Oligomeric proanthocyanidins – Food sources and health benefits

Proanthocyanidins are condensed tannins with various pharmacological properties. The compound forms a unique class of high-molecular weight oligomeric and polymeric secondary metabolites. Proanthocyanidins are present in flowers, nuts, fruits, bark, and seeds of various plants, as a defense against biotic and abiotic stressors. Their astringency protects the plants from pathogens and predators.

Proanthocyanidin degree of polymerization can range between 3 and 11. Usually, proanthocyanidins with a lower degree of polymerization (two to four monomers) are named oligomeric proanthocyanidins, whereas those with more than five monomers are called polymeric proanthocyanidins.

Oligomeric proanthocyanidins are one of the commonest bioflavonoids with a special molecular structure, formed by oligomerization or polymerization of subunits catechin, epicatechin, and their gallic acid esters primarily known for their excellent antioxidant activity.

Cocoa beans are a well-known source of antioxidant polyphenols. Especially individual oligomeric proanthocyanidins demonstrated a significant contribution to the total antioxidant activity of cocoa compared to monomeric compounds.

Chocolate contains flavonoids not found in tea, with high concentrations of oligomeric procyanidins. Grape seed and pine bark extracts are also rich with oligomeric proanthocyanidins. Oligomeric proanthocyanidins are also abundant in blackjack oak, horse chestnut, witch hazel and hawthorn, as well as in apples, berries, barley (and beer made from it), bean hulls, chocolate, rhubarb, rose hips and sorghum.

Proanthocyanidins are shown to be highly effective inhibitors of radical chain reactions. In cocoa, they consist of oligomers or polymers of (+)- catechin and/or (-)-epicatechin units. The size of proanthocyanidins is specified by their degree of polymerization (DP).

Oligomeric proanthocyanidins are primarily known for their antioxidant activity. It is widely reported that Oligomeric proanthocyanidin could prevent oxidative damage in tissues by reducing lipid oxidation and/or inhibit production of free radicals.

Oligomeric proanthocyanidin complexes also have 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.
Oligomeric proanthocyanidins – Food sources and health benefits

What are the functions of bioflavonoids?

Bioflavonoids are a ubiquitous class of compounds found in plants.  They are essential for the absorption of vitamin C, and the two should be taken together.

Bioflavonoids provide synergy in the utilization of vitamin C, therefore they contribute to many vitamin C applications for example, the treatment of colds and flus.

There are many different bioflavonoids, including citrin, eriodictyol, flavones, hesperetin, hesperidin, quercetin, quercetrin, and rutin. The human body cannot produce bioflavonoids, so they must be supplied in the diet.

Most bioflavonoids exhibited antioxidant activity of one form or another. One mechanism is binding of free iron or other metals that catalyze free radicals.

Antioxidant activity has been potent enough to protect collagen and hyaluronan from breakdown by generated free radicals. Bioflavonoids are used extensively in the treatment of athletic injuries because they relieve pain, bumps and bruises.

They also reduce pain located in the legs or across the back, and lessen symptoms associated with the prolonged bleeding and low serum calcium.

Bioflavonoids act synergistically with vitamin C to protect and to preserve the structure of capillaries.

Bioflavonoids may help lower the risk of heart disease. In 1996, a Finnish study found that women who ate the most flavonoids had a 46 percent lower risk for heart disease than those who ate the least.

One of major function of bioflavonoids is dilation of blood vessels, which results in improved blood flow to and from tissues all over the body, especially the brain.

Increasing oxygen content of the blood enhances the memory and improves cellular transmission.

In addition, bioflavonoids have an antibacterial effect and promote circulation, improved capillary strength, stimulate bile production, lower cholesterol levels, and treat and prevent cataracts.

Bioflavonoids keep platelets, from clumping together and forming clots that can block the arteries.

They also keep harmful low-density-lipoprotein (LDL) cholesterol from oxidizing and sticking to artery walls.

When taken with vitamin C, bioflavonoids also reduce the symptoms of oral herpes.

Some bioflavonoids can stop cancer before it starts.
What are the functions of bioflavonoids?