Grape seed proanthocyanidins regulate mitophagy of endothelial cells and promote wound healing in mice through p-JNK/FOXO3a/ROS signal pathway.

Skin wound healing is a dynamic and complex process that involves multiple physiological and cellular events. Grape seed proanthocyanidins (GSP) have strong anti-oxidation and elimination of oxygen free radicals, and have been shown to significantly promote wound healing, but the underlying mechanism remains unclear. Studies have indicated that reactive oxygen species (ROS) acts as an upstream signal to induce mitophagy, suggesting that GSP can regulate mitophagy through the signal pathway. This study aimed to investigate whether GSP regulates mitophagy by down-regulating oxidative stress to promote wound healing. In vivo, GSP treatment accelerated wound healing, granulation tissue formation, collagen deposition, and angiogenesis in mice. Moreover, GSP down-regulated ROS levels and promoted the expression of antioxidant proteins by up-regulating the expression of p-JNK/FOXO3a protein, thereby regulating the expression of mitophagy-related proteins. In vitro, 4 µg/mL GSP showed no apparent toxic effects on cells and effectively reduce the oxidative stress damage of cells induced by H2O2. Western blot and superoxide anion fluorescence probe further confirmed that GSP effectively reduced Dihydroethidium content and up-regulated the expression of antioxidant proteins by activation of p-JNK/FOXO3a protein expression, thereby regulating mitophagy. Taken together, the findings from in vitro and in vivo experiments provide new insights into the promotion of wound healing by GSP.

Proanthocyanidins-loaded complex coacervates-based drug delivery attenuates oral squamous cell carcinoma cells metastatic potential through down-regulating the Akt signaling pathway.

Oral cancer, constituted up to 90% by squamous cell carcinomas, is a significant health burden globally. Grape seed proanthocyanidins (PA) have been suggested as a potential chemopreventive agent for oral cancer. However, their efficacy can be restricted due to the low bioavailability and bioaccessibility. Inspired by sandcastle worm adhesive, we adapted the concept of complex coacervation to generate a new type of drug delivery platform. Complex coacervates are a dense liquid phase formed by the associative separation of a mixture of oppositely charged polyelectrolytes, can serve as a drug delivery platform to protect labile cargo. In this study, we developed a complex coacervates-based delivery of PA. The release kinetics was measured, and anticancer effects were determined in two human tongue squamous cell carcinoma cell lines. The results showed that complex coacervate successfully formed and able to encapsulate PA. Additionally, PA were steadily released from the system in a pH-dependent manner. The drug delivery system could significantly inhibit the cell proliferation, migration, and invasion of cancer cells. Moreover, it could markedly reduce the expression of certain matrix metalloproteinases (MMP-2, 9, and 13) crucial to metastatic processes. We also found that suppression of protein kinase B (Akt) pathway might be the underlying mechanism for these anticancer activities. Taken together, complex coacervates-based delivery of PA can act as an effective anticancer approach for oral cancer therapy.

Protective Effect of Grape Seed Proanthocyanidins on Oxidative Damage of Chicken Follicular Granulosa Cells by Inhibiting FoxO1-Mediated Autophagy.

A significant decrease in poultry egg production occurs due to ovarian aging and autophagy is one of the important factors of ovarian aging that is induced predominantly by oxidative stress. Increasing evidence showed potential roles of plant-derived grape seed proanthocyanidin (GSPs) in protecting ovarian granulosa cells (GCs) from oxidative damage, although the underlying mechanism is still unclear. Here we investigated the possible functions of autophagy involved in the preventive effect of GSPs on oxidative stress in the GCs of ovarian hierarchical follicles of laying chickens. The results showed that increased autophagy was observed in the aging hens (580-day-old, D580) compared with the peak-lay hens (D280). Treatment of GSPs significantly restored the elevated autophagy and decreased viability of cultured D280 chicken GCs that were elicited by hydrogen peroxide. GSPs also suppressed the increased autophagy in the natural aging hens. Similar to the effect of GSPs on GC viability, inhibition of autophagy also showed a protective effect on the decreased viability of GCs under oxidative damage. However, GSPs were not able to provide further protection in GCs that were pretreated with 3-methyladenine (an autophagy inhibitor). In addition to its promoting action on antioxidant capacity, treatment with GSPs increased survival of GCs from autophagy that was caused by oxidative stress through the FoxO1-related pathway. Inhibition of FoxO1 or activation of PI3K-Akt pathway by GSPs increased the confrontation of GCs to oxidative damage and decreased autophagy in GCs. In addition, activation of the SIRT1 signal inhibited the GCs autophagy that was caused by oxidative stress via GSPs-induced deacetylation of FoxO1. These results revealed a new mechanism of GSPs against oxidative stress of GCs via inhibiting FoxO1, which was probably a possible target for alleviating ovarian aging in laying poultry.

