Procyanidins extracted from pine bark protect alpha-tocopherol in ECV 304 endothelial cells challenged by activated RAW 264.7 macrophages: role of nitric oxide and peroxynitrite

A Three-Dimensional Chondrocyte-Macrophage Coculture System to Probe Inflammation in Experimental Osteoarthritis

The goal of the present study was to develop a fully three-dimensional (3D) coculture system that would allow for systematic evaluation of the interplay between activated macrophages (AMs) and chondrocytes in osteoarthritic disease progression and treatment. Toward this end, our coculture system was first validated against existing in vitro osteoarthritis models, which have generally cultured healthy normal chondrocytes (NCs)-in two-dimensional (2D) or 3D-with proinflammatory AMs in 2D. In this work, NCs and AMs were both encapsulated within poly(ethylene glycol) diacrylate hydrogels to mimic the native 3D environments of both cell types within the osteoarthritic joint. As with previous studies, increases in matrix metalloproteinases (MMPs) and proinflammatory cytokines associated with the early stages of osteoarthritis were observed during NC-AM coculture, as were decreases in protein-level Aggrecan and collagen II. Thereafter, the coculture system was extended to osteoarthritic chondrocytes (OACs) and AMs to evaluate the potential effects of AMs on pre-existing osteoarthritic phenotypes. OACs in coculture with AMs expressed significantly higher levels of MMP-1, MMP-3, MMP-9, MMP-13, IL-1β, TNF-α, IL-6, IL-8, and IFN-γ compared to OACs in mono-culture, indicating that proinflammatory macrophages may intensify the abnormal matrix degradation and cytokine secretion already associated with OACs. Likewise, AMs cocultured with OACs expressed significantly more IL-1β and VEGF-A compared to AM mono-culture controls, suggesting that OACs may intensify abnormal macrophage activation. Finally, OACs cultured in the presence of nonactivated macrophages produced lower levels of MMP-9 and proinflammatory cytokines IL-1β, TNF-α, and IFN-γ compared to OACs in the OAC-AM system, results that are consistent with anti-inflammatory agents temporarily reducing certain OA symptoms. In summary, the 3D coculture system developed herein captures several key features of inflammatory OA and may prove useful in future screening of therapeutic agents and/or assessment of disease progression mechanisms.

Pycnogenol® in Metabolic Syndrome and Related Disorders

The present review provides an update of the biological actions of Pycnogenol® in the treatment of metabolic syndrome and related disorders such as obesity, dyslipidaemia, diabetes and hypertension. Pycnogenol® is a French maritime pine bark extract produced from the outer bark of Pinus pinaster Ait. Subsp. atlantica. Its strong antioxidant, antiinflammatory, endothelium-dependent vasodilator activity, and also its anti-thrombotic effects make it appropriate for targeting the multifaceted pathophysiology of metabolic syndrome. Clinical studies have shown that it can reduce blood glucose levels in people with diabetes, blood pressure in mild to moderate hypertensive patients, and waist circumference, and improve lipid profile, renal and endothelial functions in metabolic syndrome. This review highlights the pathophysiology of metabolic syndrome and related clinical research findings on the safety and efficacy of Pycnogenol®. The results of clinical research studies performed with Pycnogenol® are discussed using an evidence-based, target-oriented approach following the pathophysiology of individual components as well as in metabolic syndrome overall.

Pycnogenol® in chronic venous insufficiency and related venous disorders

The present review provides an update of the biological profile of Pycnogenol in the light of its use in the treatment of chronic venous insufficiency (CVI) and related venous disorders such as deep vein thrombosis (DVT), post-thrombotic syndrome, long haul air-travel-related leg oedema, venous ulcers and acute haemorrhoids. Pycnogenol is a French maritime pine bark extract produced from the outer bark of Pinus pinaster Ait. subsp. atlantica. Its strong antioxidant, anti-inflammatory and vasodilator activities, antithrombotic effects and collagen stabilizing properties make it uniquely able to target the multi facet pathophysiology of CVI and related venous disorders. Clinical studies have shown that it can reduce oedema of the legs in CVI, reduce the incidence of deep venous thrombosis during long haul flights and enhance the healing of venous ulcers and haemorrhoidal episodes by topical application and/or oral administration. This review highlights clinical research findings on the safety, compliance and efficacy of Pycnogenol, including its use in combination products.

Novel, biocatalytically produced hydroxytyrosol dimer protects against ultraviolet-induced cell death in human immortalized keratinocytes

Compounds derived from botanicals, such as olive trees, have been shown to possess various qualities that make them function as ideal antioxidants and, in doing so, protect them against the damaging effect of ultraviolet (UV)-derived oxidative stress. The aim of this study was to biocatalytically synthesize a dimeric product (compound II) from a known botanical, 3-hydroxytyrosol, and test it for its antioxidant ability using a human immortalized keratinocyte cell line (HaCaT). 2,2-Diphenyl-picryhydrazyl (DPPH) antioxidant assays showed 33 and 86.7% radical scavenging activity for 3-hydroxytyrosol and its dimer, respectively. The ferric-reducing antioxidant power (FRAP) assay corroborated this by showing a 3-fold higher antioxidant activity for the dimer than 3-hydroxytyrosol. Western blot analyses, showing cells exposed to 500 μM of the dimeric product when ultraviolet A (UVA)-irradiated, increased the anti-apoptotic protein Bcl-2 expression by 16% and reduced the pro-apoptotic protein Bax by 87.5%. Collectively, the data show that the dimeric product of 3-hydroxytyrosol is a more effective antioxidant and could be considered for use in skin-care products, health, and nutraceuticals.

Gelam honey has a protective effect against lipopolysaccharide (LPS)-induced organ failure

Gelam honey exerts anti-inflammatory and antioxidant activities and is thought to have potent effects in reducing infections and healing wounds. The aim of this study was to investigate the effects of intravenously-injected Gelam honey in protecting organs from lethal doses of lipopolysaccharide (LPS). Six groups of rabbits (N = 6) were used in this study. Two groups acted as controls and received only saline and no LPS injections. For the test groups, 1 mL honey (500 mg/kg in saline) was intravenously injected into two groups (treated), while saline (1 mL) was injected into the other two groups (untreated); after 1 h, all four test groups were intravenously-injected with LPS (0.5 mg/kg). Eight hours after the LPS injection, blood and organs were collected from three groups (one from each treatment stream) and blood parameters were measured and biochemical tests, histopathology, and myeloperoxidase assessment were performed. For survival rate tests, rabbits from the remaining three groups were monitored over a 2-week period. Treatment with honey showed protective effects on organs through the improvement of organ blood parameters, reduced infiltration of neutrophils, and decreased myeloperoxidase activity. Honey-treated rabbits also showed reduced mortality after LPS injection compared with untreated rabbits. Honey may have a therapeutic effect in protecting organs during inflammatory diseases.

