Grape seed proanthocyanins protect fluoride-induced hepatotoxicity via the Nrf2 signaling pathway in male rats.

Background: Fluoride is a necessary element for human health, but excessive fluoride intake is found toxic to the liver. Previous studies confirmed that Grape seed procyanidin extract (GSPE) protects against fluoride-induced hepatic injury. However, the mechanism underlying this protective effect remains obscure. To evaluate the protective effect of GSPE against fluoride-induced hepatic injury and explore the possible hepatoprotective role of the Nrf2 signaling pathway to find effective strategies for the treatment and prevention of fluoride-induced hepatotoxicity. This study aims to explore the mechanisms by which GSPE attenuates fluoride-induced hepatotoxicity through a rat drinking water poisoning model. Methods: Hepatic injury was determined by serum biochemical parameters, oxidative parameters, HE, and TUNEL analysis. The protein expression levels of apoptosis-related proteins like Bax, B-cell lymphoma-2 (Bcl-2), and Caspase-3 and the nuclear factor, erythroid 2 like 2 (Nrf2) were analyzed by Western blot. Resluts: Our results showed that GSPE administration reduced fluoride-induced elevated serum ALT and AST and enhanced the antioxidant capacity of the liver. In addition, GSPE mitigated fluoride-induced histopathological damage and reduced the liver cell apoptosis rate. Furthermore, GSPE significantly up-regulated the expression and nuclear translocation of the Nrf2 and decreased apoptosis-related proteins like Bax and caspase-3 in the hepatic. Conclusion: Taken together, GSPE exerts protective effects on the oxidative damage and apoptosis of fluoride-induced hepatic injury via the activation of the Nrf2 signaling pathway. This study provides a new perspective for the mechanism study and scientific prevention and treatment of liver injury induced by endemic fluorosis.

Effects of grape seed procyanidins on antioxidant function, barrier function, microbial community, and metabolites of cecum in geese.

The gut is the first line of defense for body health and is essential to the overall health of geese. Grape seed procyanidins (GSPs) are proverbial for their antioxidant, anti-inflammatory, and microflora-regulating capabilities. This study aimed to inquire into the influences of dietary GSPs on the intestinal antioxidant function, barrier function, microflora, and metabolites of geese based on 16S rRNA sequencing and metabolomics. In total, 240 twenty-one-day-old Sichuan white geese were randomly divided into 4 groups, each of which was supplied with 1 of 4 diets: basal diet or a basal diet supplemented with 50, 100, or 150 mg/kg GSPs. Diets supplemented with GSPs at different concentrations significantly increased the total antioxidant capacity and superoxide dismutase activity in cecal mucosa (P < 0.001). Dietary supplementation with 50 or 100 mg/kg GSPs significantly increased catalase activity (P < 0.001). The serum diamine oxidase, D-lactic acid, and endotoxin concentrations were decreased by GSP supplementation in the goose diet. Dietary GSP supplementation increased microbial richness and diversity, enhanced the relative abundance of Firmicutes, and decreased that of Bacteroidetes in the cecum. Diets supplemented with 50 or 100 mg/kg GSPs enriched Eubacterium coprostanoligenes and Faecalibacterium. Dietary GSPs substantially raised the acetic and propionic acid concentrations in the cecum. The butyric acid concentration increased when the GSP dosage was 50 or 100 mg/kg. Additionally, dietary GSPs increased the levels of metabolites that belong to lipids and lipid-like molecules or organic acids and derivatives. Dietary GSP supplementation at 100 or 150 mg/kg reduced the levels of spermine (a source of cytotoxic metabolites) and N-acetylputrescine, which promotes in-vivo inflammation. In conclusion, dietary supplementation with GSPs was beneficial to gut health in geese. Dietary GSPs improved antioxidant activity; protected intestinal barrier integrity; increased the abundance and diversity of cecal microflora; promoted the proliferation of some beneficial bacteria; increased the production of acetic, propionic, and butyric acids in the cecum; and downregulated metabolites associated with cytotoxicity and inflammation. These results offer a strategy for promoting intestinal health in farmed geese.

Time-of-Day Circadian Modulation of Grape-Seed Procyanidin Extract (GSPE) in Hepatic Mitochondrial Dynamics in Cafeteria-Diet-Induced Obese Rats.

