Piperine attenuates cardiovascular, liver and metabolic changes in high carbohydrate, high fat-fed rats

The impact of piperine on the metabolic conditions of patients with NAFLD and early cirrhosis: a randomized double-blind controlled trial

Non-alcoholic fatty liver disease (NAFLD) is a metabolic dysfunction of the liver defined as an abnormal accumulation of fat within the liver without secondary triggers like alcohol consumption or viral hepatitis. Piperine, the bio-active ingredient of black pepper, can exert a significant function in treatment of individuals with NAFLDand early cirrhosis. We investigated the impact of piperine consumption with a duration of 12 weeks on patients with NAFLD and early cirrhosis compared toplacebo consumption. In a double-blind study, patients with NAFLD and early stage of cirrhosis were haphazardly distributed into case and control groups. They were prescribed a placebo and 5 mg of piperine for 12 weeks, respectively. The demographic and laboratory parameters of individuals were assessed as the baseline and after the duration of piperine intake. Piperine with a daily dosage of 5 mg could significantly decrease hepatic enzymes and glucose, and alleviate dyslipidemia in the case arm rather than the control arm. Moreover, HOMA levels and insulin resistance were reduced in case participants compared to the control counterparts. In the absence of approved medicinal intervention for patients with NAFLD, and regarding the favorable impact of piperine on NAFLD more studies on this subject are warranted.

Nutritional Metabolomics in Diet-Breast Cancer Relations: Current Research, Challenges, and Future Directions-A Review

Breast cancer is one of the most common types of cancer in women worldwide, and its incidence is increasing. Diet has been identified as a modifiable risk factor for breast cancer, but the complex interplay between diet, metabolism, and cancer development is not fully understood. Nutritional metabolomics is a rapidly evolving field that can provide insights into the metabolic changes associated with dietary factors and their impact on breast cancer risk. The review's objective is to provide a comprehensive overview of the current research on the application of nutritional metabolomics in understanding the relationship between diet and breast cancer. The search strategy involved querying several electronic databases, including PubMed, Scopus, Web of Science, and Google Scholar. The search terms included combinations of relevant keywords such as "nutritional metabolomics", "diet", "breast cancer", "metabolites", and "biomarkers". In this review, both in vivo and in vitro studies were included, and we summarize the current state of knowledge on the role of nutritional metabolomics in understanding the diet-breast cancer relationship, including identifying specific metabolites and metabolic pathways associated with breast cancer risk. We also discuss the challenges associated with nutritional metabolomics research, including standardization of analytical methods, interpretation of complex data, and integration of multiple-omics approaches. Finally, we highlight future directions for nutritional metabolomics research in studying diet-breast cancer relations, including investigating the role of gut microbiota and integrating multiple-omics approaches. The application of nutritional metabolomics in the study of diet-breast cancer relations, including 2-amino-4-cyano butanoic acid, piperine, caprate, rosten-3β,17β-diol-monosulfate, and γ-carboxyethyl hydrochroman, among others, holds great promise for advancing our understanding of the role of diet in breast cancer development and identifying personalized dietary recommendations for breast cancer prevention, control, and treatment.

Piperine mitigates aortic vasculopathy in streptozotocin-diabetic rats via targeting TXNIP-NLRP3 signaling

Several in vivo and in vitro studies reported a favorable effect of piperine (PIP) on vascular function. However, the potential impacts of PIP on macrovasculopathy in streptozotocin (STZ)-diabetic rats have not yet been studied. Thirty-two Sprague Dawley rats were used (n= 8/group). STZ-administered rats (50 mg/kg once, i.p) received PIP (30 mg/kg/day, orally) or its vehicle starting from day 15 till the end of the study (10 weeks). Control groups consisted of age-matched normal rats with or without PIP treatment. Metabolic and oxidative stress parameters were biochemically determined. Aortas were histologically examined. Ex vivo aortic reactivity to phenylephrine and acetylcholine was studied. Components of the TXNIP-NLRP3 pathway were assessed using real-time PCR, ELISA, and immunohistochemistry. Two-way ANOVA was used to compare groups. Statistical significance was set at P < 0.05. PIP treatment of diabetic rats significantly reduced levels of fasting glycemia, HbA_1c, and serum AGEs, TGs, TC, and LDL-C compared to control diabetic group. PIP diminished aortic endothelial denudation and fibrous tissue proliferation compared to control STZ aortas. PIP lessened aortic contractility to phenylephrine and improved aortic relaxation to acetylcholine relative to untreated STZ group. PIP administration to diabetic rats elicited significant enhancements in GSH and SOD levels, eNOS expression, and total nitrate/nitrite bioavailability compared to untreated STZ rats. Moreover, PIP attenuated aortic contents of ROS, MDA, TXNIP protein and mRNA, NF-κB p65 mRNA, NLRP3 mRNA, IL-1β protein, and caspase-3 and TNF-α expressions compared to untreated STZ levels. In conclusion, PIP might ameliorate diabetes-associated functional and structural aortic remodeling by targeting TXNIP-NLRP3 signaling.