Dietary flavonoids do not affect vitamin E status in growing rats

This study aimed at investigating potential effects of the flavonoids genistein, quercetin and catechin and the role of co-ingested dietary fat on vitamin E concentrations in rats. In experiment 1, genistein, quercetin and catechin were fed to rats, incorporated into semisynthetic diets at concentrations of 2 g/kg, either as individual compounds or in combination to investigate their individual and possible synergistic actions towards alpha-tocopherol in plasma and selected tissues. For experiments 2 and 3, quercetin was selected as a representative model flavonoid to study the effects of the quantity (5% vs. 10%) and type of dietary fat (coconut fat plus corn oil vs. rapeseed oil; experiment 2) and the role of cholesterol (experiment 3) on potential flavonoid-vitamin E interactions. The concentrations of alpha-tocopherol and gamma-tocopherol in the plasma, liver, lung and cortex of flavonoid-fed rats were not significantly different from the concentrations measured in control rats in all three experiments. However, increasing the amount of coconut fat plus corn oil from 5 to 10% resulted in lower alpha-tocopherol concentrations in plasma and tissue. The alpha-tocopherol concentrations in the rats fed rapeseed oil were significantly higher than in rats fed coconut fat plus corn oil. The addition of 0.2% cholesterol to the diet did not influence the tocopherol concentrations in plasma and tissue in both quercetin-supplemented and control rats. Additionally, the mRNA levels of alpha-TTP, CYP3A4, CYP4F and Mdr2, which are integral proteins involved in vitamin E homeostasis were measured. Only genistein reduced the Mdr2 mRNA level, but none of the other transcripts. All other flavonoids were without effect. In conclusion, co-ingested dietary fat appears to influence vitamin E concentrations in rats, but does not seem to be an important determinant of flavonoid-vitamin E interactions.

The anti-melanogenic effect of pycnogenol by its anti-oxidative actions

Pycnogenol is a natural plant extract from pine bark that contains compounds that have anti-oxidative, free-radical scavenging properties. In this work, utilizing cultured B16 melanoma cells (B16 cells), pycnogenol was investigated for its ability to inhibit tyrosinase activity and melanin biosynthesis. We also examined the anti-oxidative power of pycnogenol by measuring its suppressive effect against peroxynitrite (ONOO-), superoxide (.O2), nitric oxide (NO.), and hydroxyl radical (.OH)-scavenging activities using an electron spin resonance spectrometer. Results show that pycnogenol had a strong anti-tyrosinase activity and suppressed melanin biosynthesis. Further, our results showed that through its anti-oxidative properties, pycnogenol suppressed .O2) NO., ONOO-, and .OH in in vitro assays, and reactive species, ONOO-, .O2, and NO., while up-regulating the reduced glutathione/oxidized glutathione ratio in B16 cells. Based on the findings, we propose that pycnogenol exerts anti-melanogenic activity via its anti-oxidative actions.

Flavan-3-ols: nature, occurrence and biological activity

Representing the most common flavonoid consumed in the American diet, the flavan-3-ols and their polymeric condensation products, the proanthocyanidins, are regarded as functional ingredients in various beverages, whole and processed foods, herbal remedies and supplements. Their presence in food affects food quality parameters such as astringency, bitterness, sourness, sweetness, salivary viscosity, aroma, and color formation. The ability of flavan-3-ols to aid food functionality has also been established in terms of microbial stability, foamability, oxidative stability, and heat stability. While some foods only contain monomeric flavan-3-ols [(-)-epicatechin predominates] and dimeric proanthocyanidins, most foods contain oligomers of degree of polymerization values ranging from 1-10 or greater than 10. Flavan-3-ols have been reported to exhibit several health beneficial effects by acting as antioxidant, anticarcinogen, cardiopreventive, antimicrobial, anti-viral, and neuro-protective agents. This review summarizes the distribution and health effects of these compounds.

Oxidant/antioxidant interactions of nicotine, Coenzyme Q10, Pycnogenol and phytoestrogens in oral periosteal fibroblasts and MG63 osteoblasts

BACKGROUND

There is a growing awareness that oxidative stress may play a role in periodontal disease. The aim of this investigation was to evaluate potential oxidant/antioxidant interactions of nicotine with antioxidants (Coenzyme Q10 (CoQ), Pycnogenol and phytoestrogens in a cell culture model.

METHODS

Duplicate incubations of human periosteal fibroblasts and osteoblasts were performed with 14C-testosterone as substrate, in the presence or absence of CoQ (20 microg/ml), Pycnogenol (150 microg/ml), and phytoestrogens (10 and 40 microg/ml), alone and in combination with nicotine (250 microg/ml). At the end of a 24-h incubation period, the medium was solvent extracted and testosterone metabolites were separated by thin-layer chromatography and quantified using a radioisotope scanner.

RESULTS

The incubations of osteoblasts and periosteal fibroblasts with CoQ, Pycnogenol or phytoestrogens stimulated the synthesis of the physiologically active androgen DHT, while the yields of DHT were significantly reduced in response to nicotine compared to control values (p<0.001 for phytoestrogens). The combination of nicotine with CoQ, Pycnogenol or phytoestrogens increased the yields of DHT compared with incubation with nicotine alone in both cell types.

CONCLUSION

This investigation suggests that the catabolic effects of nicotine could be reversed by the addition of antioxidants such as CoQ or Pycnogenol and phytoestrogens.