Major susceptibility to alterations in liver function (e.g., hepatic steatosis) in a prone environment due to circadian misalignments represents a common consequence of recent sociobiological behavior (i.e., food excess and sleep deprivation). Natural compounds and, more concisely, polyphenols have been shown as an interesting tool for fighting against metabolic syndrome and related consequences. Furthermore, mitochondria have been identified as an important target for mediation of the health effects of these compounds. Additionally, mitochondrial function and dynamics are strongly regulated in a circadian way. Thus, we wondered whether some of the beneficial effects of grape-seed procyanidin extract (GSPE) on metabolic syndrome could be mediated by a circadian modulation of mitochondrial homeostasis. For this purpose, rats were subjected to "standard", "cafeteria" and "cafeteria diet + GSPE" treatments (n = 4/group) for 9 weeks (the last 4 weeks, GSPE/vehicle) of treatment, administering the extract/vehicle at diurnal or nocturnal times (ZT0 or ZT12). For circadian assessment, one hour after turning the light on (ZT1), animals were sacrificed every 6 h (ZT1, ZT7, ZT13 and ZT19). Interestingly, GSPE was able to restore the rhythm on clock hepatic genes (Bmal1, Per2, Cry1, Rorα), as this correction was more evident in nocturnal treatment. Additionally, during nocturnal treatment, an increase in hepatic fusion genes and a decrease in fission genes were observed. Regarding mitochondrial complex activity, there was a strong effect of cafeteria diet at nearly all ZTs, and GSPE was able to restore activity at discrete ZTs, mainly in the diurnal treatment (ZT0). Furthermore, a differential behavior was observed in tricarboxylic acid (TCA) metabolites between GSPE diurnal and nocturnal administration times. Therefore, GSPE may serve as a nutritional preventive strategy in the recovery of hepatic-related metabolic disease by modulating mitochondrial dynamics, which is concomitant to the restoration of the hepatic circadian machinery.

Proteomic analysis of liver mitochondria of db/db mice treated with grape seed procyanidin B2.

Hepatic damage has been recognized as one of the major complications in diabetes mellitus. Our previous studies have verified that grape seed procyanidin B2 (GSPB2) played a protective effect on hepatic damage of diabetes. We used isobaric tag for relative and absolute quantitation proteomics here to identify the alterant mitochondrial protein profile in diabetic liver and to seek the protective targets of GSPB2. Proteomics found that 171 proteins were upregulated or downregulated in the liver mitochondria of diabetic group compared to the control group. Of these proteins, 61 were normalized after GSPB2 treatment. These back-regulated proteins are involved in the process of fatty acid oxidation, tricarboxylic acid cycle, oxidative phosphorylation, oxidative stress, and apoptosis. Some differentially expressed proteins were confirmed by western blotting. Our study might help to better understand the mechanism of mitochondrial dysfunction in diabetic liver damage, and provide novel targets for estimating the protective effects of GSPB2. PRACTICAL APPLICATIONS: Grape seed procyanidin B2 (GSPB2), a polyphenolic component found in red wine and grapes, has beneficial effects such as antioxidative stress, antiapoptosis, and cardiovascular protection. We used proteomics here to identify the differentially expressed mitochondrial proteins in diabetic liver after GSPB2 treatment and to seek the protective targets of GSPB2. We found that the differentially expressed proteins were involved in carbon metabolism, oxidative phosphorylation, fatty acid metabolism, citrate cycle, oxidative stress, and apoptosis. These proteins may play a key role in diabetic hepatic damage as functional proteins. Targeting these proteins including apply of GSPB2 could potentially lead to an effective treatment in the diabetic hepatic disease.

Grape seed procyanidin suppresses inflammation in cigarette smoke-exposed pulmonary arterial hypertension rats by the PPAR-γ/COX-2 pathway.

