Preventive Effects of Catechins on Cardiovascular Disease

Current insights and future perspectives of flavonoids: A promising antihypertensive approach

Hypertension, or high blood pressure (BP), is a complex disease influenced by various risk factors. It is characterized by persistent elevation of BP levels, typically exceeding 140/90 mmHg. Endothelial dysfunction and reduced nitric oxide (NO) bioavailability play crucial roles in hypertension development. L-NG-nitro arginine methyl ester (L-NAME), an analog of L-arginine, inhibits endothelial NO synthase (eNOS) enzymes, leading to decreased NO production and increased BP. Animal models exposed to L-NAME manifest hypertension, making it a useful design for studying the hypertension condition. Natural products have gained interest as alternative approaches for managing hypertension. Flavonoids, abundant in fruits, vegetables, and other plant sources, have potential cardiovascular benefits, including antihypertensive effects. Flavonoids have been extensively studied in cell cultures, animal models, and, to lesser extent, in human trials to evaluate their effectiveness against L-NAME-induced hypertension. This comprehensive review summarizes the antihypertensive activity of specific flavonoids, including quercetin, luteolin, rutin, troxerutin, apigenin, and chrysin, in L-NAME-induced hypertension models. Flavonoids possess antioxidant properties that mitigate oxidative stress, a major contributor to endothelial dysfunction and hypertension. They enhance endothelial function by promoting NO bioavailability, vasodilation, and the preservation of vascular homeostasis. Flavonoids also modulate vasoactive factors involved in BP regulation, such as angiotensin-converting enzyme (ACE) and endothelin-1. Moreover, they exhibit anti-inflammatory effects, attenuating inflammation-mediated hypertension. This review provides compelling evidence for the antihypertensive potential of flavonoids against L-NAME-induced hypertension. Their multifaceted mechanisms of action suggest their ability to target multiple pathways involved in hypertension development. Nonetheless, the reviewed studies contribute to the evidence supporting the useful of flavonoids for hypertension prevention and treatment. In conclusion, flavonoids represent a promising class of natural compounds for combating hypertension. This comprehensive review serves as a valuable resource summarizing the current knowledge on the antihypertensive effects of specific flavonoids, facilitating further investigation and guiding the development of novel therapeutic strategies for hypertension management.

Separation and Detection of Catechins and Epicatechins in Shanxi Aged Vinegar Using Solid-Phase Extraction and Hydrophobic Deep Eutectic Solvents Combined with HPLC

This research presents a new, eco-friendly, and swift method combining solid-phase extraction and hydrophobic deep eutectic solvents (DES) with high-performance liquid chromatography (SPE-DES-HPLC) for extracting and quantifying catechin and epicatechin in Shanxi aged vinegar (SAV). The parameters, such as the elution solvent type, the XAD-2 macroporous resin dosage, the DES ratio, the DES volume, the adsorption time, and the desorption time, were optimized via a one-way experiment. A central composite design using the Box-Behnken methodology was employed to investigate the effects of various factors, including 17 experimental runs and the construction of three-dimensional response surface plots to identify the optimal conditions. The results show that the optimal conditions were an HDES (tetraethylammonium chloride and octanoic acid) ratio of 1:3, an XAD-2 macroporous resin dosage of 188 mg, and an adsorption time of 11 min. Under these optimal conditions, the coefficients of determination of the method were greater than or equal to 0.9917, the precision was less than 5%, and the recoveries ranged from 98.8% to 118.8%. The environmentally friendly nature of the analytical process and sample preparation was assessed via the Analytical Eco-Scale and AGREE, demonstrating that this method is a practical and eco-friendly alternative to conventional determination techniques. In summary, this innovative approach offers a solid foundation for the assessment of flavanol compounds present in SAV samples.

Biological properties of caffeine, (+)-catechin, and theobromine: an in silico study

We analyzed here the in silico biological activities of caffeine, (+)-catechin, and theobromine. For this, the PubChem database of the NIH (National Institutes of Health) was used to obtain the SMILE canonical form of the bioactive molecules, and the free software PASS Online (Prediction of Activity Spectra for Substances) from the Way2Drug portal. Also, we conducted an in vitro experiment using a chronic myeloid leukemia (CML) cell line (K562) to confirm some results found in in silico investigation. These cells were exposed to different concentrations of caffeine, (+)-catechin, and theobromine for 72 h. The results found in this in silico study suggested that caffeine, (+)-catechin, and theobromine showed excellent biological properties, such as antioxidant, anti-inflammatory, and anticarcinogenic, as well as protection against cardiovascular, diabetes, neurological, allergic, respiratory, and other therapeutic activities. These findings can be elucidated through the modulation exerted by these bioactive molecules in many biochemical pathways involved in organism homeostasis, such as free radical scavenger action, oxidoreductase inhibitor, membrane permeability inhibitor, and lipid peroxidase inhibitor. In addition, we have found here that caffeine, (+)-catechin, and theobromine have a remarkable anti-inflammatory activity which plays an important role in the therapeutic approach of COVID-19. Moreover, our in vitro findings confirmed the in silico results regarding anticancer activity since these molecules reduce cell proliferation at all tested concentrations. Therefore, since these molecules exhibit important medicinal activities, further investigations should be conducted to reveal new therapies to improve the treatments and prevention of numerous disorders and, consequently, promote human health.

Metabolomics investigation of the chemical variations in white teas with different producing areas and storage durations

In this study, we employed nontargeted metabolomics and quantitative analysis to explore the variations in metabolites among white teas from different production areas and with varying storage durations. A total of 83 compounds exhibited differential levels between Zhenghe and Fuding white tea, 89 between Zhenghe and Jinggu, and 75 between Fuding and Jinggu white tea. Concerning the storage of white tea, the concentrations of flavanols, dimeric catechins, and amino acids decreased over time, while N-ethyl-2-pyrrolidone-substituted flavanols (EPSFs), caffeine, adenosine monophosphate (AMP), and adenosine increased. Galloylated flavanols showed a higher propensity to form EPSFs with theanine compared to nongalloylated flavanols during storage. Theanine and epigallocatechin gallate were more inclined to generate S-configuration EPSFs during storage in Fuding and Jinggu white tea samples, while R-configuration EPSFs were more readily formed in Zhenghe white tea samples. This study offers a comprehensive understanding of the changes in metabolites during the storage of white tea.

Natural Product-Based Glycolysis Inhibitors as a Therapeutic Strategy for Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitor-Resistant Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is a leading cause of cancer-related deaths worldwide. Targeted therapy against the epidermal growth factor receptor (EGFR) is a promising treatment approach for NSCLC. However, resistance to EGFR tyrosine kinase inhibitors (TKIs) remains a major challenge in its clinical management. EGFR mutation elevates the expression of hypoxia-inducible factor-1 alpha to upregulate the production of glycolytic enzymes, increasing glycolysis and tumor resistance. The inhibition of glycolysis can be a potential strategy for overcoming EGFR-TKI resistance and enhancing the effectiveness of EGFR-TKIs. In this review, we specifically explored the effectiveness of pyruvate dehydrogenase kinase inhibitors and lactate dehydrogenase A inhibitors in combating EGFR-TKI resistance. The aim was to summarize the effects of these natural products in preclinical NSCLC models to provide a comprehensive understanding of the potential therapeutic effects. The study findings suggest that natural products can be promising inhibitors of glycolytic enzymes for the treatment of EGFR-TKI-resistant NSCLC. Further investigations through preclinical and clinical studies are required to validate the efficacy of natural product-based glycolytic inhibitors as innovative therapeutic modalities for NSCLC.

