Grape seed proanthocyanidin extract alleviates inflammation in experimental colitis mice by inhibiting NF-κB signaling pathway

Ulcerative colitis (UC) is a complex inflammatory disease of colorectum that induces abnormal immune responses and severely affects the quality of life of the patients. Grape seed proanthocyanidin extract (GSPE) exerts anti-inflammatory and antioxidant functions in many inflammatory diseases. The objective of this study was to investigate the potential therapeutic effects and underlying mechanisms of GSPE in UC using a dextran sodium sulfate (DSS)-induced mouse UC model and a lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage model. In this study, we found that the GSPE markedly prevented DSS-induced weight loss and colon length shortening in UC mice. Further investigations showed that GSPE significantly attenuated the expression of pro-inflammatory cytokines TNF-α, IL-6, and IL-1β, and elevated the expression of anti-inflammatory cytokine IL-10 in the colon tissues and serum of DSS-induced colitis mice by suppressing NF-κB signaling pathway. Furthermore, LPS-induced inflammation in RAW264.7 cells was also reversed by GSPE. Taken together, our results confirm that GSPE can ameliorate inflammatory response in experimental colitis via inhibiting NF-κB signaling pathway. This study advances the research progress on a potentially effective therapeutic strategy for inflammatory bowel diseases.

Grape seed proanthocyanidin extract promotes skeletal muscle fiber type transformation through modulation of cecal microbiota and enhanced butyric acid production

The conversion of fast-twitch fibers into slow-twitch fibers within skeletal muscle plays a crucial role in improving physical stamina and safeguarding against metabolic disorders in individuals. Grape seed proanthocyanidin extract (GSPE) possesses numerous pharmacological and health advantages, effectively inhibiting the onset of chronic illnesses. However, there is a lack of research on the specific mechanisms by which GSPE influences muscle physiology and gut microbiota. This study aims to investigate the role of gut microbiota and their metabolites in GSPE regulation of skeletal muscle fiber type conversion. In this experiment, 54 male BALB/c mice were randomly divided into three groups: basal diet, basal diet supplemented with GSPE, and basal diet supplemented with GSPE and antibiotics. During the feeding period, glucose tolerance and forced swimming tests were performed. After euthanasia, samples of muscle and feces were collected for analysis. The results showed that GSPE increased the muscle mass and anti-fatigue capacity of the mice, as well as the expression of slow-twitch fibers. However, the beneficial effects of GSPE on skeletal muscle fibers disappeared after adding antibiotics to eliminate intestinal microorganisms, suggesting that GSPE may play a role by regulating intestinal microbial structure. In addition, GSPE increased the relative abundance of Blautia, Muribaculaceae, and Enterorhabdus, as well as butyrate production. Importantly, these gut microbes exhibited a significant positive correlation with the expression of slow-twitch muscle fibers. In conclusion, supplementation with GSPE can increase the levels of slow-twitch fibers by modulating the gut microbiota, consequently prolonging the duration of exercise before exhaustion. PRACTICAL APPLICATION: This research suggests that grape seed proanthocyanidin extract (GSPE) has potential applications in improving physical stamina and preventing metabolic disorders. By influencing the gut microbiota and increasing butyric acid production, GSPE contributes to the conversion of fast-twitch muscle fibers into slow-twitch fibers, thereby enhancing anti-fatigue capacity and exercise endurance. While further studies are needed, incorporating GSPE into dietary supplements or functional foods could support individuals seeking to optimize their exercise performance and overall metabolic health.

Grape seed proanthocyanidin extract suppresses oxidative stress in the rat pancreas of type-1 diabetes

AIM

This study aimed to elucidate the effects of grape seed proanthocyanidin extract (GSPE) on oxidative stress (OS), antioxidant enzymes, free radicals and cytokines in the pancreas of T1DM rats.