Antioxidant Status of Faeces of Captive Black Rhinoceros (Diceros bicornis) in Relation to Dietary Tannin Supplementation

In context with the frequent observations of excessive iron (Fe) storage in captive black rhinoceroses (Diceros bicornis), it has been suggested that both an excessive dietary Fe content and a lack of dietary Fe-chelating substances, such as tannins, is the underlying cause. Therefore, studies on the effects of tannin supplementation to captive diet are warranted. Six captive rhinoceroses were fed their normal zoo diet (N), and a similar diet supplemented with either tannic acid (T, hydrolysable tannin) or quebracho (Q, condensed tannins), and the total antioxidant capacity (TAC) was measured as mmol Trolox equivalents per kg fresh faeces. The TAC values on diets N (1.24 +/- 0.39 mmol/kg fresh faeces) and T (1.34 +/- 0.33 mmol/kg fresh faeces) were similar, but significantly higher on diet Q (2.32 +/- 0.61 mmol/kg fresh faeces). In contrast to expectations, faecal TAC increased with increasing faecal Fe, possibly as a result of the fact that the faecal Fe content was positively correlated to the proportion of concentrate feeds in the diet, which also contain antioxidants, such as vitamin E, in addition to Fe. Increased antioxidant status caused by the use of tannin substances could have a beneficial effect on animal health, but if tannins should be incorporated in designed diets, other tannin sources, such as grape pomace should be tested.

The reaction of flavanols with nitrous acid protects against N-nitrosamine formation and leads to the formation of nitroso derivatives which inhibit cancer cell growth

Studies have suggested that diets rich in polyphenols such as flavonoids may lead to a reduced risk of gastrointestinal cancers. We demonstrate the ability of monomeric and dimeric flavanols to scavenge reactive nitrogen species derived from nitrous acid. Both epicatechin and dimer B2 (epicatechin dimer) inhibited nitrous acid-induced formation of 3-nitrotyrosine and the formation of the carcinogenic N-nitrosamine, N-nitrosodimethylamine. The reaction of monomeric and dimeric epicatechin with nitrous acid led to the formation of mono- and di-nitroso flavanols, whereas the reaction with hesperetin resulted primarily in the formation of nitrated products. Although, epicatechin was transferred across the jejunum of the small intestine yielding metabolites, its nitroso form was not absorbed. Dimer B2 but not epicatechin monomer inhibited the proliferation of, and triggered apoptosis in, Caco-2 cells. The latter was accompanied by caspase-3 activation and reductions in Akt phosphorylation, suggesting activation of apoptosis via inhibition of prosurvival signaling. Furthermore, the dinitroso derivative of dimer B2, and to a lesser extent the dinitroso-epicatechin, also induced significant toxic effects in Caco-2 cells. The inhibitory effects on cellular proliferation were paralleled by early inhibition of ERK 1/2 phosphorylation and later reductions in cyclin D1 levels, indicating modulation of cell cycle regulation in Caco-2 cells. These effects highlight multiple routes in which dietary derived flavanols may exert beneficial effects in the gastrointestinal tract.

Cancer chemopreventive effects of Pinus Maritima bark extract on ultraviolet radiation and ultraviolet radiation-7,12,dimethylbenz(a)anthracene induced skin carcinogenesis of hairless mice

The bark extract of Pinus Maritima (PBE), a rich in phenolic acids, polyphenols and in particular flavonoids mixture, was examined for skin cancer preventive action that was evaluated in two different experimental animal tumor models induced by ultraviolet radiation (UVR) and combination of UVR with 7,12-dimethylbenz[a]anthracene. Significant decrease in the number of animals bearing tumors and the number of tumors per animal was observed in the PBE treated animals. In the same time significant increase in the viability of these animals was also observed. Furthermore, PBE delayed the appearance of tumors. These results provide strong evidence about the preventive anticancer activity of this extract on non-melanoma skin cancer and its protective effect not only from UVR, but also from more potent carcinogenic agents.

Dietary proanthocyanidins: Occurrence, dietary intake, bioavailability, and protection against cardiovascular disease

The French have one of the lowest incidences of coronary heart disease in the Western world despite a diet with a relatively high fat content. This phenomenon that has puzzled researchers worldwide for more than a decade is known as the 'French paradox' and has been linked to the high consumption of red wine in France. Red wine is rich in the complex polyphenols, the proanthocyanidins, and these compounds have recently attracted attention as potential cardiac-protective compounds. The present review summarizes the literature on proanthocyanidins with focus on their chemical structure, the occurrence, the daily intake from foods, the bioavailability and metabolism, and the evidence for a protective effect against cardiovascular diseases.

Pycnogenol as an adjunct in the management of childhood asthma

A randomized, placebo-controlled, double-blind study involving 60 subjects, aged 6-18 years old, was conducted over a period of 3 months to determine the effect of Pycnogenol (a proprietary mixture of water-soluble bioflavonoids extracted from French maritime pine) on mild-to-moderate asthma. After baseline evaluation, subjects were randomized into two groups to receive either Pycnogenol or placebo. Subjects were instructed to record their peak expiratory flow with an Assess Peak Flow Meter each evening. At the same time, symptoms, daily use of rescue inhalers (albuterol), and any changes in oral medications were also recorded. Urine samples were obtained from the subjects at the end of the run-in period, and at 1-, 2-, and 3-month visits. Urinary leukotriene C4/D4/E4 was measured by an enzyme immunoassay. Compared with subjects taking placebo, the group who took Pycnogenol had significantly more improvement in pulmonary functions and asthma symptoms. The Pycnogenol group was able to reduce or discontinue their use of rescue inhalers more often than the placebo group. There was also a significant reduction of urinary leukotrienes in the Pycnogenol group. The results of this study demonstrate the efficacy of Pycnogenol as an adjunct in the management of mild-to-moderate childhood asthma.

Influence of treatment of diabetic rats with combinations of pycnogenol, ?-carotene, and ?-lipoic acid on parameters of oxidative stress