Neurotoxicity and neuroinflammatory effects of bisphenol A in male rats: the neuroprotective role of grape seed proanthocyanidins.

Exposure to bisphenol A (BPA) contributes to neurological disorders, but the underlying mechanisms are still not completely understood. We studied the neurotoxic effect of BPA and how it promotes inflammation and alteration in the neurotransmission synthesis, release, and transmission. This study was also designed to investigate the neuroprotective effect of grape seed proanthocyanidins (GSPE) against BPA-induced neurotoxicity in rats. Rats were equally divided into 4 groups with 7 rats in each: control group, BPA group, GSPE + BPA group, and GSPE group. Rats were orally treated with their respective doses (50 mg BPA/kg BW and/or 200 mg GSPE/kg BW) daily for 70 days. BPA elicits significant elevation in malondialdehyde (MDA) and nitric oxide (NO) associated with a significant reduction in glutathione (GSH), total thiols, glutathione peroxidase (GPx), superoxide dismutase (SOD), and glutathione-S-transferase (GST). BPA exposure results in increased dopamine and serotonin levels, elevation in acetylcholinesterase (AChE) activity, and reduction in Na/K-ATPase and total ATPase activities in the brain. Also, BPA induces upregulation in the gene expression of the inflammatory markers, tumor necrosis factor-α (TNF-α) and cyclooxygenase-2 (COX-2), and in the tumor suppressor and pro-oxidant p53 protein. The pretreatment with GSPE attenuates or ameliorate all the oxidative and neurotoxic parameters induced by BPA. Our results suggest that GSPE has a promising role in modulating BPA-induced neuroinflammation and neurotoxicity and its antioxidant and free radical scavenging activities may in part be responsible for such effects.

Effects of grape seed proanthocyanidins on the expression of inflammatory mediators in gingival epithelial cells.

OBJECTIVES: This study aims to determine the effect of grape seed proanthocyanidin (GSP) pretreatment on lipopolysaccharide (LPS)-induced inflammation of human gingival epithelial cells (HGECs). METHODS: HGECs were cultivated with different concentrations of GSPs (0, 1, 5, 10, 20, 40, 60, 80, 100 µg·mL-1) for 6, 12, 24, and 48 h. CCK-8 was used to detect the proliferation activity of HGECs. HGECs were treated with different concentrations of GSPs (0, 10, 20, and 40 µg·mL-1) for 24 h and then cultured with 1.0 µg·mL-1 LPS. Enzyme-linked immunosorbent assay (ELISA) was used to detect the expression levels of pro-inflammatory cytokine tumor necrosis factor-α (TNF-α), interleukin (IL)-1ß, and IL-6 and anti-inflammatory cytokines IL-4, IL-10, and transforming growth factor-ß (TGF-ß). Quantitative real-time polymerase chain reaction (QRT-PCR) was used to detect the mRNA expression levels of TNF-α, IL-1ß, IL-6, IL-4, IL-10, and TGF-ß. RESULTS: When the GSP concentration was 0-40 µg·mL-1, the cell proliferation had no significant difference. When the action time reached 24 h, the cell proliferation was the highest. The results of ELISA and QRT-PCR showed that 10, 20, and 40 µg·mL-1 GSPS decreased the expression levels of TNF-α, IL-1ß, and IL-6 (P<0.05) and increased the expression levels of IL-4, IL-10, and TGF-ß compared with 0 µg·mL-1 GSPS (P<0.05). CONCLUSIONS: GSPS (0-40 µg·mL-1) has no significant effect on the proliferation activity of HGECs. Pretreatment with GSPS can inhibit the expression of pro-inflammatory factors and enhance the expression of anti-inflammatory factors. Hence, GSPS has a certain preventive effect on the resistance of HGECs to the stimulation of endotoxin.

Grape seed proanthocyanidins protect PC12 cells from hydrogen peroxide-induced damage via the PI3K/AKT signaling pathway.