Food Components in Health Promotion and Disease Prevention

In recent years, more plant-based sources of functional foods have been shown to be effective in preventing, reducing, and treating chronic inflammatory and metabolic diseases, and promoting health [...].

Natural compounds as lactate dehydrogenase inhibitors: potential therapeutics for lactate dehydrogenase inhibitors-related diseases

Lactate dehydrogenase (LDH) is a crucial enzyme involved in energy metabolism and present in various cells throughout the body. Its diverse physiological functions encompass glycolysis, and its abnormal activity is associated with numerous diseases. Targeting LDH has emerged as a vital approach in drug discovery, leading to the identification of LDH inhibitors among natural compounds, such as polyphenols, alkaloids, and terpenoids. These compounds demonstrate therapeutic potential against LDH-related diseases, including anti-cancer effects. However, challenges concerning limited bioavailability, poor solubility, and potential toxicity must be addressed. Combining natural compounds with LDH inhibitors has led to promising outcomes in preclinical studies. This review highlights the promise of natural compounds as LDH inhibitors for treating cancer, cardiovascular, and neurodegenerative diseases.

Therapeutic Potential of Polyphenols and Other Micronutrients of Marine Origin

Polyphenols are compounds found in various plants and foods, known for their antioxidant and anti-inflammatory properties. Recently, researchers have been exploring the therapeutic potential of marine polyphenols and other minor nutrients that are found in algae, fish and crustaceans. These compounds have unique chemical structures and exhibit diverse biological properties, including anti-inflammatory, antioxidant, antimicrobial and antitumor action. Due to these properties, marine polyphenols are being investigated as possible therapeutic agents for the treatment of a wide variety of conditions, such as cardiovascular disease, diabetes, neurodegenerative diseases and cancer. This review focuses on the therapeutic potential of marine polyphenols and their applications in human health, and also, in marine phenolic classes, the extraction methods, purification techniques and future applications of marine phenolic compounds.

Evaluation of oxidative stress-mediated cytotoxicity and genotoxicity of copper and flubendiamide: amelioration by antioxidants in vivo and in vitro

Present study was designed to evaluate toxic effects of copper (Cu) (@ 33 mg/kg b.wt.) and flubendimide (Flb) (@ 200 mg/kg b.wt.) alone and/or in combination on blood-biochemical indices, oxidative stress, and drug metabolizing enzymes (DMEs) in vivo in male Wistar rats following oral exposure continuously for 90 days and their immunotoxic (cyto-genotoxic and apoptotic) potential in vitro on thymocytes. In in vivo study, ameliorative potential of α-tocopherol was assessed, whereas α-tocopherol, curcumin, resveratrol, and catechin were evaluated for protective effect in vitro. Significantly (P < 0.05) increased AST activity and increment in total bilirubin, uric acid, creatinine, and BUN levels; however, reduction in total protein, GSH content, reduced activities of SOD and GST, and increased lipid peroxidation and GPx activity with severe degenerative changes in histopathological examination of liver and kidney in group of Cu and Flb were observed. Treatment with α-tocopherol improved biochemical variables, redox status, and histoarchitecture of liver and kidney tissues. Reduced hepatic CYP450, CYPb5, APH, UGT, and GST activities observed in both Cu and α-tocopherol alone and their combination groups, whereas significant increment in Flb alone, while α-tocopherol in combination with xenobiotics improved the activities of hepatic DMEs. Primary cell culture of thymocytes (106 cells/ml) exposed to Cu and Flb each @ 40 μM increased TUNEL+ve cells, micronuclei induction, DNA shearing, and comet formation establishes their apoptotic and genotoxic potential, whereas treatment with antioxidants showed concentration-dependent significant reduction and their order of potency on equimolar concentration (10 μM) basis is: curcumin > resveratrol > catechin = α-tocopherol.

Screening potential ligands of endothelin receptor A from Choerospondias axillaris and evaluation of their drug-like properties by affinity chromatographic methods

Tibetan medicine is traditionally prescribed as crude extracts or mixtures owing to the theoretical basis with cross fertilization from other medical systems like Ayurveda and traditional Chinese medicine. This is challenged to elucidate the action mechanism and material foundation of Tibetan medicine due to lacking a method to confirm the bioactive compounds determining the therapy. This work created a new strategy for screening and evaluating the bioactive compounds against cardiovascular ailments from Choerospondias axillaris. It involved the immobilization of endothelin receptor A (ET_AR) by a one-step covalent assay, the screening and identification of the bioactive compounds by ET_AR column combined with tandem mass spectrometry, and the evaluation of their drug-like properties by calculating the efficiency indexes using the data collected by frontal analysis and adsorption energy distribution. The immobilized ET_AR remained good stability in three weeks in terms of specificity and repeatability. Catechin, pinocembrin, and hyperoside were identified as potential ET_AR ligands from Choerospondias axillaris with two types of binding sites on the immobilized receptor. Their association constants on the high and low affinity binding sites were (2.53 ± 0.11) × 10⁵ and (9.94 ± 0.02) × 10³ M^-1 for catechin, (1.01 ± 0.12) × 10⁶ and (7.40 ± 0.03) × 10⁴ for hyperoside, and (2.05 ± 0.04) × 10⁵ and (2.47 ± 0.09)× 10⁴ M^-1 for pinocembrin, respectively. Owing to the highest association constant, hyperoside presented a surface efficiency index of 7.95, and binding efficiency index of 20.7, and the ligand-lipophilicity efficiency of 1.38. These indicated that the three compounds were the main ingredients for the therapy of Choerospondias axillaris, and had potential to become lead compounds for anti-cardiovascular drugs based on drug-ET_AR interaction. The immobilized receptor-based strategy is possible to become an alternative for screening and assessing bioactive compounds from Tibetan medicine.

Role of polyphenolic compounds and their nanoformulations: a comprehensive review on cross-talk between chronic kidney and cardiovascular diseases

Chronic kidney disease (CKD) affects a huge portion of the world's population and frequently leads to cardiovascular diseases (CVDs). It might be because of common risk factors between chronic kidney disease and cardiovascular diseases. Renal dysfunction caused by chronic kidney disease creates oxidative stress which in turn leads to cardiovascular diseases. Oxidative stress causes endothelial dysfunction and inflammation in heart which results in atherosclerosis. It ends in clogging of veins and arteries that causes cardiac stroke and myocardial infarction. To develop an innovative therapeutic approach and new drugs to treat these diseases, it is important to understand the pathophysiological mechanism behind the CKD and CVDs and their interrelationship. Natural phytoconstituents of plants such as polyphenolic compounds are well known for their medicinal value. Polyphenols are plant secondary metabolites with immense antioxidant properties, which can protect from free radical damage. Nowadays, polyphenols are generating a lot of buzz in the scientific community because of their potential health benefits especially in the case of heart and kidney diseases. This review provides a detailed account of the pathophysiological link between CKD and CVDs and the pharmacological potential of polyphenols and their nanoformulations in promoting cardiovascular and renal health.