METHODS

Two-month-old Wistar rats were assigned to the control (CON), CON + GSPE (CON + PA), diabetics (STZ, 60 mg/kg b.w.), diabetes + GSPE (STZ + PA), diabetes + insulin (STZ + INS, 3 U/day) and diabetics + GSPE and INS (STZ + INS + PA) groups. GSPE (75 mg/kg b.w.) was administered daily either alone or with INS for 8 weeks.

RESULTS

Glutathione was lowest in diabetics while it increased in the STZ + INS + PA (p < .001) group, similar to catalase activity (p < .05). Hydrogen peroxide, superoxide and lipid peroxidation increased with iNOS, TNF-α and IL-1β in the diabetic pancreases, while GSPE decreased (p < .001). Further, reduced β-cells/islet number was improved in diabetics (p < .001) with treatment.

CONCLUSION

This study suggests that GSPE with INS is effective in minimising OS and pancreatic degeneration in T1DM rats.

Grape seed extract proanthocyanidin antagonizes aristolochic acid I-induced liver injury in rats by activating PI3K-AKT pathway

Aristolochic acid is internationally recognized as a carcinogen. It has been shown that the main toxic mechanism of aristolochic acid on the liver and kidney is the induction of ROS-induced oxidative stress damage. To investigate whether proanthocyanidins (GSPE), a natural antioxidant product from grape seed extract, could antagonize AA-I-induced liver injury. Thirty-two SD rats were selected and divided into aristolochic acid exposure group (AA-I), normal control group, GSPE group and GSPE intervention group. The protective effects of GSPE on AA-I liver injury were evaluated by examining the body weight, liver index, liver function and liver pathological sections of rats. The results of body weight, liver index, liver function and liver pathological sections of rats showed that GSPE had antagonistic effects on AA-I-induced liver injury. antioxidant enzyme activity in the GSPE intervention group was significantly higher than that in the aristolochic acid group, apoptotic cells were significantly lower than that in the aristolochic acid group, protein and mRNA expression of PI3K-AKT and BCL-2 were significantly higher than that in the aristolochic acid group, BAX, The protein and mRNA expression of BAX, CASPAES-3, CASPAES-9 were significantly lower than those of the aristolochic acid group. GSPE can antagonize aristolochic acid-induced hepatotoxicity, and its mechanism of action is to antagonize aristolochic acid I-induced liver injury by inhibiting PI3K-AKT pathway-mediated hepatocyte apoptosis.

Grape seed proanthocyanidin extract targets p66Shc to regulate mitochondrial biogenesis and dynamics in diabetic kidney disease

Mitochondrial biogenesis and dynamics are associated with renal mitochondrial dysfunction and the pathophysiological development of diabetic kidney disease (DKD). Decreased p66Shc expression prevents DKD progression by significantly regulating mitochondrial function. Grape seed proanthocyanidin extract (GSPE) is a potential therapeutic medicine for multiple kinds of diseases. The effect of GSPE on the mitochondrial function and p66Shc in DKD has not been elucidated. Hence, we decided to identify p66Shc as a therapeutic target candidate to probe whether GSPE has a renal protective effect in DKD and explored the underlying mechanisms.

METHODS

In vivo, rats were intraperitoneally injected with streptozotocin (STZ) and treated with GSPE. Biochemical changes, mitochondrial morphology, the ultrastructure of nephrons, and protein expression of mitochondrial biogenesis (SIRT1, PGC-1α, NRF1, TFAM) and dynamics (DRP1, MFN1) were determined. In vitro, HK-2 cells were transfected with p66Shc and treated with GSPE to evaluate changes in cell apoptosis, reactive oxygen species (ROS), mitochondrial quality, the protein expression.

RESULTS

In vivo, GSPE significantly improved the renal function of rats, with less proteinuria and a lower apoptosis rate in the injured renal tissue. Besides, GSPE treatment increased SIRT1, PGC-1α, NRF1, TFAM, and MFN1 expression, decreased p66Shc and DRP1 expression. In vitro, overexpression of p66Shc decreased the resistance of HK-2 cells to high glucose toxicity, as shown by increased apoptosis and ROS production, decreased mitochondrial quality and mitochondrial biogenesis, and disturbed mitochondrial dynamic homeostasis, ultimately leading to mitochondrial dysfunction. While GSPE treatment reduced p66Shc expression and reversed these changes.

