Concentration Dependent Effect of (−)‐Epicatechin on Na+/K+‐ATPase and Ca2+‐ATPase Inhibition Induced by Free Radicals in Hypertensive Patients: Comparison with L‐ascorbic Acid

Although the antioxidant properties of flavonoids are well documented, it is still unclear whether these effects are dependent on radical scavenging or iron chelating activities. Oxidative stress, a state of excessive reactive oxygen species (ROS) activity, is associated with vascular disease conditions such as hypertension. Both the anti‐ and pro‐oxidant effects of tea catechins have been implicated in the alterations of cellular functions that determine their chemoprotective and therapeutic potentials in health and diseases. The present study examined the concentration dependent (10^?7 to 10^?4 m ) effects of (?)‐epicatechin and L‐ascorbic acid on Na⁺/K⁺‐ATPase and Ca²⁺‐ATPase activity in hypertensive patients and normal subjects. L‐ascorbic acid has been used as a positive control to compare the effect of (?)‐epicatechin. A significant (p < 0.0001) decrease in the activities of Na⁺/K⁺‐ATPase and Ca²⁺‐ATPase was observed in hypertensive patients compared with normal subjects. We report that (?)‐epicatechin shows a significant (p < 0.001) dose‐dependent protective effect against oxidative stress induced by tert‐butyl hydroperoxide (t‐BHP), which is manisfested as a decrease in the activity of erythrocyte Na⁺/K⁺‐ATPase and Ca²⁺‐ATPase, in hypertensive patients as well as normal subjects. The effect of L‐ascorbic acid was also significant (p < 0.001) and was comparable with that of (?)‐epicatechin. Copyright © 2012 John Wiley & Sons, Ltd.     

(−)‐Epicatechin‐induced relaxation of isolated human saphenous vein: Roles of K+ and Ca2+ channels

In this study, we aimed to investigate relaxant effect of flavanol (?)‐epicatechin on the isolated human saphenous vein (HSV), as a part of its cardioprotective action, and to define the mechanisms underlying this vasorelaxation. (?)‐Epicatechin induced a concentration‐dependent relaxation of HSV pre‐contracted by phenylephrine. Among K⁺ channel blockers, 4‐aminopyridine, margatoxin, and iberiotoxin significantly inhibited relaxation of HSV, while glibenclamide considerably reduced effects of the high concentrations of (?)‐epicatechin. Additionally, (?)‐epicatechin relaxed contraction induced by 80 mM K⁺, whereas in the presence of nifedipine produced partial relaxation of HSV rings pre‐contracted by phenylephrine. In Ca²⁺‐free solution, (?)‐epicatechin relaxed contraction induced by phenylephrine, but had no effect on contraction induced by caffeine. A sarcoplasmic reticulum Ca²⁺‐ATPase inhibitor, thapsigargin, significantly reduced relaxation of HSV produced by (?)‐epicatechin. These results demonstrate that (?)‐epicatechin produces endothelium‐independent relaxation of isolated HSV rings. Vasorelaxation to (?)‐epicatechin probably involves activation of 4‐aminopyridine‐ and margatoxin‐sensitive K_V channels, BK_Ca channels, and at least partly, K_ATP channels. In addition, not only the inhibition of extracellular Ca²⁺ influx, but regulation of the intracellular Ca²⁺ release, via inositol‐trisphosphate receptors and reuptake into sarcoplasmic reticulum, via stimulation of Ca²⁺‐ATPase, as well, most likely participate in (?)‐epicatechin‐induced relaxation of HSV.     

Protection of human HepG2 cells against oxidative stress by the flavonoid epicatechin

Flavanols, such as epicatechin (EC), constitute an important part of the human diet; they can be found in green tea, grapes and cocoa and possess different biological activities such as antioxidant, anti‐inflammatory and anticarcinogenic. This study investigated the potential chemo‐protective effect of EC against oxidative stress induced by tert‐butylhydroperoxide (t‐BOOH) on human HepG2 cells. Cell viability by lactate dehydrogenase assay and markers of oxidative status: reduced glutathione (GSH), malondialdehyde (MDA), reactive oxygen species (ROS), glutathione peroxidase (GPx) and glutathione reductase (GR) were evaluated. Pretreatment of cells with EC for 20 h prevented the enhanced cell damage and GPx and GR activities as well as the decrease in GSH induced by t‐BOOH. The increased ROS generation induced by t‐BOOH was also partly prevented by a pretreatment for 20 h with EC. In addition, pretreatment of cells with EC for 20 h recovered the t‐BOOH‐induced MDA concentration to control values. A pretreatment for 2 h with EC did not reduce cell damage but partly recovered GSH, reduced ROS levels and muffled the increase of GPx and GR after exposure to t‐BOOH. Treatment of HepG2 cells with concentrations of EC in the micromolar range confers a significant protection against oxidative stress. Copyright © 2009 John Wiley & Sons, Ltd.     