Treatment with antioxidants may act more effectively to alter markers of free radical damage in combinations than singly. This study has determined whether treatment with combinations of pycnogenol, beta-carotene, and alpha-lipoic acid was more effective at reducing oxidative stress in diabetic rats than treatment with these antioxidants alone. It is not feasible, based on this study, to assume that there are interactive effects that make combinations of these antioxidants more effective than any one alone to combat oxidative stress. Female Sprague-Dawley rats, normal and streptozotocin-induced diabetic, were treated (10 mg/kg/day ip for 14 days) with pycnogenol, beta-carotene, pycnogenol + beta-carotene, or pycnogenol + beta-carotene + alpha-lipoic acid; controls were untreated. Concentrations of thiobarbituric acid reactive substances, glutathione and glutathione disulfide, and activities of glutathione reductase, glutathione peroxidase, superoxide dismutase, and catalase were measured in liver, kidney, and heart. Four types of effects were observed: (1) treatment with beta-carotene alone either reversed (cardiac glutathione disulfide) or elevated (cardiac glutathione, hepatic glutathione peroxidase activity) levels seen in diabetic animals; (2) beta-carotene alone produced no effect, but pycnogenol both alone and in combinations elevated (renal glutathione peroxidase and glutathione reductase activities, hepatic glutathione reductase activity and glutathione disulfide) or depressed (cardiac glutathione disulfide) levels seen in untreated diabetic animals; (3) all treatments with antioxidants, either alone or in combination, either normalized (lipid peroxidation in all tissues), elevated (hepatic GSH, cardiac glutathione peroxidase activity), or had no effect on (activities of hepatic catalase and superoxide dismutase in all tissues) levels seen in diabetic animals; (4) in only one case (cardiac glutathione reductase activity) levels in diabetic animals treated with combinations of antioxidants were normal, but elevated in animals treated with either antioxidant alone. Antioxidant effects seem to be dependent on the nature of the antioxidant used and not on combination effects.

Flavonoids and the brain: interactions at the blood-brain barrier and their physiological effects on the central nervous system

Over the past few years there has been an exponential growth in the number of reports describing the effects of nutritional modulation on aging and age-related diseases. Specific attention has been directed toward the beneficial effects afforded by dietary antioxidants, in particular those from fruit and vegetables, in ameliorating age-related deficits in brain performance. The rationale for studying the effects of dietary intervention stems from evidence implicating free radicals in aspects related to the aging process. Age-dependent neuropathology is a cumulative response to alterations induced by reactive oxygen species. Therefore cognitive aging, according to this hypothesis, should be slowed, and possibly even reversed, by appropriately increasing levels of antioxidants or decreasing overproduction of free radicals in the body.

The effect of Pycnogenol on fluoride induced rat kidney lysosomal damage in vitro

Pycnogenol (PYC) is a procyanidin-rich extract of the bark of French maritime pine (Pinus pinaster) with a potent ability to scavenge free radicals. Lysosome-rich fractions from rat renal cortices were incubated with varying amounts of PYC and challenged with noxious doses of fl uoride. Controls were also included. The release of N-acetyl-beta-D-glucosaminidase (NAG) isozymes in the supernatant was estimated by spectrophotometric methods. The protein content of the renal cortex was also determined. Our results show that fluoride in unhealthy doses can cause a concentration dependent release of N-acetyl-beta-D-glucosaminidase (NAG) isozymes from the renal lysosomes. This may be related to its known ability to initiate free radical formation or direct damaging effects on the lysosomal membrane. As a blend of bio flavonoids pycnogenol has a potent ability to scavenge free radicals. In our study PYC was effective in preventing fluoride induced release of NAG isozymes from the renal lysosomes.

Antioxidant activity and inhibition of matrix metalloproteinases by metabolites of maritime pine bark extract (pycnogenol)

The procyanidin-rich maritime pine bark extract Pycnogenol has well-documented antioxidant and anti-inflammatory activity. After oral administration of Pycnogenol two major metabolites are formed in vivo, delta-(3,4-dihydroxyphenyl)-gamma-valerolactone (M1) and delta-(3-methoxy-4-hydroxyphenyl)-gamma-valerolactone (M2). We elucidated the effects of these metabolites on matrix metalloproteinases (MMPs) and determined their antioxidant activity to understand their contribution to the effects of maritime pine bark extract. We discovered strong inhibitory effects of M1 and M2 toward the activity of MMP-1, MMP-2, and MMP-9. On a microgram-per-milliliter basis both metabolites appeared more active than Pycnogenol. The metabolites were more effective than their metabolic precursor (+)-catechin in MMP inhibition. On a cellular level, we detected highly potent prevention of MMP-9 release by both metabolites, with concentrations of 0.5 microM resulting in about 50% inhibition of MMP-9 secretion. M1 was significantly more effective in superoxide scavenging than (+)-catechin, ascorbic acid, and trolox, while M2 displayed no scavenging activity. Both metabolites exhibited antioxidant activities in a redox-linked colorimetric assay, with M1 being significantly more potent than all other compounds tested. Thus, our data contribute to the comprehension of Pycnogenol effects and provide a rational basis for its use in prophylaxis and therapy of disorders related to imbalanced or excessive MMP activity.

Inhibition of phorbol ester-induced COX-2 expression by some edible African plants

Cancer bush (CB, Sutherlandia frutescens), Devil's claw (DEV, Harpagophytum procumbens), Rooibos tea (RT, Aspalathus linearis), and Bambara groundnut (BB, Vignea subterranean) have been used to treat some malignancies and inflammatory disorders in Africa. However, biochemical basis for chemopreventive effects of these medicinal plants remains unclear. An abnormally elevated expression of cyclooxygenase-2 (COX-2) has been implicated in pathogenesis and progression of carcinogenesis. In the present study, we found that the methanol extracts of CB, DEV, RT, and BB inhibited, to a different extent, 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced COX-2 expression in human breast epithelial (MCF10A) cells and in mouse skin in vivo. To determine the molecular mechanism of COX-2 inhibition by the above medicinal plants, we examined their effects on activation of NF-kappaB which is one of the major transcription factors responsible for regulating COX-2 expression. Methanol extracts of both CB and BB inhibited the DNA binding of NF-kappaB activated by TPA in MCF10A cells in a dose-dependent manner. Based on above findings, CB and BB are likely to inhibit TPA-induced COX-2 expression through suppression of DNA binding of NF-kappaB, which may contribute to the chemopreventive or chemoprotective activity of these African plants.

Interaction between flavonoids and the blood-brain barrier: in vitro studies

There is considerable current interest in the neuroprotective effects of flavonoids. This study focuses on the potential for dietary flavonoids, and their known physiologically relevant metabolites, to enter the brain endothelium and cross the blood-brain barrier (BBB) using well-established in vitro models (brain endothelial cell lines and ECV304 monolayers co-cultured with C6 glioma cells). We report that the citrus flavonoids, hesperetin, naringenin and their relevant in vivo metabolites, as well as the dietary anthocyanins and in vivo forms, cyanidin-3-rutinoside and pelargonidin-3-glucoside, are taken up by two brain endothelial cell lines from mouse (b.END5) and rat (RBE4). In both cell types, uptake of hesperetin and naringenin was greatest, increasing significantly with time and as a function of concentration. In support of these observations we report for the first time high apparent permeability (Papp) of the citrus flavonoids, hesperetin and naringenin, across the in vitro BBB model (apical to basolateral) relative to their more polar glucuronidated conjugates, as well as those of epicatechin and its in vivo metabolites, the dietary anthocyanins and to specific phenolic acids derived from colonic biotransformation of flavonoids. The results demonstrate that flavonoids and some metabolites are able to traverse the BBB, and that the potential for permeation is consistent with compound lipophilicity.

