Effects of Grape Seed Proanthocyanidin Extract on Vascular Endothelial Function in Participants with Prehypertension: A Randomized, Double-Blind, Placebo-Controlled Study.

This study aimed to investigate the effects of grape seed proanthocyanidin extract (GSPE) on blood pressure and vascular endothelial function in middle-aged Japanese adults with prehypertension. We conducted a randomized, double-blind, placebo-controlled study on 6 men and 24 women aged 40-64 years old. The participants were randomized to receive tablets containing either low-dose (200 mg/day) or high-dose (400 mg/day) GSPE, or placebo, for 12 weeks. Systolic and diastolic blood pressures (SBP and DBP, respectively), brachial flow-mediated dilation (FMD), and other cardiovascular parameters were measured before and after 4, 8, and 12 weeks of treatment. The mean SBP in the high-dose group significantly decreased by 13 mmHg after 12 weeks (P = 0.028), although FMD did not change. In an ad hoc analysis of non-smoking participants (n = 21), the mean SBP, DBP, stiffness parameter ß, distensibility, incremental elastic modulus (Einc), and pulse wave velocity (PWV) also significantly improved in the high-dose group after 12 weeks. Changes in Einc and PWV from baseline to 12 weeks were significantly greater in the high-dose group than in the placebo group (Einc, P = 0.023; PWV, P = 0.03). GSPE consumption could help maintain vascular elasticity and normal blood pressure in this population.

A Pilot Study of a Grape Seed Procyanidin Extract for Lung Cancer Chemoprevention.

Grape seed procyanidin extract (GSE) had been reported to exert antineoplastic properties in preclinical studies. A modified phase I, open-label, dose-escalation clinical study was conducted to evaluate the safety, tolerability, MTD, and potential chemopreventive effects of leucoselect phytosome (LP), a standardized GSE complexed with soy phospholipids to enhance bioavailability, in heavy active and former smokers. Eight subjects ages 46-68 years were enrolled into the study and treated with escalating oral doses of LP for 3 months. Bronchoscopies with bronchoalveolar lavage and bronchial biopsies were performed before and after 3 months of LP treatment. Hematoxylin and eosin stain for histopathology grading and IHC examination for Ki-67 proliferative labeling index (Ki-67 LI) were carried out on serially matched bronchial biopsy samples from each subject to determine responses to treatment. Two subjects were withdrawn due to issues unrelated to the study medication, and a total of 6 subjects completed the full study course. In general, 3 months of LP, reaching the highest dose per study protocol was well tolerated and no dosing adjustment was necessary. Such a treatment regimen significantly decreased bronchial Ki-67 LI by an average of 55% (P = 0.041), with concomitant decreases in serum miR-19a, -19b, and -106b, which were oncomirs previously reported to be downregulated by GSE, including LP, in preclinical studies. In spite of not reaching the original enrollment goal of 20, our findings nonetheless support the continued clinical translation of GSE as an antineoplastic and chemopreventive agent against lung cancer.

[Efficacy and safety of D-mannose (2 g), 24h prolonged release, associated with Proanthocyanidin (PAC), versus isolate PAC, in the management of a series of women with recurrent urinary infections.] / Eficacia y tolerancia terapéutica de la D­manosa (2 g) de liberación prolongada 24 horas (asociada a proantocianidinas), frente a proantocianidinas aisladas en el manejo de una serie de mujeres con infecciones urinarias recurrentes.