BACKGROUND AND AIM: Pulmonary arterial hypertension (PAH) is characterized by pulmonary vascular remodeling, which is mainly caused by inflammation. Inhibiting inflammation can relieve PAH. Grape seed procyanidin (GSP) possesses remarkable anti-inflammatory property and vascular protective function. In this experiment, we verified the anti-inflammatory property of GSP in cigarette smoke-exposed PAH rats and revealed its molecular mechanism. METHODS AND RESULTS: In vivo, 45 Sprague Dawley (SD) rats were divided into 5 groups randomly, treated with normoxia/cigarette smoke (CS)/GSP + CS/CS + solvent/GSP. After GSP + CS administration, a decrease in mPAP, PVR, RVHI, WT%, and WA% was detected in the rats as compared to those treated with CS. In vitro, the proliferation of pulmonary arterial smooth muscle cells (PASMCs) caused by cigarette smoke extract (CSE) was effectively attenuated with GSP + CSE administration. Furthermore, GSP significantly increased the expression of peroxisome proliferator-activated receptor γ (PPAR-γ) together with the lowered expression level of cyclooxygenase 2 (COX-2) in PASMCs co-incubated with CSE. CONCLUSION: These findings indicate that GSP ameliorates inflammation by the PPAR-γ/COX-2 pathway and finally inhibits the proliferation of PASMCs, which leads to pulmonary vascular remodeling.

The protective effects of grape seed procyanidin B2 against asporin mediates glycated low-density lipoprotein induced-cardiomyocyte apoptosis and fibrosis.

The progression of diabetic cardiomyopathy is related to cardiomyocyte dysfunction and apoptosis. Our previous studies showed that asporin (ASPN) was significantly increased in the myocardium of db/db mice through proteomics, and grape seed procyanidin B2 (GSPB2) significantly inhibited the expression of ASPN in the heart of db/db mice. We report here that ASPN played a critical role in glycated low-density lipoproteins (gly-LDL) induced-cardiomyocyte apoptosis. We found that gly-LDL upregulated ASPN expression. ASPN increased H9C2 cardiomyocyte apoptosis with down-regulation of Bcl-2, upregulation of transforming growth factor-ß1, Bax, collagen III, fibronectin, and phosphorylation of smad2 and smad3. However, GSPB2 treatment reversed ASPN-induced impairments in H9C2 cardiomyocytes. These results provide evidence for the cardioprotective action of GSPB2 against ASPN injury, and thus suggest a new target for fighting against diabetic cardiomyopathy.

Illumina MiSeq sequencing reveals the effects of grape seed procyanidin on rumen archaeal communities in vitro.

OBJECTIVE: The present study explored the effects of grape seed procyanidin extract (GSPE) on rumen fermentation, methane production and archaeal communities in vitro. METHODS: A completely randomized experiment was conducted with in vitro incubation in a control group (CON, no GSPE addition; n = 9) and the treatment group (GSPE, 1 mg/bottle GSPE, 2 g/kg dry matter; n = 9). The methane and volatile fatty acid concentrations were determined using gas chromatography. To explore methane inhibition after fermentation and the response of the ruminal microbiota to GSPE, archaeal 16S rRNA genes were sequenced by MiSeq high-throughput sequencing. RESULTS: The results showed that supplementation with GSPE could significantly inhibit gas production and methane production. In addition, GSPE treatment significantly increased the proportion of propionate, while the acetate/propionate ratio was significantly decreased. At the genus level, the relative abundance of Methanomassiliicoccus was significantly increased, while the relative abundance of Methanobrevibacter decreased significantly in the GSPE group. CONCLUSION: In conclusion, GSPE is a plant extract that can reduce methane production by affecting the structures of archaeal communities, which was achieved by a substitution of Methanobrevibacter with Methanomassiliicoccus.

Grape Seed Procyanidin Extract (GSPE) Improves Goat Sperm Quality When Preserved at 4 °C.

Grape seed procyanidin extract (GSPE) has been shown to possess antioxidative effects. This experiment was designed to study the effect of GSPE during the liquid storage of goat semen. Semen samples were collected from six sexually mature goats. The samples were treated with different concentrations of GSPE (10, 30, 50, and 70 mg/L) in basic diluent and stored at 4 °C for 120 h; samples without GSPE were used as the control group. The results showed that sperm motility, acrosome membrane integrity, mitochondrial activity, plasma membrane integrity, total antioxidative capacity (T-AOC), catalase (CAT) activity, and superoxide dismutase (SOD) activity in the treatment groups were significantly higher than in the control group, whereas malondialdehyde (MDA) content was lower than in the control group (p < 0.05). In the treatment group, sperm quality in the 30 mg/L GSPE group was significantly higher than the other groups (p < 0.05). Furthermore, artificial insemination (AI) results showed that litter sizes were higher in the 30 mg/L GSPE group than in the control group (p < 0.05). In summary, this experiment showed that adding GSPE to the basic diluent improved sperm quality and that 30 mg/L of GSPE was the most suitable concentration for the liquid preservation of goat semen at 4 °C.