Effects of astaxanthin on oxidative stress in overweight and obese adults

Oxidative stress is caused by an imbalance between the antioxidant and the reactive oxygen species, which results in damage to cells or tissues. Recent studies have reported that oxidative stress is involved in obesity, in addition to many other human diseases and aging. A prospective, randomized, double‐blind study was performed to investigate the effect of astaxanthin (ASX), which is known to be a potent antioxidant, on oxidative stress in overweight and obese adults in Korea. Twenty‐three adults with BMI > 25.0 kg/m² enrolled in this study and were randomly assigned to two dose groups: ASX 5 mg and 20 mg once daily for 3 weeks. Malondialdehyde (MDA), isoprostane (ISP), superoxide dismutase (SOD) and total antioxidant capacity (TAC), as oxidative stress biomarkers, were measured at baseline and 1, 2 and 3 weeks after ASX administration. Compared with baseline, the MDA (by 34.6% and 35.2%) and ISP (by 64.9% and 64.7%) levels were significantly lowered, whereas SOD (by 193% and 194%) and TAC (by 121% and 125%) levels were significantly increased in two dose groups after the 3 week intervention. This study revealed that supplemental ASX for 3 weeks improved oxidative stress biomarkers by suppressing lipid peroxidation and stimulating the activity of the antioxidant defense system. Copyright © 2011 John Wiley & Sons, Ltd.     

Effects of Grape Seed Polyphenols on Oxidative Damage in Liver Tissue of Acutely and Chronically Exercised Rats

The objective of the present study was to investigate the effects of grape seed extract (GSE) supplementation on oxidative stress and antioxidant defense markers in liver tissue of acutely and chronically exercised rats. Rats were randomly assigned to six groups: Control (C), Control Chronic Exercise (CE), Control Acute Exercise (AE), GSE‐supplemented Control (GC), GSE‐supplemented Chronic Exercise(GCE) and GSE‐supplemented Acute Exercise (GAE). Rats in the chronic exercise groups were subjected to a six‐week treadmill running and in the acute exercise groups performed an exhaustive running. Rats in the GSE supplemented groups received GSE (100 mg.kg^?1.day^?1) in drinking water for 6 weeks. Liver tissues of the rats were taken for the analysis of malondialdehyde (MDA), nitric oxide (NO) levels and total antioxidant activity (AOA) and xanthine oxidase (XO) activities. MDA levels decreased with GSE supplementation in control groups but increased in acute and chronic exercise groups compared to their non‐supplemented control. NO levels increased with GSE supplementation. XO activities were higher in AE group compared to the CE group. AOA decreased with GSE supplementation. In conclusion, while acute exercise triggers oxidative stress, chronic exercise has protective role against oxidative stress. GSE has a limited antioxidant effect on exercise‐induced oxidative stress in liver tissue. Copyright © 2012 John Wiley & Sons, Ltd.     

Protection of lipid peroxidation and carbonyl formation in proteins by capsaicin in human erythrocytes subjected to oxidative stress

Capsaicin (8-methyl-N-vanillyl-6-nonemide) is the major pungent principle found in hot peppers of the plant genus Capsicum. The present work was undertaken to investigate the antioxidative property of capsaicin on markers of oxidative stress; membrane lipid peroxidation (formation of malondialdehyde) and membrane carbonyl groups in human erythrocytes. The effect of capsaicin has been compared with l-ascorbic acid. Subjecting erythrocytes to oxidative stress by incubating them with t-BHP caused a significant increase in MDA level and protein carbonyl group content above the basal value. The presence of capsaicin (10 microm) in the incubation medium protected the erythrocytes from t-BHP-induced oxidative stress as evidenced by the decrease in MDA level and protein carbonyl group content, l-ascorbic acid also showed similar protective effect. The results conclusively prove the efficacy of the antioxidant property of capsaicin. This evidence suggests that dietary factors that act as antioxidants to decrease membrane lipid peroxidation and protein carbonyl formation may contribute to a protective effect against cancer, atherosclerosis and age related diseases. This antioxidant effect may, in part, explain the high consumption of capsicum in certain regions of the world.     

