Grape seed proanthocyanidin extracts prevent high glucose-induced endothelia dysfunction via PKC and NF-κB inhibition

Impact of thermal processing on polyphenols, carotenoids, glucosinolates, and ascorbic acid in fruit and vegetables and their cardiovascular benefits

Bioactive compounds in fruit and vegetables have a positive impact on human health by reducing oxidative stress, inflammation, and the risk of chronic diseases such as cancer, cardiovascular (CV) diseases, and metabolic disorders. However, some fruit and vegetables must be heated before consumption and thermal processes can modify the amount of nutraceuticals, that is, polyphenols, carotenoids, glucosinolates, and ascorbic acid, that can increase or decrease in relation to different factors such as type of processing, temperature, and time but also the plant part (e.g., flower, leaf, tuber, and root) utilized as food. Another important aspect is related to the bioaccessibility and bioavailability of nutraceuticals. Indeed, the key stage of nutraceutical bioefficiency is oral bioavailability, which involves the release of nutraceuticals from fruit and vegetables in gastrointestinal fluids, the solubilization of nutraceuticals and their interaction with other components of gastrointestinal fluids, the absorption of nutraceuticals by the epithelial layer, and the chemical and biochemical transformations into epithelial cells. Several studies have shown that thermal processing can enhance the absorption of nutraceuticals from fruit and vegetable. Once absorbed, they reach the blood vessels and promote multiple biological effects (e.g., antioxidant, anti-inflammatory, antihypertensive, vasoprotective, and cardioprotective). In this review, we described the impact of different thermal processes (such as boiling, steaming and superheated steaming, blanching, and microwaving) on the retention/degradation of bioactive compounds and their health-promoting effects after the intake. We then summarized the impact of heating on the absorption of nutraceuticals and the biological effects promoted by natural compounds in the CV system to provide a comprehensive overview of the potential impact of thermal processing on the CV benefits of fruit and vegetables.

Proanthocyanidins Promote Endothelial Cell Viability and Angiogenesis

ABSTRACT

Botanic drugs are reportedly effective in treating ischemic conditions by improving vascular circulation. However, it has been very rare for biomaterial researchers to look into the possibility of using such products in the context of tissue regeneration. This work studied 4 botanic drugs to explore their effects on vascular endothelial cell growth. Human umbilical endothelial cells were cultured in the presence of different doses of astragalus powder extract, astragalus injection, puerarin injection, and proanthocyanidin (PAC). Among the 4 drugs, PAC showed a potent effect on cell viability and stimulated cell growth in a dose-dependent manner. In particular, the PAC under test was able to maintain a high level of cell viability/proliferation comparable with the cells supplemented with the endothelial cell growth medium, at both low and normal serum conditions. Blocking either endothelial cell growth factor receptors or epithelial cell growth factor receptors was ineffective in reducing the stimulatory effect. The PAC released from polyvinyl alcohol cryogels stimulated HUVECs proliferation. The chick embryo chorioallantoic membrane model was further used to test the angiogenicity of PAC, showing that this botanic drug was potent in stimulating vasculature development. This work therefore demonstrates for the first time that PAC is capable of upregulating endothelial cell activity and growth in vitro in the absence of growth factors and that PAC can be loaded and released from drug carriers and can stimulate angiogenesis. These findings suggest the application of PAC in angiogenesis and tissue regeneration.

Tannins as Hemostasis Modulators

The hemostasis system is often affected by complications associated with cardiovascular diseases, which results in thromboembolic events. Compounds of plant origin and plant extracts are considered as a promising source of substances that could modulate the functioning of the hemostasis system and thus reduce the risk of thromboembolism. Among them, tannins, which are plant-origin compounds with potential effects in hemostasis, deserve a special mention. This paper describes the hemostasis-modifying ability of three groups of tannins, namely ellagitannins, gallotannins, and procyanidins. The review highlights the desirable as well as undesirable influence of tannins on specific components of hemostasis, namely platelets, coagulation system, fibrinolysis system, and endothelium, and the multidirectional effect of these compounds on the thrombotic process. Studies performed under normal and pathological conditions such as diabetes or hypercoagulation are described, and the pathophysiology-dependent action of tannins is also highlighted. Most of the studies presented in the paper were performed in vitro, and due to the low bioavailability of tannins more studies should be conducted in the future to understand their actual activity in vivo.

