Gypenoside XLIX, a naturally occurring PPAR-alpha activator, inhibits cytokine-induced vascular cell adhesion molecule-1 expression and activity in human endothelial cells

PPARs in atherosclerosis: The spatial and temporal features from mechanism to druggable targets

BACKGROUND

Atherosclerosis is a chronic and complex disease caused by lipid disorder, inflammation, and other factors. It is closely related to cardiovascular diseases, the chief cause of death globally. Peroxisome proliferator-activated receptors (PPARs) are valuable anti-atherosclerosis targets that showcase multiple roles at different pathological stages of atherosclerosis and for cell types at different tissue sites.

AIM OF REVIEW

Considering the spatial and temporal characteristics of the pathological evolution of atherosclerosis, the roles and pharmacological and clinical studies of PPARs were summarized systematically and updated under different pathological stages and in different vascular cells of atherosclerosis. Moreover, selective PPAR modulators and PPAR-pan agonists can exert their synergistic effects meanwhile reducing the side effects, thereby providing novel insight into future drug development for precise spatial-temporal therapeutic strategy of anti-atherosclerosis targeting PPARs.

KEY SCIENTIFIC

Concepts of Review: Based on the spatial and temporal characteristics of atherosclerosis, we have proposed the importance of stage- and cell type-dependent precision therapy. Initially, PPARs improve endothelial cells' dysfunction by inhibiting inflammation and oxidative stress and then regulate macrophages' lipid metabolism and polarization to improve fatty streak. Finally, PPARs reduce fibrous cap formation by suppressing the proliferation and migration of vascular smooth muscle cells (VSMCs). Therefore, research on the cell type-specific mechanisms of PPARs can provide the foundation for space-time drug treatment. Moreover, pharmacological studies have demonstrated that several drugs or compounds can exert their effects by the activation of PPARs. Selective PPAR modulators (that specifically activate gene subsets of PPARs) can exert tissue and cell-specific effects. Furthermore, the dual- or pan-PPAR agonist could perform a better role in balancing efficacy and side effects. Therefore, research on cells/tissue-specific activation of PPARs and PPAR-pan agonists can provide the basis for precision therapy and drug development of PPARs.

Gypenoside XLIX alleviates sepsis-associated encephalopathy by targeting PPAR-α

Sepsis-related systemic inflammation is a deadly condition with high rates of morbidity and mortality. There is evidence that sepsis affects the brain, and the most frequent organ dysfunction linked to sepsis is sepsis-associated encephalopathy. Sepsis-related brain damage can drastically reduce a patient's chances of survival. However, a specific treatment for sepsis-associated encephalopathy is not currently available. Consequently, to treat the brain damage caused by sepsis, investigating novel therapeutic strategies is imperative. After establishing the CLP-induced mouse SAE model, we treated the mice with Gyp-XLIX and evaluated apoptosis, neuroinflammation, brain damage, and oxidative stress in the brain tissue of each group of mice. Furthermore, the protective effects of Gyp-XLIX on LPS-treated BV-2 cells were assessed. We discovered that Gyp-XLIX treatment increased the survival rate of CLP-treated mice, alleviated SAE-related cerebral nerve abnormalities, and decreased blood-brain barrier breakdown, all of which could better preserve brain tissue in vivo. Furthermore, we identified associated proteins and found that Gyp-XLIX may reduce oxidative stress, cell apoptosis, and inflammation in the brain tissues of SAE mice. This observation was further validated in vitro. We established that Gyp-XLIX alleviates SAE by targeting PPAR-α. These findings may be important for the clinical applicability of Gyp-XLIX in SAE treatment. We found that Gyp-XLIX can alleviate brain injury in SAE by targeting PPAR-α and is a potential protective agent for SAE.

Gypenoside XLIX alleviates acute liver injury: Emphasis on NF-κB/PPAR-α/NLRP3 pathways

Liver is one of the vital organs in the human body and liver injury will have a very serious impact on human damage. Gypenoside XLIX is a PPAR-α activator that inhibits the activation of the NF-κB signaling pathway. The components of XLIX have pharmacological effects such as cardiovascular protection, antihypoxia, anti-tumor and anti-aging. In this study, we used cecum ligation and puncture (CLP) was used to induce in vivo mice hepatic injury, and lipopolysaccharide (LPS)-induced inflammation in RAW264.7 cells, evaluated whether Gypenoside XLIX could have a palliative effect on sepsis-induced acute liver injury via NF-κB/PPAR-α/NLRP3. In order to gain insight into these mechanisms, six groups were created in vivo: the Contol group, the Sham group, the CLP group, the CLP + XLIX group (40 mg/kg) and the Sham + XLIX (40 mg/kg) group, and the CLP + DEX (2 mg/kg) group. Three groups were created in vitro: Control, LPS, LPS + XLIX (40 μM). The analytical methods used included H&E staining, qPCR, reactive oxygen species (ROS), oil red O staining, and Western Blot. The results showed that XLIX attenuated hepatic inflammatory injury in mice with toxic liver disease through inhibition of the TLR4-mediated NF-κB pathway, attenuated lipid accumulation through activation of PPAR-α, and attenuated hepatic pyroptosis by inhibiting NLRP3 production. Regarding the imbalance between oxidative and antioxidant defenses due to septic liver injury, XLIX reduced liver oxidative stress-related biomarkers (ALT, AST), reduced ROS accumulation, decreased the amount of malondialdehyde (MDA) produced by lipid peroxidation, and increased the levels of antioxidant enzymes such as glutathione (GSH) and catalase (CAT). Our results demonstrate that XLIX can indeed attenuate septic liver injury. This is extremely important for future studies on XLIX and sepsis, and provides a potential pathway for the treatment of acute liver injury.

Saponins derived from Gynostemma pentaphyllum regulate triglyceride and cholesterol metabolism and the mechanisms: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Gynostemma pentaphyllum (Thunb.) Makino (G. pentaphyllum) can be used for both medicinal and tea and has lipid-lowering properties. Modern research has shown that its main bioactive components are flavonoids and saponins. It has many beneficial effects such as hypolipidemic, anti-cancer, cardioprotective, hepatoprotective, neuroprotective, anti-diabetic and anti-inflammatory.

AIMS OF THE REVIEW

This review aimed to summarize its anti-glycolipid metabolic models and mechanisms are reviewed to facilitate a deeper understanding of the mechanism in lowering lipids.

MATERIALS AND METHODS

Information related to lipid lowering in G. pentaphyllum was collated by reviewing the relevant literature in the PubMed database from 1985 to 2023.