Schisandrin B stereoisomers protect against hypoxia/reoxygenation‐induced apoptosis and associated changes in the Ca2+‐induced mitochondrial permeability transition and mitochondrial membrane potential in AML12 hepatocytes

The effects of the schisandrin B stereoisomers, (±)γ‐schisandrin [(±)γ‐Sch] and (?)schisandrin B [(?)Sch B], on hypoxia/reoxygenation‐induced apoptosis were investigated in AML12 hepatocytes. Changes in cellular reduced glutathione (GSH) levels, Ca²⁺‐induced mitochondrial permeability transitions (MPTs) and mitochondrial membrane potentials (Δψ_m values) were also examined in (±)γ‐Sch‐ and (?)Sch B‐treated cells, without or with hypoxia/reoxygenation challenge. The (±)γ‐Sch/(?)Sch B pretreatments (2.5–5.0 µm ) protected against hypoxia/reoxygenation‐induced apoptosis in AML12 cells in a concentration‐dependent manner, with the (?)Sch B effect being more potent. Drug antiapoptotic effects were further evidenced by suppression of hypoxia/reoxygenation‐induced mitochondrial cytochrome c release and subsequent cleavage of caspase 3 and poly‐ADP‐ribose polymerase by (?)Sch B pretreatment. Whereas hypoxia/reoxygenation challenge increased the extent of Ca²⁺‐induced MPT pore opening, and Δψ_m, in AML12 hepatocytes, cytoprotection afforded by (±)γ‐Sch/(?)Sch B pretreatment against hypoxia/reoxygenation‐induced apoptosis was associated with a decreased sensitivity to Ca²⁺‐induced MPT and an increased Δψ_m in both unchallenged and challenged cells, compared with the drug‐free control. The results indicate that (±)γ‐Sch/(?)Sch B pretreatment protected against hypoxia/reoxygenation‐induced apoptosis in AML12 hepatocytes and that the cytoprotection afforded by (±)γ‐Sch/(?)Sch B may at least in part be mediated by a decrease in sensitivity to Ca²⁺‐induced MPT, which may in turn result from enhancement of cellular GSH levels by drug pretreatments. Copyright © 2009 John Wiley & Sons, Ltd.     

Ameliorative effects of pycnogenol on carbon tetrachloride-induced hepatic oxidative damage in rats

This study evaluated the putative antioxidant activity of Pycnogenol (PYC) against CCl4-induced hepatic oxidative damage in Sprague-Dawley rats. A single oral dose of CCl4 (1.25 mL/kg) produced significantly increased levels of serum aminotransferase (AST) and alanine aminotransferase (ALT) activities. In addition, increased malondialdehyde (MDA) concentration, reduced glutathione (GSH) content, and decreased catalase, superoxide dismutase (SOD) and glutathione-S-transferase (GST) activities were observed in the hepatic tissues. However, concomitant administration with PYC (10 or 20 mg/kg) significantly improved CCl4-induced hepatic injury, as evidenced by the decline of serum AST and ALT activities in a dose dependent manner. Moreover, PYC reduced MDA concentration and increased GSH levels and catalase, SOD and GST activities in hepatic tissues, indicating that concomitant administration with PYC efficiently prevent the CCl4-induced oxidative damage in rats. The free radical scavenging assay showed that PYC has a dose-dependent scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals. These results indicate that PYC has an antioxidant effect against CCl4-induced hepatic oxidative damage and is useful as a hepatoprotective agent against various liver diseases induced by oxidative stress.     

