of obesity-induced insulin resistance across mammalian species. In this study, we set out to determine whether the overexpression of Hsp72, specifically in skeletal muscle, can protect against high-fat diet (HFD)-induced obesity and insulin resistance.

MATERIALS AND METHODS

An Adeno-Associated Viral vector (AAV), designed to overexpress Hsp72 in skeletal muscle only, was used to study the effects of increasing Hsp72 levels on various metabolic parameters. Two studies were conducted, the first with direct intramuscular (IM) injection of the AAV:Hsp72 into the tibialis anterior hind-limb muscle and the second with a systemic injection to enable body-wide skeletal muscle transduction.

RESULTS

IM injection of the AAV:Hsp72 significantly improved skeletal muscle insulin-stimulated glucose clearance in treated hind-limb muscles, as compared with untreated muscles of the contralateral leg when mice were fed an HFD. Despite this finding, systemic administration of AAV:Hsp72 did not improve body composition parameters such as body weight, fat mass or percentage body fat, nor did it lead to an improvement in fasting glucose levels or glucose tolerance. Furthermore, no differences were observed for other metabolic parameters such as whole-body oxygen consumption, energy expenditure or physical activity levels.

CONCLUSIONS

At the levels of Hsp72 over-expression reported herein, skeletal muscle-specific Hsp72 overexpression via IM injection has the capacity to increase insulin-stimulated glucose clearance in this muscle. However, upon systemic injection, which results in lower muscle Hsp72 overexpression, no beneficial effects on whole-body metabolism are observed.

Exercise, heat shock proteins and insulin resistance

Best known as chaperones, heat shock proteins (HSPs) also have roles in cell signalling and regulation of metabolism. Rodent studies demonstrate that heat treatment, transgenic overexpression and pharmacological induction of HSP72 prevent high-fat diet-induced glucose intolerance and skeletal muscle insulin resistance. Overexpression of skeletal muscle HSP72 in mice has been shown to increase endurance running capacity nearly twofold and increase mitochondrial content by 50%. A positive correlation between HSP72 mRNA expression and mitochondrial enzyme activity has been observed in human skeletal muscle, and HSP72 expression is markedly decreased in skeletal muscle of insulin resistant and type 2 diabetic patients. In addition, decreased levels of HSP72 correlate with insulin resistance and non-alcoholic fatty liver disease progression in livers from obese patients. These data suggest the targeted induction of HSPs could be a therapeutic approach for preventing metabolic disease by maintaining the body's natural stress response. Exercise elicits a number of metabolic adaptations and is a powerful tool in the prevention and treatment of insulin resistance. Exercise training is also a stimulus for increased HSP expression. Although the underlying mechanism(s) for exercise-induced HSP expression are currently unknown, the HSP response may be critical for the beneficial metabolic effects of exercise. Exercise-induced extracellular HSP release may also contribute to metabolic homeostasis by actively restoring HSP72 content in insulin resistant tissues containing low endogenous levels of HSPs.This article is part of the theme issue 'Heat shock proteins as modulators and therapeutic targets of chronic disease: an integrated perspective'.

Matrine Directly Activates Extracellular Heat Shock Protein 90, Resulting in Axonal Growth and Functional Recovery in Spinal Cord Injured-Mice

After spinal cord injury (SCI), reconstruction of neuronal tracts is very difficult because an inhibitory scar is formed at the lesion site, in which several axonal growth inhibitors, such as chondroitin sulfate proteoglycans (CSPG), accumulate. We previously found that matrine, a major alkaloid in Sophora flavescens, enhanced axonal growth in neurons seeded on CSPG coating. The aims of this study were to investigate therapeutic effects of matrine in SCI mice and to clarify the underlying mechanism. Matrine was orally administered to contusion SCI mice. In the matrine-treated mice, motor dysfunction of the hindlimbs was improved, and the density of 5-HT-positive tracts was increased in the injured spinal cord. We explored putative direct binding proteins of matrine in cultured neurons using drug affinity responsive target stability (DARTS). As a result, heat shock protein 90 (HSP90) was identified, and matrine enhanced HSP90 chaperon activity. We then presumed that extracellular HSP90 is a matrine-targeting signaling molecule, and found that specific blocking of extracellular HSP90 by a neutralizing antibody completely diminished matrine-induced axonal growth and SCI amelioration. Our results suggest that matrine enhances axonal growth and functional recovery in SCI mice by direct activation of extracellular HSP90. Matrine could be a significant candidate for therapeutic drugs for SCI with a novel mechanism.