Grape seed procyanidin B2 promotes the autophagy and apoptosis in colorectal cancer cells via regulating PI3K/Akt signaling pathway.

Aim: Colorectal cancer (CRC) is a major malignancy in China, which is the critical risk of people health. Many natural herbs extracts have been found to exhibit good therapeutic effect on CRC. Our previous study found that grape seed procyanidins B2 (PB2) would induce CRC cell death. However, the molecular mechanism underlying its anti-tumor effect on CRC remains unclear. Thereby, this study aimed to investigate the anti-tumor mechanism of PB2 on CRC. Methods: CCK-8, western blotting, flow cytometry, qRT-PCR and animal study were used in the current study. Results: The in vitro and in vivo data demonstrated that PB2 could promote the apoptosis of CRC cells in a dose-dependent manner, which was significantly reversed by caspase 3 inhibitor. Meanwhile, PB2 dose-dependently induced autophagy in CRC cells, which was markedly attenuated by autophagy inhibitor 3-MA. In addition, PB2 dose-dependently inhibited the expressions of p-PI3K, p-Akt and p-mTOR in the cells. Conclusion: PB2 dose-dependently induced apoptosis and autophagy in CRC cells via downregulation of PI3K/Akt pathway. This study provided the experimental basis for further development of PB2 as a new effective anticancer drug for the patients with CRC.

Dietary grape seed procyanidin extract protects against lead-induced heart injury in rats involving endoplasmic reticulum stress inhibition and AKT activation.

To investigate the protective role of grape seed procyanidin extract (GSPE) against lead-induced heart injury and the possible molecular mechanism associated with this event, Wistar rats were orally given GSPE (200 mg/kg) daily with or without lead acetate (PbA) (0.5 g/L) in drinking water for 56 d. GSPE attenuated oxidative stress, heart dysfunction, and lead accumulation in lead-exposed rat hearts. Meanwhile, GSPE inhibited the protein kinase RNA-like endoplasmic reticulum (ER) kinase/eukaryotic initiation factor 2α signaling pathway, and promoted protein kinase B (AKT) and glycogen synthase kinase 3ß phosphorylation altered by lead, and regulated lead-activated apoptosis and its related signaling pathway. This study suggests that dietary GSPE ameliorates lead-induced heart injury associated with ER stress inhibition and AKT activation. Dietary GSPE may be a protector against lead-induced heart injury and a novel therapy for lead exposure.

Grape seed procyanidin extract protects against Pb-induced lung toxicity by activating the AMPK/Nrf2/p62 signaling axis.

Lead (Pb) is one of the most relevant heavy metals contaminants which cause oxidative stress and threaten human health. The lung is one of the organs most severely damaged by Pb. In this study, we investigated the protective effect of grape seed procyanidin extract (GSPE) on Pb-induced lung injury in rats. We found that GSPE alleviated Pb-induced lung injury by relieving oxidative stress, reducing release of inflammatory factors, and inhibiting apoptosis. Furthermore, GSPE enhanced the antioxidant defense systems by activating the nuclear factor-erythroid-2-related factor (Nrf2) signaling pathway to promote downstream expression of heme oxygenase 1 and NAD(P)H quinone oxidoreductase 1. The subsequent ubiquitin-binding protein p62 (sequestosome 1), a downstream target of Nrf2, formed a positive feedback loop with Nrf2 during oxidative stress responses. GSPE treatment resulted in activation of adenosine monophosphate-activated protein kinase (AMPK), which was highly involved in Nrf2 activation. Overall, our findings demonstrate that theprotective effect of GSPE on Pb-induced lung injury arises from activation of the AMPK/Nrf2/p62 signaling pathway, thus providing a new approach for treatment of Pb intoxication.