Adsorption Behavior of the L-Theanine onto Cation Exchange Resin ZGSPC106Na and D001SD

Adsorption is an important technology for the separation of different tea components. The adsorption behavior of L-theanine onto adsorbents was comprehensively studied in this paper. Among tested adsorbents, cation exchange resin ZGSPC106Na and D001SD were suitable for separating L-theanine, PVPP and PA-6 for catechins and macroporous resin HPD-400 for caffeine. Adsorption of L-theanine onto the cation resins was significantly influenced by the acidity, contact time and temperature. The adsorption behavior could be described by the pseudo-second-order rate equation and fitted to Langmuir and Freundlich models. ZGSPC106Na exhibited higher adsorption capacity, while D001SD showed higher adsorption selectivity. These might be attributed to the distinctive structure of the two resins and different ionization of the adsorbates. A method for simultaneous preparation of decaffeinated polyphenols, caffeine-enriched extract and decaffeinated L-theanine was established through successive separation on the columns fulfilled with PA-6, HPD-400 and D001SD, respectively.

Active Compounds in Fruits and Inflammation in the Body

Inflammation plays an important role in the pathogenesis of many diseases, including cardiovascular diseases, atherosclerosis, diabetes, asthma, and cancer. An appropriate diet and the active compounds contained in it can affect various stages of the inflammatory process and significantly affect the course of inflammatory diseases. Recent reports indicate that polyphenolic acids, vitamins, minerals, and other components of fruits may exhibit activity stimulating an anti-inflammatory response, which may be of importance in maintaining health and reducing the risk of disease. The article presents the latest data on the chemical composition of fruits and the health benefits arising from their anti-inflammatory and antioxidant effects. The chemical composition of fruits determines their anti-inflammatory and antioxidant properties, but the mechanisms of action are not fully understood.

Theabrownins Produced via Chemical Oxidation of Tea Polyphenols Inhibit Human Lung Cancer Cells in vivo and in vitro by Suppressing the PI3K/AKT/mTOR Pathway Activation and Promoting Autophagy

During the fermentation of dark tea, theabrownins (TBs), carbohydrates, and other substances get irreversibly complex. Recent research on the biological activity of TBs is not based on free TBs. In the present study, some brown polyphenol oxidized polymers, the generalized TBs (TBs-C), were prepared via alkali oxidation from tea polyphenols (TP). We also investigated the inhibitory mechanism of TBs-C on non-small-cell-lung cancer (NSCLC). TBs-C demonstrated a stronger inhibition than TP on the NSCLC cell lines A549, H2030, HCC827, H1975, and PC9. Next, A549 and H2030 cell lines were selected as subjects to explore this mechanism. TBs-C was found to inhibit proliferation, promote apoptosis, and induce G1 cell-cycle arrest in the cells. In addition, TBs-C increased autophagic flux, which in turn promoted the death of lung cancer cells. Moreover, TBs-C suppressed the PI3K/AKT/mTOR pathway activation, promoted autophagy, and increased the expression of p21 downstream of AKT, which resulted in G1 cell-cycle arrest. In xenotransplanted NSCLC nude mice derived from A549 cells, TBs-C could significantly suppress tumor growth by inhibiting the PI3K/AKT/mTOR pathway without causing hepatotoxicity, brain toxicity, or nephrotoxicity. We believe that our present findings would facilitate advancement in the research and industrialization of TBs.

Comparative Analysis of Purine Alkaloids and Main Quality Components of the Three Camellia Species in China

Tea (Camelliasinensis var. sinensis) is a widely consumed caffeine-containing beverage, however the Camellia genus also includes other species, which are consumed as tea in their local growing regions. Presently, HPLC analysis assessed 126 unique Camellia germplasms belonging to three Camellia species, C. sinensis var. pubilimba Chang (Csp), C. gymnogyna Chang (CgC) and C. crassicolumna Chang (CcC). Theobromine was the predominant purine alkaloid in all species, representing over 90% of purine alkaloids in Csp and CgC, and 50% in CcC. Significant variability existed in purine alkaloid patterns both between and within species, and some germplasms possessed highly unique alkaloid profiles. Sensory evaluation and quality composition analysis of green tea products produced from the three Camellia species suggested their unsuitability for use in tea production due to their unpalatable flavor. The results of this study revealed the differences in purine alkaloids and main quality components between Camellia species and tea, which contributed to understand why tea, rather than other Camellia species, has become a popular beverage in the world after long-term artificial selection. In addition, unique alkaloid profiles suggest usefulness of these germplasm resources in future breeding of decaffeinated tea plant varieties and alkaloid metabolism research.

Phytochemical Characterization and Antioxidant and Enzyme Inhibitory Activities of Different Parts of Prinsepia utilis Royle

The objective of this study was to evaluate the phenolic composition and antioxidant and enzyme inhibitory activities of the flowers, leaves, and stems of Prinsepia utilis Royle. In the work, their total phenol content and flavonoid content were determined. In addition, the scavenging effects of DPPH and ABTS free radicals and ferric reducing antioxidant power were measured. The results showed the flowers had the highest total phenol and flavonoid content, followed by the leaves and stems. A total of 11 phenolic substances were identified and quantified using UHPLC-ESI-HRMS/MS, of which rutin was the dominant phenolic compound in all samples. All three samples had good antioxidant activity and dose dependently inhibited the activity of α-glucosidase, pancreatic lipase, and tyrosinase. In summary, the ethanol extracts of the flowers have the best antioxidant and enzyme inhibitory ability among three samples. The outcome could provide support for the development and utilization of P. utilis.

Feasibility study of PET dynamic imaging of [18F]DHMT for quantification of reactive oxygen species in the myocardium of large animals

OBJECTIVES

We aimed to develop a dynamic imaging technique for a novel PET superoxide tracer, [18F]DHMT, to allow for absolute quantification of myocardial reactive oxygen species (ROS) production in a large animal model.

METHODS

Six beagle dogs underwent a single baseline dynamic [18F]DHMT PET study, whereas one animal underwent three serial dynamic studies over the course of chronic doxorubicin administration (1 mg·kg-1·week-1 for 15 weeks). During the scans, sequential arterial blood samples were obtained for plasma metabolite correction. The optimal compartment model and graphical analysis method were identified for kinetic modeling. Values for the left ventricular (LV) net influx rate, Ki, were reported for all the studies and compared with the LV standard uptake values (SUVs) and the LV-to-blood pool SUV ratios from the 60 to 90 minute static images. Parametric images were also generated.

RESULTS

[18F]DHMT followed irreversible kinetics once oxidized within the myocardium in the presence of superoxide, as evidenced by the fitting generated by the irreversible two-tissue (2Ti) compartment model and the linearity of Patlak analysis. Myocardial Ki values showed a weak correlation with LV SUV (R2 = 0.27), but a strong correlation with LV-to-blood pool SUV ratio (R2 = 0.92). Generation of high-quality parametric images showed superior myocardial to blood contrast compared to static images.

CONCLUSIONS

A dynamic PET imaging technique for [18F]DHMT was developed with full and simplified kinetic modeling for absolute quantification of myocardial superoxide production in a large animal model.