Grape seed proanthocyanidins (GSP) are natural flavonoids with strong antioxidant and anti-apoptotic effects. Oxidative stress and neuronal apoptosis are major contributors to spinal cord injury (SCI). In this study, we assessed the potential protective effects of GSP on hydrogen peroxide (H2O2)-damaged pheochromocytoma-12 (PC12) cells in an in vitro model of SCI as well as the putative mechanism of action. We established a model using PC12 cells with oxidative damage induced by H2O2. Cells were treated with various concentrations of GSP (control group, 200 µmol/L H2O2 group, 5 µM GSP + H2O2 group, 10 µM GSP + H2O2 group, and 25 µM GSP + H2O2 group). The CCK-8 assay was used to determine cell activity. Dichloro-dihydro-fluorescein diacetate was used to detect intracellular reactive oxygen species (ROS), and flow cytometry was used to determine apoptosis rate. Western blot analysis was used to detect the expression of caspase-3, Bax, Bcl-2, and PI3K/AKT proteins. The results showed that GSP reduced H2O2-induced intracellular ROS and inhibited apoptosis. Furthermore, GSP inhibited the expression of caspase-3 and Bax, while promoting the expression of Bcl-2. In addition, GSP promoted the phosphorylation of PI3K and AKT. Moreover, a PI3K inhibitor (LY294002) weakened the protective effects of GSP on H2O2-induced PC12 cells. In conclusion, GSP pretreatment can protect PC12 cells from oxidative damage induced by H2O2 via the PI3K/AKT signaling pathway.

Grape seed proanthocyanidins improves depression-like behavior by alleviating oxidative stress and NLRP3 activation in the hippocampus of prenatally-stressed female offspring rats.

Over several decades, there is a growing evidence, which has shown that prenatal stress (PS) contributes to depression in offspring. Grape seed proanthocyanidins (GSPs), which contain dimers, trimers, oligomers of catechin and epicatechin, are known to possess antidepressant effects. The present study aimed to investigate the mechanism of antidepressant effects of GSPs on female juvenile prenatally stressed offspring rats. The results showed that the female juvenile offspring rats exposed to PS exhibited depression-like behavior manifested as longer immobility time and lesser consumption of sucrose solution. Prenatal stress reduced the number of hippocampal neurons and increased the level of the reactive oxygen species (ROS) in the hippocampus of the female juvenile offspring rats. Furthermore, the expression of PYD domains-containing protein 3 (NLRP3) and its downstream cytokines, Caspase-1, and interleukin-1ß (IL-1ß), were increased in the hippocampus of the female juvenile offspring rats exposed to PS. Administration of GSPs not only improved depression-like behavior and enhanced the number of hippocampal neurons, but also abated excessive ROS generation and inhibited the activation of the NLRP3-Caspase-1 signaling pathway. Taken together, GSPs counteract PS-induced hippocampal neuron loss and depression-like behavior by alleviating oxidative stress and NLRP3 activation. The present study provides a new insight for GSPs as an effective therapeutic agent for adolescent depression.

Grape Seed Proanthocyanidins Induce Apoptosis and Cell Cycle Arrest of HepG2 Cells Accompanied by Induction of the MAPK Pathway and NAG-1.

Hepatocellular carcinoma (HCC) is one of the common malignancies leading to death. Although radiotherapy and chemotherapy have certain effects, their side effects limit their therapeutic effect. Phytochemicals have recently been given more attention as promising resources for cancer chemoprevention or chemotherapy due to their safety. In this study, the effects of grape seed proanthocyanidins (GSPs) on the apoptosis, cell cycle, and mitogen-activated protein kinase (MAPK) pathway-related proteins and non-steroidal anti-inflammatory drug-activated gene-1 (NAG-1) expression of HepG2 cells were investigated. The results showed that GSPs inhibited the viability of HepG2 cells in a time- and dose-dependent manner, induced apoptosis and G2/M phase cell cycle arrest, and regulated cell cycle-related proteins, cyclin B1, cyclin-dependent kinase 1, and p21. GSPs also increased reactive oxygen species production and caspase-3 activity. In addition, GSPs also increased the expression of p-ERK, p-JNK, p-p38 MAPK and NAG-1, and GSPs-induced NAG-1 expression was related to the MAPK pathway-related proteins. These data suggest that GSPs may be promising phytochemicals for HCC chemoprevention or chemotherapy.