Reduction of oxidative damages induced by titanium dioxide nanoparticles correlates with induction of the Nrf2 pathway by GSPE supplementation in mice.

Titanium dioxide nanoparticles (TiO2 NPs) are widely used to additives in cosmetics, pharmaceuticals, paints and foods. Recent studies have demonstrated that TiO2 NPs increased the risk of cancer and the mechanism might relate with oxidative stress. Grape seed procyanidin extract (GSPE) is a natural compound which has been demonstrated to possess a wide array of pharmacological and biochemical actions, including anti-inflammatory, anti-carcinogenic, and antioxidant properties. Our data show that GSPE prevents the changes of histopathology and biomarkers in heart, liver and kidney that occur in mice exposed to TiO2 NPs. After pretreatment with GSPE, the DNA damage, reactive oxygen species (ROS) generation and malondialdehyde (MDA) content in mice exposed to TiO2 NPs had statistically significant decreases in dose dependent manners. GSPE increased the expression of nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2), NAD(P)H dehydrogenase[quinine] 1(NQO1), heme oxygenase 1 (HO-1) and glutamate-cysteine ligase catalytic subunit (GCLC). We conclude that grape seed procyanidin extract prevents the majority of tissue and molecular damage resulting from nanoparticle treatment. The protective effect of GSPE may be due to its strong antioxidative activities which related with the activated Nrf2 and its down-regulated genes including NQO1, HO-1 and GCLC.

GSPE reduces lead-induced oxidative stress by activating the Nrf2 pathway and suppressing miR153 and GSK-3ß in rat kidney.

Lead (Pb) is a global environmental health hazard that leads to nephrotoxicity. However, the effective treatment of Pb-induced nephrotoxicity remains elusive. Grape seed procyanidin extract (GSPE) has beneficial properties for multiple biological functions. Therefore, the present study investigated whether GSPE reduced Pb-induced nephrotoxicity as well as the protective mechanism of GSPE in a well-established 35-day Pb induced nephrotoxicity rat model. The results showed that GSPE normalized Pb-induced oxidative stress, histological damage, inflammatory, apoptosis, and changes of miR153 and glycogen synthase kinase 3ß (GSK-3ß) levels in rat kidney. Moreover, GSPE enhanced the induction of phase II detoxifying enzymes (heme oxygenase-1 and NAD(P)H quinone oxidoreductase 1) by increasing nuclear factor-erythroid-2-related factor 2 (Nrf2) expression. This study identifies for the first time that Pb-induced oxidative stress in rat kidney is attenuated by GSPE treatment via activating Nrf2 signaling pathway and suppressing miR153 and GSK-3ß. Nrf2 signaling provides a new therapeutic target for renal injury induced by Pb, and GSPE could be a potential natural agent to protect against Pb-induced nephrotoxicity.

Grape seed procyanidin extract attenuates hypoxic pulmonary hypertension by inhibiting oxidative stress and pulmonary arterial smooth muscle cells proliferation.

Hypoxia-induced oxidative stress and excessive proliferation of pulmonary artery smooth muscle cells (PASMCs) play important roles in the pathological process of hypoxic pulmonary hypertension (HPH). Grape seed procyanidin extract (GSPE) possesses antioxidant properties and has beneficial effects on the cardiovascular system. However, the effect of GSPE on HPH remains unclear. In this study, adult Sprague-Dawley rats were exposed to intermittent chronic hypoxia for 4 weeks to mimic a severe HPH condition. Hemodynamic and pulmonary pathomorphology data showed that chronic hypoxia significantly increased right ventricular systolic pressures (RVSP), weight of the right ventricle/left ventricle plus septum (RV/LV+S) ratio and median width of pulmonary arteries. GSPE attenuated the elevation of RVSP, RV/LV+S, and reduced the pulmonary vascular structure remodeling. GSPE also increased the levels of SOD and reduced the levels of MDA in hypoxia-induced HPH model. In addition, GSPE suppressed Nox4 mRNA levels, ROS production and PASMCs proliferation. Meanwhile, increased expression of phospho-STAT3, cyclin D1, cyclin D3 and Ki67 in PASMCs caused by hypoxia was down-regulated by GSPE. These results suggested that GSPE might potentially prevent HPH via antioxidant and antiproliferative mechanisms.