OBJECTIVE: To compare the efficacy and safety of dietary supplement "Manosar®" composed of D-mannose (2 g), 24 h prolonged release, associated with Proanthocyanidin (PAC) (140 mg), ursolic acid (7.98 mg), A, C, and D vitamins and the oligoelement zinc, versus 240 mg of PAC in recurrent urinary tract infections (UTI), for a designed follow-up of 24 weeks, in women. METHODS: A multicenter randomized experimental double-blind study was carried out. The study was approved by review board of "Complejo Hospitalario de Toledo" (Spain), and all patients gave informed consent. A total of 150 women with non complicated UTI were screened for participation. Valid data was obtained from 93, with mean age of 48 years. Fortyfour patients were assigned to the Manosar® group and 51 patients to the PAC group. Patients were followed during six months. A previous UTI was defined based on a combination of symptoms and a positive reactive urine trip. Confirmation of a new UTI was based on symptoms, reactive urine strip and urine culture. RESULTS: Thirty-three patients (35%) had an UTI during the six months follow-up. The percentage of UTI of the Manosar® group during this period was 24%, while the percentage of the PAC group was 45% (p〈0.05). The disease-free time for the Manosar® group was 95 days, while this time was 79 days for the PAC group. The incidence of side effects was low. Diarrhea was the most frequent side-effect in both groups. CONCLUSION: Manosar® (oral once a day) is more effective than single dose PAC (240 mg daily orally) to prevent recurrent UTI in women.

Hepatic protective effect of grape seed proanthocyanidin extract against Gleevec-induced apoptosis, liver Injury and Ki67 alterations in rats

ABSTRACT Gleevec (imatinib) is an antineoplastic chemotherapeutic agent used in the treatment of many types of cancer. The current study was conducted to examine the possible modifying effects of grape seeds proanthocyandins extract (GSPE) against apoptosis, liver injury and Ki67 alterations induced by Gleevec in male rats. 40 male albino rats were equally divided into four groups (First and second groups were control and GSPE groups; third group was Gleevec group and fourth group was treated with Gleevec and GSPE). Gleevec induced elevations in P53 and depletion of Bcl2 levels in liver tissues were compared with the control group. Liver sections in rats treated with Gleevec exhibited marked cellular infiltrations, vacuolar degeneration hepatocytes, numerous apoptotic cells, and congestion in central and portal veins, as well as a significant increase in the proliferating of Ki67 after Gleevec injection as compared with control group. In contrast, treatment with Gleevec and GSPE showed a moderate to good degree of improvement in hepatocytes with a significant increase in Ki67, a decrease in P53 and an increase in Bcl2 levels in liver tissues compared to treatment with Gleevec. Therefore, Gleevec induces apoptosis, injury and Ki67 changes in rat liver, whereas GSPE modulates these alternations.

Safety assessment of 4-week oral intake of proanthocyanidin-rich grape seed extract in healthy subjects.

A clinical study was conducted to assess the safety and tolerability of oral doses of proanthocyanidin-rich grape seed extract (GSE) in healthy Japanese adult volunteers. In an open-label, 4-week toxicity test, 29 subjects daily received 1000, 1500, or 2500 mg GSE orally. Serum Fe levels of two subjects in the 2500 mg GSE group decreased to 61 and 60 µg/100 mL from 205 and 182 µg/100 mL at baseline respectively, at second week of GSE consumption; these values are low but within the normal range for the Japanese population. Two weeks after completing the 4-week course of GSE ingestion, the serum Fe levels of both subjects returned to near baseline levels (210 and 189 µg/100 mL). No subject discontinued the study. Oral intake of GSE up to 2500 mg for 4 weeks was found to be generally safe and well tolerated in humans. Research with a larger number of subjects is required to confirm these findings.

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.

Grape seed proanthocyanidins protects against cadmium induced oxidative pancreatitis in rats by attenuating oxidative stress, inflammation and apoptosis via Nrf-2/HO-1 signaling.