Grape seed proanthocyanidin extract ameliorates cisplatin-induced testicular apoptosis via PI3K/Akt/mTOR and endoplasmic reticulum stress pathways in rats

Testicular toxicity is an adverse reaction of the effective chemotherapy drug cisplatin (CIS). Our previous study found that grape seed proanthocyanidin extract (GSPE) had a protective effect on CIS-induced testicular toxicity. However, the protective mechanism of GSPE against CIS-induced testicular toxicity remains unknown. In this study, we aimed to investigate whether GSPE can reduce CIS-induced testicular toxicity and its potential mechanism in rats. The results showed that GSPE ameliorated CIS-induced the apoptosis of testicular cells and inhibited the protein levels of Bad, Cyt c, caspase-9, caspase-3, caspase-12, GRP78, CHOP, IRE1α, p-IRE1α, XBP-1S, PERK, p-PERK, eIF2α, and p-eIF2α. Besides, GSPE reversed the downregulation of PI3K, p-PI3K, Akt, p-Akt, mTOR, and p-mTOR protein expression induced by CIS. These results indicated that GSPE can improve CIS-induced testicular cells apoptosis via activating PI3K/Akt/mTOR and inhibiting Bad/Cyt c/caspase-9/caspase-3 pathways. And GSPE relieved endoplasmic reticulum stress-mediated apoptosis via inhibiting PREK/eIF2α and IRE1α/XBP-1S/caspase-12 pathways. In conclusion, the evidence suggested that GSPE can act as a protective agent against testicular toxicity induced by CIS. PRACTICAL APPLICATIONS: Testicular toxicity was a well-known adverse effect of cisplatin (CIS) in cancer treatment. Grape seed proanthocyanidin extract (GSPE) has been reported to serve as one of the most therapeutic potentials agents. In present study, we explored the regulatory effects of GSPE on the apoptosis induced by CIS, which involved testicular apoptosis mechanisms in rats. Our results indicated that CIS caused testicular toxicity via PI3K/AKT/mTOR and ERS mediated apoptosis pathway in rats. This toxicity was attenuated by GSPE treatment via activated PI3K/Akt/mTOR pathway, and inhibiting Bad/CytC/caspase-9/caspase-3 as well as PREK/eIF2α, IRE1α/XBP-1S/caspase-12 pathways. Our findings suggest that GSPE may be a novel protective agent against testicular toxicity induced by CIS.

Role of Polyphenols and Carotenoids in Endothelial Dysfunction: An Overview from Classic to Innovative Biomarkers

Nowadays, the dramatically increased prevalence of metabolic diseases, such as obesity and diabetes mellitus and their related complications, including endothelial dysfunction and cardiovascular disease, represents one of the leading causes of death worldwide. Dietary nutrients together with healthy lifestyles have a crucial role in the endothelium health-promoting effects. From a growing body of evidence, active natural compounds from food, including polyphenols and carotenoids, have attracted particular attention as a complementary therapy on atherosclerosis and cardiovascular disease, as well as preventive approaches through the attenuation of inflammation and oxidative stress. They mainly act as radical scavengers by promoting a variety of biological mechanisms, such as improvements in endothelial function, blood pressure, platelet activity, and insulin sensitivity, and by modulating various known biomarkers. The present review highlights the role of polyphenols and carotenoids in early endothelial dysfunction with attention to their beneficial effect in modulating both classical and recent technologically generated emerging biomarkers. These, alone or in combination, can play an important role in the prediction, diagnosis, and evolution of cardiovascular disease. However, a main challenge is to speed up early and prompt new interventions in order to prevent or slow down disease progression, even with an adequate intake of bioactive compounds. Hence, there is an urgent need of new more validated, appropriate, and reliable diagnostic and therapeutic biomarkers useful to diagnose endothelial dysfunction at an earlier stage.

Proanthocyanidins: Components, Pharmacokinetics and Biomedical Properties

Proanthocyanidins (PAs) are a group of polyphenols enriched in plant and human food. In recent decades, epidemiological studies have upheld the direct relationship between PA consumption and health benefits; therefore, studies on PAs have become a research hotspot. Although the oral bioavailability of PAs is quite low, pharmacokinetics data revealed that some small molecules and colonic microbial metabolites of PAs could be absorbed and exert their health beneficial effects. The pharmacological effects of PAs mainly include anti-oxidant, anticancer, anti-inflammation, antimicrobial, cardiovascular protection, neuroprotection, and metabolism-regulation behaviors. Moreover, current toxicological studies show that PAs have no observable toxicity to humans. This review summarizes the resources, extraction, structures, pharmacokinetics, pharmacology, and toxicology of PAs and discusses the limitations of current studies. Areas for further research are also proposed.

Grape seed proanthocyanidin extract alleviates arsenic-induced lung damage through NF-κB signaling

IMPACT STATEMENT

Arsenic-induced respiratory inflammatory damage is an important occupational hazard in many areas of the world, particularly in underdeveloped and developing countries. Effective treatments are lacking and expensive. Therefore, the aim of the study was to examine the anti-inflammatory effects of proanthocyanidin (PC) and the molecular mechanisms in vivo and in vitro. The present study showed that PC extracted from grape seed could attenuate the lung damage in a mouse model of arsenic poisoning. The effects were observed at the level of lung histology and inflammasome expression. This study suggests that a natural compound is effective in mitigating the toxic effects of arsenic in the lungs, providing an inexpensive and more readily accessible method for treating arsenic exposure in some parts of the world.

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.