The Benefits of Oligomeric Proanthocyanidins (OPCs)

Other Common Names: Grape seed extract, Oligomeric Proanthocyanidins (OPCs), Procyanidolic Oligomers (PCOs), Pycnogenol, Procyanidins

During the winter of 1534, the French explorer Jacques Cartier and his crew avoided scurvy by using Anneda, an Indian medicine probably containing ascorbic acid and procyanidins. Four centuries later, Szent-Gyorgyi was misguided in proposing citrin [lemon flavonoid compound] as a second antiscorbutic factor, for flavonoids are devoid of true vitamin-like behavior. On the other hand, pycnogenols, widely found in old empirical antiscorbutic remedies, seem more appropriate in this respect, since they are active per os, bioavailable, linked to various living tissues, and concerned with essential metabolic pathways. As histidine decarboxylase inhibitors, pycnogenols lower the histamine level in the aortic endothelium and are believed to protect it against the vascular permeability alterations occurring early in the atherogenic process.

In 1947, a student at the biological and medical faculty of the University of Bordeaux, France named Jack Masquelier was assigned the task of determining whether or not the red inner skin of peanuts was toxic. For his doctoral dissertation, Masquelier undertook a series of experiments to answer this question. Fairly early in his investigations, Masquelier was able to determine that in fact peanut skins were not toxic. In the course of his research, however, he came upon a colorless substance in peanut skin which called for further examination. By 1948, he had succeeded in isolating that substance, OPC, from peanut skin, and had identified that it possessed vasoprotective (protective of blood vessels) potential. After casting about among many possible sources, he found what he was searching for in the bark of Landes pine trees, a waste product of the lumber industry typically used as a mulch for gardens. This new source yielded sufficient quantifies of OPC to be useful for manufacturing purposes.

Subsequent studies by Masquelier eventually revealed another source of OPC besides the bark of the Landes pine. Grape seeds, which are the waste product of the winemaking industry and are used to make grape seed oil for cooking, were found to contain even greater amounts of the same beneficial antioxidant. Though grape seeds did not supplant pine bark completely, they came to be the primary source of OPC for extraction. Today in France, Flavan, from Landes pine bark, and Resivit from grape seeds, are both registered OFC medicines for vascular protection.

Mainstream medical science now regards oxidation as a primary cause of degeneration and ageing. Oxidation, the slow deterioration of matter as a result of chemical reactions involving oxygen, is a familiar phenomenon found throughout nature. The rusting of metals, the spoilage of foods, the rancidification of oils and the crumbling of rubber are examples of the common process of oxidation. In the body oxidative reactions of many kinds occur due to exposure to environmental toxins. In the air we breathe and the water we drink, we are exposed to as many as 60,000 chemical toxins of different kinds, including cigarette smoke, car exhaust vapors from cleaning fluids and solvents. Some chemical agents, such as the trihalomethanes, are toxic in quantities almost too small to be detected. In addition, we are subjected to a variety of chemical food additives such as preservatives, artificial colors, flavors emulsifiers, lubricants, bleaching agents, flavor enhancers and synthetic sweeteners. Many of these agents con tribute to oxidative reactions in the body.

Fortunately, there are nutritional agents that help to prevent against oxidative damage in the body and fight free radicals, and further help to repair damage that has already occurred. Antioxidant dietary factors include nutrients such as tocopherol (vitamin E) and ascorbate (vitamin C), as well as numerous carotenoids and a number of phenols and flavonoids found in common foods. Dietary fruits and vegetables are the primary sources of antioxidant dietary factors, though some antioxidants occur in grains, beans, meats, seafood's and dairy products. But while antioxidants are available in a healthy diet it is difficult to get enough of them to fend off the damage caused by free radicals resulting from air and water pollution and other environmental factors.

In terms of protective value, Dr Masquelier's OPC is a superior antioxidant. OPC is very rapidly absorbed, and is quickly distributed throughout the body as a free radical fighter, OPC comes to the aid of the body more quickly than other antioxidants, thereby reducing the potential for free radical damage and the ravages of aging. OPC also possesses more reactive sites for neutralising free radicals than other known antioxidants. Furthermore, OPC possesses nucleophilic as well as electrophilic reactive centers, permitting reactivity with both positively charged and negatively charged free radical species. what this means is that OPC can "scavenge" or "quench" (neutralize) a broad variety of types of free radicals.