RESULTS

Only 101 G. pentaphyllum compounds have been initially explored for their hypolipidemic activity. There are cell models, animal models and human subjects for lipid-lowering of it. It reduced triglyceride level via PPAR/UCP-1/PGC-1α/PRDM16 and (SREBP-1c)-ACC/FAS-CPT1 signal pathways. Cholesterol-lowering effects via (SREBP-2)-HMGCR, PCSK9-LDLR and bile acid biosynthetic pathways. Activation of adenosine 5'-monophosphate-activated protein kinase (AMPK) is a key factor in the regulation of glycolipid metabolism in G. pentaphyllum. Other pathways of action of G. pentaphyllum in regulating glucolipid metabolism are also discussed in this paper.

CONCLUSION

To date, more than 328 saponins have been isolated and identified in Gynostemma. Further studies on these components, including molecular mechanisms and in vivo metabolic regulation, need to be further confirmed. G. pentaphyllum has the potential to be developed into drugs or functional foods, but further research is needed.

Gamma-glutamyl transferase predicts pemafibrate treatment response in non-alcoholic fatty liver disease

BACKGROUND AND AIM

Pemafibrate, a selective peroxisome proliferator activated receptor α modulator, has been shown to improve liver function among nonalcoholic fatty liver disease (NAFLD) patients with dyslipidemia. The aim of this retrospective study is to identify predictors of pemafibrate efficacy in NAFLD patients.

METHODS

A total of 75 NAFLD patients with dyslipidemia who received pemafibrate twice per day for 48 weeks were enrolled in this study. We used the FibroScan-aspartate aminotransferase (FAST) score as a benchmark for treatment efficacy.

RESULTS

Median FAST score significantly decreased from 0.96 at baseline to 0.93 at week 48 (P < 0.001). Significant improvements in levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT), and triglycerides were also noted. The serum level of GGT at baseline was correlated with change in FAST score (r = -0.22, P = 0.049). Changes in AST, ALT, and GGT were positively correlated with change in FAST score (r = 0.71, r = 0.61, and r = 0.38). Multivariate analyses identified age and GGT level at baseline as significantly associated with improvement of FAST score by pemafibrate therapy (odds ratio 1.11, 1.02, respectively). Patients over 50 years of age and with a GGT of 90 IU/L or higher showed significantly greater improvement in the FAST score than other groups.

CONCLUSIONS

Pemafibrate improves the FAST score of NAFLD patients with complicating dyslipidemia, especially in older patients with high GGT level. GGT is useful as an indicator of optimal treatment choice for NAFLD patients with dyslipidemia.

Dietary regulation of peroxisome proliferator-activated receptors in metabolic syndrome

BACKGROUND

Peroxisome proliferator-activated receptors (PPARs) are a class of ligand-activated nuclear transcription factors, members of the type nuclear receptor superfamily, with three subtypes, namely PPARα, PPARβ/δ, and PPARγ, which play a key role in the metabolic syndrome. In the past decades, a large number of studies have shown that natural products can act by regulating metabolic pathways mediated by PPARs.

PURPOSE

This work summarizes the physiological importance and clinical significance of PPARs and reviews the experimental evidence that natural products mediate metabolic syndrome via PPARs.

METHODS

This study reviews relevant literature on clinical trials, epidemiology, animals, and cell cultures published in NCBI PubMed, Scopus, Web of Science, Google Scholar, and other databases from 2001 to October 2022. Search keywords were "natural product" OR "botanical" OR "phytochemical" AND "PPAR" as well as free text words.

RESULTS

The modulatory involvement of PPARs in the metabolic syndrome has been supported by prior research. It has been observed that many natural products can treat metabolic syndrome by altering PPARs. The majority of currently described natural compounds are mild PPAR-selective agonists with therapeutic effects that are equivalent to synthetic medicines but less harmful adverse effects.

CONCLUSION

PPAR agonists can be combined with natural products to treat and prevent metabolic syndrome. Further human investigations are required because it is unknown how natural products cause harm and how they might have negative impacts.

Recent advances of traditional Chinese medicine for the prevention and treatment of atherosclerosis

ETHNOPHARMACOLOGICAL RELEVANCE

Atherosclerosis (AS) is a common systemic disease with increasing morbidity and mortality worldwide. Traditional Chinese medicine (TCM) with characteristics of multiple pathways and targets, presents advantages in the diagnosis and treatment of atherosclerosis.

AIM OF THE STUDY

With the modernization of TCM, the active ingredients and molecular mechanisms of TCM for AS treatment have been gradually revealed. Therefore, it is necessary to examine the existing studies on TCM therapies aimed at regulating AS over the past two decades.

MATERIALS AND METHODS

Using "atherosclerosis" and "Traditional Chinese medicine" as keywords, all relevant TCM literature published in the last 10 years was collected from electronic databases (such as Elsevier, Springer, PubMed, CNKI, and Web of Science), books and papers until March 2022, and the critical information was statistically analyzed.

RESULTS

In this review, we highlighted extracts of 8 single herbs, a total of 41 single active ingredients, 20 TCM formulae, and 25 patented drugs, which were described with chemical structure, source, model, efficacy and potential mechanism.

CONCLUSION

We summarized the cytopathological basis for the development of atherosclerosis involving vascular endothelial cells, macrophages and vascular smooth muscle cells, and categorically elaborated the medicinal TCM used for AS, all of which provide the current evidence on the better management of atherosclerosis by TCM.

Advances in the Bioactivities of Phytochemical Saponins in the Prevention and Treatment of Atherosclerosis

Atherosclerosis (AS) is a chronic inflammatory disease characterized by hardening and narrowing of arteries. AS leads to a number of arteriosclerotic vascular diseases including cardiovascular diseases, cerebrovascular disease and peripheral artery disease, which pose a big threat to human health. Phytochemicals are a variety of intermediate or terminal low molecular weight secondary metabolites produced during plant energy metabolism. Phytochemicals from plant foods (vegetables, fruits, whole grains) and traditional herb plants have been shown to exhibit multiple bioactivities which are beneficial for prevention and treatment against AS. Many types of phytochemicals including polyphenols, saponins, carotenoids, terpenoids, organic sulfur compounds, phytoestrogens, phytic acids and plant sterols have already been identified, among which saponins are a family of glycosidic compounds consisting of a hydrophobic aglycone (sapogenin) linked to hydrophilic sugar moieties. In recent years, studies have shown that saponins exhibit a number of biological activities such as anti-inflammation, anti-oxidation, cholesterol-lowering, immunomodulation, anti-platelet aggregation, etc., which are helpful in the prevention and treatment of AS. This review aims to summarize the recent advances in the anti-atherosclerotic bioactivities of saponins such as ginsenoside, soyasaponin, astra-galoside, glycyrrhizin, gypenoside, dioscin, saikosaponin, etc.