The present study has been designed and carried out to explore the role of grape seed proanthocyanidins (GSP) in the pancreas of cadmium (Cd)-induced cellular oxidative stress-mediated toxicity in rats. Four groups of healthy rats were given oral doses of Cd (5-mg/kg BW) and to identify the possible mechanism of action of GSP 100-mg/kg BW was selected and was given 90 min before Cd intoxication. The causative molecular and cellular mechanism of Cd was determined using various biochemical assays, histology, western blotting and ELISA. Cd intoxication revealed increased levels of proinflammatory cytokines (TNF-α, IL1ß and IFN-γ), reduced levels of cellular defense proteins (Nrf-2 and HO-1) and glucose transporter (GLUT-2 and GLUT-4) along with the enhanced levels of signaling molecules of apoptosis (cleaved Caspase-12/9/8/3) in the pancreas of Cd-intoxicated rats. Results suggested that the treatment with GSP reduced blood glucose level, increased plasma insulin and mitigated oxidative stress-related markers. GSP protects pancreatic tissue by attenuated inflammatory responses and inhibited apoptosis. This uniqueness and absence of any detectable adverse effect of GSP proposes the possibility of using it as an effective protector in the oxidative stress-mediated pancreatic dysfunction in rats.

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.

Cranberry versus placebo in the prevention of urinary infections in multiple sclerosis: a multicenter, randomized, placebo-controlled, double-blind trial.

OBJECTIVE: Our aim was to assess the usefulness of cranberry extract in multiple sclerosis (MS) patients suffering from urinary disorders. METHODS: In total, 171 adult MS outpatients with urinary disorders presenting at eight centers were randomized (stratification according to center and use of clean intermittent self-catheterization) to cranberry versus placebo in a 1-year, prospective, double-blind study that was analyzed using a sequential method on an intent-to-treat basis. An independent monitoring board analyzed the results of the analyses each time 40 patients were assessed on the main endpoint. Cranberry extract (36 mg proanthocyanidins per day) or a matching placebo was taken by participants twice daily for 1 year. The primary endpoint was the time to first symptomatic urinary tract infection (UTI), subject to validation by a validation committee. RESULTS: The second sequential analyses allowed us to accept the null hypothesis (no difference between cranberry and placebo). There was no difference in time to first symptomatic UTI distribution across 1 year, with an estimated hazard ratio of 0.99, 95% CI [0.61, 1.60] (p = 0.97). Secondary endpoints and tolerance did not differ between groups. CONCLUSION: Taking cranberry extract versus placebo twice a day did not prevent UTI occurrence in MS patients with urinary disorders. Trial Registration NCT00280592.

Assessment of the effect of condensed (acacia and quebracho) and hydrolysable (chestnut and valonea) tannins on rumen fermentation and methane production in vitro.

BACKGROUND: Tannins added to animal diets may have a positive effect on energy and protein utilisation in the rumen. The objective of this study was to examine the impact of different sources and concentrations (20, 50, 100, 150 and 200 g kg⁻¹ dry matter (DM)) of condensed (acacia and quebracho) and hydrolysable (chestnut and valonea) tannins on rumen microbial fermentation in vitro. The experiment also included a negative control with no tannins (control) and a positive control with monensin (10 mg L⁻¹). RESULTS: In vitro gas production and total volatile fatty acid (VFA) concentration decreased as tannin concentration increased. Addition of acacia, chestnut or valonea tannins at ≥ 50 g kg⁻¹ or quebracho tannins at ≥ 100 g kg⁻¹ resulted in a decrease (up to 40%) in methane (CH4) production compared with the control. Valonea tannins were the only tannin source that reduced (-11%) CH4 production at 50 g kg⁻¹ without affecting VFA concentration. Tannin treatments reduced ammonia (NH3) and branched-chain VFA concentrations, indicating a reduction in ruminal protein degradation. Monensin reduced CH4 production (-37%) and NH3 concentration (-20%) without affecting total VFA concentration. CONCLUSION: Supplying acacia, chestnut or valonea tannins at 50 g kg⁻¹ has the potential to reduce CH4 production and ruminal protein degradation with minimum detrimental effects on efficiency of ruminal fermentation.

Chronic dietary supplementation of proanthocyanidins corrects the mitochondrial dysfunction of brown adipose tissue caused by diet-induced obesity in Wistar rats.