MicroRNA-19a/b mediates grape seed procyanidin extract-induced anti-neoplastic effects against lung cancer.

Oncomirs are microRNAs (miRNA) associated with carcinogenesis and malignant transformation. They have emerged as potential molecular targets for anti-cancer therapy. We hypothesize that grape seed procyanidin extract (GSE) exerts antineoplastic effects through modulations of oncomirs and their downstream targets. We found that GSE significantly down-regulated oncomirs miR-19a and -19b in a variety of lung neoplastic cells. GSE also increased mRNA and protein levels of insulin-like growth factor II receptor (IGF-2R) and phosphatase and tensin homolog (PTEN), both predicted targets of miR-19a and -19b. Furthermore, GSE significantly increased PTEN activity and decreased AKT phosphorylation in A549 cells. Transfection of miR-19a and -19b mimics reversed the up-regulations of IGF2R and PTEN gene expression and abrogated the GSE induced anti-proliferative response. Additionally, oral administration of leucoselect phytosome, comprised of standardized grape seed oligomeric procyanidins complexed with soy phospholipids, to athymic nude mice via gavage, significantly down-regulated miR-19a, -19b and the miR-17-92 cluster host gene (MIR17HG) expressions, increased IGF-2R, PTEN, decreased phosphorylated-AKT in A549 xenograft tumors, and markedly inhibited tumor growth. To confirm the absorption of orally administered GSE, plasma procyanidin B1 levels, between 60 and 90 min after gavage of leucoselect phytosome (400 mg/kg), were measured by LC/MS at week 2 and 8 of treatment; the estimated concentration that was associated with 50% growth inhibition (IC50) (1.3 µg/mL) in vitro was much higher than the IC50 (0.032-0.13 µg/ml) observed in vivo. Our findings reveal novel antineoplastic mechanisms by GSE and support the clinical translation of leucoselect phytosome as an anti-neoplastic and chemopreventive agent for lung cancer.

Grape seed procyanidin B2 ameliorates mitochondrial dysfunction and inhibits apoptosis via the AMP-activated protein kinase-silent mating type information regulation 2 homologue 1-PPARγ co-activator-1α axis in rat mesangial cells under high-dose glucosamine.

Grape seed procyanidin B2 (GSPB2), an antioxidative and anti-inflammatory polyphenol in grape seed, has been found to have protective effects on diabetic nephropathy. Based on its favourable biological activities, in the present study, we aimed to investigate whether GSPB2 could inhibit apoptosis in rat mesangial cells treated with glucosamine (GlcN) under high-dose conditions. The results showed that the administration of GSPB2 (10 µg/ml) significantly increased the viability of mesangial cells treated with GlcN at a dose of 15 mM. We found that GSPB2 inhibited apoptosis in mesangial cells using terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphates (dUTP) nick-end labelling staining and flow cytometry technique (P< 0·05 for both). GSPB2 treatment also suppressed oxidative stress by elevating the activity of glutathione peroxidase (P< 0·05) and superoxide dismutase (P< 0·01), as well as prevented cellular damage. GSPB2 enhanced the mRNA expression of nuclear respiratory factor 1, mitochondrial transcription factor A and mitochondrial DNA copy number in mesangial cells as determined by real-time PCR (P< 0·05 for each). Finally, GSPB2 treatment activated the protein expression of PPARγ co-activator-1α (PGC-1α), silent mating type information regulation 2 homologue 1 (SIRT1) and AMP-activated protein kinase (AMPK) in mesangial cells. These findings suggest that GSPB2 markedly ameliorates mitochondrial dysfunction and inhibits apoptosis in rat mesangial cells treated with high-dose GlcN. This protective effect could be, at least in part, due to the activation of the AMPK-SIRT1-PGC-1α axis.

Quantitative proteomics study of protective effects of grape seed procyanidin B2 on diabetic cardiomyopathy in db/db mice.