Chemical Characterization and Atherosclerosis Alleviation Effects of Gypenosides from Gynostemma pentaphyllum through Ameliorating Endothelial Dysfunction via the PCSK9/LOX-1 Pathway

Dietary saponins have the potential to ameliorate atherosclerosis (AS). Gypenosides of Gynostemma pentaphyllum (GPs) have been used as functional foods to exhibit antiatherosclerotic activity. The present study aimed to explore the protective effect, underlying mechanism and active substances of GPs on AS in vivo and in vitro. Results demonstrated GPs administration reduced the serum concentrations of TC and LDL-C, upregulated the plasma HDL-C content, inhibited the secretion of ICAM-1, VCAM-1, and MCP-1, and alleviated vascular lesions in VitD₃ plus high cholesterol diet-induced AS rats as well as reduced adhesion factors levels in ox-LDL-stimulated HUVECs, which was potentially associated with suppressing PCSK9/LOX-1 pathway. Further activity-guided phytochemical investigation of GPs led to the identification of five new dammarane-type glycosides (1-5) and ten known analogs (6-15). Bioassay evaluation showed compounds 1, 6, 7, 12, 13, and 14 observably reduced the expressions of PCSK9 and LOX-1, as well as the secretion of adhesion factors in injured HUVECs. Molecular docking experiments suggested that the active saponins of GPs might bind to the allosteric pocket of PCSK9 located at the catalytic and C-terminal domains, and 2α-OH-protopanaxadiol-type gypenosides might exert a higher affinity for an allosteric binding site on PCSK9 by hydrogen-bond interaction with ARG-458. These findings provide new insights into the potential nutraceutical application of GPs and their bioactive compounds in the prevention and discovery of novel therapeutic strategies for AS.

Determination of Gypenoside A and Gypenoside XLIX in Rat Plasma by UPLC-MS/MS and Applied to the Pharmacokinetics and Bioavailability

In this work, a UPLC-MS/MS method was developed for the determination of gypenoside A and gypenoside XLIX in rat plasma. For chromatographic separation, a UPLC BEH C18 column was employed, the mobile phase comprised acetonitrile: water (w/0.1% formic acid), and the elution time was 4 min. Detection of each compound was enabled by electrospray ionization in negative-ion mode, and quantitative analysis was enabled by operating in multiple reaction monitoring (MRM) mode by monitoring the transitions of m/z 897.5⟶403.3 for gypenoside A, m/z 1045.5⟶118.9 for gypenoside XLIX, and m/z 825.4⟶617.5 for the internal standard. The calibration curves for gypenoside A and gypenoside XLIX demonstrated excellent linearity (r > 0.995) over the range of 2–3000 ng/mL. The intraday and interday precisions of gypenoside A and gypenoside XLIX were within 14.9%, the intraday and interday accuracies ranged from 90.1% to 113.9%, the recoveries were all greater than 88.3%, and the matrix effect ranged from 87.1% to 94.1%. The developed method was successfully applied in the determination of the pharmacokinetics of gypenoside A and gypenoside XLIX. Gypenoside A and gypenoside XLIX had very short half-lives in rats, with oral t_1/2z of 1.4 ± 0.2 h and 1.8 ± 0.6 h, respectively, and low bioavailabilities (0.90% and 0.14%, respectively).

PPARα: A potential therapeutic target of cholestasis

The accumulation of bile acids in the liver leads to the development of cholestasis and hepatocyte injury. Nuclear receptors control the synthesis and transport of bile acids in the liver. Among them, the farnesoid X receptor (FXR) is the most common receptor studied in treating cholestasis. The activation of this receptor can reduce the amount of bile acid synthesis and decrease the bile acid content in the liver, alleviating cholestasis. Ursodeoxycholic acid (UDCA) and obeticholic acid (OCA) have a FXR excitatory effect, but the unresponsiveness of some patients and the side effect of pruritus seriously affect the results of UDCA or OCA treatment. The activator of peroxisome proliferator-activated receptor alpha (PPARα) has emerged as a new target for controlling the synthesis and transport of bile acids during cholestasis. Moreover, the anti-inflammatory effect of PPARα can effectively reduce cholestatic liver injury, thereby improving patients’ physiological status. Here, we will focus on the function of PPARα and its involvement in the regulation of bile acid transport and metabolism. In addition, the anti-inflammatory effects of PPARα will be discussed in some detail. Finally, we will discuss the application of PPARα agonists for cholestatic liver disorders.

Enzymatic Biotransformation of Gypenoside XLIX into Gylongiposide I and Their Antiviral Roles against Enterovirus 71 In Vitro

Biotransformation of specific saponins in the valuable medical plants to increase their bioavailability and pharmaceutical activities has attracted more and more attention. A gene encoding a thermophilic glycoside hydrolase from Fervidobaterium pennivorans DSM9078 was cloned and expressed in Escherichia coli. The purified recombinant enzyme, exhibiting endoglucanase cellulase activity, was used to transform gypenoside XLIX into gylongiposide I via highly selective and efficient hydrolysis of the glucose moiety linked to the C21 position in gypenoside XLIX. Under the optimal reaction conditions for large scale production of gylongiposide I, 35 g gypenoside XLIX was transformed by using 20 g crude enzyme at pH 6.0 and 80 °C for 4 h with a molar yield of 100%. Finally, 11.51 g of gylongiposide I was purified using a silica gel column with 91.84% chromatographic purity. Furthermore, inhibitory activities of gypenoside XLIX and gylongiposide I against Enterovirus 71 (EV71) were investigated. Importantly, the EC50 of gypenoside XLIX and gylongiposide I calculated from viral titers in supernatants was 3.53 μM and 1.53 μM, respectively. Moreover, the transformed product gylongiposide I has better anti-EV71 activity than the glycosylated precursor. In conclusion, this enzymatic method would be useful in the large-scale production of gylongiposide I, which would be a novel potent anti-EV71 candidate.

Gypenoside XLIX protects against acute kidney injury by suppressing IGFBP7/IGF1R-mediated programmed cell death and inflammation

BACKGROUND

Acute kidney injury (AKI), characterised by excessive inflammatory cell recruitment and programmed cell death, has a high morbidity and mortality; however, effective and specific therapies for AKI are still lacking.

OBJECTIVE

This study aimed to evaluate the renoprotective effects of gypenoside XLIX (Gyp XLIX) in AKI.