The present study aims to determine the effects of grape seed proanthocyanidin extract (GSPE) on brown adipose tissue (BAT) mitochondrial function in a state of obesity induced by diet. Wistar male rats were fed with a cafeteria diet (Cd) for 4 months; during the last 21 d, two groups were treated with doses of 25 and 50 mg GSPE/kg body weight. In the BAT, enzymatic activities of citrate synthase, cytochrome c oxidase (COX) and ATPase were determined and gene expression was analysed by real-time PCR. The mitochondrial function of BAT was determined in fresh mitochondria by high-resolution respirometry using both pyruvate and carnitine-palmitoyl-CoA as substrates. The results show that the Cd causes an important decrease in the gene expression of sirtuin 1, nuclear respiratory factor 1, isocitrate dehydrogenase 3γ and COX5α and, what is more telling, decreases the levels of mitochondrial respiration both with pyruvate and canitine-palmitoyl-CoA. Most of these parameters, which are indicative of mitochondrial dysfunction due to diet-induced obesity, are improved by chronic supplementation of GSPE. The beneficial effects caused by the administration of GSPE are exhibited as a protection against weight gain, in spite of the Cd the rats were fed. These data indicate that chronic consumption of a moderate dose of GSPE can correct an energy imbalance in a situation of diet-induced obesity, thereby improving the mitochondrial function and thermogenic capacity of the BAT.

Proanthocyanidins inhibit iron absorption from soybean (Glycine max) seed ferritin in rats with iron deficiency anemia.

The objective of this study was to evaluate the effect of proanthocyanidins (PAs) on iron uptake from soybean seed ferritin (SSF) crude by rats with iron deficiency anemia (IDA) for the first time. Six groups of Sprague-Dawley (SD) rats (n = 10) were used, which contain (1) SSF crude group; (2) SSF crude + PAs group; (3) PAs group; (4) FeSO(4) group; (5) iron deficiency control group; and (6) control group. The bioavailability of iron was examined by measuring hemoglobin (Hb) concentration value, red blood cell (RBC) numbers, and serum iron stores. After 8 weeks, Hb concentration was almost recovered to the normal level upon feeding SSF crude or FeSO(4) to rats. In contrast, Hb concentration was recovered to less extent when SSF crude plus PAs was used instead of SSF crude alone (P < 0.05). A similar profile was observed with these three sample groups when serum iron and RBC were used as parameters. All rats in PAs group died at the 8th week. Taken together, all these results demonstrated that PAs inhibited iron uptake of rats from SSF, and are toxic for rats with IDA.

Oenothera paradoxa defatted seeds extract containing pentagalloylglucose and procyanidins potentiates the cytotoxicity of vincristine.

The purpose of the study was a comparison of Oenothera paradoxa Hudziok defatted seeds extract (EPE) effect with the activity of individual constituents of the extract: pentagalloylglucose (PGG), gallic acid, (+)-catechin and the procyanidin fraction, as well as an assessment of the combined effect of EPE and vincristine (VCR) in the absence or presence of MRP1 (indomethacin) and P-glycoprotein (verapamil) inhibitors, on two human cancer cell lines, metastatic melanoma (HTB-140) and hepatoma (HepG2). The presence of EPE, PGG and procyanidins caused a marked reduction in viability (MTT assay) and rise in mortality (LDH release assay) of HTB-140 cells. The combined use of EPE (25 µg/mL) and VCR (1 µM) in HTB-140 and HepG2 cells produced an increased cytotoxicity as compared to vincristine alone - by more than 4 and 1.5 times, respectively. In HTB-140 cells, the level of intracellular ATP (measured by bioluminescence) was lowered over 7-fold as a result of exposure to the combination of EPE and VCR, while the addition of MRP-1 inhibitor did not cause an increased cytotoxicity or further lowering of the ATP level. Our results demonstrate that EPE, containing PGG and procyanidins, significantly increased the sensitivity of cancer cells, particularly the melanoma cells, to the action of vincristine.