CONCLUSION

GSPE can maintain the balance between mitochondrial biogenesis and dynamics by negatively regulating p66Shc expression.

Pilot study on the effect of grape seed proanthocyanidin extract on inferior vene cava blood flow in patients with chronic venous insufficiency using 4D flow MRI

BACKGROUND

Four-dimensional (4D) flow magnetic resonance imaging (MRI) was used to objectively assess changes in blood flow velocity in patients with chronic venous insufficiency (CVI) who underwent stocking treatment alone and stocking combined with Grape seed proanthocyanidin extract (GSPE) treatment.

METHODS

Patients diagnosed with CVI were recruited from August 31, 2018 to December 31, 2020. A total of 23 participants were selected, with 10 and 13 patients in the stocking treatment and stocking + GSPE treatment groups, respectively. The blood flow velocity (Th-plane peak and average velocities) was calculated using 4D flow MRI. A paired t test was used to evaluate the differences in blood flow velocity before and after treatment.

RESULTS

In the stocking treatment group, The Th-Plane peak velocity increased by 2.48 ± 5.05 cm/s after treatment (P = .16). In the stocking + GSPE treatment group, the Th-Plane peak velocity increased by 4.85 ± 5.57 cm/s after treatment (P < .001).

CONCLUSION

The blood flow velocity on 4D flow MRI was significantly increased in participants who underwent GSPE, highlighting the potential of GSPE for CVI treatment.

Grape seed proanthocyanidin extract induces apoptotic and autophagic cell death in rheumatoid arthritis fibroblast-like synoviocytes

Objectives

In this study, we aimed to evaluate the association between grape seed proanthocyanidin extract (GSPE) and rheumatoid arthritis-fibroblast-like synoviocytes (RA-FLSs) and to investigate whether GSPE induces cell death in RA-FLSs.

Materials and methods

The FLSs were isolated from RA synovial tissues. Cell viability and cell cycle staging were analyzed using a hemocytometer and flow cytometry. Caspase 3 and poly (ADP-ribose) polymerase (PARP) proteins were analyzed using Western blotting with z-VAD-fmk. Protein LC3 and polyubiquitin-binding protein p62 that were degraded by autophagy were evaluated using Western blotting with 3-methyladenine and chloroquine. Reactive oxygen species (ROS) were also evaluated.

Results

When RA-FLSs were treated with GSPE, cell viability decreased, the number of cells in sub-G1 and G2/M phases increased, and the expression of pro-PARP and pro-caspase 3 proteins decreased in a concentration-dependent manner. This result was offset, when the cells were co-treated with the pan-caspase inhibitor z-VAD-fmk. The reduced cell viability, increased expression of LC3-II protein, and reduced expression of p62 protein with GSPE treatment were offset, when RA-FLSs were co-treated with GSPE and autophagy inhibitors 3-methyladenine and chloroquine. The level of ROS in RA-FLSs treated with GSPE was significantly lower than treatment with N-acetyl-cysteine, a ROS inhibitor.

Conclusion

Our study results show that GSPE induces apoptotic and autophagic cell death and inhibites reactive oxygen species in RA-FLSs.

Grape Seed Proanthocyanidin Extract Ameliorates Cardiac Remodelling After Myocardial Infarction Through PI3K/AKT Pathway in Mice