Piperine attenuates hepatic steatosis and insulin resistance in high-fat diet-induced obesity in Sprague-Dawley rats

Substantial evidence suggests that pepper consumption is associated with a reduced risk of obesity-related complications. However, whether piperine, the main component of pepper, improves obesity-induced hepatic lipid accumulation and insulin resistance and the action mechanism of piperine still remain unclear. We hypothesized that piperine attenuates high-fat diet (HFD)-induced obesity and improves the related metabolic complications in HFD-induced obese rats. Adult Sprague-Dawley (SD) male rats were fed a control diet (CON) or an HFD for 16 weeks. Obese rats were divided into 4 groups: HFD and HFD with daily gavage of piperine 2.7 mg/kg body weight (PIP-Low), 13.5 mg/kg body weight (PIP-Medium), and 27 mg/kg body weight (PIP-High) for another 8 weeks. Rats were euthanized after an 8-hour fast, and the liver, heart, kidney, and white adipose tissue were collected and stored at -80 °C. Piperine administration significantly reduced weight gain, plasma insulin, and glucose concentration. For oral piperine at a dose of 27 mg/kg body weight, body weight significantly decreased by 5.7% compared with that in the HFD group. Additionally, oral piperine administration considerably reduced serum triglyceride concentration. Furthermore, piperine administration reversed the HFD-induced downregulation of adenosine 5'-monophosphate-activated protein kinase (AMPK) signaling molecules and increased the plasma levels of adiponectin and the messenger RNA expression of the adiponectin receptor; additionally, it increased the phosphorylation of phosphatidylinositol-3 kinase (PI3K) and protein kinase B. Overall, oral piperine administration reversed HFD-induced liver lipid accumulation and insulin resistance, possibly via the inactivation of adiponectin-AMPK and PI3K-Akt signaling. These findings imply that piperine could serve as an effective agent for healthy weight loss.

Phytochemicals targeting Toll-like receptors 4 (TLR4) in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a collective term for inflammatory diseases including Crohn's disease and ulcerative colitis. Toll-like receptor 4 (TLR4) is thought to play a key role in the pathogenesis of IBD. Inhibition of TLR4 has been recognized as an effective target for the treatment of IBD. Many phytochemicals have been shown to have potential as new drugs for the treatment of IBD. This review surveyed the available literature and reports which focused on the in vivo effects of phytochemicals targeting TLR4 in different models of IBD, and clarified the significance of TLR4 as a current therapeutic target for IBD. Based on our review, we have concluded that phytochemicals targeting TLR4 are potentially effective candidates for developing new therapeutic drugs against IBD.

Molecular and pharmacological aspects of piperine as a potential molecule for disease prevention and management: evidence from clinical trials

BACKGROUND

Piperine is a type of amide alkaloid that exhibits pleiotropic properties like antioxidant, anticancer, anti-inflammatory, antihypertensive, hepatoprotective, neuroprotective and enhancing bioavailability and fertility-related activities. Piperine has the ability to alter gastrointestinal disorders, drug-metabolizing enzymes, and bioavailability of several drugs. The present review explores the available clinical and preclinical data, nanoformulations, extraction process, structure-activity relationships, molecular docking, bioavailability enhancement of phytochemicals and drugs, and brain penetration properties of piperine in the prevention, management, and treatment of various diseases and disorders.

MAIN BODY

Piperine provides therapeutic benefits in patients suffering from diabetes, obesity, arthritis, oral cancer, breast cancer, multiple myeloma, metabolic syndrome, hypertension, Parkinson's disease, Alzheimer's disease, cerebral stroke, cardiovascular diseases, kidney diseases, inflammatory diseases, and rhinopharyngitis. The molecular basis for the pleiotropic activities of piperine is based on its ability to regulate multiple signaling molecules such as cell cycle proteins, anti-apoptotic proteins, P-glycoprotein, cytochrome P450 3A4, multidrug resistance protein 1, breast cancer resistance protein, transient receptor potential vanilloid 1 proinflammatory cytokine, nuclear factor-κB, c-Fos, cAMP response element-binding protein, activation transcription factor-2, peroxisome proliferator-activated receptor-gamma, Human G-quadruplex DNA, Cyclooxygenase-2, Nitric oxide synthases-2, MicroRNA, and coronaviruses. Piperine also regulates multiple signaling pathways such as Akt/mTOR/MMP-9, 5'-AMP-activated protein kinase-activated NLR family pyrin domain containing-3 inflammasome, voltage-gated K+ current, PKCα/ERK1/2, NF-κB/AP-1/MMP-9, Wnt/β-catenin, JNK/P38 MAPK, and gut microbiota.

SHORT CONCLUSION

Based on the current evidence, piperine can be the potential molecule for treatment of disease, and its significance of this molecule in the clinic is discussed.

GRAPHICAL ABSTRACT

Mechanistic Basis for the Role of Phytochemicals in Inflammation-Associated Chronic Diseases

Chronic inflammatory diseases occur in a large portion of the population and are associated with a poor diet. Key natural products found in fruits and vegetables may assist in lowering inflammation associated with chronic diseases such as obesity, diabetes, cardiovascular diseases, and cancer. This review seeks to examine the roles of several natural products, resveratrol (RES), quercetin (QUE), curcumin (CUR), piperine (PIP), epigallocatechin gallate (EGCG), and gingerol (GIN), in their ability to attenuate inflammatory markers in specific diseases states. Additionally, we will discuss findings in past and ongoing clinical trials, detail possible phytochemical–drug interactions, and provide a brief resource for researchers and healthcare professionals on natural product and supplement regulation as well as names of databases with information on efficacy, indications, and natural product–drug interactions. As diet and over-the-counter supplement use are modifiable factors and patients are interested in using complementary and alternative therapies, understanding the mechanisms by which natural products have demonstrated efficacy and the types of drugs they interact with and knowing where to find information on herbs and supplements is important for practicing healthcare providers and researchers interested in this field.

Therapeutic spectrum of piperine for clinical practice: a scoping review

Translation of traditional knowledge of herbs into a viable product for clinical use is still an uphill task. Piperine, a pungent alkaloid molecule derived from Piper nigrum and Piper longum possesses diverse pharmacological effects. Traditionally, pepper is used for arthritis, bronchitis, gastritis, diarrhea, snake bite, menstrual pain, fever, and bacterial infections, etc. The anti-inflammatory, antioxidant and immunomodulatory actions of piperine are the possible mechanisms behind its therapeutic potential. Various in-silico and experimental studies have shown piperine as a possible promising molecule in coronavirus disease (COVID-19), ebola, and dengue due to its immunomodulatory and antiviral activities. The other important clinical applications of piperine are due to its bio enhancing effect on drugs, by modulating, absorption in the gastrointestinal tract, altering activities of transporters like p-glycoprotein substrates, and modulating drug metabolism by altering the expression of cytochrome P450 or UDP-glucuronosyltransferase enzymes. Piperine attracted clinicians in treating patients with arthritis, metabolic syndrome, diabetes, skin infections, gastric and liver disorders. This review focused on systematic, evidence-based insight into the use of piperine in clinical settings and mechanistic details behind its therapeutic actions. Also, highlights a number of clinical trials of piperine at various stages exploring its clinical application in cancer, neurological, respiratory, and viral disease, etc.