Pycnogenol does not impact the antioxidant or vitamin C status of healthy young adults

OBJECTIVE

The objectives of this study were to determine if Pycnogenol (PYC), a water-processed extract made from the bark of Pinus maritima, interacts with vitamin C to increase its concentration and to increase total antioxidant capacity of serum and urine.

DESIGN

The study design was a nonrandom intervention.

SUBJECTS

Subjects (N=27; 15 women, 12 men) were aged 19 to 42 years.

INTERVENTION

Subjects consumed a placebo twice daily with meals for the first 2 weeks (baseline) and PYC (200 mg/day) for the second 2 weeks. Main outcome measures On days 15 and 29, subjects had a fasting blood sample collected and then consumed a daily dose of placebo or PYC with a 310-calorie beverage. One hour later a second blood sample was collected. Blood samples were analyzed for vitamin C and total antioxidant capacity using the ORAC (oxygen radical absorbance capacity) assay. Twenty-four-hour urine samples were collected on days 14-15 and 28-29 and analyzed for total phenolics, FRAP (ferric reducing antioxidant potential), and ORAC. Statistical analyses Paired t tests were used to test the impact of PYC on the outcome variables. A univariate ANOVA was used to determine the influence of gender. Pearson's correlation analysis was used to explore the relationships between dietary factors and outcome measures.

RESULTS

There was no apparent increase in fasting vitamin C concentration (P=.18) 2 weeks after supplementing the diet with PYC. Fasting ORAC values actually declined (P=.005). One hour after the ingestion of a daily dose of placebo or PYC, the total antioxidant capacity of serum increased by 15% to 19%, but the increase after ingesting PYC was not significantly (P=.80) more than after placebo. Antioxidant results from 24-hour urine samples were similar.

APPLICATIONS/CONCLUSIONS

The present findings fail to support the vitamin C or antioxidant claims made for PYC. PYC does not impact the antioxidant or vitamin C status of healthy young adults.

The role of food supplements in the treatment of the infertile man

Recently, concerns have been raised about the presumptive increased risk of serious undesirable side effects in children born after IVF and intracytoplasmic sperm injection (ICSI). These treatments must, therefore, be reserved as the ultimate option after evidence-based and cause-directed treatment of the male patient with deficient semen has been exhausted. The present authors found that sperm quality and function improved with the intake of complementary food supplementation using a combination of zinc and folic acid, or the antioxidant astaxanthin (Astacarox), or an energy-providing combination containing (actyl)-carnitine (Proxeed). Also, double blind trials showed that the latter two substances increase spontaneous or intrauterine insemination- (IUI-) assisted conception rates. Extracts of Pinus maritima bark (Pycnogenol), which inhibits the cyclo-oxygenase enzyme, reducing prostaglandin production and inflammatory reaction, and extracts of the Peruvian plant Lepidium meyenii were shown to improve sperm morphology and concentration, respectively, in uncontrolled trials. Linseed (flaxseed) oil contains alfa-linolenic acid and lignans. The former corrects the deficient intake of omega-3 essential fatty acids, which is correlated with impaired sperm motility among subfertile men. Lignans are precursors of enterolacton, which inhibits aromatase and reduces the ratio of 16-OH over 2-OH oestrogen metabolites. The resulting reduction in oestrogen load may favourably influence Sertoli cell function.

Procyanidins from Vitis vinifera seeds: in vivo effects on oxidative stress

The purpose of this study was to evaluate the effect of supplementation with procyanidins from Vitis vinifera on markers of oxidative stress. Ten healthy volunteers received a daily dose of 110 mg of procyanidins for 30 days. Fasting venous blood samples were taken before and at the end of the supplementation period and after 7 days of wash-out. The total antioxidant activity and the plasma concentrations of alpha-tocopherol were not modified. Conversely, the levels of alpha-tocopherol in red blood cell membranes increased significantly from 1.8 +/- 0.1 to 2.8 +/- 0.2 mg/g. Similarly, the lymphocyte oxidized DNA [8-oxo-7,8-dihydro-2'-deoxyguanosine/2'-deoxyguanosine ratio] was reduced from 7.23 +/- 2.47 to 2.34 +/- 0.51, and the red blood cell membrane fatty acid composition shifted to a higher level of polyunsaturated fatty acids. On the basis of these results, it may be suggested that dietary procyanidins exert their antioxidant protection in vivo by sparing liposoluble vitamin E and reducing DNA oxidative damage.

Potential role of dietary flavonoids in reducing microvascular endothelium vulnerability to oxidative and inflammatory insults ( small star, filled)

Although antioxidant systems help control the level of reactive oxygen species they may be overwhelmed during periods of oxidative stress. Evidence suggests that oxidative stress components as well as inflammatory mediators may be involved in the pathogenesis of vascular disorders, where localized markers of oxidative damage have been found. In this regard we investigated the putative antioxidant and anti-inflammatory effects of blueberry and cranberry anthocyanins and hydroxycinnamic acids against H(2)O(2) and TNFalpha induced damage to human microvascular endothelial cells. Polyphenols from both berries were able to localize into endothelial cells subsequently reducing endothelial cells vulnerability to increased oxidative stress at both the membrane and cytosol level. Furthermore, berry polyphenols also reduced TNFalpha induced up-regulation of various inflammatory mediators (IL-8, MCP-1 and ICAM-1) involved in the recruitment of leukocytes to sites of damage or inflammation along the endothelium. In conclusion, polyphenols isolated from both blueberry and cranberry were able to afford protection to endothelial cells against stressor induced up-regulation of oxidative and inflammatory insults. This may have beneficial actions against the initiation and development of vascular diseases and be a contributing factor in the reduction of age-related deficits in neurological impairments previously reported by us.