METHODS

The protective effects of Gyp XLIX were tested in two AKI mouse models established using male C57BL/6 mice (aged 6-8 weeks) by a single intraperitoneal injection of cisplatin (20 mg/kg) or renal ischemia-reperfusion for 40 min. Gyp XLIX was administered intraperitoneally before cisplatin administration or renal ischemia-reperfusion. Renal function, tubular injury, renal inflammation and programmed cell death were evaluated. In addition, the renoprotective effects of Gyp XLIX were also evaluated in cisplatin- or hypoxia-treated tubular epithelial cells. The mechanisms underlying these effects were then explored using RNA sequencing.

RESULTS

In vivo, Gyp XLIX substantially suppressed the increase in serum creatinine and blood urea nitrogen levels. Moreover, tubular damage was alleviated by Gyp XLIX as shown by periodic acid-Schiff staining, electron microscopy and molecular analysis of KIM-1. Consistently, we found that Gyp XLIX suppressed renal necroptosis though the RIPK1/RIPK3/MLKL pathway. The anti-inflammatory and antinecroptotic effects were further confirmed in vitro. Mechanistically, RNA sequencing showed that Gyp XLIX markedly suppressed the levels of IGF binding protein 7 (IGFBP7). Co-immunoprecipitation and western blot analysis further showed that Gyp XLIX reduced the binding of IGFBP7 to IGF1 receptor (IGF1R). Additionally, picropodophyllin, an inhibitor of IGF1R, abrogated the therapeutic effects of Gyp XLIX on cisplatin-induced renal cell injury; this finding indicated that Gyp XLIX may function by activating IGF1R-mediated downstream signalling Additionally, we also detected the metabolic distribution of Gyp XLIX after injection; Gyp XLIX had a high concentration in the kidney and exhibited a long retention time. These findings may shed light on the application of Gyp XLIX for AKI treatment clinically.

CONCLUSION

Gyp XLIX may serve as a potential therapeutic agent for AKI treatment via IGFBP7/ IGF1R-dependent mechanisms.

Endothelial activation and dysfunction in COVID-19: from basic mechanisms to potential therapeutic approaches

On 12 March 2020, the outbreak of coronavirus disease 2019 (COVID-19) was declared a pandemic by the World Health Organization. As of 4 August 2020, more than 18 million confirmed infections had been reported globally. Most patients have mild symptoms, but some patients develop respiratory failure which is the leading cause of death among COVID-19 patients. Endothelial cells with high levels of angiotensin-converting enzyme 2 expression are major participants and regulators of inflammatory reactions and coagulation. Accumulating evidence suggests that endothelial activation and dysfunction participate in COVID-19 pathogenesis by altering the integrity of vessel barrier, promoting pro-coagulative state, inducing endothelial inflammation, and even mediating leukocyte infiltration. This review describes the proposed cellular and molecular mechanisms of endothelial activation and dysfunction during COVID-19 emphasizing the principal mediators and therapeutic implications.

Gypenoside inhibits ox-LDL uptake and foam cell formation through enhancing Sirt1-FOXO1 mediated autophagy flux restoration

BACKGROUND

Gypenoside (GP) is the major bioactive constituent of G. pentaphyllum, a traditional Chinese medicine. It has been reported that GP can affect autophagy and lipid metabolism in cultured cells. We hypothesize that GP can inhibit foam cell formation in cultured macrophages through autophagy modulation.

METHODS

THP1 cells were cultured and treated with oxidized low-density lipoprotein (ox-LDL), followed by GP treatment at different concentrations. The autophagy flux was evaluated using western blot and confocal microscope analyses. The ox-LDL uptake and foam cell formation abilities were measured.

RESULTS

We found that ox-LDL impaired the autophagy flux in the cultured macrophages, indicated by a significant reduction of LC3-II and autophagosome puncta quantification, as well as an accumulation of p62 proteins. GP treatment, however, dose-dependently restored the autophagy flux impaired by ox-LDL and reduced the ox-LDL uptake and foam cell transformation from THP1 cells, which can be alleviated, or exacerbated, by modulation of autophagy status using autophagy enhancer or inhibitor. Coimmunoprecipitation assays showed that GP up-regulated Srit1 and FOXO1 expression and enhanced their direct interaction, and thus contributed to the regulation of autophagy.

CONCLUSION

GP inhibits ox-LDL uptake and foam cell formation through enhancing Sirt1-FOXO1 mediated autophagy flux restoration, suggesting this compound has therapeutic potential for atherosclerosis.

Natural Drugs as a Treatment Strategy for Cardiovascular Disease through the Regulation of Oxidative Stress

Oxidative stress (OS) refers to the physiological imbalance between oxidative and antioxidative processes leading to increased oxidation, which then results in the inflammatory infiltration of neutrophils, increased protease secretion, and the production of a large number of oxidative intermediates. Oxidative stress is considered an important factor in the pathogenesis of cardiovascular disease (CVD). At present, active components of Chinese herbal medicines (CHMs) have been widely used for the treatment of CVD, including coronary heart disease and hypertension. Since the discovery of artemisinin for the treatment of malaria by Nobel laureate Youyou Tu, the therapeutic effects of active components of CHM on various diseases have been widely investigated by the medical community. It has been found that various active CHM components can regulate oxidative stress and the circulatory system, including ginsenoside, astragaloside, and resveratrol. This paper reviews advances in the use of active CHM components that modulate oxidative stress, suggesting potential drugs for the treatment of various CVDs.

Protective Effect of Saponins-Enriched Fraction of Gynostemma pentaphyllum against High Choline-Induced Vascular Endothelial Dysfunction and Hepatic Damage in Mice

Choline as a quaternary amine nutrient is metabolized to trimethylamine by gut microbiota and subsequently oxidized to circulating trimethylamine-N-oxide (TMAO), a gut-derived metabolite associated with liver toxicity and cardiovascular disease. The study was to probe the possible vasoprotective and hepatoprotective effects of total saponins of Gynostemma pentaphyllum (TSGP) in 3% high-choline water-feeding mice. The purified TSGP was obtained with content of 83.0% saponins, and its antioxidant activities were evaluated in vitro. Furthermore, the mice fed with high choline for 8 weeks significantly expressed vascular endothelial dysfunction and liver oxidative stress (p < 0.01 vs. Normal). Administration of TSGP at 400 and 800 mg/kg·body weight (b.w.) significantly lowered the serum total cholesterol (TC), triglyceride (TG), low density lipoprotein-cholesterol (LDL-C), endothelin-1 (ET-1) and thromboxane A₂ (TXA₂) levels, as well as hepatic malondialdehyde (MDA) formation, but effectively elevated the serum nitric oxide (NO), endothelial nitric oxide synthase (eNOS) and prostaglandin I₂ (PGI₂) levels, as well as alanine aminotransferase (ALT), aspartate aminotransferase (AST), T-superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in high choline-fed mice. Hematoxylin-eosin (H&E) and oil red O staining also suggested that TSGP could exert the significant protection against endothelial dysfunction and liver injury in high choline-treated mice. These findings suggest that TSGP is of the saponins-enriched extract, and is a good candidate of dietary supplement and therapeutic application in vascular and hepatic oxidative injury.