Modulating Effects of Pycnogenol® on Oxidative Stress and DNA Damage Induced by Sepsis in Rats

The aim of this study was to evaluate the protective effects of Pycnogenol® (Pyc), a complex plant extract from the bark of French maritime pine, on oxidative stress parameters (superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities and total glutathione (GSH) and malondialdehyde (MDA) levels), an inflammatory cytokine (tumor necrosis factor alpha (TNF‐α) level) and also DNA damage in Wistar albino rats. Rats were treated with 100 mg/kg intraperitonally Pyc following the induction of sepsis by cecal ligation and puncture. The decreases in MDA levels and increases in GSH levels, and SOD and GPx activities were observed in the livers and kidneys of Pyc‐treated septic rats. Plasma TNF‐α level was found to be decreased in the Pyc‐treated septic rats. In the lymphocytes, kidney, and liver tissue cells of the sepsis‐induced rats, Pyc treatment significantly decreased the DNA damage and oxidative base damage using standard alkaline assay and formamidopyrimidine DNA glycosylase‐modified comet assay, respectively. In conclusion, Pyc treatment might have a role in the prevention of sepsis‐induced oxidative damage not only by decreasing DNA damage but also increasing the antioxidant status and DNA repair capacity in rats. Copyright © 2014 John Wiley & Sons, Ltd.     

Protective Effects of Pine Bark Extract on Hexavalent Chromium‐Induced Dermatotoxicity in Rats

The present study investigated the protective effects of pine bark extract (PBE) against hexavalent chromium [Cr(VI)]‐induced dermatotoxicity in rats. Skin reactions were evaluated by visual inspection, histopathological changes and oxidative stress parameters. Topical application of Cr(VI) produced a significant increase in the incidence and severity of erythema and edema upon visual inspection. Histopathological examination showed moderate to severe necrosis and desquamation in the epidermis and inflammation and hemorrhage in the dermis. In addition, an increased malondialdehyde (MDA) concentration, and decreased glutathione (GSH), catalase, superoxide dismutase, glutathione‐S‐transferase (GST) and glutathione reductase of the skin were observed in the Cr(VI) group. On the contrary, concomitant administration with PBE significantly improved Cr(VI)‐induced dermatotoxicity, evidenced by a decrease in the incidence and severity of skin irritation and histopathological lesions in a dose‐dependent manner. Moreover, PBE treatment reduced MDA concentrations and increased catalase and GST activities in skin tissues, indicating that concomitant administration with PBE effectively prevents Cr(VI)‐induced oxidative damage in rats. The results indicate that PBE has a protective effect against Cr(VI)‐induced dermatotoxicity and is useful as a protective agent against various dermal lesions induced by oxidative stress. Copyright © 2012 John Wiley & Sons, Ltd.     

Prophylaxis with Centella asiatica confers protection to prepubertal mice against 3‐nitropropionic‐acid‐induced oxidative stress in brain

While the usage of Centella asiatica (CA) is on the increase worldwide, evidence demonstrating its protective efficacy against neurotoxicants is scarce. Hence the present study aimed to understand the neuroprotective efficacy of a standardized aqueous extract of CA against 3‐nitropropionic‐acid(3‐NPA)‐induced oxidative stress in the brain of prepubertal mice. We assessed the degree of oxidative stress in cytoplasm of brain regions of male mice (4 wk‐ old) given CA prophylaxis (5 mg/kg bw) for 10 days followed by 3‐NPA administration (i.p.75 mg/kg bw) on the last 2 days. The neurotoxicant elicited marked oxidative stress in the brain of untreated mice as evident by enhanced malondialdehyde levels, reactive oxygen species (ROS) generation, hydroperoxides and protein carbonyls (a measure of protein oxidation) in striatum and other regions (cortex, cerebellum and hippocampus), while CA prophylaxis completely ameliorated the 3‐NPA‐ induced oxidative stress. Depletion of glutathione (GSH) levels, total thiols, perturbations in antioxidant enzymes and cholinergic enzymes in brain discernible among 3‐NPA‐treated mice were predominantly restored to normalcy with CA prophylaxis. It is hypothesized that the prophylactic protection offered by CA extract against neurotoxicant exposure may be largely due to its ability to enhance GSH, thiols and antioxidant defenses in the brain of prepubertal mice. Copyright © 2009 John Wiley & Sons, Ltd.     

Antioxidant effect of beta-carotene on hypoxia induced oxidative stress in male albino rats.

