Composition and Biological Activities of Hydrolyzable Tannins of Fruits of Phyllanthus emblica

Fruits of emblic leafflower have been used as food and traditional medicine in Asia. A wide range of biological activities have been shown in modern research suggesting potential of the fruits as healthy food and raw material for bioactive ingredients of food. Hydrolyzable tannins are among the major bioactive components of the fruits. Mucic acid gallate, mucic acid lactone gallate, monogalloylglucose, gallic acid, digalloylglucose, putranjivain A, galloyl-HHDP-glucose, elaeocarpusin, and chebulagic acid are the most abundant hydrolyzable tannins. The compositional profiles of tannins in the fruits vary depending on the cultivars as well as ripening stages. Fruits and tannin-rich extracts of fruits have shown antidiabetic, antimicrobial, anti-inflammatory, and immune-regulating activities in vitro and in animal studies. The fruits and fruit extracts have manifested protective effects on organs/tissues from damages induced by chemicals, stresses, and aging in animal models. The fruits and fruit extracts have potential in inhibiting the growth of cancer cells and reducing DNA damage induced by chemicals and radiation. Antioxidative activities are likely among the mechanisms of the biological activities and physiological effects. Human intervention/clinical studies are needed to investigate the bioavailability and metabolism of the tannins and to substantiate the health benefits in humans. Emblic leafflower may be a potential raw material for natural food preservatives.