Myocardial infarction is one of the most serious fatal diseases in the world, which is due to acute occlusion of coronary arteries. Grape seed proanthocyanidin extract (GSPE) is an active compound extracted from grape seeds that has anti-oxidative, anti-inflammatory and anti-tumor pharmacological effects. Natural products are cheap, easy to obtain, widely used and effective. It has been used to treat numerous diseases, such as cancer, brain injury and diabetes complications. However, there are limited studies on its role and associated mechanisms in myocardial infarction in mice. This study showed that GSPE treatment in mice significantly reduced cardiac dysfunction and improved the pathological changes due to MI injury. In vitro, GSPE inhibited the apoptosis of H9C2 cells after hypoxia culture, resulting in the expression of Bax decreased and the expression of Bcl-2 increased. The high expression of p-PI3K and p-AKT was detected in MI model in vivo and in vitro. The use of the specific PI3K/AKT pathway inhibitor LY294002 regressed the cardio-protection of GSPE. Our results showed that GSPE could improve the cardiac dysfunction and remodeling induced by MI and inhibit cardiomyocytes apoptosis in hypoxic conditions through the PI3K/AKT signaling pathway.

Grape Seed Proanthocyanidin Extract Prevents Bone Loss via Regulation of Osteoclast Differentiation, Apoptosis, and Proliferation

Dietary procyanidin has been shown to be an important bioactive component that regulates various pharmacological activities to maintain metabolic homeostasis. In particular, grape seed proanthocyanidin extract (GSPE) is a commercially available medicine for the treatment of venous and lymphatic dysfunction. This study aimed to investigate whether GSPE protects against lipopolysaccharide (LPS)-induced bone loss in vivo and the related mechanism of action in vitro. The administration of GSPE restored the inflammatory bone loss phenotype stimulated by acute systemic injection of LPS in vivo. GSPE strongly suppressed receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclast differentiation and bone resorption activity of mature osteoclasts by decreasing the RANKL-induced nuclear factor-κB transcription activity. GSPE mediates this effect through decreased phosphorylation and degradation of NF-κB inhibitor (IκB) by IκB kinaseβ, subsequently inhibiting proto-oncogene cellular Fos and nuclear factor of activated T cells. Additionally, GSPE promotes osteoclast proliferation by increasing the phosphorylation of components of the Akt and mitogen-activated protein kinase signaling pathways and it also inhibits apoptosis by decreasing the activity of caspase-8, caspase-9, and caspase-3, as corroborated by a decrease in the Terminal deoxynucleotidyl transferase dUTP nick end labeling -positive cells. Our study suggests a direct effect of GSPE on the proliferation, differentiation, and apoptosis of osteoclasts and reveals the mechanism responsible for the therapeutic potential of GSPE in osteoclast-associated bone metabolism disease.

Grape Seed Proanthocyanidin Extract Ameliorates Streptozotocin-induced Cognitive and Synaptic Plasticity Deficits by Inhibiting Oxidative Stress and Preserving AKT and ERK Activities

Progressive memory loss and cognitive impairment are the main clinical manifestations of Alzheimer's disease (AD). Currently, there is no effective drug available for the treatment of AD. Previous studies have demonstrated that the cognitive impairment of AD is associated with oxidative stress and the inhibition of AKT and ERK phosphorylation. Grape seed proanthocyanidin extract (GSPE) has been shown to have strong antioxidant effect and can protect the nervous system from oxidative stress damage. This study aimed to investigate the protective effect of GSPE on the cognitive and synaptic impairments of AD using a sporadic AD rat model induced by intracerebroventricular (ICV) injection of streptozotocin (STZ) (ICV-STZ). Rats were treated with GSPE (50, 100, or 200 mg/kg every day) by intragastrical (ig.) administration for continuous 7 weeks, and ICV-STZ (3 mg/kg) was performed on the first day and third day of week 5. Learning and memory abilities were assessed by the Morris water maze (MWM) test at week 8. After behavioral test, hippocampal long-term potentiation (LTP) was recorded, and the levels of malondialdehyde (MDA), superoxide dismutases (SOD), glutathione (GSH) and the protein expression of AKT and ERK were measured in the hippocampus and cerebral cortex of rats. Our study revealed that ICV-STZ significantly impaired the working learning ability and hippocampal LTP of rats, significantly increased the levels of MDA, and decreased the activity of SOD and GSH in the hippocampus and cerebral cortex. In contrast, GSPE treatment prevented the impairment of cognitive function and hippocampal LTP induced by ICV-STZ, decreased the level of MDA, and increased the level of SOD and GSH. Furthermore, Western blot results showed that GSPE treatment could prevent the loss of AKT and ERK activities in the hippocampus and cerebral cortex induced by ICV-STZ. Our findings demonstrate that GSPE treatment could ameliorate the impairment of cognitive ability and hippocampal synaptic plasticity in a rat model of sporadic AD by inhibiting oxidative stress and preserving AKT and ERK activities. Therefore, GSPE may be an effective agent for the treatment of cognitive deficits associated with sporadic AD.