Natural products for the treatment of type 2 diabetes mellitus: Pharmacology and mechanisms

Epidemiological studies have implied that diabetes mellitus (DM) will become an epidemic accompany with metabolic and endocrine disorders worldwide. Most of DM patients are affected by type 2 diabetes mellitus (T2DM) with insulin resistance and insulin secretion defect. Generally, the strategies to treat T2DM are diet control, moderate exercise, hypoglycemic and lipid-lowing agents. Despite the therapeutic benefits for the treatment of T2DM, most of the drugs can produce some undesirable side effects. Considering the pathogenesis of T2DM, natural products (NPs) have become the important resources of bioactive agents for anti-T2DM drug discovery. Recently, more and more natural components have been elucidated to possess anti-T2DM properties, and many efforts have been carried out to elucidate the possible mechanisms. The aim of this paper was to overview the activities and underlying mechanisms of NPs against T2DM. Developments of anti-T2DM agents will be greatly promoted with the increasing comprehensions of NPs for their multiple regulating effects on various targets and signal pathways.

Design, synthesis and biological evaluation of novel bouchardatine analogs as potential inhibitors of adipogenesis/lipogenesis in 3T3-L1 adipocytes

Inhibition of the differentiation of adipocytes and reduced lipid synthesis are efficacious approaches for treating obesity-related metabolic disorders. Bouchardatine (Bou) is a natural alkaloid that has been reported to moderately inhibit the differentiation of 3T3-L1 cells without inducing toxicity. To explore the importance of aldehyde group at 8a-position of Bou and optimize the activity, we synthesized 35 (31 novel) compounds by discarding or replacing aldehyde group with halogen and introducing different amine chains at 5-position of Bou. The lipid-lowering activity was evaluated using a cell-based screening system. The substitution of the group at the 8a-position of compounds was important for its lipid-lowering activity, and the SAR was discussed. The selective compound 6e showed a 93-fold increase in its lipid-lowering effect (EC₅₀ = 0.24 μM) compared with Bou (EC₅₀ ≈ 25 μM). Further mechanistic studies revealed that compound 6e activated AMP-activated protein kinase (AMPK) pathway and inhibited MCE activity to block cell proliferation and induce cell cycle arrest at the early stage of differentiation, thus decreasing the expression of adipogenic factors and fatty acid synthesis-related proteins.

Matrine Inhibits Neuroblastoma Cell Proliferation and Migration by Enhancing Tribbles 3 Expression

Neuroblastoma is a major contributor of cancer-specific mortality. Although remarkable enhancement has been achieved in the treatment of neuroblastoma in patients with early stage disease, limited progress has been made in the treatment of patients with high-risk neuroblastoma. Thus, innovative approaches are required to achieve further improvements in neuroblastoma patient survival outcomes. The major alkaloid obtained from Sophora flavescens Ait, matrine, has been shown to counteract malignancy in various kinds of cancers. In the current study, we evaluated the effects of matrine on the migration and proliferation of neuroblastoma cells. Cell cycle analysis coupled with Transwell and wound healing experiments showed that matrine triggers G₂/M cell cycle arrest and suppresses neuroblastoma migration. This effect of matrine is due to upregulation of TRB3 expression followed by inhibition of the PI3K/AKT activation. Consistent with the in vitro data, growth of xenograft cancer was also suppressed by matrine. Our results indicate that matrine inhibits neuroblastoma cell proliferation and migration by enhancing TRB3 expression, suggesting that matrine may serve as a promising agent for the treatment of neuroblastoma.