Grape seed proanthocyanidins protect retinal ganglion cells by inhibiting oxidative stress and mitochondrial alteration.

Grape seed proanthocyanidins (GSP) are known as condensed tannins and have been used as an anti-oxidant in various neurodegenerative diseases. In our study, GSP was used as a daily dietary supplement and the neuroprotective effects were evaluated on the retinal ganglion cells (RGCs) in the retinal tissues in glaucomatous DBA/2D (D2) mice. D2 mice and age-matched non-glaucomatous DBA/2J-Gpnmb+ (D2-Gpnmb+) mice were fed with GSP or a control diet for up to 6 months. The intraocular pressure (IOP), RGC survival, glial fibrillary acidic protein (GFAP), the levels of apoptotic proteins, and the expression of oxidative stress markers in retinal tissues were determined. In our study, the neuroprotective effects of GSP on retinal tissues were confirmed, as evidenced by (a) GSP inhibited the IOP elevation in D2 mice; (b) GSP enhanced RGC survival and mediated the apoptotic protein expression; (c) GSP suppressed GFAP expression; and (d) the oxidative stress and the levels of mitochondrial reactive oxygen species were regulated by GSP. Our findings indicate that GSP has promising potential to preserve retinal tissue functions via regulating oxidative stress and mitochondrial functions.

Protective effects of grape seed proanthocyanidins against iron overload-induced renal oxidative damage in rats.

BACKGROUND: Excessive exposure to iron can cause kidney damage, and chelating drugs such as deferoxamine and deferiprone have limited usefulness in treating iron poisoning. This study was designed to investigate the protective effects of grape seed proanthocyanidins (GSPAs) against iron overload induced nephrotoxicity in rats. The roles of GSPAs in chelating iron, antioxidant activity, renal function, pathological section, and apoptosis-related gene expression were assessed. METHODS: Newly weaned male Sprague-Dawley rats aged 21 days (weight, 65 ±â€¯5 g) were randomly divided into four groups containing 10 rats each: normal control (negative) group, iron overload (positive) group, GSPAs group, and GSPAs + iron overload (test) group. Iron dextran injections (2.5 mg⋅ kg-1) and GSPAs (25 mg⋅ kg-1) were intraperitoneally and intragastrically administered to rats daily for 7 weeks, respectively. Measurements included red blood cell (RBC) count and hemoglobin (Hb) level, serum total iron-binding capacity (TIBC), renal iron content, glutathione peroxidase (GSH-Px) activity, superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, total antioxidant activity (T-AOC), creatinine (CR) and blood urea nitrogen (BUN) levels, pathological changes, and apoptotic Fas, Bax expressions in the kidney tissue. Differences among the dietary groups were determined using one-way analysis of variance with post-hoc Tukey's test. P < 0.05 was considered statistically significant. RESULTS: RBC count, Hb level, renal iron content, MDA content, CR and BUN levels, and Fas, Bax expressions significantly increased in the positive group than in the negative group; contrarily, TIBC, GSH-Px activity, and T-AOC significantly decreased in the positive group than in the negative group (P < 0.05). Although not statistically significant, SOD activity was slightly reduced in the positive group than in the negative group. Inflammatory cell infiltration and fibrous tissue proliferation were observed in the kidney tissue of the rats in the positive group; in contrast, the rats exhibited better recovery when GSPAs were used instead of iron alone. Compared with the positive group, RBC counts, Hb levels, renal iron contents, the MDA content, CR and BUN levels, and Fas, Bax expressions significantly decreased, whereas the TIBC, the GSH-Px and SOD activities as well as T-AOC significantly increased in the test group rats (P < 0.05). There were no significant differences in the RBC counts, Hb levels, TIBC, renal iron contents, the SOD activity and MDA content, CR and BUN levels, and Fas expression between the GSPAs and negative groups. The GSH-Px activity and T-AOC were significantly increased whereas Bax expression was significantly decreased in the GSPAs group rats than in the negative group rats (P < 0.05). The rats in the GSPAs, test, and negative groups displayed glomeruli and tubules with a clear structure; further, the epithelial cells in the renal tubules were neatly arranged. CONCLUSIONS: GSPAs have protective effects on nephrotoxicity in rats with iron overload. Thus, further investigation of GSPAs as a new and natural phytochemo-preventive agent against iron overload is warranted.