Gypenosides Protect Orbital Fibroblasts in Graves Ophthalmopathy via Anti-Inflammation and Anti-Fibrosis Effects

Purpose

To investigate the effect of Gypenosides (Gyps) on the inflammation and fibrosis in orbital fibroblasts (OFs) in Graves ophthalmopathy (GO).

Methods

Bioinformatics analyses were performed to identify the enriched genes and signaling pathways related to Gyps function. For ex vivo experiments, OFs were cultured from orbital connective tissues from patients with GO. OF proliferation was estimated by Cell Counting Kit-8 assay. Effects of Gyps treatment on interleukin (IL)-1β-induced inflammation and transforming growth factor-β1 (TGF-β1)-induced fibrosis were evaluated by real-time quantitative PCR (RT-qPCR), enzyme-linked immunosorbent assay (ELISA), and Western blotting. OFs were treated with IL-1β or TGF-β1 in the absence or presence of Gyps pretreatment, and the levels of related mRNA or proteins were evaluated by RT-qPCR or ELISA.

Results

Eight inflammation-related target genes and nine fibrosis-related target genes were screened out. These genes were mainly enriched in pathways corresponding to inflammation and fibrosis, respectively. IL-1β-induced upregulation of inflammatory cytokines, and TGF-β-induced upregulation of fibrotic mediators in OFs were downregulated by Gyps. Moreover, Gyps reduced the activation of Toll like receptors 4/nuclear factor-κ B signaling and TGF-β1/SMAD2/SMAD4 signaling in GO OFs.

Conclusions

Gyps could protect GO-derived OFs against IL-1β-induced inflammation and TGF-β1-induced fibrosis. Thus Gyps might have therapeutic potential on inflammation and fibrosis in GO.

Medicinal Value and Potential Therapeutic Mechanisms of Gynostemma pentaphyllum (Thunb.) Makino and Its Derivatives: An Overview

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Gynostemma pentaphyllum (Thunb.) Makino (GpM) and its derivatives, especially gypenosides (Gyps), are widely used as safe and convenient natural herbal drugs for the treatment of many diseases for a long time, and Gyps have different oral bioavailability (OB) values and low ability to cross the blood-brain barrier (BBB). The effects of GpM and isolates on fibrosis, inflammation, oxidation, proliferation and migration are proved. GpM shows bidirectional regulation effect on proliferation, oxidation and apoptosis in tumor and non-tumor cells. GpM and its extractions can resist proliferation, activate oxidation and apoptosis in tumor cells and have opposite effects on non-tumor cells. We succinctly present some current views of medicinal value and potential therapeutic mechanisms of GpM and its derivatives.

Saponins as modulators of nuclear receptors

As plant-derived natural products, saponins have been widely applied for the dietary modification of metabolic syndrome. However, the underlying mechanisms of their preventive and therapeutic effects are still largely unclear. Nuclear receptors have been identified as potential pharmaceutical targets for treating various types of metabolic disorders. With similar structure to endogenous hormones, several saponins may serve as selective ligands for nuclear receptors. Recently, a series of saponins are proved to exert their physiological activities through binding to nuclear receptors. This review summarizes the biological and pharmacological activities of typical saponins mediated by some of the most well described nuclear receptors, including the classical steroid hormone receptors (ER, GR, MR, and AR) and the adopted orphan receptors (PPAR, LXR, FXR, and PXR).

Preventive Effect of Flavonol Derivatives Abundant Sanglan Tea on Long-Term High-Fat-Diet-Induced Obesity Complications in C57BL/6 Mice

Sanglan Tea (SLT) is a Chinese medicine-based formulation that is consumed as a health drink for the effective management of obesity-associated complications. However, its chemical components and mechanism of action in the prevention of hepatic steatosis and obesity-related impairments have been uncertain. In this study, we aimed to unveil the chemical profile of SLT and to explore its preventive mechanism in high-fat-diet-induced non-alcoholic fatty liver disease (NAFLD) and obesity-related consequences in C57BL/6 mice. Ultrahigh-performance liquid chromatography (UHPLC) coupled to a quadrupole-orbitrap high-resolution mass spectrometry (MS) analysis of SLT indicated that analogs of quercetin and kaempferol are major compounds of flavonoids in SLT. A dietary supplement of SLT efficiently managed the blood glucose elevation, retained the serum total cholesterol (TC), LDL-cholesterol (LDL-C), and triglyceride (TG) levels, as well as aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activity, and reduced the fat storage in the liver induced by a high-fat diet. The underlying mechanism of this preventive effect is hypothesized to be related to the inhibition of over-expression of lipogenesis and adipogenesis-related genes. Overall, this study suggests that SLT, being rich in quercetin and kaempferol analogs, could be a potential food supplement for the prevention of high-fat-diet-induced NAFLD and obesity-related complications.

Atheroprotective effects and molecular targets of bioactive compounds from traditional Chinese medicine

Traditional Chinese medicine (TCM) has served the Chinese people since antiquity, and is playing an important role in today's healthcare. However, there has been controversy in the use of these traditional herbs due to unclear components and absence of scientific proof. As China plans to modernize traditional medicine, successful attempts to better understand the molecular mechanisms of TCM have been made by focusing on isolating active ingredients from these remedies. In this review, we critically examined the current evidence on atheroprotective effects of bioactive compounds from TCM using in vitro or in vivo models in the past two decades. A total of 47 active compounds were included in our review, which were introduced in the order of chemical structures, source, model, efficacy and mechanism. Notablely, this review highlighted the cellular and molecular mechanisms of these active compounds in prevention and treatment of atherosclerosis. Two compounds were also involved in double-blind, randomized, placebo-controlled clinical trials (RCTs). Besides, we introduced the legislations of the People's Republic of China ensuring quality and safety of products used in TCM. In summary, studies on bioactive compounds from TCM will provide a new approach for better management of atherosclerosis.