Diabetic cardiomyopathy is one of the major complications of diabetes mellitus. Oxidative stress appears to play a substantial role in cardiomyopathy. Grape seed procyanidin B2 (GSPB2) has been known as an anti-oxidant in treating diabetes mellitus; however, little is known about its effects and underlying mechanisms on diabetic cardiomyopathy. The present study is to explore the molecular targets of GSPB2 responsible for the anti-oxidative effects in db/db mice by quantitative proteomics. GSPB2 (30 mg/kg body weight/day) were intragastric administrated to db/db mice for 10 weeks. Proteomics of the heart tissue extracts by isobaric tags for relative and absolute quantification analysis was obtained from db/db mice. Our study provides important evidence that GSPB2 protect against cardiomyopathy in diabetes mellitus, which are believed to result from regulating the expression of key proteins involving cardiac fibrosis and proliferation. GSPB2 could be expected to become novel clinical application in fighting against diabetic cardiomyopathy.

Cocoa flavonoids attenuate high glucose-induced insulin signalling blockade and modulate glucose uptake and production in human HepG2 cells.

Insulin resistance is the primary characteristic of type 2 diabetes. Cocoa and its main flavanol, (-)-epicatechin (EC), display some antidiabetic effects, but the mechanisms for their preventive activities related to glucose metabolism and insulin signalling in the liver remain largely unknown. In the present work, the preventive effect of EC and a cocoa polyphenolic extract (CPE) on insulin signalling and on both glucose production and uptake are studied in insulin-responsive human HepG2 cells treated with high glucose. Pre-treatment of cells with EC or CPE reverted decreased tyrosine-phosphorylated and total levels of IR, IRS-1 and -2 triggered by high glucose. EC and CPE pre-treatment also prevented the inactivation of the PI3K/AKT pathway and AMPK, as well as the diminution of GLUT-2 levels induced by high glucose. Furthermore, pre-treatment of cells with EC and CPE avoided the increase in PEPCK levels and the diminished glucose uptake provoked by high glucose, returning enhanced levels of glucose production and decreased glycogen content to control values. These findings suggest that EC and CPE improved insulin sensitivity of HepG2 treated with high glucose, preventing or delaying a potential hepatic dysfunction through the attenuation of the insulin signalling blockade and the modulation of glucose uptake and production.

The protective effect of grape seed procyanidin extract against cadmium-induced renal oxidative damage in mice.

As an important environmental pollutant, cadmium (Cd) can lead to serious renal damage. Grape seed procyanidins extract (GSPE), a biological active component of grape seed, has been shown to possess antioxidative effects. Here, we assessed the protective effect of GSPE on Cd-induced renal damage using animal experiment. After 30 days, the oxidative damage of kidney was evaluated through measurement of superoxide dismutase (SOD), glutathione peroxidation (GSH-Px) and malondialdehyde (MDA). Since, oxidative stress could lead to apoptosis, the renal apoptosis was measured using flow cytometer. Moreover, the expression of apoptosis-related protein Bax and Bcl-2 was analyzed by immunohistochemistry and Western blot. The results showed that Cd led to the decrease of SOD and GSH-Px activities, and the increase of MDA level, induced renal apoptosis. However, the coadministration of GSPE attenuated Cd-induced lipid peroxidation, and antagonized renal apoptosis, probably associated with the expression of Bax and Bcl-2. These data suggested that GSPE has protective effect against renal oxidative damage induced by Cd, which provide a potential natural chemopreventive agent against Cd-poisoning.

Grape seed procyanidin extract arrests cell cycle of human bladder cancer cell line BIU87 / 第三军医大学学报

Objective To study the effect of grape seed procyanidin extract(GSPE) on the cell cycle arrest in human bladder cancer BIU87 cells and investigate the underlying molecular mechanism.Methods BIU87 cells were treated with different concentrations of GSPE(50,100 and 200 ?g/ml) and cultured for 24 h.The untreated group served as control.Flow cytometry was used to evaluate the cell cycle,and RT-PCR and Western blotting were used to detect the mRNA and protein expressions of CyclinD1 and cyclin-dependent kinase 4(CDK4).Results GSPE inhibited the cell growth through cell cycle arrest at G1 phrase in a dose-dependent manner.Semi-quantitated RT-PCR and Western blot analyses indicated that GSPE decreased CyclinD1 and CDK4 expressions in a dose-dependent fashion(P