Novel Antihypertensive Prodrug from Grape Seed Proanthocyanidin Extract via Acid-Mediated Depolymerization in the Presence of Captopril: Synthesis, Process Optimization, and Metabolism in Rats

Grape seed extract contains a high content of proanthocyanidins that can be depolymerized into C-4-substituted (epi)catechin derivatives in the presence of nucleophiles. However, the biological and medicinal values of depolymerization products have been rarely investigated. Recently, we developed a novel depolymerization product (-)-epicatechin-4β- S-captopril methyl ester (ECC) derived from the reaction of grape seed proanthocyanidin extract with captopril in the presence of acidified methanol. A central composite design was employed to select the most appropriate depolymerization temperature and time to obtain the target product ECC with a high yield. A total of 16 metabolites of ECC in rat urine, feces, and plasma were identified using liquid chromatography quadrupole time-of-flight tandem mass spectrometry. The in vivo results suggested that ECC could release captopril methyl ester and epicatechin, followed by the generation of further metabolites captopril and epicatechin sulfate conjugates. Therefore, ECC may be used as a potential prodrug with synergistic or additive hypotensive effects.

Ameliorative Effects of Grape Seed Proanthocyanidin Extract on Growth Performance, Immune Function, Antioxidant Capacity, Biochemical Constituents, Liver Histopathology and Aflatoxin Residues in Broilers Exposed to Aflatoxin B₁

Aflatoxicosis is a grave threat to the poultry industry. Dietary supplementation with antioxidants showed a great potential in enhancing the immune system; hence, protecting animals against aflatoxin B₁-induced toxicity. Grape seed proanthocyanidin extract (GSPE) one of the most well-known and powerful antioxidants. Therefore, the purpose of this research was to investigate the effectiveness of GSPE in the detoxification of AFB₁ in broilers. A total of 300 one-day-old Cobb chicks were randomly allocated into five treatments of six replicates (10 birds per replicate), fed ad libitum for four weeks with the following dietary treatments: 1. Basal diet (control); 2. Basal diet + 1 mg/kg AFB₁ contaminated corn (AFB₁); 3. Basal diet + GSPE 250 mg/kg; (GSPE 250 mg/kg) 4. Basal diet + AFB₁ (1 mg/kg) + GSPE 250 mg/kg; (AFB₁ + GSPE 250 mg/kg) 5. Basal diet + AFB₁ (1mg/kg) + GSPE 500 mg/kg, (AFB₁ + GSPE 500 mg/kg). When compared with the control group, feeding broilers with AFB₁ alone significantly reduced growth performance, serum immunoglobulin contents, negatively altered serum biochemical contents, and enzyme activities, and induced histopathological lesion in the liver. In addition, AFB₁ significantly increased malondialdehyde content and decreased total superoxide dismutase, catalase, glutathione peroxide, glutathione-S transferase, glutathione reductase activities, and glutathione concentration within the liver and serum. The supplementation of GSPE (250 and 500 mg/kg) to AFB₁ contaminated diet reduced AFB₁ residue in the liver and significantly mitigated AFB₁ negative effects. From these results, it can be concluded that dietary supplementation of GSPE has protective effects against aflatoxicosis caused by AFB₁ in broiler chickens.