Interaction between cultured endothelial cells and macrophages: in vitro model for studying flavonoids in redox-dependent gene expression

This article focused on two methods to measure the activity of NF-kB. Both methods evalute "post-IkB phosphorylation" stages in the NF-kB activation cascade. In fact, EMSA performed with nuclear extracts provides an information only on NF-kB nuclear translocation and its ability to bind kB-DNA sequences. Likewise, the reporter gene assay is limited to assessing NF-kB-dependent gene expression no matter the mechanism that originally activated NF-kB. Nevertheless, the latter assay represents a more physiological and more reproducible way of measuring NF-kB activity in mammalian cells than the EMSA does. In order to obtain further insights into NF-kB signal transduction pathways, investigating IkB degradation and phosphorylation are recommended. The cloning and characterization of IkB kinases provided new testing possibilities based on measure of their activity.

Inhibition mechanisms of bioflavonoids extracted from the bark of Pinus maritima on the expression of proinflammatory cytokines

The effect of bioflavonoids extracted from the bark of Pinus maritima, Pycnogenol (PYC), on gene expression of the proinflammatory cytokines interleukin-1beta (IL-1beta) and interleukin-2 (IL-2) were investigated in RAW 264.7 cells and Jurkat E6.1 cells, respectively. PYC exerted strong scavenging activities against reactive oxygen species (ROS) generated by H2O2 in RAW 264.7. In situ ELISA, immunoblot analysis, and competitive RT-PCR demonstrated that pretreatment of LPS-stimulated RAW 264.7 cells with PYC dose-dependently reduced both the production of IL-1beta and its mRNA levels. Furthermore, in the same cells, PYC blocked the activation of nuclear factor kappaB (NF-kappaB) and activator protein-1 (AP-1), two major transcription factors centrally involved in IL-1beta gene expression. Concordantly, pretreatment of the cells with PYC abolished the LPS-induced IkappaB degradation. We also investigated the effect of PYC on IL-2 gene expression in phorbol 12-myristate 13acetate plus ionomycin (PMA/Io)-stimulated human T-cell line Jurkat E6.1. PYC inhibited the PMA/Io-induced IL-2 mRNA expression. However, as demonstrated in a reporter gene assay system, the mechanism of IL-2 gene transcriptional regulation by PYC was different from the regulation of IL-1beta. PYC inhibited both NF-AT and AP-1 chloramphenicol acetyltransferase (CAT) activities in transiently transfected Jurkat E6.1, but not NF-kappaB CAT activity. We also found that PYC can destabilize PMA/Io-induced IL-2 mRNA by posttranscriptional regulation. All these results suggest that bioflavonids can be useful therapeutic agents in treating many inflammatory, autoimmune, and cardiovascular diseases based on its diverse action mechanisms.

Molecular aspects of procyanidin biological activity: disease preventative and therapeutic potentials

There is a growing interest in the utilization of procyanidins for their dietary and pharmacological properties. A wide spectrum of beneficial activity for human health has been advocated for procyanidins due, in part, to their strong antioxidant activity. More recently the ability of procyanidins to affect gene expression and cell response in vitro has been reported, providing a novel mechanistic perspective on the biological activity of these phytochemicals. This article reviews recent cellular and molecular aspects of the biological activity of procyandins and discusses their disease preventative and therapeutic potentials.

Solar ultraviolet-induced erythema in human skin and nuclear factor-kappa-B-dependent gene expression in keratinocytes are modulated by a French maritime pine bark extract

The procyanidin-rich French maritime pine bark extract Pycnogenol (PBE) has been investigated for its effect in protecting human skin against solar UV-simulated light-induced erythema. Twenty-one volunteers were given an oral supplementation of Pycnogenol: 1.10 mg/kg body weight (b. wt.)/d for the first 4 weeks and 1.66 mg/kg b. wt./d for the next 4 weeks. The minimal erythema dose (MED) was measured twice before supplementation (baseline MED), once after the first 4 weeks of supplementation, and a last time at the end of the study. The UVR dose necessary to achieve 1 MED was significantly increased during PBE supplementation. Since the activation of the pro-inflammatory and redox-regulated transcription factor NF-kappaB is thought to play a major role in UVR-induced erythema, the effect of PBE was also investigated in the human keratinocyte cell line HaCaT. PBE, added to the cell culture medium, inhibited UVR-induced NF-kappaB-dependent gene expression in a concentration-dependent manner. However, NF-kappaB-DNA-binding activity was not prevented, suggesting that PBE affects the transactivation capacity of NF-kappaB. These data indicate that oral supplementation of PBE reduces erythema in the skin. Inhibition of NF-kappaB-dependent gene expression by PBE possibly contributes to the observed increase in MED.

Effect of select antioxidants on malondialdehyde modification of proteins

To determine whether commonly used antioxidants alter malondialdehyde (MDA) modification of proteins, a known mechanism of free radical-related tissue injury, we studied the effect of adding 1 mg/mL of pycnogenol, 5 mM of alpha-tocopherol, 5 mM of ascorbate, and 0.2 mg/mL of an ethanol equivalent of red and white wine on MDA-protein content of endothelial cells in culture. The addition of pycnogenol but not of the other antioxidants was associated with significant reduction in MDA-protein content compared with controls (0.521 +/- 0.041 in arbritrary units versus 1.011 +/- 0.021, P < 0. 001). To determine whether the observed effect occurs distal to MDA generation, the effect of these antioxidants on the modification of bovine serum albumin with MDA generated in a cell-free system was studied. In this cell-free assay, pycnogenol but not the other antioxidants reduced MDA-BSA generation by approximately 50%. It is concluded that pycnogenol may reduce MDA modification of proteins at a step distal to MDA generation. This may be an additional mechanism of protective effects of pycnogenol against oxidative stress.