The Hepatoprotective Effect of Piperine Against Thioacetamide-Induced Liver Fibrosis in Mice: The Involvement of miR-17 and TGF-β/Smads Pathways

Liver fibrosis is characterized by a series of events including activation of quiescent hepatic stellate cells (HSCs) into proinflammatory, contractile, and fibrogenic myofibroblasts, which is the primary trigger for the fibrogenesis process. HSC activation involves many signaling pathways such as the TGF-β/smads pathway. Specific microRNAs have been identified to play a crucial role in the activation of HSCs via various signaling pathways. Piperine has recently been studied as a promising anti-fibrotic agent against pancreatic fibrosis through altering the TGF-β1/Smad pathway. Hence, the current study evaluated the beneficial effects of piperine in thioacetamide-induced liver fibrosis in mice through the modulation of miRNA-17 and TGF-β/smads pathways. Mice were allocated into three groups randomly. Thioacetamide was used to induce liver fibrosis for 6 weeks. Starting from the fourth week of the experiment, mice were treated with piperine daily for 21 days. Piperine treatment resulted in a significant downregulation of miRNA-17 expression, leading to the restoration of smad-7 accompanied with marked inhibition of TGF-β/smads signaling with further suppression of the activated HSCs and collagen deposition in the hepatocytes. In conclusion, piperine has the potential to be a promising therapeutic drug for the treatment of liver fibrosis through inhibiting the TGF-β/smads pathway.

Piperine: A review of its biological effects

Medicinal plants have been used for years as a source of food, spices, and, in traditional medicine, as a remedy to numerous diseases. Piper nigrum, belonging to the family Piperaceae is one of the most widely used spices all over the world. It has a distinct sharp flavor attributed to the presence of the phytochemical, piperine. Apart from its use as a spice, P. nigrum is frequently used for medicinal, preservation, and perfumery purposes. Black pepper contains 2-7.4% of piperine, varying in content is associated with the pepper plant. Piperine displays numerous pharmacological effects such as antiproliferative, antitumor, antiangiogenesis, antioxidant, antidiabetic, anti-obesity, cardioprotective, antimicrobial, antiaging, and immunomodulatory effects in various in vitro and in vivo experimental trials. Furthermore, piperine has also been documented for its hepatoprotective, anti-allergic, anti-inflammatory, and neuroprotective properties. This review highlights and discusses the medicinal and health-promoting effects of piperine, along with possible mechanisms of its action in health promotion and disease prevention. In addition, the present review summarizes the recent literature related to piperine as a therapeutic agent against several diseases.

Design, synthesis and anti-HIV evaluation of 5-alkyl- 6-(benzo[d][1,3]dioxol-5-alkyl)-2-mercaptopyrimidin-4(3H)-ones as potent HIV-1 NNRTIs

In order to discover and develop the new HIV-1 NNRTIs, a series of 5-alkyl-6-(benzo[d][1,3]dioxol-5-ylalkyl)-2-mercaptopyrimidin-4(3H)-ones was synthesized and screened for their in vitro cytotoxicity against HIV-1. Most of the compounds we synthetized showed high activity against wild-type HIV-1 strain (IIIB) while IC₅₀ values are in the range of 0.06-12.95 μM. Among them, the most active HIV-1 inhibitor was compound 6-(benzo[d][1,3]dioxol-5-ylmethyl)-5-ethyl-2-((2-(4-hydroxyphenyl)-2-oxoethyl)thio)pyrimidin-4(3H)-one (5b), which exhibited similar HIV-1 inhibitory potency (IC₅₀ = 0.06 μM, CC₅₀ = 96.23 μM) compared with nevirapine (IC₅₀ = 0.04 μM, CC₅₀ >200 μM) and most of compounds exhibited submicromolar IC₅₀ values indicating they were specific RT inhibitors. The compounds 5b, 6-(benzo[d] [1,3]dioxol-5-yl)-5-ethyl-2-((2-(4-hydroxyphenyl)-2-oxoethyl)thio)pyrimidin-4(3H)-one (5c) and 4-(2-((4-(benzo[d][1,3]dioxol-5-ylmethyl)-5-ethyl-6-oxo-1,6-dihydropyrimidin-2-yl)thio)acetyl)phenylbenzo[d][1,3]dioxole-5-carboxylate (5r) were selected for further study. It was found that all of them had little toxicity to peripheral blood mononuclear cell (PBMC), and had a good inhibitory effect on the replication of HIV-1 protease inhibitor resistant strains, fusion inhibitor resistant strains and nucleosides reverse transcriptase inhibitor resistant strains, as well as on clinical isolates. Besides, compound 5b and 5c showed inhibition of HIV-1 RT RNA-dependent DNA polymerization activity and DNA-dependent DNA polymerization activity, while compound 5r only showed inhibition of HIV DNA-dependent DNA polymerization activity, which was different from classical reverse transcriptase inhibitors. Our study which offered the preliminary structure-activity relationships and modeling studies of these new compounds has provided the valuable avenues for future molecular optimization.

Diet-Related Metabolomic Signature of Long-Term Breast Cancer Risk Using Penalized Regression: An Exploratory Study in the SU.VI.MAX Cohort

BACKGROUND

Diet has been recognized as a modifiable risk factor for breast cancer. Highlighting predictive diet-related biomarkers would be of great public health relevance to identify at-risk subjects. The aim of this exploratory study was to select diet-related metabolites discriminating women at higher risk of breast cancer using untargeted metabolomics.