Hypoxia is known to induce oxidative stress in organisms leading to tissue injury. In the present study beta-carotene (BC) given at 10 mg/kg body weight (BW) in reducing the oxidative stress induced by hypoxia was evaluated on male albino rats. Hypoxia exposure caused an increase in malondialdehyde (MDA) levels in plasma and tissues, a concurrent decrease in blood glutathione (GSH), glutathione peroxidase (GPx), plasma protein and plasma BC content. Hemoglobin concentration, Red blood corpuscles (RBC) and White blood corpuscles (WBC) count were also increased under hypoxia. BC supplementation reversed the trend, inducing a significant decrease (P<0.05) in MDA and subsequent increase in plasma and tissue GSH levels in animals exposed to hypoxia. Blood GPx and plasma protein also increased significantly in BC supplemented animals. BC supplementation did not alter the changes in Hb concentration, RBC and WBC count. BC has potent antioxidant activities in reducing the oxidative stress induced by hypobaric hypoxia.     

Vasodilatory Effects of Cinnamic Acid via the Nitric Oxide–cGMP–PKG Pathway in Rat Thoracic Aorta

Cinnamic acid (CA) and its derivatives have a broad therapeutic spectrum that includes antimicrobial, antifungal, and antitumoral activities. However, the vasodilative effect of CA has not been demonstrated. The present study characterizes the vasodilative activity and the mechanism of CA in rat thoracic aorta. The vasomotion of aortic strips following CA treatment was measured in an organ bath system. In addition, vascular strips and human umbilical vein endothelial cells (HUVECs) were used in organ bath, Western blot, nitrite, and cyclic guanosine monophosphate (cGMP) measurements. CA relaxed phenylephrine‐precontracted aortic strips in an endothelium‐dependent manner. Pretreatment of the endothelium‐intact aortic strips with N^G‐nitro‐l ‐arginine methyl ester (10^?4 M), 1 H‐[1,2,4]‐oxadiazolole‐[4,3‐a] quinoxalin‐10‐one, (10^?6 M) and methylene blue (10^?5 M) inhibited CA‐induced vasorelaxation. CA also increased the phosphorylation of endothelial nitric oxide synthase and nitric oxide generation in a concentration‐dependent manner in HUVECs. In addition, cGMP generation and cGMP‐dependent protein kinase G (PKG) expression in aortic strips were increased by CA treatment. Furthermore, CA‐induced vasorelaxation was inhibited by the PKG inhibitor KT5823 (0.3 μM) and the Ca²⁺‐activated K⁺ channel inhibitor tetraethylammonium (10^?3 M). These findings suggest that CA exerts an endothelium‐dependent vasodilation effect via the nitric oxide–cGMP–PKG‐mediated pathway in rat thoracic aorta. Copyright © 2012 John Wiley & Sons, Ltd.     

Effect of Curcumin on Hepatic Antioxidant Enzymes Activities and Gene Expressions in Rats Intoxicated with Aflatoxin B1

Twenty‐eight rats were examined in a 5‐week experiment to investigate the effect of curcumin on gene expression and activities of hepatic antioxidant enzymes in rats intoxicated with aflatoxin B1 (AFB₁). The rats were divided into four groups. Rats in 1–4 groups served as control, oral curcumin treated (15 mg/kg body weight), single i.p. dose of AFB₁ (3 mg/kg body weight) and combination of single i.p. dose of AFB₁ with oral curcumin treated, respectively. AFB₁ Liver damage and oxidative stress were evident in untreated AFB₁‐intoxicated rats as indicated by a significant elevation in hepatic transaminases, elevation in lipid peroxide biomarkers (thiobarbituric acid reactive substances; TBARS), reduction of reduced glutathione (GSH) concentration, reduction in the activities of antioxidant enzymes namely catalase (CAT), total superoxide dismutase (SOD), glutathione peroxidase (GPX) and glutathione‐S‐transferase (GST) and down‐regulation of gene expression of these antioxidant enzymes compared to control. Liver sections of rats intoxicated with AFB₁ showed a disrupted lobular architecture, scattered necrotic cells and biliary proliferation. Administration of curcumin with AFB₁ resulted in amelioration of AFB₁‐induced effects compared to untreated AFB₁‐intoxicated rats via an up‐regulation of antioxidant enzyme gene expression, activation of the expressed genes and increase in the availability of GSH. Copyright © 2014 John Wiley & Sons, Ltd.     