Effect of bioflavonoids extracted from the bark of Pinus maritima on proinflammatory cytokine interleukin-1 production in lipopolysaccharide-stimulated RAW 264.7

Currently, bioflavonoids have been known to have strong antioxidant capacities, and a variety of efforts have been made to identify the utilities of bioflavonoids in treating various diseases based on their antioxidant capacities. The effects of bioflavonoids extracted from the bark of Pinus maritima Pycnogenol (PYC) on free radical formation, activation of redox sensitive transcription factors, as well as interleukin-1 beta (IL-1 beta) production were investigated in murine macrophage cell lines. PYC exerted strong scavenging activities against reactive oxygen species generated either by H(2)O(2) or PMA in RAW 264.7 and IC-21 cells, respectively. In situ ELISA, immunoblot analysis, and competitive RT-PCR demonstrated that PYC pretreatment of LPS-stimulated RAW 264.7 cells dose-dependently reduced both the production of IL-1 beta and its mRNA levels. Furthermore, in the same cells, PYC blocked the activation of nuclear factor kappa B (NF-kappa B) and activator protein-1 (AP-1), two major transcription factors centrally involved in IL-1 beta gene expression. When RAW 264.7 cells were stimulated with LPS, the inhibitor protein I kappa B largely disappeared from cytosolic fractions. However, pretreatment of the cells with PYC abolished the LPS-induced I kappa B degradation. These results suggest that PYC can inhibit the expression of the proinflammatory cytokine IL-1 by regulating redox-sensitive transcription factors. This study may support the possibility that bioflavonoids including PYC can be used as antiinflammatory and immunosuppressive drugs based on their radical scavenging activities.

Inhibition of lipogenesis by pycnogenol

The influence of pycnogenol on the adipose conversion of 3T3-L1 cells by insulin was studied. In week 3 of culture with insulin, pycnogenol was found to inhibit significantly the expression of glycerophosphate dehydrogenase (p < 0.01). This finding suggests that pycnogenol inhibits the accumulation of lipid droplets in adipose tissue.

The prophylactic effects of natural water-soluble antioxidant from spinach and apocynin in a rabbit model of lipopolysaccharide-induced endotoxemia

Radical-scavenging antioxidants, as part of the cellular defense system, function to inhibit the formation and propagation of free radicals and active oxygen species formation. In previous studies we demonstrated that endotoxin lipopolysaccharide (LPS) promotes oxidative stress and associated pathological changes in a rat model and that use of selected antioxidants was effective in reducing LPS-related lipid peroxidation product formation in the liver, as well as LPS-related pathological changes in different organs. In this study, several toxicological parameters (ie, clinical signs, blood chemistry, and histopathological changes) were compared among groups of male New Zealand rabbits injected with LPS following prophylactic pretreatment with either of 2 antioxidants, a group injected with LPS without pretreatment with antioxidants, groups injected with either of the 2 antioxidants only, and an untreated control group. The antioxidants used were a water-soluble natural antioxidant (NAO) from spinach and the NADPH oxidase inhibitor, apocynin. Exposure to LPS alone was associated clinically with depression, tachypnea, outer ear vasodilation, and iris congestion; biochemically with a significant increase in blood total bilirubin, transaminase activity, and glucose, total cholesterol, and triglyceride levels; macroscopically with multiple whitish areas in the liver; and histologically with hepatocellular focal necrosis and acute inflammation, thymic and splenic lymphoid necrosis and depletion, acute uveitis and hemorrhages in the ciliary processes, and decreased adrenal cortical cytoplasmic vacuolation considered consistent with depletion of steroidal hormone contents. The NAO had more effective prophylactic capacities than the apocynin. The protective effects were obvious in all investigated parameters. The results indicate the possible therapeutic efficacy of NAO in the treatment of clinical endotoxemia associated with gram-negative bacterial sepsis that is known to be associated with oxidative stress.

Ferulic acid excretion as a marker of consumption of a French maritime pine (Pinus maritima) bark extract

French maritime pine (Pinus maritima) bark extract (PBE) is a polyphenol-rich food supplement patented under the name of Pycnogenol and known to have strong antioxidant activity and different beneficial effects on human health. Although its biological properties have begun to be extensively studied both in vitro, in laboratory animals and more recently in humans, little is known about its bioavailability. The present study investigated the urinary excretion of free and conjugated ferulic acid, present in quantitatively detectable amounts in PBE, after oral PBE administration to human subjects. Eleven healthy adult subjects (4 women and 7men) consumed either a single dose (200 mg PBE) or two doses of PBE (100 and 200 mg, respectively) within a 48-h interval. Two days before the oral administration of PBE and during the urine sample collection period volunteers adhered to a diet low in polyphenols. Aliquots of all urine production were collected over 24 h. Free and conjugated ferulic acid was assessed in urine by HPLC using diode array detection. A close association between the dietary intake of PBE and the urinary excretion of ferulic acid was detected. Moreover, the results indicate that a considerable proportion of ferulic acid is excreted as glucuronide or sulfate after PBE consumption, varying over the range 2 to 20% between individuals. The kinetics of excretion associated with the administration of 100 mg PBE was quite similar to that obtained after 200 mg PBE. A a biphasic trend was evident in a number of subjects. All subjects studied here displayed a significant, although variable level of excretion of ferulic acid after supplementation with PBE, Thus, the data provide evidence that at least a part of the phenolic components of PBE are absorbed, metabolized, and eliminated by humans.

In vitro inhibition of the activity of phosphorylase kinase, protein kinase C and protein kinase A by caffeic acid and a procyanidin-rich pine bark (Pinus marittima) extract

Caffeic acid (CA) is a common constituent of human diet while pine bark extract (PBE) is utilized either as nutritional supplement or as phytochemical remedy for different diseases. CA and PBE, are reported as efficient antioxidants and more recently have been described to modulate cellular response to oxidative challenge and to possess many other biological activities, i.e. anti-inflammatory, antimutagenic, antitumoral effects. In order to investigate in depth the mechanism of action of these polyphenols, the effects of CA and PBE on the activity of some protein kinases involved in the regulation of fundamental cellular processes were studied in vitro: phosphorylase kinase (PhK), protein kinase A (PKA), protein kinase C (PKC). PBE at the concentration of 20 microg/ml (corresponding to 69 microM catechin equivalents) inhibited PKA, PhK and PKC by about 90, 59, 57%, respectively, while 100 microM CA inhibited by 37, 52 and 54%, respectively. Considerable inhibitions have been still observed at even lower concentrations of CA and PBE. For PhK and PKA, the inhibition follows a non-competitive mechanism. CA also inhibits PKC activity in a partially purified cellular extract. The results suggest a possible involvement of CA and PBE in modulation of cellular functions.