Assessment of Biochemical Composition and Antioxidant Properties of Algerian Date Palm (Phoenix dactylifera L.) Seed Oil

Date palm (Phoenix dactylifera L.) trees are largely cultivated across the Algerian oases; they are principal sources of remuneration and the economic basis for residents of these areas. Date palm fruits are rich sources of essential nutrients, vitamins, minerals, and dietary fibers, with many potential health benefits, yet there are few studies on the chemical composition and biological properties of date palm seed oil. In this study, we present an in-depth characterization of the biochemical composition and antioxidant properties of date palm seed oil (DPSO) produced in Algeria. DPSOs of eight Algerian cultivars, Arechti, Degla-Baida, Deglet-Nour, Ghars, Haloua, Itima, Mech-Degla, and Tentbouchet, were investigated to determine their biochemical compositions and antioxidant properties. The results highlight the potential of DPSO as an alternative food and a natural resource, thanks to several important compounds having high antioxidant capacity. In particular, fatty acids and triacylglycerol (TAGs) analyses showed that oleic (42.74–50.19%), lauric (18.40–22.2%), and myristic (8.83–10.17%) were the major fatty acids, while 1-myristoyl 2-oleoyl 3-linoleoyl glycerol, 1-linolenoyl 2-oleoyl 3-linoleoyl glycerol, 1-2-linolenoyl 3-linoleoyl glycerol, and 1-linolenoyl 2-myristoyl 3-linoleoyl glycerol were the major TAGs. Biophenols and tocopherols analyses revealed the presence of important compounds, such as catechin (22.04–24.92 mg/kg), vanillin (10.67–23.98 mg/kg), and α-tocopherol (443.59 mg/kg), at high remarkable levels. Therefore, a comparison with the literature data concerning other seed oils, including olive oil, confirms that DPSO can be considered a high-quality oil, from a biochemical and biological point of view.

Characterization of Fruit Development, Antioxidant Capacity, and Potential Vasoprotective Action of Peumo (Cryptocarya alba), a Native Fruit of Chile

The peumo (Cryptocarya alba) is a native fruit from central Chile that belongs to the Lauraceae family. To characterize the development and the potential health benefits of this edible fruit, quality and physiological parameters, along with antioxidant capacity, were evaluated during three clearly defined developmental stages of the fruit in two seasons. The most distinguishable attributes of ripe fruit were the change in size and color. Low CO₂ production and no detectable ethylene levels suggested non-climacteric behavior of the peumo fruit. Peumo demonstrate a significant increase in their antioxidant capacity per 1 g of fresh weight (FW) of the sample, from small to ripe fruit. Higher values in ripe fruit (FRAP: 37.1–38.3 µmol FeSO4/gFW, TEAC: 7.9–8.1 mmol TE/gFW, DPPH: 8.4-8.7 IC₅₀ μg/mL, and ORAC: = 0.19–0.20 mmol TE/gFW) were observed than those in blueberry fruit (FRAP: 4.95 µmol FeSO4/gFW, TEAC: 1.25 mmol TE/gFW, DPPH: 11.3 IC₅₀ μg/mL, and ORAC: 0.032 mmol TE/ gFW). The methanol extracts of ripe fruit displayed the presence of polyphenol acids and quercetin, an ORAC value of 0.637 ± 0.061 mmol TE per g dried weight (DW), and a high cellular antioxidant and anti-inflammatory potential, the latter exceeding the effect of quercetin and indomethacin used as standard molecules. Also, the assay of isolated rat aorta with endothelium-dependent relaxation damage demonstrated that the peumo extract induced vascular protection, depending on its concentration under a high glucose condition. These results demonstrate that these endemic fruits have a good chance as ingredients or foods with functional properties.

Multiple Risk Factors for Heart Disease: A Challenge to the Ethnopharmacological Use of Croton urucurana Baill

Croton urucurana Baill. is a native Brazilian tree, popularly known as "sangra-d'água" or "sangue-de-dragão," based on the red resinous sap of the trunk. Its use has been transmitted through generations based on popular tradition that attributes analgesic, anti-inflammatory, and cardioprotective properties to the tree. However, its cardioprotective effects have not yet been scientifically investigated. Thus, the present study investigated the pharmacological response to an ethanol-soluble fraction from the leaves of C. urucurana in Wistar rats exposed to smoking and dyslipidemia, two important cardiovascular risk factors. The extract was evaluated by high-performance liquid chromatography. Wistar rats received a 0.5% cholesterol-enriched diet and were exposed to cigarette smoke (9 cigarettes/day for 10 weeks). During the last 5 weeks, the animals were orally treated with vehicle (negative control group), C. urucurana extract (30, 100, and 300 mg/kg), or simvastatin (2.5 mg/kg) + enalapril (15 mg/kg). One group of rats that was not exposed to these risk factors was also evaluated (basal group). Electrocardiograms and systolic, diastolic, and mean blood pressure were measured. Blood was collected to measure total cholesterol, triglycerides, urea, and creatinine. The heart and kidneys were collected and processed for oxidative status and histopathological evaluation. The phytochemical analysis revealed different classes of flavonoids and condensed tannins. The model induced dyslipidemia and cardiac and renal oxidative stress and increased levels of urea and creatinine in the negative control group. Treatment with the C. urucurana extract (300 mg/kg) and simvastatin + enalapril decreased cholesterol and triglyceride levels. In contrast to simvastatin + enalapril treatment, the C. urucurana extract exerted cardiac and renal antioxidant effects. No alterations of electrocardiograms, blood pressure, or histopathology were observed between groups. These findings indicate that C. urucurana exerts lipid-lowering, renal, and cardioprotective effects against oxidative stress in a preclinical model of multiple risk factors for heart disease.

Oxidative Stress and Antioxidant Pathway in Allergic Rhinitis

Oxidative stress is the cause and consequence of redox metabolism in various physiological and pathological conditions. Understanding the molecular pathways underlying oxidative stress and the role of antioxidants could serve as the key to helping treat associated diseases. Allergic rhinitis is a condition that deteriorates the daily function and quality of life of afflicted individuals and is associated with a high socioeconomic burden and prevalence. Recent studies have focused on the role of oxidative stress and antioxidants in allergic rhinitis. This review discusses animal and clinical studies on oxidative markers and the potential therapeutic dietary antioxidants for allergic rhinitis.

Hydroethanolic Extract of A. officinarum Hance Ameliorates Hypertension and Causes Diuresis in Obesogenic Feed-Fed Rat Model

Alpinia officinarum Hance (Zingiberaceae) has been used widely in traditional Chinese and Ayurvedic medicines. Its folkloric uses include relieving stomach ache, treating cold, improving the circulatory system, and reducing swelling. Its effectiveness and mechanism of antihypertension in obesity-induced hypertensive rats have not been studied yet as per our knowledge. This study has been designed to provide evidence of underlying mechanisms to the medicinal use of A. officinarum as a cardiotonic using an obesity-induced hypertension model in rats. Chronic administration of A. officinarum caused a marked reduction in the body weight gain and Lee index of rats compared to the obesogenic diet-fed rats. Its administration also caused attenuation in blood pressure (systolic, diastolic, and mean), serum total cholesterol, triglyceride, and leptin, while an increase in serum HDL and adiponectin levels was noticed. The catalase and superoxide dismutase enzymatic activities were found to be remarkable in the serum of A. officinarum-treated animal groups. A. officinarum showed mild to moderate diuretic, hepatoprotective, and reno-protective effects. The A. officinarum-treated group showed less mRNA expression of 3-hydroxy-3-methylglutaryl-CoA reductase while the mRNA expression of peroxisome proliferator-activated receptor and mRNA expression of cholesterol 7 alpha-hydroxylase were raised in comparison to the hypertensive group of rats evaluated by quantitative real-time polymerase chain reaction. These findings show that A. officinarum possesses antihypertensive and diuretic activities, thus providing a rationale to the medicinal use of A. officinarum in cardiovascular ailments.