The Protective Effect of Grape-Seed Proanthocyanidin Extract on Oxidative Damage Induced by Zearalenone in Kunming Mice Liver

Although grape-seed proanthocyanidin extract (GSPE) demonstrates strong anti-oxidant activity, little research has been done to clearly reveal the protective effects on the hepatotoxicity caused by zearalenone (ZEN). This study is to explore the protective effect of GSPE on ZEN-induced oxidative damage of liver in Kunming mice and the possible protective molecular mechanism of GSPE. The results indicated that GSPE could greatly reduce the ZEN-induced increase of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities. GSPE also significantly decreased the content of MDA but enhanced the activities of antioxidant enzymes SOD and GSH-Px. The analysis indicated that ZEN decreased both mRNA expression levels and protein expression levels of nuclear erythroid2-related factor2 (Nrf2). Nrf2 is considered to be an essential antioxidative transcription factor, as downstream GSH-Px, γ-glutamyl cysteine synthetase (γ-GCS), hemeoxygenase-1 (HO-1), and quinone oxidoreductase 1 (NQO1) decreased simultaneously, whereas the pre-administration of GSPE groups was shown to elevate these expressions. The results indicated that GSPE exerted a protective effect on ZEN-induced hepatic injury and the mechanism might be related to the activation of the Nrf2/ARE signaling pathway.

Intervention of Grape Seed Proanthocyanidin Extract on the Subchronic Immune Injury in Mice Induced by Aflatoxin B1

The aim was to investigate the prevention of grape seed proanthocyanidin extract (GSPE) on the subchronic immune injury induced by aflatoxin B1 (AFB1) and the possible ameliorating effect of GSPE in mice. The subchronic AFB1-induced immune injury mice model was set up with the continuous administration of 100 μg/kg body weight (BW) AFB1 for six weeks by intragastric administration. Then, intervention with different doses (50 and 100 mg/kg BW) of GSPE was conducted on mice to analyze the changes of body weight, immune organ index, antioxidant capability of spleen, serum immunoglobulin content, and the expression levels of inflammatory cytokines. The prevention of GSPE on the immune injury induced by AFB1 was studied. The GSPE could relieve the AFB1-induced reduction of body weight gain and the atrophy of the immune organ. The malondialdehyde (MDA) level of the spleen in the AFB1 model group significantly increased, but levels of catalase (CAT), glutathione (GSH), glutathione peroxidase (GSH-P_X), and superoxide dismutase (SOD) significantly decreased. The GSPE could significantly inhibit the oxidative stress injury of the spleen induced by AFB1. AFB1 exposure could not significantly change the contents of IgA, IgG, or IgM. AFB1 significantly improved the expression of interleukin 1β (IL-1β), IL-6, tumor necrosis factor α (TNF-α), and interferon γ (IFN-γ). Additionally, GSPE could decrease the expression of these four proinflammatory factors to different degrees and inhibit the inflammatory reaction of mice. The results suggest that GSPE alleviates AFB1-induced oxidative stress and significantly improves the immune injury of mice induced by AFB1.

Protective effects of grape seed extract on cadmium-induced testicular damage, apoptosis, and endothelial nitric oxide synthases expression in rats

This study aims to evaluate the protective effect of grape seed proanthocyanidin extract (GSPE) on cadmium (Cd)-induced testicular apoptosis, endothelial nitric oxide synthases (eNOS) expression, and toxicity in rats. A total of 24 male Wistar rats were divided into four groups, namely, control, Cd (2.5 mg/kg), Cd + GSPE (100 mg/kg/day), and GSPE. Spermatogenesis and mean seminiferous tubule diameter were significantly decreased in the Cd groups. Furthermore, the GSPE-treated animals showed an improved histological appearance in the Cd group. The immunoreactivity of eNOS and the number of apoptotic cells were increased in Cd group. Our data indicate a significant reduction of terminal deoxynucleotide transferase-mediated 2'-deoxyuridine 5'-triphosphate nick end-labeling staining and a decrease in the expression of eNOS in the testes tissue of the Cd group treated with GSPE therapy. Therefore, our results suggest that GSPE acts as a potent protective agent against Cd-induced testicular toxicity in rats.