Matrine Is Identified as a Novel Macropinocytosis Inducer by a Network Target Approach

Comprehensively understanding pharmacological functions of natural products is a key issue to be addressed for the discovery of new drugs. Unlike some single-target drugs, natural products always exert diverse therapeutic effects through acting on a "network" that consists of multiple targets, making it necessary to develop a systematic approach, e.g., network pharmacology, to reveal pharmacological functions of natural products and infer their mechanisms of action. In this work, to identify the "network target" of a natural product, we perform a functional analysis of matrine, a marketed drug in China extracted from a medical herb Ku-Shen (Radix Sophorae Flavescentis). Here, the network target of matrine was firstly predicted by drugCIPHER, a genome-wide target prediction method. Based on the network target of matrine, we performed a functional gene set enrichment analysis to computationally identify the potential pharmacological functions of matrine, most of which are supported by the literature evidence, including neurotoxicity and neuropharmacological activities of matrine. Furthermore, computational results demonstrated that matrine has the potential for the induction of macropinocytosis and the regulation of ATP metabolism. Our experimental data revealed that the large vesicles induced by matrine are consistent with the typical characteristics of macropinosome. Our verification results also suggested that matrine could decrease cellular ATP level. These findings demonstrated the availability and effectiveness of the network target strategy for identifying the comprehensive pharmacological functions of natural products.

Efficacy and Safety of Compound Kushen Injection on Patients with Advanced Colon Cancer: A Meta-Analysis of Randomized Controlled Trials

Objective

The efficacy and safety of Compound Kushen Injection (CKI) on advanced colon cancer remain controversial. We undertook a systematic meta-analysis of randomized controlled clinical studies on this issue.

Methods

A comprehensive literature search was conducted by searching the following electronic databases: PubMed, Cochrane, Chinese Biological Medical disc, Chinese National Knowledge Infrastructure, and Wan-Fang Database in China by the end of January 31, 2017, without language restriction. Meta-analysis was performed by using the random effects model to estimate the summary odd ratio (OR) with 95% confidence interval (CI) according to the study design. Stata 12.0 software was used for data analysis. The heterogeneity, sensitivity, and publication bias were assessed, respectively.

Results

A total of 14 trials met the inclusion criteria in present meta-analysis. The results suggested that CKI combined with chemotherapeutic drugs was favorable for the treatment of advanced colon cancer and could improve the patients' life quality. Funnel plot analysis and Egger's test suggested that there was not significant publication bias, and the sensitivity analysis indicated stable results.

Conclusion

The current evidence suggested that CKI is favorable to improve the efficacy of chemotherapeutic drugs in patients with advanced colon cancer.

Matrine prevents bone loss in ovariectomized mice by inhibiting RANKL-induced osteoclastogenesis

Osteoporosis is a metabolic bone disease characterized by decreased bone density and strength due to excessive loss of bone protein and mineral content. The imbalance between osteogenesis by osteoblasts and osteoclastogenesis by osteoclasts contributes to the pathogenesis of postmenopausal osteoporosis. Estrogen withdrawal leads to increased levels of proinflammatory cytokines. Overactivated osteoclasts by inflammation play a vital role in the imbalance. Matrine is an alkaloid found in plants from the Sophora genus with various pharmacological effects, including anti-inflammatory activity. Here we demonstrate that matrine significantly prevented ovariectomy-induced bone loss and inhibited osteoclastogenesis in vivo with decreased serum levels of TRAcp5b, TNF-α, and IL-6. In vitro matrine significantly inhibited osteoclast differentiation induced by receptor activator for NF-κB ligand (RANKL) and M-CSF in bone marrow monocytes and RAW264.7 cells as demonstrated by tartrate-resistant acid phosphatase (TRAP) staining and actin-ring formation as well as bone resorption through pit formation assays. For molecular mechanisms, matrine abrogated RANKL-induced activation of NF-κB, AKT, and MAPK pathways and suppressed osteoclastogenesis-related marker expression, including matrix metalloproteinase 9, NFATc1, TRAP, C-Src, and cathepsin K. Our study demonstrates that matrine inhibits osteoclastogenesis through modulation of multiple pathways and that matrine is a promising agent in the treatment of osteoclast-related diseases such as osteoporosis.-Chen, X., Zhi, X., Pan, P., Cui, J., Cao, L., Weng, W., Zhou, Q., Wang, L., Zhai, X. Zhao, Q., Hu, H., Huang, B., Su, J. Matrine prevents bone loss in ovariectomized mice by inhibiting RANKL-induced osteoclastogenesis.