METHODS

Baseline plasma samples of 200 incident breast cancer cases and matched controls, from a nested case-control study within the Supplémentation en Vitamines et Minéraux Antioxydants (SU.VI.MAX) cohort, were analyzed by untargeted LC-MS. Diet-related metabolites were identified by partial correlation with dietary exposures, and best predictors of breast cancer risk were then selected by Elastic Net penalized regression. The selection stability was assessed using bootstrap resampling.

RESULTS

595 ions were selected as candidate diet-related metabolites. Fourteen of them were selected by Elastic Net regression as breast cancer risk discriminant ions. A lower level of piperine (a compound from pepper) and higher levels of acetyltributylcitrate (an alternative plasticizer to phthalates), pregnene-triol sulfate (a steroid sulfate), and 2-amino-4-cyano butanoic acid (a metabolite linked to microbiota metabolism) were observed in plasma from women who subsequently developed breast cancer. This metabolomic signature was related to several dietary exposures such as a "Western" dietary pattern and higher alcohol and coffee intakes.

CONCLUSIONS

Our study suggested a diet-related plasma metabolic signature involving exogenous, steroid metabolites, and microbiota-related compounds associated with long-term breast cancer risk that should be confirmed in large-scale independent studies.

IMPACT

These results could help to identify healthy women at higher risk of breast cancer and improve the understanding of nutrition and health relationship.

The TRPV1 channel regulates glucose metabolism

Endocannabinoids (ECs) mediate effects via cannabinoid receptor types 1 and 2 (CB1 and 2) and transient receptor potential channel-vanilloid subfamily member 1 (TRPV1) channels. In high-fat diet (HFD)-induced obese mice overactivity of the EC system and inhibition of CB1 increase skeletal muscle glucose uptake. We explored the role of TRPV1. Male TRPV1^+/+(WT) and TRPV1^-/-(KO)-mice were fed (20 wk) a standard laboratory diet (SLD) or HFD. An intraperitoneal glucose tolerance test was performed. RT-PCR was performed to measure mRNA of genes involved in glucose/lipid metabolism and the EC system in soleus (SOL) and extensor digitorum longus (EDL) muscles. Cultured L6 cells were used to measure glucose uptake in skeletal muscle. HFD mice weighed more and had higher insulin levels than SLD mice, with no genotype differences. Basal and peak glucose were higher in HFD mice irrespective of genotype, but glucose cleared faster in HFD WT vs. HFD KO-mice. 2-Arachidonoylglycerol augmented insulin-induced glucose uptake in skeletal L6-cells, an effect blocked by the TRPV1 antagonist SB-366791. In EDL, fatty acid amide hydrolase (FAAH) mRNA was increased in KO vs. WT mice, irrespective of diet. Pyruvate dehydrogenase kinase isozyme 4 (PDK4) and mitochondrial uncoupling protein 3 (UCP3) were elevated and FA desaturase 2 (FADS2) mRNA lower in HFD mice, irrespective of genotype. CB1 and stearoyl-CoA desaturase 1 (SCD1) were lower in HFD WT mice only. In SOL, PDK4, UCP3, hormone-sensitive lipase (LIPE), fatty acid translocase (CD36), and carnitine palmitoyl transferase 2 (CPT2) were elevated and SCD1, FAAH, FADS2, and Troponin 1 (TNNC1) mRNA lower in HFD mice, irrespective of genotype. In conclusion, TRPV1 regulates glucose disposal in HFD mice. We propose that TRPV1 plays a role in coordinating glucose metabolism in EDL under conditions of metabolic stress.

Piperine ameliorates the severity of fibrosis via inhibition of TGF‑β/SMAD signaling in a mouse model of chronic pancreatitis

Chronic pancreatitis (CP) is characterized by recurrent pancreatic injury, resulting in inflammation and fibrosis. Currently, there are no drugs for the treatment of pancreatic fibrosis associated with CP. Piperine, a natural alkaloid found in black pepper, has been reported to show anti-inflammatory, anti-oxidative, and antitumor activities. Although piperine exhibits numerous properties in regards to the regulation of diverse diseases, the effects of piperine on CP have not been established. To investigate the effects of piperine on CP in vivo, we induced CP in mice through the repetitive administration of cerulein (50 µg/kg) six times at 1-h intervals, 5 times per week, for a total of 3 weeks. In the pre-treatment groups, piperine (1, 5, or 10 mg/kg) or corn oil were administrated orally at 1 h before the first cerulein injection, once a day, 5 times a week, for a total of 3 weeks. In the post-treatment groups, piperine (10 mg/kg) or corn oil was administered orally at 1 or 2 week after the first cerulein injection. Pancreases were collected for histological analysis. In addition, pancreatic stellate cells (PSCs) were isolated to examine the anti-fibrogenic effects and regulatory mechanisms of piperine. Piperine treatment significantly inhibited histological damage in the pancreas, increased the pancreatic acinar cell survival, reduced collagen deposition and reduced pro-inflammatory cytokines and chemokines. In addition, piperine treatment reduced the expression of fibrotic mediators, such as α-smooth muscle actin (α-SMA), collagen, and fibronectin 1 in the pancreas and PSCs. Moreover, piperine treatment reduced the production of transforming growth factor (TGF)-β in the pancreas and PSCs. Furthermore, piperine treatment inhibited TGF-β-induced pSMAD2/3 activation but not pSMAD1/5 in the PSCs. These findings suggest that piperine treatment ameliorates pancreatic fibrosis by inhibiting TGF-β/SMAD2/3 signaling during CP.