Management of oxidative stress and inflammation in cardiovascular diseases: mechanisms and challenges

Cardiovascular diseases (CVDs) have diverse physiopathological mechanisms with interconnected oxidative stress and inflammation as one of the common etiologies which result in the onset and development of atherosclerotic plaques. In this review, we illustrate this strong crosstalk between oxidative stress, inflammation, and CVD. Also, mitochondrial functions underlying this crosstalk, and various approaches for the prevention of redox/inflammatory biological impacts will be illustrated. In part, we focus on the laboratory biomarkers and physiological tests for the evaluation of oxidative stress status and inflammatory processes. The impact of a healthy lifestyle on CVD onset and development is displayed as well. Furthermore, the differences in oxidative stress and inflammation are related to genetic susceptibility to cardiovascular diseases and the variability in the assessment of CVDs risk between individuals; Omics technologies for measuring oxidative stress and inflammation will be explored. Finally, we display the oxidative stress-related microRNA and the functions of the redox basis of epigenetic modifications.

Preventive Effects of Green Tea Extract against Obesity Development in Zebrafish

Various natural products (NPs) have been used to treat obesity and related diseases. However, the best way to fight obesity is preventive, with accurate body weight management through exercise, diet, or bioactive NPs to avoid obesity development. We demonstrated that green tea extract (GTE) is an anti-obesity NP using a zebrafish obesity model. Based on a hypothesis that GTE can prevent obesity, the objective of this study was to assess GTE's ability to attenuate obesity development. Juvenile zebrafish were pretreated with GTE for seven days before obesity induction via a high-fat diet; adult zebrafish were pretreated with GTE for two weeks before obesity induction by overfeeding. As a preventive intervention, GTE significantly decreased visceral adipose tissue accumulation in juveniles and ameliorated visceral adiposity and plasma triglyceride levels in adult zebrafish obesity models. RNA sequencing analysis was performed using liver tissues from adult obese zebrafish, with or without GTE administration, to investigate the underlying molecular mechanism. Transcriptome analysis revealed that preventive GTE treatment affects several pathways associated with anti-obesity regulation, including activation of STAT and downregulation of CEBP signaling pathways. In conclusion, GTE could be used as a preventive agent against obesity.

Nutritional Composition and Bioactive Compounds in Tomatoes and Their Impact on Human Health and Disease: A Review

Tomatoes are consumed worldwide as fresh vegetables because of their high contents of essential nutrients and antioxidant-rich phytochemicals. Tomatoes contain minerals, vitamins, proteins, essential amino acids (leucine, threonine, valine, histidine, lysine, arginine), monounsaturated fatty acids (linoleic and linolenic acids), carotenoids (lycopene and β-carotenoids) and phytosterols (β-sitosterol, campesterol and stigmasterol). Lycopene is the main dietary carotenoid in tomato and tomato-based food products and lycopene consumption by humans has been reported to protect against cancer, cardiovascular diseases, cognitive function and osteoporosis. Among the phenolic compounds present in tomato, quercetin, kaempferol, naringenin, caffeic acid and lutein are the most common. Many of these compounds have antioxidant activities and are effective in protecting the human body against various oxidative stress-related diseases. Dietary tomatoes increase the body's level of antioxidants, trapping reactive oxygen species and reducing oxidative damage to important biomolecules such as membrane lipids, enzymatic proteins and DNA, thereby ameliorating oxidative stress. We reviewed the nutritional and phytochemical compositions of tomatoes. In addition, the impacts of the constituents on human health, particularly in ameliorating some degenerative diseases, are also discussed.

A META-ANALYSIS OF THE EFFECTS OF GREEN TEA COMBINED WITH PHYSICAL ACTIVITY ON BLOOD LIPIDS IN HUMANS

ABSTRACT Introduction: Most studies of green tea extract (GTE) combined with physical activity have reported a preventative effect for cardiovascular disease; however, the findings regarding the effects on serum lipids are controversial. Objective: This meta-analysis aimed to examine the evidence of the effects of GTE combined with physical activity on the serum lipid content in humans. Methods: In June 2017, we conducted electronic searches of PubMed, Web of Science, and Cochrane Library to identify pertinent studies: those with an experiment period exceeding two weeks, human randomized controlled trials (RCTs), and those that only assessed GTE with physical activity were included. A random effects model meta-analysis was used in this review. Results: A total of 271 citations were retrieved in our search of the electronic literature, and 7 RCTs, which included 608 individuals, were identified. Overall, there was no significant decrease in low-density lipoprotein cholesterol (LDL-C) (SMD:-0.169; 95% confidence interval [CI]:-0.414 to 0.076; I2=22.7%; p=0.177) or total cholesterol (TC) levels between the GTE and placebo combined with the physical activity group. Similar results were also observed for high density-lipoprotein cholesterol (HDL-C) and triglycerides (TG). In the subgroup and sensitivity analyses of the five studies, the TC levels of the subjects who received a lower dose of epigallocatechin gallate (EGCG) together with performing physical activity were significantly decreased. Conclusion: Current evidence suggests that green tea combined with physical activity does not improve the lipid and lipoprotein levels in humans. Level of evidence I; Systematic review.

Pathophysiology of atherosclerosis: Association of risk factors and treatment strategies using plant-based bioactive compounds

Under physiological conditions, endothelial cells act as protective barrier which prevents direct contact of blood with circulating factors via production of tissue plasminogen activator. Risk factors of metabolic disorders are responsible to induce endothelial dysfunction and may consequently lead to prognosis of atherosclerosis. This article summarizes the process of atherosclerosis which involves number of sequences including formation and interaction of AGE-RAGE, activation of polyol pathway, protein kinase C, and hexosamine-mediated pathway. All these mechanisms can lead to the development of oxidative stress which may further aggravate condition. Different pharmacological interventions are being used to treat atherosclerosis, however, these might be associated with mild to severe side effects. Therefore, plant-based bioactive compounds having potential to combat and prevent atherosclerosis in diabetic patients are attaining recent focus. By understanding process of development and mechanisms involved in atherosclerotic plaque formation, these bioactive compounds can be better option for future therapeutic interventions for atherosclerosis treatment. PRACTICAL APPLICATIONS: Atherosclerosis is one of major underlying disorders of cardiovascular diseases which occur through multiple mechanisms and is associated with metabolic disorders. Conventional therapeutic interventions are not only used to treat atherosclerosis, but are also commonly associated with mild to severe side effects. Therefore, nowadays, bioactive compounds having potential to combat and prevent atherosclerosis in diabetic patients are preferred. By understanding mechanisms involved in atherosclerotic plaque formation, bioactive compounds can be better understood for treatment of atherosclerosis. In this manuscript, we have focused on treatment strategies of atherosclerosis using bioactive compounds notably alkaloids and flavonoids having diverse pharmacological and therapeutic potentials with special focus on the mechanism of action of these bioactive compounds suitable for treatment of atherosclerosis. This manuscript will provide the scientific insights of bioactive compounds to researchers who are working in the area of drug discovery and development to control pathogenesis and development of atherosclerosis and its associated cardiometabolic disorders.