Gynostemma pentaphyllum Attenuates the Progression of Nonalcoholic Fatty Liver Disease in Mice: A Biomedical Investigation Integrated with In Silico Assay

Nonalcoholic fatty liver disease (NAFLD) is the most common type of liver disease in developed countries. Oxidative stress plays a critical role in the progression of NAFLD. Modern pharmacological study and clinical trials have demonstrated the remarkable antioxidant activity of Gynostemma pentaphyllum (GP) in chronic liver disease. One aim of this study was to explore the potential protective effects and mechanisms of action of GP extract on NAFLD. The in vivo results showed that GP extract could alleviate fatty degeneration and haptic fibrosis in NAFLD mice. For exploring the hepatoprotective mechanisms of GP, we used network pharmacology to predict the potential active components of GP and their intracellular targets in NAFLD. Based on the network pharmacology results, we further utilized biomedical assays to validate this in silico prediction. The results showed that Gypenoside XL could upregulate the protein level of PPARα in NAFLD; the transcription level of several PPARα downstream target genes such as acyl-CoA oxidase (ACO) and carnitine palmitoyltransferase-1 (CPT-1) also increased after Gypenoside XL treatment. The overexpression of ACO and CPT-1 may involve the hepatoprotective effects of GP and Gypenoside XL on NAFLD by regulating mitochondrial fatty acid β-oxidation.

Chinese Herbal Medicine on Cardiovascular Diseases and the Mechanisms of Action

Cardiovascular diseases are the principal cause of death worldwide. The potentially serious adverse effects of therapeutic drugs lead to growing awareness of the role of Chinese herbal medicine in the treatment of cardiovascular diseases. Chinese herbal medicine has been widely used in many countries especially in China from antiquity; however, the mechanisms by which herbal medicine acts in the prevention and treatment of cardiovascular diseases are far from clear. In this review, we briefly describe the characteristics of Chinese herbal medicine by comparing with western medicine. Then we summarize the formulae and herbs/natural products applied in the clinic and animal studies being sorted according to the specific cardiovascular diseases. Most importantly, we elaborate the existing investigations into mechanisms by which herbal compounds act at the cellular levels, including vascular smooth muscle cells, endothelial cells, cardiomyocytes and immune cells. Future research should focus on well-designed clinic trial, in-depth mechanic study, investigations on side effects of herbs and drug interactions. Studies on developing new agents with effectiveness and safety from traditional Chinese medicine is a promising way for prevention and treatment of patients with cardiovascular diseases.

Development of a targeted method for quantification of gypenoside XLIX in rat plasma, using SPE and LC-MS/MS

A sensitive, selective and rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the quantification of gypenoside XLIX, a naturally occurring gypenoside of Gynostemma pentaphyllum in rat plasma and then validated according to the US Food and Drug Administration's Guidance for Industry: Bioanalytical Method Validation. Plasma samples were prepared by a simple solid-phase extraction. Separation was performed on a Waters XBridgeTM BEH C₁₈ chromatography column (4.6 × 50 mm, 2.5 μm) using a mobile phase of acetonitrile and water (62.5:37.5, v/v). Gypenoside XLIX and the internal standard gypenoside A were detected in the negative ion mode using selection reaction monitoring of the transitions at m/z 1045.6 → 913.5 and 897.5 → 765.4, respectively. The calibration curve was linear (R²  > 0.990) over a concentration range of 10-7500 ng/mL with the lower quantification limit of 10 ng/mL. Intra- and inter-day precision was within 8.6% and accuracy was ≤10.2%. Stability results proved that gypenoside XLIX and the IS remained stable throughout the analytical procedure. The validated LC-MS/MS method was then applied to analyze the pharmacokinetics of gypenoside XLIX after intravenous administration to rats (1.0, 2.0 and 4.0 mg/kg).

Peroxisome Proliferator-Activated Receptor α in Lipid Metabolism and Atherosclerosis

Atherosclerosis is a chronic inflammatory disease with deposition of excessive cholesterol in the arterial intima. Peroxisome proliferator-activated receptor α (PPARα) is a nuclear receptor that can activate or inhibit the expression of many target genes by forming a heterodimer complex with the retinoid X receptor. Activation of PPARα plays an important role in the metabolism of multiple lipids, including high-density lipoprotein, cholesterol, low-density lipoprotein, triglyceride, phospholipid, bile acids, and fatty acids. Increased PPARα activity also mitigates atherosclerosis by blocking macrophage foam cell formation, vascular inflammation, vascular smooth muscle cell proliferation and migration, plaque instability, and thrombogenicity. Clinical use of synthetic PPARα agonist fibrate improved dyslipidemia and attenuated atherosclerosis-related disease risk. This review summarizes PPARα in lipid and lipoprotein metabolism and atherosclerosis, and also highlights its potential therapeutic benefits.

Gypenosides induce apoptosis by ca2+ overload mediated by endoplasmic-reticulum and store-operated ca2+ channels in human hepatoma cells

Gypenosides (Gyps) are triterpenoid saponins contained in an extract from Gynostemma pentaphyllum Makino and reported to induce apoptosis in human hepatoma cells through Ca(2+)-implicated endoplasmic reticulum (ER) stress and mitochondria-dependent pathways. The mechanism underlying the Gyp-increased intracellular Ca(2+) concentration ([Ca(2+)]i) is unclear. Here, we examined Gyp-induced necrosis and apoptosis in human hepatoma HepG2 cells. Gyp-induced apoptotic cell death was accompanied by a sustained increase in [Ca(2+)]i level. Gyp-increased [Ca(2+)]i level was partly inhibited by removal of extracellular Ca(2+) by Ca(2+) chelator EGTA, store-operated Ca(2+) channel (SOC) inhibitor 2- aminoethoxydiphenyl borate (2-APB), and ER Ca(2+)-release-antagonist 3,4,5-trimethoxybenzoic acid 8-(diethylamino) octyl ester (TMB-8). The strongest inhibitory effect was observed with TMB-8. EGTA, 2-APB, and TMB-8 also protected against Gyp-induced apoptosis in HepG2 cells. The combination of 2-APB and TMB-8 almost completely abolished the Gyp-induced Ca(2+) response and apoptosis. In contrast, the sarco/endoplasmic-reticulum-Ca(2+)-ATPase (SERCA) inhibitor thapsigargin slightly elevated Gyp-induced [Ca(2+)]i increase and apoptosis in HepG2 cells. Exposure to 300 μg/mL Gyp for 24 hours upregulated protein levels of inositol 1,4,5-trisphosphate receptor and SOC and downregulated that of SERCA for at least 72 hours. Thus, Gyp-induced increase in [Ca(2+)]i level and consequent apoptosis in HepG2 cells may be mainly due to enhanced Ca(2+) release from ER stores and increased store-operated Ca(2+) entry.