Grape seed proanthocyanidins antagonize osteocyte apoptosis due to steroid-induced osteonecrosis of the femoral head / 中国组织工程研究

BACKGROUND: Steroid-induced avascular necrosis of the femoral head has a complex biological process, and its pathogenesis is unknown. To date, there is no effective treatment in clinical practice. Therefore, exploring the etiology of steroid-induced avascular necrosis of the femoral head is still an important content of research in this field. OBJECTIVE: To explore the effect of grape seed proanthocyanidins on osteocyte apoptosis due to steroid-induced osteonecrosis of the femoral head. METHODS: Twenty-seven Japanese white rabbits were randomly divided into three groups. The model group was intravenously injected with E. coli endotoxin, 100 μg/kg, twice at an interval of 24 hours. Two injections of E. coli endotoxin were followed by intramuscular injection of methylprednisolone 20 mg/kg, for 3 times. The interval was 24 hours. The treatment group was intravenously injected with E. coli endotoxin, 100 μg/kg, twice at an interval of 24 hours. After the second injection of E. coli endotoxin, methylprednisolone 20 mg/kg and grape seed proanthocyanidin extract 200 μg/kg were injected intramuscularly three times at an interval of 24 hours. The control group was treated with the same dose of saline intravenously. The animals were killed by air embolization at the 4th week after the last injection. Under the relatively aseptic condition, the bilateral femoral heads were routinely fixed, decalcified, embedded and sliced. Histomorphological observation and hematoxylin-eosin staining were performed to count empty bone lacunae under light microscope. Hoechst staining was used to detect cell apoptosis. The expressions of Caspase-9 and Bcl-2 in the femoral head were detected by immunohistochemical staining.

Grape Seed Proanthocyanidins Induce Autophagy and Modulate Survivin in HepG2 Cells and Inhibit Xenograft Tumor Growth in Vivo.

Liver cancer is one of the leading causes of death worldwide. Although radiotherapy and chemotherapy are effective in general, they present various side effects, significantly limiting the curative effect. Increasing evidence has shown that the dietary intake of phytochemicals plays an essential role in the chemoprevention or chemotherapy of tumors. In this work, HepG2 cells and nude mice with HepG2-derived xenografts were treated with grape seed proanthocyanidins (GSPs). The results showed that GSPs induced autophagy, and inhibition of autophagy increased apoptosis in HepG2 cells. In addition, GSPs also reduced the expression of survivin. Moreover, survivin was involved in GSPs-induced apoptosis. GSPs at 100 mg/kg and 200 mg/kg significantly inhibited the growth of HepG2 cells in nude mice without causing observable toxicity and autophagy, while inducing the phosphorylation of mitogen-activated protein kinase (MAPK) pathway-associated proteins, p-JNK, p-ERK and p-p38 MAPK and reducing the expression of survivin. These results suggested that GSPs might be promising phytochemicals against liver cancer.

Grape seed proanthocyanidins ameliorate neuronal oxidative damage by inhibiting GSK-3ß-dependent mitochondrial permeability transition pore opening in an experimental model of sporadic Alzheimer's disease.

Mitochondria-associated oxidative stress plays a crucial role in Alzheimer's disease (AD). Grape seed proanthocyanidins (GSPs) have been reported to prevent oxidative stress. In this study, we investigated the underlying mechanisms of GSPs in protecting neurons against oxidative injury in an experimental model of sporadic AD. Primary mouse cortical neurons were subjected to streptozotocin (STZ) to mimic neuronal oxidative damage in vitro, and mice were subjected to intracerebroventricular (ICV) injection of STZ as an in vivo sporadic AD model. GSPs not only significantly ameliorated neuron loss and mitochondrial dysfunction in mouse cortical neurons pretreated of STZ, but also reduced cognitive impairments, apoptosis and mitochondrial oxidative stress in the cerebral cortex and hippocampus of sporadic AD mice. Moreover, GSPs increased phosphorylation levels of phosphatidylinositol 3-kinase (PI3K), Akt and glycogen synthase kinase 3ß (GSK-3ß) at its Ser9. Notably, GSPs inhibited STZ-induced mitochondrial permeability transition pore (mPTP) opening via enhancing phosphorylated GSK-3ß (p-GSK-3ß) binds to adenine nucleotide translocator (ANT), thereby reducing the formation of the complex ANT-cyclophilin D (CypD). In conclusion, GSPs ameliorate neuronal oxidative damage and cognitive impairment by inhibiting GSK-3ß-dependent mPTP opening in AD. Our study provides new insights into that GSPs may be a new therapeutic candidate for treatment of AD.

