Green Tea and Ginkgo biloba

Japanese green tea (Camellia sinensis) and Ginkgo biloba contains oligomeric proanthocyanidins (OPC), flavanols that, along with flavonoids, belong in a subcategory of antioxidant polyphenols with widespread therapeutic applications. Catechins are another chemical entity involved in this complex, one aggregation of which is the active form of vitamin C. Without the complete complex of chemicals, none of its constituent parts is effective. But when activated, it has a natural affinity for tissues rich in glycosaminoglycans, binds to proteins that form the vascular walls, and provides the body with a protective mechanism that supports the healthy functioning of capillaries while protecting critical intercellular structures from free radical attack. (1)

The OPCs in green tea and Ginkgo biloba are ubiquitous in nature although they are found in the parts of plants that are normally removed in preparation. It is particularly abundant in the bark of trees (especially pine bark), in the leaves and blossoms of trees and shrubs, the skin of nuts and seeds (particularly grape seeds), and the peels and skin of fruit. Hence it is present in red wine but not white wine. (2-7) One particular OPC is considered by some to be a vitamin (vitamin P--the complete form of vitamin C), since the human body does not produce it, and plants are the sole source of it. (8) Taken together, there is ample evidence for the need to supplement the diet with OPCs.

Chinese green tea polyphenols in a concentration of 0.2% used as a rinse and dentifrice completely inhibited the growth of oral Streptococcus mutans with a significant improvement in both Plaque Index and Gingival Index. (9)

Among the catechins in green tea are catechin, epicatechin, gallocatechin, epigallocatechin, epicatechin gallate (ECg), and epigallocatechin gallate (EGCg). ECg and EGCg completely inhibited collagenase activity in the gingival crevicular fluid from highly progressive adult periodontitis. (10) One of these catechins demonstrated bactericidal activity against oral anaerobic rods, a decrease in gingival pocket depth, and reduced peptidase activity when combined with mechanical scaling of dental plaque in a series of Japanese patients. (11) Antibacterial activity is a property of many types of green (and black) tea catechins and is active against a wide variety of bacteria. (12,13) Of the catechins tested, theaflavin and its mono- and digallates, catechin, epicatechin, epicatechin and their enantiomers, galloyl esters of epicatechin, epigallocatechin and gallocatechin all showed inhibition of the glucosyltransferase activity of S. mutans. Rats in one of these studies had significantly lower caries scores when their drinking water contained crude tea polyphenolic compounds. (14)

EGCg is also one of many hydrolyzable tannins that have demonstrated cytotoxic activity against human oral squamous cell carcinoma and salivary gland tumor cell lines. The macrocyclic ellagitannin oligomers (dimeric)--such as oenothein B, woodfordin C and woodfordin D--had even greater activity than the monomerics EGCg and gallic acid. (15)

After rinsing with an aqueous solution of green tea extract (5.0 mg/ml), salivary concentrations of catechins remain elevated for a full hour. (16)

Wine

Red wine contains a number of chemicals that are health promoting. The polyphenol bioflavonoids resveratrol and quercitin, also found in green vegetables and citrus fruits, have demonstrated anti-inflammatory, antiviral and antitumor properties. In a laboratory culture of human oral squamous carcinoma cells one or both of these chemicals, in concentrations equivalent to that present in red wines, were effective in inhibiting the growth and proliferation of these cells. (17)

Folate

Although the effect of folic acid supplementation (taken internally) on gingival health is not striking, (18,19) a folate mouthwash significantly improved gingivitis in a double-blind study of 60 patients after four weeks of twice daily rinsing (20) and in another month-long study of women in their third trimester of pregnancy, where folate mouthwash produced highly significant improvement in the gingival index, but oral folate performed no better than placebo. (21) Plaque index did not improve in any of the study groups.