Antihypertensive Effects of Polyphenolic Extract from Korean Red Pine (Pinus densiflora Sieb. et Zucc.) Bark in Spontaneously Hypertensive Rats

Korean red pine (Pinus densiflora Sieb. et Zucc.) bark is a by-product of the wood industry and contains a high level of antioxidative phenolics including flavonoids, which have a variety of beneficial health effects. This study aimed to investigate the antihypertensive effects of P. densiflora bark extract (Korean red pine bark extract; KRPBE) in spontaneously hypertensive rats (SHRs). A group of Wistar-Kyoto rats (WKRs) as a normotensive group was orally fed tap water. Four groups of SHRs were orally fed tap water, captopril (a positive control), 50 mg/kg/day of KRPBE, and 150 mg/kg/day of KRPBE, respectively. Blood pressure of rats was measured once every week for seven weeks of oral administration. After seven weeks, the lungs, kidneys, and serum were collected from rats, then angiotensin-converting enzyme (ACE) activity, angiotensin II content, and malondialdehyde (MDA) content were determined. Blood pressure of the captopril- and KRPBE-treated groups was significantly lower than that of the SHR control group. The ACE activity, angiotensin II content, and MDA content significantly decreased in the captopril- and KRPBE-treated groups than those in the SHR control group. High-performance liquid chromatography analysis revealed six phenolics in KRPBE: protocatechuic acid, procyanidin B1, catechin, caffeic acid, vanillin, and taxifolin. KRPBE, which contains plenty of antioxidative phenolics, has antihypertensive effects partly due to reduction of ACE activity and angiotensin II content, and its antioxidative effect.

Ganoderma atrum polysaccharide ameliorates intestinal mucosal dysfunction associated with autophagy in immunosuppressed mice

The aim of this study was to investigate the protective effect and underlying mechanisms of Ganoderma atrum polysaccharide (PSG-1) on cyclophosphamide (Cy)-induced intestinal mucosal dysfunction in mice. Results showed that PSG-1 promoted the formation of IgA-secreting cells, modulated sIgA, IgE, IgG, IgM secretion, and improved TLR-2, TLR-4, TLR-6 mRNA levels while these factors were suppressed after Cy treatment. CD4⁺ and CD8⁺ T cell numbers were also elevated by PSG-1. Cytokines including IFN-γ, TNF-α, IL-2, IL-12p70, IL-4, IL-1β, IL-17, IL-21, IL-23, TGF-β3 and transcription factors including T-bet, GATA-3, RORγt, Foxp3 increased after PSG-1 administration. Besides, PSG-1 reversed goblet cell numbers, and upregulated tight junction proteins like ZO-1, occludin and claudin-1 in immunosuppressed mice. Apart from these, the autophagy-related proteins LC3, Beclin-1, Atg5 and Atg7 were enhanced by PSG-1. These findings demonstrated that PSG-1 could ameliorate Cy-induced impairment of intestinal immunity and mucosal integrity, which maybe associated with autophagy in mice.

Therapeutic Potential of Flavonoids in Pain and Inflammation: Mechanisms of Action, Pre-Clinical and Clinical Data, and Pharmaceutical Development

Pathological pain can be initiated after inflammation and/or peripheral nerve injury. It is a consequence of the pathological functioning of the nervous system rather than only a symptom. In fact, pain is a significant social, health, and economic burden worldwide. Flavonoids are plant derivative compounds easily found in several fruits and vegetables and consumed in the daily food intake. Flavonoids vary in terms of classes, and while structurally unique, they share a basic structure formed by three rings, known as the flavan nucleus. Structural differences can be found in the pattern of substitution in one of these rings. The hydroxyl group (-OH) position in one of the rings determines the mechanisms of action of the flavonoids and reveals a complex multifunctional activity. Flavonoids have been widely used for their antioxidant, analgesic, and anti-inflammatory effects along with safe preclinical and clinical profiles. In this review, we discuss the preclinical and clinical evidence on the analgesic and anti-inflammatory proprieties of flavonoids. We also focus on how the development of formulations containing flavonoids, along with the understanding of their structure-activity relationship, can be harnessed to identify novel flavonoid-based therapies to treat pathological pain and inflammation.

The Pomace Extract Taurisolo Protects Rat Brain From Ischemia-Reperfusion Injury

Taurisolo^® is a pomace extract from Aglianico Grapes, a wine cultivar native to Campania (Southern Italy). It exhibits a very high polyphenolic content and, consumed as a nutraceutical, is effective in reducing the level of Trimethylamine N-oxide (TMAO), a cardiovascular disease risk factor marker. We here show the effects of Taurisolo^® on rat brain microvascular alterations induced by a diminution in cerebral blood flow (CBFD) for 30 min, due to bilateral common carotid artery occlusion, and subsequent blood flow restoration (CBFR) for 60 min. The rat pial microcirculation was investigated by intravital fluorescence microscopy through a parietal closed window implanted into the skull bone. The rat pial arterioles were classified according to Strahler’s ordering scheme, from smaller penetrating arterioles up to the larger ones. Western blotting analysis and mass spectrometry (MS)-based metabolomics were used to investigate the expression of endothelial nitric oxide synthase (eNOS) or the presence of peroxidized cardiolipin and several inflammatory mediators, respectively. Radical Oxygen Species (ROS) formation and neuronal loss were assessed. In rats CBFD and CBFR caused a decrease in arteriolar diameter, increase in fluorescent leakage and in adhesion of leukocytes to venular walls, reduction in the length of perfused capillaries and increment of ROS formation with large infarct size. Taurisolo^®, intravenously or orally administered, induced pial arteriolar dilation (up to >30% of baseline), prevented fluorescent leakage, adhesion of leukocytes, ROS formation, while facilitated capillary perfusion and significantly reduced infarct size. These effects were accompanied by an increase in eNOS expression. Mass-spectrometry metabolomics analysis detected a marked decrease in the amount of peroxidized cardiolipin and pronounced reduction in pro-inflammatory prostaglandins and thromboxane Txb2. Altogether, these results extend the nutraceutical potential of Taurisolo^® and suggest their eligibility for preventing brain damage due to ischemia-reperfusion injury.

Oxidative Stress in Cardiovascular Diseases: Still a Therapeutic Target?

Cardiovascular diseases (CVD) are complex entities with heterogenous pathophysiologic mechanisms and increased oxidative stress has been viewed as one of the potential common etiologies. A fine balance between the presence of reactive oxygen species (ROS) and antioxidants is essential for the proper normal functioning of the cell. A basal concentration of ROS is indispensable for the manifestation of cellular functions, whereas excessive levels of ROS cause damage to cellular macromolecules such as DNA, lipids and proteins, eventually leading to necrosis and apoptotic cell death. CVD is the main cause of death worldwide with several conditions being affected by oxidative stress. Increased ROS lead to decreased nitric oxide availability and vasoconstriction, promoting arterial hypertension. ROS also negatively influence myocardial calcium handling, causing arrhythmia, and augment cardiac remodeling by inducing hypertrophic signaling and apoptosis. Finally, ROS have also been shown to promote atherosclerotic plaque formation. This review aims at giving an introduction into oxidative stress in CVD, with special focus on endothelial dysfunction, and then examining in detail the role of oxidative stress in the most prevalent of these diseases. Finally, potential nutraceuticals and diets that might be beneficial in diminishing the burden of oxidative stress in CVD are presented.