Grape seeds proanthocyanidin extract ameliorates Ehrlich solid tumor induced renal tissue and DNA damage in mice.

The current study was carried out to evaluate the protective effect of grape seed proanthocyanidins extract (GSPE) against Ehrlich solid tumor (EST) induced renal injury, with the respect to DNA fragmentation and P53 and PCNA proteins expression in renal tissue. A total of 50 female mice were randomly assigned into five groups. Control mice were injected with physiological saline solution. Mice of the 2nd group were administered with GSPE (50 mg/kg bw/every 2day/per OS) for 2 weeks and injected with physiological saline solution. Mice of the 3rd group were injected subcutaneously with 2.5 million cells of EAC/mouse. Mice of the 4th group were injected with EAC as the 3rd group and administered with GSPE as the 2nd group simultaneously for 2 weeks. Mice of the 5th group were injected with EAC as the 3rd group and left for 2 weeks (till development of solid tumor), then treated with GSPE for another 2 weeks. EST significantly increased serum levels of urea, creatinine, potassium and chloride. In addition, it induced renal tissue and DNA injuries and increased P53, PCNA and ki67 proteins expression in renal tissues. On the other hand, it decreased serum levels of sodium and calcium ions. However, treatment of EST bearing mice with GSPE normalized serum levels of the above-mentioned parameters and improved renal tissue structure and reduced renal tissue DNA damage and P53, PCNA and ki67 proteins expression. These results indicated that GSPE is a promising nephron protective agent against EST induced renal injury.

Grape seed proanthocyanidins inhibit proliferation of pancreatic cancer cells by modulating microRNA expression.

MicroRNAs (miRNAs) are small non-coding RNAs of 18-25 nucleotides that modulate gene expression at the post-transcriptional level. Grape seed proanthocyanidins (GSPs), which are biologically active components in grape seeds, have been demonstrated to exhibit anticancer effects. The current study investigated whether GSPs can regulate miRNA expression and the possible anticancer molecular mechanisms of GSPs. Pancreatic cancer (PC) cell samples, SS3, SS12 and SS24, were treated with 20 µg/ml GSPs for 3, 12 and 24 h, respectively. Control samples, SC3, SC12 and SC24, were also prepared. Using miRNA-seq, transcriptome analysis identified 24, 83 and 83 differentially expressed (DE) miRNAs in SS3 vs. SC3, SS12 vs. SC12 and SS24 vs. SC24, respectively. This indicated that treatment with GSPs could modulate the expression of miRNAs. Subsequently, 74, 598 and 1,204 target genes for the three sets of DE miRNAs were predicted. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis revealed that multiple target genes were associated with the proliferation and apoptosis of PC cells. In addition, a network was constructed of the DE miRNAs and the target genes associated with PC. The associations identified suggested that treatment with GSPs may inhibit the proliferation of PC cells through the modulation of miRNA expression.

miR-96 and autophagy are involved in the beneficial effect of grape seed proanthocyanidins against high-fat-diet-induced dyslipidemia in mice.

We aimed to investigate the possible signaling pathways underlying the regulation of grape seed proanthocyanidins extracts (GSPE) on lipid metabolism. One hundred male C57BL/6 mice were divided into four groups: control group (normal diet), GSPE group (normal diet + GSPE), high-fat diet group (HFD), and high-fat diet plus GSPE (200 mg/kg/day) group (HFD + GSPE). Mice received the diets for 180 days. Body weight and serum lipid levels were measured. Autophagic flux characteristics, such as accumulation of lipids, mitochondria, and autophagosomes in the liver, were detected using transmission electron microscopy. Expression profile of microRNAs (miRNAs) in the liver was determined using RNA microarray and quantitative real time polymerase chain reaction (qRt-PCR). GSPE significantly decreased the weight gain, serum levels of triglycerides, total cholesterol, and low-density lipoprotein cholesterol but increased high-density lipoprotein cholesterol in the HFD mice. Autophagic flux was significantly increased by HFD but decreased by GSPE treatment. GSPE significantly attenuated HFD-induced miR-96 upregulation, which in turn reduced the expressions of miR-96 downstream molecules, FOXO1, mTOR, p-mTOR, and LC3A/B. These results suggested that the miR-96 is involved in the protective effect of GSPE against HFD-induced dyslipidemia. Possible mechanisms might be through mTOR and FOXO1, which facilitate autophagic flux for clearance of lipid accumulation.