Macrophages stimulated with IFN-gamma activate NF-kappa B and induce MCP-1 gene expression in primary human endothelial cells

A novel coculture model was established to study the effects of reactive oxygen (ROS) and reactive nitrogen species (RNS) generated by RAW 264.7 macrophages on NF-kappa B activation and monocyte chemoattractant protein (MCP-1) gene expression in primary human endothelial cells (HUVEC). This model simulates free radical-mediated interactions occurring in the process of cardiovascular diseases. The coculture of macrophages grown on filters and stimulated by IFN-gamma-induced a pro-oxidant environment and resulted in increased DNA binding and NF-kappa B transactivation in HUVEC. Activation of NF-kappa B in endothelial cells was accompanied by an evident increase in the expression of the mRNA encoding for the MCP-1 protein, which stimulates the recruitment of monocytes into the arterial wall. Present data suggest that the influx of stimulated monocytes into the subendothelial space could affect redox-sensitive transcription factors and gene expression in the endothelium, thereby possibly leading to endothelial dysfunction.

Effect of procyanidins from Pinus maritima on glutathione levels in endothelial cells challenged by 3-morpholinosydnonimine or activated macrophages

The effects of reactive nitrogen species on glutathione homeostasis in human endothelial ECV 304 cells challenged by 3-morpholinosydnonimine-N-ethylcarbamide (SIN-1) on RAW 264.7 activated macrophages using a co-culture model were investigated. SIN-1 or macrophages activated by lipopolysaccharide plus interferon-gamma induced a significant glutathione decrease in ECV 304 cells. Pre-incubation of ECV 304 cells with French maritime pine bark extract containing mainly oligomeric procyanidins protected endothelial cells from activated macrophage-induced glutathione depletion. Data demonstrate that reactive nitrogen species generated with different kinetics and mechanisms impair glutathione levels in endothelial cells, and that pine bark extract significantly enhances antioxidant defenses.

Activity of monomeric, dimeric, and trimeric flavonoids on NO production, TNF-alpha secretion, and NF-kappaB-dependent gene expression in RAW 264.7 macrophages

Flavonoids are potent antioxidants and have been associated with lowering the risk of cardiovascular diseases. In this study, the effect of flavonoids (monomers, dimers and a trimer) as well as French maritime pine bark extract, Pycnogenol, on NO production, tumor necrosis factor-alpha (TNF-alpha) secretion and nuclear factor (NF)-kappaB activity was compared. Monomers and dimers repressed NO production, TNF-alpha secretion and NF-kappaB-dependent gene expression induced by interferon gamma, whereas the trimeric procyanidin C2 and Pycnogenol enhanced these parameters. In addition, in unstimulated RAW 264.7 macrophages, both procyanidin C2 and Pycnogenol increased TNF-alpha secretion in a concentration- and time-dependent manner. These results demonstrate that procyanidins act as modulators of the immune response in macrophages.

Antioxidant capacity of flavanols and gallate esters: pulse radiolysis studies

Reactivities of several proanthocyanidins (monomers of condensed tannins) and gallate esters (representing hydrolyzable tannins) with hydroxyl radicals, azide radicals, and superoxide anions were investigated using pulse radiolysis combined with kinetic spectroscopy. We determined the scavenging rate constants and the decay kinetics of the aroxyl radicals both at the wavelength of the semiquinone absorption (275 nm) and the absorption band of the gallate ester ketyl radical (400-420 nm). For most compounds second-order decay kinetics were observed, which reflect disproportionation of the semiquinones. In the case of the oligomeric hydrolysable tannins, pentagalloyl glucose and tannic acid, the decay kinetics were more complex involving sequential first-order and second-order reactions, which could only be resolved by kinetic modeling. A correlation of the reaction rates with hydroxyl radicals (k*OH) with the number of adjacent aromatic hydroxyl groups (i.e., representing catechol and/or pyrogallol structures) was obtained for both condensed and hydrolyzable tannins. Similar correlation for the reactions with azide radicals and superoxide anions are less obvious, but exist as well. We consider proanthocyanidins superior radical scavenging agents as compared with the monomeric flavonols and flavones and propose that these substances rather than the flavonoids proper represent the antioxidative principle in red wine and green tea.

Electron spin resonance study of free radicals formed from a procyanidin-rich pine (Pinus maritima) bark extract, pycnogenol

The free radical generated from the oxidation of a French maritima pine bark extract Pycnogenol (PYC), by the horseradish peroxidase (HRP)-hydrogen peroxide (H2O2) system at pH 7.4-10.0 was studied using electron spin resonance (ESR) spectrometer. The formation rate of the PYC radical (aH = 0.92 G; g = 2.0055) was dependent on the PYC and HRP concentrations and pH; the lifetime of the radical was up to 90 min. Furthermore, it was found that the PYC radical was mainly composed of the secondary radical formed from procyanidin B3, one of major procyanidins in PYC. The primary radical signal of procyanidin B3 with hyperfine splitting constants aH = 3.67 G (1H), aH = 0.92 G (3H), and g = 2.0055 was transient and disappeared quickly, whereas its secondary radical signal appeared and increased with time. The secondary radical from dimer procyanidin B3 showed quite high stability, differing from the radical from monomer (+)-catechin that could not be observed possibly because of its instability. These results provide evidence to support the idea that the intramolecular hydrogen bond between the O* at the 4' position in one B ring and an OH group in the other B ring of procyanidin B3 is formed during its oxidation in the presence of HRP and H2O2.

Methods to assess free radicals and oxidative stress in biological systems

Oxidative stress results from a disruption of the prooxidant/antioxidant cellular balance and monitoring free radical status becomes an interesting challenge in animal and human nutrition. In the present work, merits and limitations of different analytical techniques (HPLC, GC-MS, fluorometric and colourometric assays, ELISA, gel electrophoresis) for the measurement of radical mediated alterations in the cellular integrity of lipids (malondialdehyde, hydrocarbon gases, F2-isoprostanes) proteins (protein carbonyls, 3-nitrotyrosine) and DNA (8-hydroxy-2'-deoxyguanosine) are discussed. Besides these indirect methods, owing to the fact that free radicals are paramagnetic, electron paramagnetic resonance spectroscopy combined with spin trapping has become a valuable tool to directly assess and to better understand the mechanisms of free radical reactions. With this approach a radical that is too short-lived to be detected, adds to a spin-trapping agent to form a relatively long-lived radical adduct. Information obtained from the hyperfine splitting of the spin-trapped adduct can provide identification and quantification of the originally generated free radicals.