Natural alkaloid bouchardatine ameliorates metabolic disorders in high-fat diet-fed mice by stimulating the sirtuin 1/liver kinase B-1/AMPK axis

BACKGROUND AND PURPOSE

Promoting energy metabolism is known to provide therapeutic effects for obesity and associated metabolic disorders. The present study evaluated the therapeutic effects of the newly identified bouchardatine (Bou) on obesity-associated metabolic disorders and the molecular mechanisms of these effects.

EXPERIMENTAL APPROACH

The molecular mode of action of Bou for its effects on lipid metabolism was first examined in 3T3-L1 adipocytes and HepG2 cells. This was followed by an evaluation of its metabolic effects in mice fed a high-fat diet for 16 weeks with Bou being administered in the last 5 weeks. Further mechanistic investigations were conducted in pertinent organs of the mice and relevant cell models.

KEY RESULTS

In 3T3-L1 adipocytes, Bou reduced lipid content and increased sirtuin 1 (SIRT1) activity to facilitate liver kinase B1 (LKB1) activation of AMPK. Chronic administration of Bou (50 mg∙kg^-1 every other day) in mice significantly attenuated high-fat diet-induced increases in body weight gain, dyslipidaemia and fatty liver without affecting food intake and no adverse effects were detected. These metabolic effects were associated with activation of the SIRT1-LKB1-AMPK signalling pathway in adipose tissue and liver. Of particular note, UCP1 expression and mitochondrial biogenesis were increased in both white and brown adipose tissues of Bou-treated mice. Incubation with Bou induced similar changes in primary brown adipocytes isolated from mice.

CONCLUSIONS AND IMPLICATIONS

Bou may have therapeutic potential for obesity-related metabolic diseases by increasing the capacity of energy expenditure in adipose tissues and liver through a mechanism involving the SIRT1-LKB1-AMPK axis.

Effect of oxymatrine HSPC liposomes on improving bioavailability, liver target distribution and hepatoprotective activity of oxymatrine

Oxymatrine (OMT) and matrine (MT) are two naturally occurring alkaloids, both of them provide anti-hepatitis effects. However OMT effect was heavily limited due to its low bioavailability, short half-life and whole body distribution. Herein, we investigated hydrogenated soybean phosphatidylcholine (HSPC) liposomes made by pH gradient active loading to understand the improved hepatoprotective effect mechanisms. Pharmacokinetics researches demonstrated the half-life time of OMT HSPC liposomes was 17.10h in mice. Compared with OMT solution, AUC _(0-8) of OMT and MRT _(0-8) of MT had been increased 11.8 fold and 14.3 fold in HSPC liposomes. Moreover, tissue distribution revealed the relative AUC_s of total alkaloids in liver of OMT HSPC liposomes was as 4.18 times as that of OMT solution. Our data suggested that pathological topical necrosis and mild vacuolar degeneration of liver progressively returned to normal, and serum level of alanine-aminotransferase (ALT) and aspartate-aminotransferase (AST) were significantly reduced after treating with OMT HSPC liposomes in acute liver injury mice induced by CCl₄. Pharmacokinetics, biodistribution and pathological researches manifested that HSPC liposomes served as an ideal and potential oxymatrine liver target carrier to prolong OMT retention time and maintain high therapeutically level in liver.