Grape Seed Proanthocyanidins Protect N2a Cells against Ischemic Injury via Endoplasmic Reticulum Stress and Mitochondrial-associated Pathways.

BACKGROUND/OBJECTIVE: Grape seed proanthocyanidins (GSPs) are a group of polyphenolic bioflavonoids, which possess a variety of biological functions and pharmacological properties. We studied the neuroprotective effects of GSP against oxygen-glucose deprivation/reoxygenation (OGD/R) injury and the potential mechanisms in mouse neuroblastoma N2a cells. METHODS: OGD/R was conducted in N2a cells. Cell viability was evaluated by CCK-8 and LDH release assay. Apoptosis was assessed by TUNEL staining and flow cytometry. Protein levels of cleaved caspase-3, Bax and Bcl-2 were detected by Western blotting. CHOP, GRP78 and caspase-12 mRNA levels were assessed by real-time PCR. JC-1 dying was used to detect mitochondrial membrane potential. ROS levels, activities of endogenous antioxidant enzymes and ATP production were examined to evaluate mitochondrial function. RESULTS: GSP increased cell viability after OGD/R injury in a dose-dependent manner. Furthermore, GSP inhibited cell apoptosis, reduced the mRNA levels of CHOP, GRP78 and caspase-12 (ER stressassociated genes), restored mitochondrial membrane potential and ATP generation, improved activities of endogenous anti-oxidant ability (T-AOC, GXH-Px, and SOD), and decreased ROS level. CONCLUSION: Our findings suggest that GSP can protect N2a cells from OGD/R insult. The mechanism of anti-apoptotic effects of GSP may involve attenuating ER stress and mitochondrial dysfunction.

Transcriptome analysis of pancreatic cancer cell response to treatment with grape seed proanthocyanidins.

Grape seed proanthocyanidins (GSPs) have been demonstrated to exhibit potential chemotherapeutic efficacy against various cancer types. To determine the underlying molecular mechanisms involved in GSP-induced apoptosis, the present study prepared pancreatic cancer (PC) cells samples, S3, S12 and S24, which were treated with 20 µg/ml GSPs for 3, 12 and 24 h, respectively. Control cell samples, C3, C12 and C24, were also prepared. Using RNA-sequencing, transcriptome comparisons were performed, which identified 966, 3,543 and 4,944 differentially-expressed genes (DEGs) in S3 vs. C3, S12 vs. C12 and S24 vs. C24, respectively. Gene Ontology analysis of the DEGs, revealed that treatment with GSPs is associated with disruption of the cell cycle (CC) in PC cells. Additionally, disruption of transcription, DNA replication and DNA repair were associated with GSP-treatment in PC cells. Network analysis demonstrated that the common DEGs involved in the CC, transcription, DNA replication and DNA repair were integrated, and served essential roles in the control of CC progression in cancer cells. In summary, GSPs may exhibit a potential chemotherapeutic effect on PC cell proliferation.

Grape seed proanthocyanidins and metformin combination attenuate hepatic endoplasmic reticulum stress in rats subjected to nutrition excess.

CONTEXT: Endoplasmic reticulum (ER) stress in the liver is a pathological outcome of nutrient excess and is suggested to be one of the hits for progressive liver injury. OBJECTIVE: This study investigated whether grape seed proanthocyanidins (GSP) and metformin (MET) alone or in combination can relieve hepatic ER stress induced in rats subjected to calorie excess. MATERIAL AND METHODS: Male albino Wistar rats were given high calorie diet (HCD) for 45 days, while GSP (100 mg/kg body weight) and MET (50 mg/kg body weight) were administered either alone or in combination for last 15 days. RESULTS: GSP, MET or both had reduced the levels of ER stress markers and chaperons, and suppressed the activation of lipogenic and inflammatory mediators in rat liver. DISCUSSION: Though GSP and MET had reduced ER stress and inflammation individually, combination treatment with GSP + MET was more effective. CONCLUSION: We suggest intervention with GSP and MET intake has to be considered for the management of liver disorders.