Modifiable factors associated with symptomatic knee osteoarthritis: The Murakami cohort study

OBJECTIVES

Modifiable risk factors for knee osteoarthritis (OA) have not been studied in detail. This study aimed to determine lifestyle-related modifiable factors of symptomatic knee osteoarthritis in an East Asian population.

STUDY DESIGN

This 5-year cohort study involved 11,091 individuals (age range 40-72 years) living in the Murakami region of Niigata, Japan, who did not have a history of knee OA. At baseline, information on sociodemographic characteristics, body size, lifestyle, and living condition was obtained using a self-administered questionnaire.

MAIN OUTCOME MEASURES

Incident symptomatic knee OA observed at hospitals and orthopaedic clinics in the five years to 2016. Clinical grades of knee OA were based on the Kellgren-Lawrence scale. P for trend was assessed to examine linear associations between predictors and the outcome in multiple logistic regression analysis.

RESULTS

The mean age of participants was 58.1 (SD 9.3) years. The number of cases of grade 2 or more incident knee OA was 429. In men, older age (P for trend < 0.0001), higher BMI (P for trend < 0.0001), higher METs score (P for trend = 0.0150), less smoking (P for trend = 0.0249), and lower green tea consumption (P for trend = 0.0437) were associated with incident knee OA. In women, older age (P for trend < 0.0001), higher BMI (P for trend < 0.0001), and alcohol consumption (P = 0.0153) were associated with incident knee OA.

CONCLUSIONS

Several lifestyle-related factors were found to be associated with incident knee OA and exhibited sex-dependent differences. In particular, higher consumption of green tea was associated with a lower incidence of knee OA in men.

Dietary Polyphenols-Important Non-Nutrients in the Prevention of Chronic Noncommunicable Diseases. A Systematic Review

The improvement of the social and economic conditions of society has eliminated the threat of death from the majority of infectious diseases. However, the rapid progress of civilization has created new possibilities for the appearance of factors with adverse effects for the health of society. This has led to increased morbidity from certain diseases, the presence of which had not been observed several centuries ago. Chronic noncommunicable diseases (e.g., cancers, cardio-vascular disorders, diabetes, obesity, neurodegenerative diseases) result from an inappropriate relationship between people and their environment. The common characteristic for all chronic diseases is a “new” form of inflammation, very often called metaflammation, which is considered as a subclinical, permanent inflammation. As a result, metabolic cascade, including cellular oxidative stress, atherosclerotic process, and insulin resistance, occurs, which slowly generates significant deterioration in the organism. Polyphenols are the major group of non-nutrients, considering their diversity, food occurrence, and biological properties. The current review aims to present a wide spectrum of literature data, including the molecular mechanism of their activity and experimental model used, and summarize the recent findings on the multitude of physiological effects of dietary polyphenols towards the prevention of several chronic diseases. However, despite several studies, the estimation of their dietary intake is troublesome and inconclusive, which will be also discussed.

Effects of Tea-Polysaccharide Conjugates and Metal Ions on Precipitate Formation by Epigallocatechin Gallate and Caffeine, the Key Components of Green Tea Infusion

The mechanism of tea-infusion precipitation is not clear. Epigallocatechin gallate (EGCG) and caffeine (CAF) are the core components of green tea infusion precipitate. The critical precipitation concentration ( C_CPC) of EGCG-CAF mixed aqueous solutions was assayed through a turbidity assay performed at 25 °C and verified by a differential-scanning calorimeter (DSC) for reliability. Different concentrations of the green tea polysaccharide conjugate fraction (gTPC-D), with a molecular weight of 2.32 × 10⁵ Da, and of metal ions (K⁺, Mg²⁺, Ca²⁺, and Al³⁺) were respectively introduced into the mixed solution to study their effects on C_CPC. On the basis of the changed C_CPC, the clarification-precipitation phase diagrams of the mixed aqueous solutions were constructed. By calculating the integral area of the clarification phase, it was determined that the four metal ions and gTPC-D could accelerate precipitate formation with a dose-response relationship; among the metal ions, the effect of Al³⁺ is the strongest, followed by that of Ca²⁺.

Protective Role of Polyphenols against Vascular Inflammation, Aging and Cardiovascular Disease

Aging is a major risk factor in the development of chronic diseases affecting various tissues including the cardiovascular system, muscle and bones. Age-related diseases are a consequence of the accumulation of cellular damage and reduced activity of protective stress response pathways leading to low-grade systemic inflammation and oxidative stress. Both inflammation and oxidative stress are major contributors to cellular senescence, a process in which cells stop proliferating and become dysfunctional by secreting inflammatory molecules, reactive oxygen species (ROS) and extracellular matrix components that cause inflammation and senescence in the surrounding tissue. This process is known as the senescence associated secretory phenotype (SASP). Thus, accumulation of senescent cells over time promotes the development of age-related diseases, in part through the SASP. Polyphenols, rich in fruits and vegetables, possess antioxidant and anti-inflammatory activities associated with protective effects against major chronic diseases, such as cardiovascular disease (CVD). In this review, we discuss molecular mechanisms by which polyphenols improve anti-oxidant capacity, mitochondrial function and autophagy, while reducing oxidative stress, inflammation and cellular senescence in vascular smooth muscle cells (VSMCs) and endothelial cells (ECs). We also discuss the therapeutic potential of polyphenols in reducing the effects of the SASP and the incidence of CVD.

Polyphenol-Rich Extracts from Cotoneaster Leaves Inhibit Pro-Inflammatory Enzymes and Protect Human Plasma Components against Oxidative Stress In Vitro

The present study investigated the phenolic profile and biological activity of dry extracts from leaves of C. bullatus, C. zabelii and C. integerrimus-traditional medicinal and dietary plants-and evaluated their potential in adjunctive therapy of cardiovascular diseases. Complementary UHPLC-PDA-ESI-MS³, HPLC-PDA-fingerprint, Folin-Ciocalteu, and n-butanol/HCl assays of the extracts derived by fractionated extraction confirmed that they are rich in structurally diverse polyphenols (47 analytes, content up to 650.8 mg GAE/g dw) with proanthocyanidins (83.3⁻358.2 mg CYE/g) dominating in C. bullatus and C. zabelii, and flavonoids (53.4⁻147.8 mg/g) in C. integerrimus. In chemical in vitro tests of pro-inflammatory enzymes (lipoxygenase, hyaluronidase) inhibition and antioxidant activity (DPPH, FRAP), the extracts effects were dose-, phenolic- and extraction solvent-dependent. The most promising polyphenolic extracts were demonstrated to be effective antioxidants in a biological model of human blood plasma-at in vivo-relevant levels (1⁻5 µg/mL) they normalized/enhanced the non-enzymatic antioxidant capacity of plasma and effectively prevented peroxynitrite-induced oxidative/nitrative damage of plasma proteins and lipids. As demonstrated in cytotoxicity tests, the extracts were safe-they did not affect viability of human peripheral blood mononuclear cells. In conclusion, Cotoneaster leaves may be useful in development of natural-based products, supporting the treatment of oxidative stress/inflammation-related chronic diseases, including cardiovascular disorders.