Capsaicin in Metabolic Syndrome

Capsaicin, the major active constituent of chilli, is an agonist on transient receptor potential vanilloid channel 1 (TRPV1). TRPV1 is present on many metabolically active tissues, making it a potentially relevant target for metabolic interventions. Insulin resistance and obesity, being the major components of metabolic syndrome, increase the risk for the development of cardiovascular disease, type 2 diabetes, and non-alcoholic fatty liver disease. In vitro and pre-clinical studies have established the effectiveness of low-dose dietary capsaicin in attenuating metabolic disorders. These responses of capsaicin are mediated through activation of TRPV1, which can then modulate processes such as browning of adipocytes, and activation of metabolic modulators including AMP-activated protein kinase (AMPK), peroxisome proliferator-activated receptor α (PPARα), uncoupling protein 1 (UCP1), and glucagon-like peptide 1 (GLP-1). Modulation of these pathways by capsaicin can increase fat oxidation, improve insulin sensitivity, decrease body fat, and improve heart and liver function. Identifying suitable ways of administering capsaicin at an effective dose would warrant its clinical use through the activation of TRPV1. This review highlights the mechanistic options to improve metabolic syndrome with capsaicin.

Therapeutic Potential of Polyphenols in Cardiac Fibrosis

Cardiac fibrosis, in response to injury and stress, is central to a broad constellation of cardiovascular diseases. Fibrosis decreases myocardial wall compliance due to extracellular matrix (ECM) accumulation, leading to impaired systolic and diastolic function and causing arrhythmogenesis. Although some conventional drugs, such as β-blockers and renin-angiotensin-aldosterone system (RAAS) inhibitors, have been shown to alleviate cardiac fibrosis in clinical trials, these traditional therapies do not tend to target all the fibrosis-associated mechanisms, and do not hamper the progression of cardiac fibrosis in patients with heart failure. Polyphenols are present in vegetables, fruits, and beverages and had been proposed as attenuators of cardiac fibrosis in different models of cardiovascular diseases. Together with results found in the literature, we can show that some polyphenols exert anti-fibrotic and myocardial protective effects by mediating inflammation, oxidative stress, and fibrotic molecular signals. This review considers an overview of the mechanisms of cardiac fibrosis, illustrates their involvement in different animal models of cardiac fibrosis treated with some polyphenols and projects the future direction and therapeutic potential of polyphenols on cardiac fibrosis.

Piperine and Its Various Physicochemical and Biological Aspects: A Review

Piper nigrumL. is examined as the king of species worldwide by virtue of its principle piperine. In Ayurveda, since from the ancient times, it is known as “Yogvahi”. It is one of the important alkaloids of Pepper fruits (Family Piperaceae) and has been found to have numerous medicinal properties such as antioxidant, antiplatelet, anti-inflammatory, antihypertensive, hepatoprotective, antithyroid, antitumor, antiasthmatic activity and also have significant role as fertility enhancer. The present review discusses the biosynthetic pathway, extraction process, chemistry and various analytical methods of piperine. It also describes the structural modification of piperine and its various effects on biological system. The utility of piperine as a bioenhancer for certain antibacterial- antibiotics and a potent inhibitor of drug metabolism are also discussed. Thus, review provides knowledgeable erudition on the piperine which paves way for further work.

Piperine inhibits ABCA1 degradation and promotes cholesterol efflux from THP-1-derived macrophages

Scope

Increased macrophage cholesterol efflux (ChE) is considered to have anti‐atherosclerotic effect counteracting cardiovascular disease. The principle pungent ingredient of the fruits of Piper nigrum, piperine, is identified in this study as a ChE inducer in THP‐1‐derived macrophages, and mechanisms underlying this effect are explored.

Methods and results

Without affecting cell viability, piperine concentration‐dependently enhances ChE in THP‐1‐derived macrophages from 25 to 100 μM. The expression level of the key cholesterol transporter protein ATP‐binding cassette transporter A1 (ABCA1) is significantly upregulated by piperine, as revealed by western blot analyses. However, two other ChE‐mediating transporter proteins, ATP‐binding cassette transporter G1 (ABCG1) and scavenger receptor class B member 1 (SR‐B1), remain unaffected. Piperine exerts no influence on ABCA1 mRNA levels, but significantly inhibits the degradation of ABCA1, as evident by an increased half‐life of the protein in the presence of cycloheximide. Furthermore, it is found that piperine likely interferes with the calpain‐mediated ABCA1 degradation pathway and exhibits significant inhibition of calpain activity.

Conclusion

Our findings suggest that piperine promotes ChE in THP‐1‐derived macrophages by upregulation of ABCA1, which might be mediated by inhibition of calpain activity. This novel bioactivity makes the dietary constituent piperine a good candidate to be further explored for therapeutic or preventive applications in the context of atherosclerosis.

Piperine's mitigation of obesity and diabetes can be explained by its up-regulation of the metabolic rate of resting muscle

We identify a target for treating obesity and type 2 diabetes, the consumption of calories by an increase in the metabolic rate of resting skeletal muscle. The metabolic rate of skeletal muscle can be increased by shifting myosin heads from the super-relaxed state (SRX), with a low ATPase activity, to a disordered relaxed state (DRX), with a higher ATPase activity. The shift of myosin heads was detected by a change in fluorescent intensity of a probe attached to the myosin regulatory light chain in skinned skeletal fibers, allowing us to perform a high-throughput screen of 2,128 compounds. The screen identified one compound, which destabilized the super-relaxed state, piperine (the main alkaloid component of black pepper). Destabilization of the SRX by piperine was confirmed by single-nucleotide turnover measurements. The effect was only observed in fast twitch skeletal fibers and not in slow twitch fibers or cardiac tissues. Piperine increased ATPase activity of skinned relaxed fibers by 66 ± 15%. The K_d was ∼2 µM. Piperine had little effect on the mechanics of either fully active or resting muscle fibers. Previous work has shown that piperine can mitigate both obesity and type 2 diabetes in rodent models of these conditions. We propose that the increase in resting muscle metabolism contributes to these positive effects. The results described here show that up-regulation of resting muscle metabolism could treat obesity and type 2 diabetes and that piperine would provide a useful lead compound for the development of these therapies.