Attenuation of exercise-induced heat shock protein 72 expression blunts improvements in whole-body insulin resistance in rats with type 2 diabetes

Heat shock proteins (HSPs) play an important role in insulin resistance and improve the cellular stress response via HSP induction by exercise to treat type 2 diabetes. In this study, the effects of exercise-induced HSP72 expression levels on whole-body insulin resistance in type 2 diabetic rats were investigated. Male 25-week-old Otsuka Long-Evans Tokushima Fatty rats were divided into three groups: sedentary (Sed), trained in a thermal-neutral environment (NTr: 25 °C), and trained in a cold environment (CTr: 4 °C). Exercise training was conducted 5 days/week for 10 weeks. Rectal temperature was measured following each bout of exercise. An intraperitoneal glucose tolerance test (IPGTT) was performed after the training sessions. The serum, gastrocnemius muscle, and liver were sampled 48 h after the final exercise session. HSP72 and heat shock cognate protein 73 expression levels were analyzed by Western blot, and serum total cholesterol, triglyceride (TG), and free fatty acid (FFA) levels were measured. NTr animals exhibited significantly higher body temperatures following exercise, whereas, CTr animals did not. Exercise training increased HSP72 levels in the gastrocnemius muscle and liver, whereas, HSP72 expression was significantly lower in the CTr group than that in the NTr group (p < 0.05). Glucose tolerance improved equally in both trained animals; however, insulin levels during the IPGTT were higher in CTr animals than those in NTr animals (p < 0.05). In addition, the TG and FFA levels decreased significantly only in NTr animals compared with those in Sed animals. These results suggest that attenuation of exercise-induced HSP72 expression partially blunts improvement in whole-body insulin resistance and lipid metabolism in type 2 diabetic rats.

Anti-ageing active ingredients from herbs and nutraceuticals used in traditional Chinese medicine: pharmacological mechanisms and implications for drug discovery

Ageing, an unanswered question in the medical field, is a multifactorial process that results in a progressive functional decline in cells, tissues and organisms. Although it is impossible to prevent ageing, slowing down the rate of ageing is entirely possible to achieve. Traditional Chinese medicine (TCM) is characterized by the nourishing of life and its role in anti-ageing is getting more and more attention. This article summarizes the work done on the natural products from TCM that are reported to have anti-ageing effects, in the past two decades. The effective anti-ageing ingredients identified can be generally divided into flavonoids, saponins, polysaccharides, alkaloids and others. Astragaloside, Cistanche tubulosa acteoside, icariin, tetrahydrocurcumin, quercetin, butein, berberine, catechin, curcumin, epigallocatechin gallate, gastrodin, 6-Gingerol, glaucarubinone, ginsenoside Rg1, luteolin, icarisid II, naringenin, resveratrol, theaflavin, carnosic acid, catalpol, chrysophanol, cycloastragenol, emodin, galangin, echinacoside, ferulic acid, huperzine, honokiol, isoliensinine, phycocyanin, proanthocyanidins, rosmarinic acid, oxymatrine, piceid, puerarin and salvianolic acid B are specified in this review. Simultaneously, chemical structures of the monomers with anti-ageing activities are listed, and their source, model, efficacy and mechanism are also described. The TCMs with anti-ageing function are classified according to their action pathways, including the telomere and telomerase, the sirtuins, the mammalian target of rapamycin, AMP-activated kinase and insulin/insulin-like growth factor-1 signalling pathway, free radicals scavenging and the resistance to DNA damage. Finally, Chinese compound prescription and extracts related to anti-ageing are introduced, which provides the basis and the direction for the further development of novel and potential drugs.

LINKED ARTICLES

This article is part of a themed section on Principles of Pharmacological Research of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.11/issuetoc.