Antioxidant activity of yellow dock (Rumex crispus L., Polygonaceae) fruit extract

The methanol extract of ripe Rumex crispus L. fruits was evaluated for its antioxidant potential by assays for ferric‐reducing antioxidant power (FRAP), DPPH‐free radical scavenging activity (DPPH) and the influence on lipid peroxidation in liposomes (LP). Considerable activity was observed in all test systems (FRAP: 9.9 mmol Fe²⁺/g; DPPH IC₅₀: 3.7 μg/mL; LP IC₅₀: 4.9 μg/mL), comparable to that of BHT (FRAP: 8.0 μg/mL; DPPH IC₅₀: 19.4 μg/mL; LP IC₅₀: 3.5 μg/mL), but lower than the activity of ascorbic acid, rutin and quercetin, used as positive control substances. The in vivo effects were evaluated in several hepatic antioxidant systems (activities of LPx, GSH‐Px, Px, CAT and XOD, as well as GSH content), after treatment with the studied yellow dock extract in different doses, or in combination with carbon tetrachloride (CCl₄). Pretreatment with the R. crispus extract inhibited CCl₄‐induced oxidative stress by decreasing LPx and increasing GSH content in a dose dependent manner, bringing the levels of antioxidant enzymes to near control values. Copyright © 2010 John Wiley & Sons, Ltd.     

霍山石斛多糖对糖尿病性白内障大鼠眼球晶状体组织抗氧化作用的研究

目的 研究霍山石斛多糖对糖尿病性白内障大鼠眼球晶状体组织的抗氧化作用.方法 采用链脲佐菌素对SD大鼠腹腔注射制造糖尿病性大鼠白内障模型,酶法测定各组大鼠眼球晶状体组织的谷胱甘肽( GSH)、丙二醛(MDA)、蛋白质羰基化产物的含有量以及谷胱甘肽过氧化物酶(GSH-PX)、谷胱甘肽还原酶(GR)、谷胱甘肽-S-转移酶(GST)、过氧化氢酶(CAT)、超氧化物岐化酶(SOD)的酶活力.结果 霍山石斛多糖能够显著增加糖尿病性白内障大鼠晶状体组织中GSH水平、降低MDA及羰基的含有量,提高其GSH-PX、GR、GST、SOD、CAT酶活力.结论 霍山石斛多糖可能通过干预氧化应激途径延缓糖尿病性白内障的发展.     

Hypericum perforatum Reduces Paracetamol‐Induced Hepatotoxicity and Lethality in Mice by Modulating Inflammation and Oxidative Stress

Hypericum perforatum is a medicinal plant with anti‐inflammatory and antioxidant properties, which is commercially available for therapeutic use in Brazil. Herein the effect of H. perforatum extract on paracetamol (acetaminophen)‐induced hepatotoxicity, lethality, inflammation, and oxidative stress in male swiss mice were investigated. HPLC analysis demonstrated the presence of rutin, quercetin, hypericin, pseudohypericin, and hyperforin in H. perforatum extract. Paracetamol (0.15–3.0 g/kg, p.o.) induced dose‐dependent mortality. The sub‐maximal lethal dose of paracetamol (1.5 g/kg, p.o.) was chosen for the experiments in the study. H. perforatum (30–300 mg/kg, i.p.) dose‐dependently reduced paracetamol‐induced lethality. Paracetamol‐induced increase in plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) concentrations, and hepatic myeloperoxidase activity, IL‐1β, TNF‐α, and IFN‐γ concentrations as well as decreased reduced glutathione (GSH) concentrations and capacity to reduce 2,2′‐azinobis‐(3‐ethylbenzothiazoline‐6‐sulfonate radical cation; ABTS˙⁺) were inhibited by H. perforatum (300 mg/kg, i.p.) treatment. Therefore, H. perforatum protects mice against paracetamol‐induced lethality and liver damage. This effect seems to be related to the reduction of paracetamol‐induced cytokine production, neutrophil recruitment, and oxidative stress. Copyright © 2015 John Wiley & Sons, Ltd.     