Rice bran protein hydrolysates reduce arterial stiffening, vascular remodeling and oxidative stress in rats fed a high-carbohydrate and high-fat diet

PURPOSE

Rice bran protein hydrolysates (RBPH) contain highly nutritional proteins and antioxidant compounds which show benefits against metabolic syndrome (MetS). Increased arterial stiffness and the components of MetS have been shown to be associated with an increased risk of cardiovascular disease. This study aimed to investigate whether RBPH could alleviate the metabolic disorders, arterial stiffening, vascular remodeling, and oxidative stress in rats fed a high-carbohydrate and high-fat (HCHF) diet.

METHODS

Male Sprague-Dawley rats were fed either a standard chow and tap water or a HCHF diet and 15 % fructose solution for 16 weeks. HCHF rats were treated orally with RBPH (250 or 500 mg/kg/day) for the final 6 weeks of the experimental period.

RESULTS

Rats fed with HCHF diet had hyperglycemia, insulin resistance, dyslipidemia, hypertension, increased aortic pulse wave velocity, aortic wall hypertrophy and vascular remodeling with increased MMP-2 and MMP-9 expression. RBPH supplementation significantly alleviated these alterations (P < 0.05). Moreover, RBPH reduced the levels of angiotensin-converting enzyme (ACE) and tumor necrosis factor-alpha in plasma. Oxidative stress was also alleviated after RBPH treatment by decreasing plasma malondialdehyde, reducing superoxide production and suppressing p47^phox NADPH oxidase expression in the vascular tissues of HCHF rats. RBPH increased plasma nitrate/nitrite level and up-regulated eNOS expression in the aortas of HCHF-diet-fed rats, indicating that RBPH increased NO production.

CONCLUSION

RBPH mitigate the deleterious effects of HCHF through potential mechanisms involving enhanced NO bioavailability, anti-ACE, anti-inflammatory and antioxidant properties. RBPH could be used as dietary supplements to minimize oxidative stress and vascular alterations triggered by MetS.

Potential of Food and Natural Products to Promote Endothelial and Vascular Health

Endothelial dysfunction is now well established as a pivotal early event in the development of major cardiovascular diseases including hypertension, atherosclerosis, and diabetes. The alteration of the endothelial function is often triggered by an imbalance between the endothelial formation of vasoprotective factors including nitric oxide (NO) and endothelium-dependent hyperpolarization, and an increased level of oxidative stress involving several prooxidant enzymes such as NADPH oxidase and, often also, the appearance of cyclooxygenase-derived vasoconstrictors. Preclinical studies have indicated that polyphenol-rich food and food-derived products such as grape-derived products, black and red berries, green and black teas and cocoa, and omega-3 fatty acids can trigger activating pathways in endothelial cells promoting an increased formation of nitric oxide and endothelium-dependent hyperpolarization. Moreover, intake of such food-derived products has been associated with the prevention and/or the improvement of an established endothelial dysfunction in several experimental models of cardiovascular diseases and in humans with cardiovascular diseases. This review will discuss both experimental and clinical evidences indicating that different types of food and natural products are able to promote endothelial and vascular health, as well as the underlying mechanisms.

Quantitative ethnomedicinal survey of medicinal plants given for cardiometabolic diseases by the non-institutionally trained siddha practitioners of Tiruvallur district, Tamil Nadu, India

ETHNOBOTANICAL RELEVANCE

The burden of cardiometabolic diseases such as dyslipidemia, hyperglycemia, hypertension, visceral obesity and atherosclerotic cardiovascular diseases and the use of traditional medicine for the management of such diseases are high in India; hence there is a need to document and analyze such therapies.

AIM OF THE STUDY

This study documented and analyzed the medicinal plants prescribed for cardiometabolic diseases by the non-institutionally trained siddha practitioners of Tiruvallur district of Tamil Nadu, India.

METHODOLOGY

The field survey was conducted between December 2014 to November 2015. Successive free listing assisted with field-walks was used to interview the informants. After assessing the sampling sufficiency using rarefaction curve analysis, indices such as Informant Consensus Factor (Fic) and Index of Agreement on Remedies (IAR) were calculated for the data. The indicators of informant's medicinal plant knowledge such as Shannon's index, equitability index, etc., were regressed with the demographic profile of the informants.

RESULTS

For this study 70 non-institutionally trained Siddha medical practitioners were approached; the data from 36 practitioners who were treating cardiometabolic diseases were documented. This study recorded the use of 188 species which were used to prepare 368 formulations to treat illnesses categorized under cardiometabolic diseases. In this, 53.04% claims were singletons. Regression analysis showed that single species dominance was reduced and the diversity of medicinal plants was increased with the increase in the age and experience. Increase in the years of formal education increased the equitability in the uses. The plants such as Nelumbo nucifera Gaertn. (cardiovascular diseases), Allium sativum L. (dyslipidemia), Cuminum cyminum L. (hypertension), Macrotyloma uniflorum Verdc. (obesity) and Azadirachta indica A. Juss. (type 2 diabetes) were the highly cited medicinal plants.

CONCLUSION

This survey has identified the plants most commonly used by Siddha practitioners of Tiruvallur district, Tamil Nadu, India for cardiometabolic diseases. The prevalence of chronic, non-communicable metabolic illnesses such as type 2 diabetes, hypertension and obesity are increasing worldwide due to the rapid changes in the lifestyle. These ailments require a life-long care and in such instances, people tend to use complementary therapies in most cases, alongside with conventional therapies. In view of the high use of traditional therapies for treating cardiometabolic illnesses, this study supports the need for more research to evaluate the potential benefits of the treatments and to identify any safety concern.

