Green Tea Research Today is a free monthly online journal that collates and summarizes the latest research about Green Tea, including details on benefits, antioxidants, weight loss, diet, side effects.

Immunostimulating activity of a crude polysaccharide derived from green tea (Camellia sinensis) extract.

Monobe M, Ema K, Kato F, Maeda-Yamamoto M

National Institute of Vegetable and Tea Science, NARO, Shizuoka, Japan. monobe@affrc.go.jp

Green tea extract is well-known to reduce the risk of a variety of diseases. Here, we investigated the immunostimulating activity of tea polysaccharide (TPS), one of the main components in green tea extract. The water extracts from mature or immature tea leaves were precipitated by using ethanol at room temperature. The sediment was washed with ethanol and acetone alternately and then dried. We used the phagocytic activity of macrophage-like cells as an indicator of immune function activation. Chemical components were analyzed by HPLC. The immunostimulating activity of TPS from immature leaves extract was higher than that of TPS from mature leaves, and its activities were dependent on the content of strictinin in the leaf extract. Futhermore, a mixture of catechin and TPS that removed polyphenols did not increase the immunostimulating activity. These results suggest that the catechin-polysaccharide complex is a very important molecule in the immunomodulating activity of tea extracts.

Published 21 February 2008 in J Agric Food Chem, 56(4): 1423-7.
Full-text of this article is available online (may require subscription).

© 2004-2008 Green Tea Research Today. All Rights Reserved.