A REVIEW STUDY ON THE PHARMACOLOGICAL EFFECTS AND MECHANISM OF ACTION OF TANNINS

Mohammad Taleb Hossain*, Furhatun-Noor, Md. Asadujjaman, Md Abdul Matin, Fatema Tabassum, Md Harun Ar Rashid

ABSTRACT

Tannins are considered as valuable plant secondary metabolites that have a variety of health benefits. They possess potentially many pharmacological properties for which they are used in the versatile fields of treatment. Tannins are now considered as an indispensable component with external and internal effects in a variety of nutraceuticals, pharmaceuticals, and medicinal preparations. The external treatments of tannin are the treatment of skin inflammation and injuries and may prevent the inception of many chronic diseases. On the other hand, internally tannin compounds may produce effects on the gastrointestinal tract including antioxidant, free radical scavenging, antimicrobial, antiviral, anti-mutagenic, anti-carcinogen, anthelmintic, hepatoprotective effects, an inhibitor of the harmful pro-oxidative enzyme, and anti-nutrient effects. Moreover, different tannins have chemopreventive effects on the breast, oral cavity, prostate glands, stomach, and skin cancer. They also show astringent and antiseptic properties happened by binding, precipitating, or shrinking with different protein molecules. A number of tannins are available in the market as an unabsorbable and absorbable form having potent and extended pharmacological activities, higher safety profile, low toxicity, and cost-effectiveness. Although many of the above characteristics of tannins have been studied theoretically and practically but still there remains a scarcity of systematic knowledge regarding pharmacological effects and their mechanisms of action. So, the present review is designed to focus on the pharmacological effects and mechanism of action of tannin and its congeners along with slightly lighting on other significant properties.

Keywords: External treatment, internal treatment, chronic diseases, antioxidant, pro oxidative enzyme, chemo preventive effects, astringent, un-absorbable and absorbable form, etc.