Role of Dietary Components in Modulating Hypertension

Hypertension is a major health issue, particularly in medically underserved populations that may suffer from poor health literacy, poverty, and limited access to healthcare resources. Management of the disease reduces the risk of adverse outcomes, such as cardiovascular or cerebrovascular events, vision impairment due to retinal damage, and renal failure. In addition to pharmacological therapy, lifestyle modifications such as diet and exercise are effective in managing hypertension. Current diet guidelines include the DASH diet, a low-fat and low-sodium diet that encourages high consumption of fruits and vegetables. While the diet is effective in controlling hypertension, adherence to the diet is poor and there are few applicable dietary alternatives, which is an issue that can arise from poor health literacy in at-risk populations. The purpose of this review is to outline the effect of specific dietary components, both positive and negative, when formulating a dietary approach to hypertension management that ultimately aims to improve patient adherence to the treatment, and achieve better control of hypertension.

The protective effect of piperine on dextran sulfate sodium induced inflammatory bowel disease and its relation with pregnane X receptor activation

ETHNOPHARMACOLOGICAL RELEVANCE

Inflammatory bowel disease (IBD) is associated with chronic inflammation of the intestinal tract. Piperine (1-peperoylpiperidine), the primary lipophilic component in black pepper (Piper nigrum) and long pepper (Piper longum), has been reported to be effective for anti-inflammatory. Rencently, several ethnopharmacological purity compounds, such as baicalin and artemisinin, are reported to have potentially therapeutic role in treating IBD. In the present study, the effects of piperine on pregnane X receptor (PXR)-mediated CYP3A expression and its therapeutic role in IBD were investigated.

MATERIALS AND METHODS

LS174T cells and C57BL/6J mice were treated by the piperine. Gene expressions were analyzed by real-time PCR, Western blot analysis, transient transfections assay and histological analysis.

RESULTS

Data indicated that treatment of LS174T cells with piperine markedly increased both CYP3A4 and PXR mRNA and protein. Transient transfection experiments indicated that transcriptional activation of the CYP3A4 gene via piperine was PXR-dependent. Data show that pre-administration of piperine decreased clinical hallmarks of colitis in DSS-treated PXR mice as measured by body weight loss and assessment of diarrhea, rectal bleeding, colon length, and histology. Inflammatory mediators (CCR2, ICAM-1, IL-1β, IL-6, IL-10, iNOS, MCP-1, and TNFα) after DSS treatment were significantly decreased in mice pretreated with piperine but corresponding conditions did not occur in mice with down-regulation of PXR by small interfering RNA (siRNA).

CONCLUSION

Piperine is a potential agonist of PXR and an inducer of PXR, which may induce CYP3A4 gene expression at the mRNA and protein levels. These results establish that piperine may contribute to prevention or reduction of colonic inflammation.

Subclinical cardiovascular damage and fat utilization in overweight/obese individuals receiving the same dietary and pharmacological interventions

Subclinical organ damage precedes the occurrence of cardiovascular events in individuals with obesity and hypertension. The aim of this study was to assess the relationship between fuel utilization and subclinical cardiovascular damage in overweight/obese individuals free of established cardiovascular disease receiving the same diet and pharmacological intervention. In this retrospective study a total of 35 subjects following a balanced diet were enrolled. They underwent a complete nutritional and cardiovascular assessment. Echocardiography and ultrasonography of the carotid arteries was performed. The respiratory quotient (fuel utilization index) was assessed by indirect calorimetry. A total of 18 had left ventricular concentric remodeling, 17 were normal. Between these two groups, a significant difference of intima-media thickness was showed (p = 0.015). Also a difference of respiratory quotient was shown with the highest value in those with remodeling (p = 0.038). At univariate and multivariate analysis, cardiac remodeling was associated with respiratory quotient (RQ) (p = 0.04; beta = 0.38; SE = 0.021; B = 0.044). The area under the receiver operating characteristic (ROC) curve for respiratory quotient to predict remodeling was 0.72 (SE = 0.093; p = 0.031; RQ = 0.87; 72% sensitivity, 84% specificity). The respiratory quotient is significantly different between those participants with and without cardiac remodeling. Its measurement may help for interpreting the (patho)physiological mechanisms in the nutrients utilization of obese people with different response to dietary or pharmacological interventions.

Asiatic acid alleviates hemodynamic and metabolic alterations via restoring eNOS/iNOS expression, oxidative stress, and inflammation in diet-induced metabolic syndrome rats

Asiatic acid is a triterpenoid isolated from Centella asiatica. The present study aimed to investigate whether asiatic acid could lessen the metabolic, cardiovascular complications in rats with metabolic syndrome (MS) induced by a high-carbohydrate, high-fat (HCHF) diet. Male Sprague-Dawley rats were fed with HCHF diet with 15% fructose in drinking water for 12 weeks to induce MS. MS rats were treated with asiatic acid (10 or 20 mg/kg/day) or vehicle for a further three weeks. MS rats had an impairment of oral glucose tolerance, increases in fasting blood glucose, serum insulin, total cholesterol, triglycerides, mean arterial blood pressure, heart rate, and hindlimb vascular resistance; these were related to the augmentation of vascular superoxide anion production, plasma malondialdehyde and tumor necrosis factor-alpha (TNF-α) levels (p<0.05). Plasma nitrate and nitrite (NOx) were markedly high with upregulation of inducible nitric oxide synthase (iNOS) expression, but dowregulation of endothelial nitric oxide synthase (eNOS) expression (p<0.05). Asiatic acid significantly improved insulin sensitivity, lipid profiles, hemodynamic parameters, oxidative stress markers, plasma TNF-α, NOx, and recovered abnormality of eNOS/iNOS expressions in MS rats (p<0.05). In conclusion, asiatic acid improved metabolic, hemodynamic abnormalities in MS rats that could be associated with its antioxidant, anti-inflammatory effects and recovering regulation of eNOS/iNOS expression.