Botanical compounds and their regulation of nuclear receptor action: the case of traditional Chinese medicine

Nuclear receptors (NRs) are major pharmacological targets that allow an access to the mechanisms controlling gene regulation. As such, some NRs were identified as biological targets of active compounds contained in herbal remedies found in traditional medicines. We aim here to review this expanding literature by focusing on the informative articles regarding the mechanisms of action of traditional Chinese medicines (TCMs). We exemplified well-characterized TCM action mediated by NR such as steroid receptors (ER, GR, AR), metabolic receptors (PPAR, LXR, FXR, PXR, CAR) and RXR. We also provided, when possible, examples from other traditional medicines. From these, we draw a parallel between TCMs and phytoestrogens or endocrine disrupting chemicals also acting via NR. We define common principle of action and highlight the potential and limits of those compounds. TCMs, by finely tuning physiological reactions in positive and negative manners, could act, in a subtle but efficient way, on NR sensors and their transcriptional network.

Hypoglycemic effect of Gynostemma pentaphyllum saponins by enhancing the Nrf2 signaling pathway in STZ-inducing diabetic rats

Gynostemma pentaphyllum (GP) is a natural plant resources for diabetes therapy, however, there is little research on the mechanisms of GP. The present study was undertaken to characterize if G. pentaphyllum saponins (GPs) is the principal active compound of GP responsible for anti-diabetes, and to examine the relativity between blood glucose modulate and antioxidation. The GPs-treated streptozotocin diabetic rats had a more effective hypoglycemic status than those of diabetic control rats, which also ameliorate dyslipidemia. GPs has increased SOD and GSH-px activities, and the spleen and thymus indexes in diabetic rats. The insulin levels in the GPs-treated groups were significantly higher than diabetic control group. Our finding provides a new insight into the application of GPs for the treatment of oxidative stress related diseases.

Ombuin-3-O-β-D-glucopyranoside from Gynostemma pentaphyllum is a dual agonistic ligand of peroxisome proliferator-activated receptors α and δ/β

We demonstrated that ombuin-3-O-β-D-glucopyranoside (ombuine), a flavonoid from Gynostemma pentaphyllum, is a dual agonist for peroxisome proliferator-activated receptors (PPARs) α and δ/β. Using surface plasmon resonance (SPR), time-resolved fluorescence resonance energy transfer (FRET) analyses, and reporter gene assays, we showed that ombuine bound directly to PPARα and δ/β but not to PPARγ or liver X receptors (LXRs). Cultured HepG2 hepatocytes stimulated with ombuine significantly reduced intracellular concentrations of triglyceride and cholesterol and downregulated the expression of lipogenic genes, including sterol regulatory element binding protein-1c (SREBP1c) and stearoyl-CoA desaturase-1 (SCD-1), with activation of PPARα and δ/β. Activation of LXRs by ombuine was confirmed by reporter gene assays, however, SPR and cell-based FRET assays showed no direct binding of ombuine to either of the LXRs suggesting LXR activation by ombuine may be operated via PPARα stimulation. Ombuine-stimulated macrophages showed significantly induced transcription of ATP binding cassette cholesterol transporter A1 (ABCA1) and G1 (ABCG1), the key genes in reverse cholesterol transport, which led to reduced cellular cholesterol concentrations. These results suggest that ombuine is a dual PPAR ligand for PPARα and δ/β with the ability to decrease lipid concentrations by reducing lipogenic gene expression in hepatocytes and inducing genes involved in cholesterol efflux in macrophages.

Restoration of electric footshock-induced immunosuppression in mice by Gynostemma pentaphyllum components

The immunomodulatory effects of the ethanol extract of Gynostemma pentaphyllum (GP-EX) were examined in electric footshock (EFS)-stressed mice. The mice were orally administered various doses of GP-EX for 7 days before exposure to EFS (duration: 3 min, interval: 10 s, intensity: 2 mA) once a day from day 8 for 14 days with continuous daily feeding of GP-EX. Oral administration of GP-EX to mice prevented EFS stress-induced immunosuppression as determined by the lymphoid organ (thymus and spleen) weight and cellularity. In addition, oral administration of GP-EX restored EFS-suppressed functional properties of mature lymphocytes in terms of concanavalin A-induced proliferation of splenocytes and lipopolysaccharide-induced cytokine production (TNF-α, IL-1β). Furthermore, we found that mice that were orally administered with GP-EX generated much more potent ovalbumin-specific cytotoxic T lymphocyte responses upon intravenous ovalbumin injection compared to the untreated controls. These results demonstrate that oral administration of the ethanol extract of Gynostemma pentaphyllum could increase host defense in immunocompromised situations such as stress-induced immunosuppression.

Preconditioning of brain slices against hypoxia induced injury by a Gynostemma pentaphyllum extract--stimulation of anti-oxidative enzyme expression

A short period of hypoxia/hypoglycaemia (oxygen and glucose deprivation, OGD) induced by perfusion with O(2)/glucose-free medium caused immediate loss and incomplete restoration of evoked field potentials in the CA1 region of transverse hippocampus slices. OGD-dependent decrease in evoked field potentials can be prevented by a proceeding short OGD event (preconditioning). We report about a study investigating the effect of an ethanolic Gynostemma pentaphyllum extract on evoked field potentials when administered before the OGD episode. Using this procedure, the extract completely protected the cells of the slices from functional injury. In an astroglia rich cell culture the ethanolic Gynostemma pentaphyllum extract caused within 48 h of cultivation increased protein and activity levels of the anti-oxidative enzymes manganese superoxide dismutase (Mn-SOD) and glutathione peroxidase (GPx). Consequently, the cellular H(2)O(2) concentration remained at a low level. These data suggest that the Gynostemma pentaphyllum-mediated increase in antioxidative enzyme activities may contribute to the protection of transverse hippocampus slices from OGD induced functional injury. Our results demonstrate that the prophylactic administration of the ethanolic extract from Gynostemma pentaphyllum has a high potential to protect from ischemia/reperfusion injury.

Lipid-regulating effect of traditional chinese medicine: mechanisms of actions

Traditional Chinese medicine (TCM) has been increasingly used for the treatment of dyslipidemia and cardiovascular disease. Recently, much progress has been made in studies on the mechanisms of action of the lipid-regulating effect of TCM in animal experiments. Current researches showed that the lipid-regulating effect of TCM may be related to the following actions: (1) inhibiting intestinal absorption of lipids; (2) reducing the biosynthesis of endogenous lipids; (3) increasing the catabolism of lipid, sterol substances in live system; (4) increasing the secretion of sterol substances in live system; (5) regulating transcription factors related to lipid metabolism. This paper provides an overview of the recent advances and discusses their implications in future development of lipid-lowering drugs from TCM.