Considerable recent research has explored therapeutic applications of oligomeric proanthocyanidin complexes (OPCs), naturally occurring plant metabolites widely available in fruits, vegetables, nuts, seeds, flowers, and bark. OPCs are primarily known for their antioxidant activity. However, these compounds have also been reported to demonstrate antibacterial, antiviral, anticarcinogenic, anti-inflammatory, anti-allergic, and vasodilatory actions. In addition, they have been found to inhibit lipid peroxidation, platelet aggregation, capillary permeability and fragility, and to affect enzyme systems including phospholipase A2, cyclooxygenase, and lipoxygenase. Based on these reported findings, OPCs may be a useful component in the treatment of a number of conditions including venous insufficiency, varicose veins, capillary fragility and diabetic retinopathy. Experimental studies suggest potential benefit in arteriosclerosis, heart disease and stroke.

Proanthocyanidins (Procyanidins) is an important therapeutic class of flavonoids extracted from grape seeds and maritime (Landes) pine. When individual molecules bind together, the result is collectively called procyanidolic oligomers (PCO). They have a broad range of pharmacologic activity through increasing vitamin C levels, decreasing capillary permeability and fragility, scavenging free radicals and inhibiting destruction of collagen. The latter occurs through ability to cross-link collagen fibers, preventing free-radical damage, inhibiting enzymatic cleavage of collagen, and preventing the synthesis and release of inflammatory mediators. PCO has approximately 50 times the anti-oxidant activity of vitamin C or vitamin E. These influences, along with other mechanisms, explain their benefit in venous and capillary disorders, including venous insufficiency, capillary fragility, diabetic retinopathy and macular degeneration. Studies show that PCO also lowers cholesterol levels and can shrink arterial choles terol deposits.



Grape seed proanthocyanidins are natural antioxidants which possess a broad spectrum of chemoprotective properties against free radicals and oxidative stress.

There is increasing evidence to indicate cardioprotective effects of red wine consumption. Such cardioprotective properties of wine have been attributed to certain polyphenolic constituents of grapes. The purpose of this investigation was to examine whether proanthocyanidins derived from grape seeds possess cardioprotective properties. The results of our study demonstrated that proanthocyanidin-fed animals were resistant to myocardial ischemia reperfusion injury as evidenced by improved recovery of post-ischemic contractile functions. The proanthocyanidin-fed group revealed reduced extent of myocardial infarction compared to the control group. Fluorimetric study demonstrated the antioxidant property of proanthocyanidin as judged by its ability to directly scavenge peroxyl radicals. Taken together, the results of this study showed that grape seed-proanthocyanidins possess a cardioprotective effect against ischemia reperfusion injury. Such cardioprotective property, at least in part, may be attributed to its ability to directly scavenge peroxyl and hydroxyl radicals and to reduce oxidative stress developed during ischemia and reperfusion.

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.

The pharmacological treatment of non-complicated chronic venous insufficiency is a current and well-debated topic. The introduction of new products with action on the venous system, improved knowledge on the physiopathology of venous insufficiency and the possibility provided by new analytical instruments, have given new impulse to the consolidation of the clinical value of phlebotonics in this indication.

Methods: In light of this, 24 patients with non-complicated chronic venous insufficiency were treated with oral administration of Oligomeric Proanthocyanidins (Pycnogenols-OPC) 100 mg/day. To evaluate the therapeutic efficacy of the treatment, an instrumental evaluation by optical probe capillaroscope was employed in addition to the traditional subjective clinical parameters: swelling, itching, heaviness and pain. The videocapillaroscope examination was performed at the lower third of the leg and the first toe. Edema in the capillaroscopic field, the number of observable capillaries and the capillary dilatation were the parameter chosen to evaluate the efficacy of treatment. All patients completed the study with no reports of adverse events during the period of observation.

Results: The results obtained show a positive clinical response (improved or absent symptoms) in over 80% of patients, with significant improvement of symptoms already evident after the first 10 days of treatment. The mechanism of action of the OPCs explains the rapid reduction of the swelling of the lower limbs and correlated with this are the other evaluable symptoms: heaviness and itching. Particularly striking results were observed for itching and pain which completely disappeared during the course of therapy in 80% and 53% of the patients respectively. Noteworthy is the good correlation between the clinical and instrumental data, with improvement in a total of 70% of patients.

Conclusions: The results obtained in the course of this clinical experience, with evident improvement already during the first weeks of treatment, the absence of adverse events added to the benefit of a once-a-day administration, justify the use of OPC in the treatment of non-complicated chronic venous insufficiency.

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