Responses of Different Cancer Cells to White Tea Aqueous Extract

White tea from the eastern Chinese province of Fujian is a unique tea variety. Although the health effects of various teas have been investigated in recent years, most studies focused exclusively on green tea varieties. In order to study effects exerted by white tea from eastern Fujian on the viability of cancer cells, we analyzed its main bioactive ingredients. We also evaluated the antioxidant activity of white tea aqueous extract (WTAE) and employed MTT assay to evaluate effects of WTAE on viabilities of Hela and BEL-7402 cancer cell lines. Apoptosis rate detection was also applied to estimate efficacy of cellular apoptotic induction by WTAE in these two cells types. Results revealed that WTAE exhibited high antioxidant activity and inhibited effectively the proliferation of Hela and BEL-7402 cells. The half maximal inhibitory concentration (IC50) of WTAE for Hela cells (0.05 mg/mL) was lower than that for BEL-7402 cells (0.1 mg/mL). Although WTAE induced apoptosis in both cell lines, pro-apoptotic effects were markedly more apparent in Hela cells. Our study demonstrated that WTAE inhibited proliferation of cancer cells via induction of apoptosis and that Hela cells were more sensitive to WTAE than BEL-7402 cells.

PRACTICAL APPLICATION

The aim of this study is to provide a new approach toward cancer prevention by consuming white tea, the properties of which may also be helpful in formulating novel anticancer therapeutics.

Epigallocatechin gallate inhibits hepatitis B virus infection in human liver chimeric mice

Background

Persistent hepatitis B virus (HBV) infection causes liver cirrhosis and hepatocellular carcinoma and constitutes a major worldwide health problem. Currently, anti-HBV drugs are limited to peginterferon and nucleos(t)ide analogs, which are costly and have considerable side effects; the development of novel, effective anti-HBV agents is crucial.

Methods

Catechins are a major group of compounds found in green tea extract and epigallocatechin gallate (EGCG) has been shown to have antiviral properties, including inhibition of cellular entry by HBV. FRG (Fah^−/−/ Rag2^−/−/ IL-2Rγ^/−) mice were used in this study to generate chimeras carrying human primary hepatocytes, to facilitate investigation of the inhibitory effect of EGCG on HBV infection.

Results

Here, we show the inhibitory effect of EGCG on HBV infection and replication in HuS-E/2 cells. The inhibitory effect of EGCG on HBV infection in vivo was confirmed by monitoring HBV DNA and HBsAg in serum and immunostaining the liver tissues of the human liver chimeric mice.

Conclusions

The effects of EGCG suggest a robust strategy for the treatment of HBV infection and EGCG may have therapeutic potential for the treatment of HBV-associated liver diseases.

Epicatechin's cardiovascular protective effects are mediated via opioid receptors and nitric oxide

PURPOSE

Cardiovascular disease is the leading cause of mortality globally. Epicatechin has previously been shown to improve vascular responses and possess cardioprotective properties. However, the mechanisms underpinning these cardiotropic outcomes remain unknown. The aim of this study was to further identify epicatechin's mechanism of action in the cardiovasculature.

METHODS

The effects of epicatechin on isolated rat conduit arteries, resistance vessels and cardiac electrophysiology were investigated on resting tension and precontracted vessels and cardiac action potential parameters, both in the presence and in the absence of various antagonists.

RESULTS

At resting tension, epicatechin alone did not affect the vasoreactivity of either conduit or resistance vessels. In noradrenaline pre-contracted thoracic aortic arteries and potassium chloride pre-contracted mesenteric vessels, epicatechin (10^-9-10^-4 M) induced significant vasorelaxation. The addition of naloxone (10^-5 M), N^G-nitro-L-arginine methyl ester (10^-5M), 4-aminopyridine (5 mM) and verapamil (10^-5 M) attenuated epicatechin-mediated vasorelaxation. No change in epicatechin-mediated vasorelaxation was observed with the addition of atropine (10^-5 M). Epicatechin significantly improved cardiac electrophysiology by reducing the resting membrane potential, action potential amplitude and force of contraction that was mitigated following the addition of naloxone (10^-5 M). Epicatechin significantly decreased the action potential duration at 20, 50 and 90% duration and time to 90% relaxation of force that was unchanged following the addition of naloxone (10^-5 M).

CONCLUSIONS

These findings suggest epicatechin's vascular responses and cardioprotective effects are mediated through opioid receptors, nitric oxide, potassium channel and calcium channel activation and highlight the importance of the endothelium/nitric oxide in epicatechin mediated vasorelaxation.

On-line high-performance liquid chromatography coupled with biochemical detection method for screening of α-glucosidase inhibitors in green tea

An on-line high-performance liquid chromatography-biochemical detection (HPLC-BCD) method, in which compounds separated by HPLC were on-line reacted with enzyme and substrate solutions delivered by flow injection and the enzyme inhibition signal was collected by UV detection, was developed to rapidly screen α-glucosidase inhibitors from green tea extracts in this study. The chromatographic fingerprints and enzyme inhibition profiles of the different brands of green tea could be simultaneously detected by the on-line HPLC-BCD method. Enzyme inhibition profiles were detected by the UV detector at 415 nm based on the reaction of α-glucosidase and p-nitrophenyl α-d-glucopyranoside (PNPG). PNPG (1.25 mm), α-glucosidase (0.4 U/mL) and the flow rate 0.07 mL/min were applied as optimized parameters to detect α-glucosidase inhibitors in green tea. Four components in green tea showed α-glucosidase inhibition action and three of them were identified as HHDP-galloyl glucose, (-)-epigallocatechin-3-gallate and (-)-epicatechin-3-gallate by HPLC-fourier-transform mass spectrometry (HPLC-FTMS). Two brands of green tea derived from Mengding and Enshi mountainous areas might be superior to the other samples in the prevention and treatment of diabetes owing to their stronger activities of enzyme inhibitors. The proposed on-line HPLC-BCD method could be used to rapidly identify the potential enzyme inhibitors in complex matrixes.

The Role of Catechins in Cellular Responses to Oxidative Stress

Catechins are polyphenolic compounds—flavanols of the flavonoid family found in a variety of plants. Green tea, wine and cocoa-based products are the main dietary sources of these flavanols. Catechins have potent antioxidant properties, although in some cases they may act in the cell as pro-oxidants. Catechins are reactive oxygen species (ROS) scavengers and metal ion chelators, whereas their indirect antioxidant activities comprise induction of antioxidant enzymes, inhibition of pro-oxidant enzymes, and production of the phase II detoxification enzymes and antioxidant enzymes. Oxidative stress and ROS are implicated in aging and related dysfunctions, such as neurodegenerative disease, cancer, cardiovascular diseases, and diabetes. Due to their antioxidant properties, catechins may be beneficial in preventing and protecting against diseases caused by oxidative stress. This article reviews the biochemical properties of catechins, their antioxidant activity, and the mechanisms of action involved in the prevention of oxidative stress-caused diseases.