Evaluation of crofelemer in the treatment of diarrhea-predominant irritable bowel syndrome patients.

BACKGROUND: Crofelemer improves bowel function in several conditions characterized by states of prominent secretory diarrhea. AIM: This double-blind, randomized, placebo-controlled trial evaluated the effects of 3 dose levels of crofelemer in patients with diarrhea-predominant irritable bowel syndrome (D-IBS). METHODS: Male and female patients were randomly assigned to receive crofelemer 125, 250 or 500 mg or placebo twice daily for 12 weeks. The primary efficacy measure was a responder for improvement in stool consistency. In addition, abdominal pain- and discomfort-free days, pain and discomfort scores as well as other bowel function parameters (such as stool frequency and consistency, urgency, bloating) were evaluated. RESULTS: Two hundred and forty-two D-IBS patients were randomized. Crofelemer did not produce significant improvement in stool consistency (primary endpoint), stool frequency, urgency or adequate relief. However, female D-IBS patients showed improvement in the proportion of pain- and discomfort-free days during treatment with 500 mg crofelemer: month 1 (crofelemer vs. placebo: 17.7 vs. 10.2%, p = 0.098); month 2 (23.5 vs. 13.3%, p = 0.076); month 3 (26.1 vs. 10.6%, p = 0.0076). No benefit was seen in male D-IBS patients. Crofelemer was well tolerated. CONCLUSIONS: Crofelelmer did not produce benefit on bowel function; an increase in the number of pain- and discomfort-free days in female D-IBS patients was seen. Further studies with crofelemer are warranted to evaluate it as a potential visceral analgesic.

Cranberries (Vaccinium macrocarpon) and cardiovascular disease risk factors.

The American cranberry (Vaccinium macrocarpon) is one of the three commercially important fruits native to North America. Cranberries are a particularly rich source of phenolic phytochemicals, including phenolic acids (benzoic, hydroxycinnamic, and ellagic acids) and flavonoids (anthocyanins, flavonols, and flavan-3-ols). A growing body of evidence suggests that polyphenols, including those found in cranberries, may contribute to reducing the risk of cardiovascular disease (CVD) by increasing the resistance of LDL to oxidation, inhibiting platelet aggregation, reducing blood pressure, and via other anti-thrombotic and anti-inflammatory mechanisms. Research regarding the bioactivity of cranberries and their constituents on risk factors for CVD is reviewed.

Grape seed proanthocyanidins induce pro-oxidant toxicity in cardiomyocytes.

Grape seed proanthocyanidin extract (GSPE), a polyphenolic compound with antioxidant properties, may protect against cardiac ischemia and reperfusion injury. However, its potential toxicity at higher doses is unknown. The authors tested the effects of GSPE on reactive oxygen species (ROS) generation, cell survival, lactate dehydrogenase (LDH) release, and caspase- 3 activity using chick cardiomyocytes incubated with GSPE at 5, 10, 50, 100, or 500 micrograms/mL in medium for 8 h. Exposure to increasing concentrations of GSPE (100 or 500 micrograms/mL) resulted in an increase in ROS generation and cell death as measured by propidium iodide uptake and LDH release. Caspase-3 activity was significantly increased fourfold in cells exposed to GSPE 500 micrograms/ mL compared to controls; this was abolished by the selective caspase-3 inhibitor Ac-Asp-Gln-Thr-Asp-H (50 microM), which also significantly reduced the cell death resulting from GSPE (500 micrograms/mL). The antioxidant N-acetylcysteine (NAC, 100 microM) reduced cell death induced by GSPE (500 micrograms/mL) but failed to attenuate caspase-3 activation. Collectively, the authors conclude that higher doses of GSPE could cause apoptotic cell injury via effector caspase-3 activation and subsequent induction of ROS generation. Consumers may take higher doses of dietary supplements in the belief that natural herbs have no major side effects. This study demonstrates that dosages of GSPE should be optimized to avoid potential harmful pro-oxidant effects.