Synthesis, Single Crystal X-Ray Structure, and Antimicrobial Activity of 6-(1,3-Benzodioxol-5-ylmethyl)-5-ethyl-2-{[2-(morpholin-4-yl)ethyl]sulfanyl}pyrimidin-4(3H)-one

Synthesis, X-ray structure and antimicrobial activity of 6-(1,3-benzodioxol-5-ylmethyl)-5-ethyl-2-{[2-(morpholin-4-yl)ethyl]sulfanyl}pyrimidin-4(3H)-one (8) are reported. Compound8exhibited activity towardsS. aureuswith MIC value of 0.0619 μmol/mL while it showed activity towardsB. subtilis,B. cereus,C. albicans, andA. nigerwith MIC = 0.1859 μmol/mL. Single crystal X-ray structure of the title compound8confirmed itsS-alkylation. The title compound crystallizes in the triclinic,P-1,a=11.1220(5) Å,b=12.2241(5) Å,c=21.5246(9) Å,α=88.958(2)°,β=79.836(2)°,γ=79.384(2)°,V=2830.9(2) Å3,Z=6,R(F)=0.046,wR(F2)=0.110,T=100 K. The crystal structure is stabilized by weak intermolecular C–H⋯O and N–H⋯O hydrogen interactions.

Piperonal prevents high-fat diet-induced hepatic steatosis and insulin resistance in mice via activation of adiponectin/AMPK pathway

OBJECTIVE

Piperonal is an important flavor additive with antibacterial and anxiolytic properties. We investigated the effects and possible mechanisms of piperonal protection against high-fat diet (HFD)-induced hepatic steatosis and insulin resistance.

METHODS

C57BL/6 J mice were fed with a normal diet (ND; based on the AIN-76 rodent diet), HFD (20% fat and 1% cholesterol), or piperonal-supplemented diet (POD; HFD supplemented with 0.05% piperonal) for 10 weeks.

RESULTS

Piperonal supplementation reduced hepatic lipid concentrations, liver dysfunction and plasma levels of insulin and glucose in HFD-fed mice. Piperonal significantly enhanced mRNA expression and secretion of adiponectin in 3T3-L1 adipocytes. Dietary piperonal significantly increased circulating adiponectin levels and hepatic AMP-activated protein kinase (AMPK) activation in HFD-fed mice; these were associated with the suppression of sterol regulatory element binding protein-1c and activation of glucose transporter-2 translocation in the livers. Piperonal also significantly reduced the expression of endoplasmic reticulum (ER) stress markers in the livers of HFD-fed mice.

CONCLUSIONS

Piperonal may activate the adiponectin/AMPK pathway in the livers of mice. The activated adiponectin/AMPK axis may inhibit p70S6 kinase signaling and the ER stress response, with protective effects on hepatic steatosis and insulin resistance.

Piperine suppresses cerebral ischemia-reperfusion-induced inflammation through the repression of COX-2, NOS-2, and NF-κB in middle cerebral artery occlusion rat model

The pathophysiological mechanisms leading to neuronal injury in middle cerebral artery occlusion (MCAO) model of cerebral stroke are complex and multifactorial that form the bases of behavioral deficits and inflammation mediated damage. The present study demonstrates the effect of piperine pretreatment (10 mg/kg b wt, once daily p.o. for 15 days) on cerebral ischemia-induced inflammation in male Wistar rats. The right middle cerebral artery was occluded for 2 h followed by reperfusion for 22 h. A maximum infarct volume (57.80 %) was observed in ischemic MCAO group. However, piperine administration prior to ischemia showed a significant reduction in infarct volume (28.29 %; p < 0.05) and neuronal loss (12.72 %; p < 0.01). As a result of piperine pretreatment, a significant improvement in behavioral outputs of MCAO rats (p < 0.05-0.01) was observed. Piperine successfully reduced the level of proinflammatory cytokines IL-1β, IL-6 and TNF-α, in ischemic group (p < 0.01). Ischemic group brain has shown edematous morphology with vacuolated architecture and pyknotic nuclei in H & E staining which was successfully ameliorated by piperine administration. Moreover, piperine also succeeded in lowering the expression of COX-2, NOS-2, and NF-κB (p < 0.01). Both cytosolic and nuclear NF-κB were down-regulated in ischemic group pre-administered with piperine (p < 0.01). The present study suggests that piperine is able to salvage the ischemic penumbral zone neurons by virtue of its anti-inflammatory property, thereby limiting ischemic cell death.

Ellagic acid attenuates high-carbohydrate, high-fat diet-induced metabolic syndrome in rats

BACKGROUND

Fruits and nuts may prevent or reverse common human health conditions such as obesity, diabetes and hypertension; together, these conditions are referred to as metabolic syndrome, an increasing problem. This study has investigated the responses to ellagic acid, present in many fruits and nuts, in a diet-induced rat model of metabolic syndrome.

METHODS

Eight- to nine-week-old male Wistar rats were divided into four groups for 16-week feeding with cornstarch diet (C), cornstarch diet supplemented with ellagic acid (CE), high-carbohydrate, high-fat diet (H) and high-carbohydrate, high-fat diet supplemented with ellagic acid (HE). CE and HE rats were given 0.8 g/kg ellagic acid in food from week 8 to 16 only. At the end of 16 weeks, cardiovascular, hepatic and metabolic parameters along with protein levels of Nrf2, NF-κB and CPT1 in the heart and the liver were characterised.

RESULTS

High-carbohydrate, high-fat diet-fed rats developed cardiovascular remodelling, impaired ventricular function, impaired glucose tolerance, non-alcoholic fatty liver disease with increased protein levels of NF-κB and decreased protein levels of Nrf2 and CPT1 in the heart and the liver. Ellagic acid attenuated these diet-induced symptoms of metabolic syndrome with normalisation of protein levels of Nrf2, NF-κB and CPT1.

CONCLUSIONS

Ellagic acid derived from nuts and fruits such as raspberries and pomegranates may provide a useful dietary supplement to decrease the characteristic changes in metabolism and in cardiac and hepatic structure and function induced by a high-carbohydrate, high-fat diet by suppressing oxidative stress and inflammation.