Anti‐myocardial Ischemia Effect and Components of Litchi Pericarp Extracts

Litchi (Litchi chinensis Sonn.) is a famous fruit in south China, and it is also effective for chest tightness or chest pain, irritability, flatulence, epigastric pain and neuralgic pain, hernia pain and testicular swelling, cough, etc. It is valued because a great amount of polyphenol was found in litchi pericarp. In this paper, we got litchi pericarp pure extract by a simple purification method, then evaluated its activity to clear oxygen free radicals in vitro , and evaluated its myocardial protection effect in vivo through acute myocardial ischemia rat model. The results showed that the pure extract had protective effect on myocardial ischemia injury in a certain dose–effect relationship, which reflected in the electrocardiogram, myocardial pathological morphology and other indicators such as cardiac function enzymes, serum and myocardial antioxidant capacity, and eNOS, Bcl‐2 and Bax gene expression. Furthermore, we analyzed the components of pure extract by UPLC‐MS, ESI‐MS and NMR. The main components of PLPE were procyanidin which were identified as procyanidin B2(1), (?)‐epicatechin(2), epicatechin‐(4β → 8,2β → O → 7)‐epicatechin‐(4β → 8)‐epicatechin(3), A‐type procyanidin trimer(4), B‐type procyanidin dimer(5) and procyanidin A2(6).This study proved that litchi pericarp extract may have antioxidant activity and cardioprotection effect. It suggested that litchi pericarp may be good for cardiovascular disease. Copyright © 2017 John Wiley & Sons, Ltd.     

Betulinic acid protects against ischemia/reperfusion‐induced renal damage and inhibits leukocyte apoptosis

The possible protective effect of betulinic acid on renal ischemia/reperfusion (I/R) injury was studied. Wistar Albino rats were unilaterally nephrectomized and subjected to 45 min of renal pedicle occlusion followed by 6 h of reperfusion. Betulinic acid (250 mg/kg, i.p.) or saline was administered at 30 min prior to ischemia and immediately before the reperfusion. Creatinine, blood urea nitrogen (BUN), lactate dehydrogenase (LDH) and TNF‐α as well as the oxidative burst of neutrophil and leukocyte apoptosis were assayed in blood samples. Malondialdehyde (MDA), glutathione (GSH) levels, Na⁺, K⁺‐ATPase and myeloperoxidase (MPO) activities were determined in kidney tissue which was also analysed microscopically. I/R caused significant increases in blood creatinine, BUN, LDH and TNF‐α. In the kidney samples of the I/R group, MDA levels and MPO activity were increased significantly, however, GSH levels and Na⁺, K⁺‐ATPase activity were decreased. Betulinic acid ameliorated the oxidative burst response to both formyl‐methionyl‐leucyl‐phenylalanine (fMLP) and phorbol 12‐myristate 13‐acetate (PMA) stimuli, normalized the apoptotic response and most of the biochemical indices as well as histopathological alterations induced by I/R. In conclusion, these data suggest that betulinic acid attenuates I/R‐induced oxidant responses, improved microscopic damage and renal function by regulating the apoptotic function of leukocytes and inhibiting neutrophil infiltration. Copyright © 2009 John Wiley & Sons, Ltd.     

Curcumin I Mediates Neuroprotective Effect Through Attenuation of Quinoprotein Formation,p‐p38 MAPK Expression,and Caspase‐3 Activation in 6‐Hydroxydopamine Treated SH‐SY5Y Cells

6‐Hydroxydopamine (6‐OHDA) selectively enters dopaminergic neurons and undergoes auto‐oxidation resulting in the generation of reactive oxygen species and dopamine quinones, subsequently leading to apoptosis. This mechanism mimics the pathogenesis of Parkinson's disease and has been used to induce experimental Parkinsonism in both in vitro and in vivo systems. In this study, we investigated the effects of curcumin I (diferuloylmethane) purified from Curcuma longa on quinoprotein production, phosphorylation of p38 MAPK (p‐p38), and caspase‐3 activation in 6‐OHDA‐treated SH‐SY5Y dopaminergic cells. Pretreatment of SH‐SY5Y with curcumin I at concentrations of 1, 5, 10, and 20 μM, significantly decreased the formation of quinoprotein and reduced the levels of p‐p38 and cleaved caspase‐3 in a dose‐dependent manner. Moreover, the levels of the dopaminergic neuron marker, phospho‐tyrosine hydroxylase (p‐TH), were also dose‐dependently increased upon treatment with curcumin I. Our results clearly demonstrated that curcumin I protects neurons against oxidative damage, as shown by attenuation of p‐p38 expression, caspase‐3‐activation, and toxic quinoprotein formation, together with the restoration of p‐TH levels. This study provides evidence for the therapeutic potential of curcumin I in the chemoprevention of oxidative stress‐related neurodegeneration. Copyright © 2013 John Wiley & Sons, Ltd.