Targeting inflammatory pathways by triterpenoids for prevention and treatment of cancer

Traditional medicine and diet has served mankind through the ages for prevention and treatment of most chronic diseases. Mounting evidence suggests that chronic inflammation mediates most chronic diseases, including cancer. More than other transcription factors, nuclear factor-kappaB (NF-κB) and STAT3 have emerged as major regulators of inflammation, cellular transformation, and tumor cell survival, proliferation, invasion, angiogenesis, and metastasis. Thus, agents that can inhibit NF-κB and STAT3 activation pathways have the potential to both prevent and treat cancer. In this review, we examine the potential of one group of compounds called triterpenes, derived from traditional medicine and diet for their ability to suppress inflammatory pathways linked to tumorigenesis. These triterpenes include avicins, betulinic acid, boswellic acid, celastrol, diosgenin, madecassic acid, maslinic acid, momordin, saikosaponins, platycodon, pristimerin, ursolic acid, and withanolide. This review thus supports the famous adage of Hippocrates, “Let food be thy medicine and medicine be thy food”.

Applying New Science for Old Medicines: Targeting Leukocyte-Endothelial Adhesions by Antiinflammatory Herbal Drugs

During the last two decades, considerable progress has been made in understanding the molecular mechanisms of the various leukocytes and endothelial cell adhesion molecules (cell adhesion molecules - CAMs) involved in cell-cell and cell matrix interactions. This understanding has opened up a new avenue of novel chemotherapeutic targets and bioassay models for inflammatory diseases. Recently developed In Vitro bioassays on leukocyte/endothelial cell adhesions can now offer rapid and inexpensive assessment methods for herbal medicines with claimed antiinflammatory uses. Through the use of these robust in vitro methods, active principles of herbal drugs can also be isolated thereby providing the opportunity of standardizations based on a known chemical standard(s) and pharmacology. This review highlights relevant leukocyte/endothelial CAMs targets, available in vitro methods and our strategic approach for herbal standardizations.

Dammarane saponins from Gynostemma pentaphyllum

Dammarane-type saponins (1-7), together with five known compounds, were isolated from the aerial parts of Gynostemma pentaphyllum. Compounds 1-4, 6 and 7 induced the phosphorylation of ERK protein in primary rat cortical neurons, which indicates their potential neuroactivity. On the other hand, no induction of ERK phosphorylation was observed for HEK293 cells following treatment with saponins 1, 3, 4 and 7.

Selective induction of apoptosis in glioma tumour cells by a Gynostemma pentaphyllum extract

At low concentration H(2)O(2) is an important signal molecule in proliferation of tumour cells. We report about a study investigating the effect of an ethanolic extract from Gynostemma pentaphyllum on proliferation of C6 glioma tumour cells and cellular H(2)O(2) concentration. The proliferation of these cells was maximal at about 1 muM extracellular H(2)O(2). HPLC-finger prints of the extract revealed a set of saponines as essential components. In C6 glioma cells the extract caused increase in super oxide dismutase (SOD) activity, in the amount of SOD protein, and in cellular H(2)O(2) concentration. It inhibited cell proliferation and induced activation of caspase 3 as indication of apoptosis. No effect of the extract was observed on the proliferation of astrocytes of a primary cell culture. From these findings we suggest that the ethanolic extract from Gynostemma pentaphyllum may selectively shift the H(2)O(2) concentration to toxic levels exclusively in tumour cells due to increased SOD activity. It may have a high potency in cancer therapy and cancer prophylaxis.

Protection of hippocampal slices against hypoxia/hypoglycemia injury by a Gynostemma pentaphyllum extract

In transverse hippcampus slices a short period of hypoxia/hypoglycemia induced by perfusion with O(2)/glucose-free medium caused early loss and incomplete restoration of evoked field potentials to only 50% in the CA(1) region. We report about a study investigating the effect of an ethanolic Gynostemma pentaphyllum extract in this system. When given with reperfusion the extract completely protected the cells of the slices from functional injury. The extract also protected at the subcellular level isolated mitochondria which had been subjected to hypoxia/reoxygenation in combination with elevated extramitochondrial Ca(2+) concentration from functional injury. In isolated mitochondria the extract protected from Ca(2+)-induced opening of the mitochondrial permeability transition pore and reduced lipid peroxidation. Our data demonstrate that the ethanolic extract of Gynostemma pentaphyllum has a high potential to protect from ischemia/reperfusion injury. It should be beneficial as prophylactic nutrition supplement and during revascularization of arterial blood vessels from stroke and other ischemic events such as coronary occlusion.

Newly developed PPAR-alpha agonist (R)-K-13675 inhibits the secretion of inflammatory markers without affecting cell proliferation or tube formation

Peroxisome proliferator-activated receptor-alpha (PPAR-alpha) is a key regulator of lipid and glucose metabolism and has been implicated in inflammation. The vascular effects of activator for PPARs, particularly PPAR-alpha, on vascular cells remain to be fully elucidated. Therefore, we analyzed the hypothesis that newly developed (R)-K-13675 decreases the secretion of inflammatory markers without affecting cell proliferation or tube formation. Human coronary endothelial cells (HCECs) were maintained in different doses of (R)-K-13675 under serum starvation. After 20h, the levels of monocyte chemoattractant protein-1 (MCP-1), regulated on activation, normal T expressed and secreted (RANTES), interleukin-6 (IL-6) and interferon-gamma (INF-gamma) secreted in the medium and nuclear factor kappa B (NFkappaB) in cell lysate were analyzed using enzyme-linked immunosorbent assays (ELISA). Upon treatment with (R)-K-13675 at 0, 10, 20, 50 and 100nM, with the inflammatory markers at 0nM as 100 (arbitrary units), MCP-1 levels were significantly suppressed (94+/-9, 88+/-2, 80+/-5 and 74+/-11, respectively). RANTES, IL-6 and INF-gamma levels were also significantly suppressed (RANTES: 92+/-2, 74+/-9, 64+/-7 and 60+/-2, respectively, IL-6: 97+/-2, 89+/-10, 82+/-1 and 66+/-7, respectively, INF-gamma: 98+/-7, 94+/-3, 76+/-8 and 64+/-8, respectively). NFkappaB levels were also decreased to 91+/-5, 90+/-5, 84+/-7 and 82+/-8, respectively. In addition, (R)-K-13675 did not affect HCEC proliferation or tube formation at up to 100nM. Thus, (R)-K-13675 was associated with the inhibition of inflammatory responses without affecting cell proliferation or angiogenesis, and subsequently may induce an anti-atherosclerotic effect.