Protective Effects of Polysaccharide fraction Extracted from Turmeric Leaveson Intestinal Epithelial Barrier integrity

Abstract

Intestinal epithelial barrier plays an important role to regulate para-cellular transport of water, nutrients and ions and to defend against toxic agents and pathogens as a first barrier. Therefore, maintaining barrier integrity is required to enhance entire gut health. Curcuma longa L. (Turmeric) is a well-known natural product with its outstanding antioxidant and anti-inflammatory properties. However, an aerial part of turmeric such as leaves has been wasted as a byproduct, even though it has a bioactive property. In order to prepare the turmeric leaf polysaccharide fraction (TPF), turmeric leaf water extract was dialyzed with 12~14 kD membrane (MW cut off 12,000) and precipitated with ethanol. A prebiotic activity score of TPF was measured with Lactobacillus plantarum and L.paracasi subsp. tolerans, and compared with that of control, fructooligosaccharides (FOS) and inulin. The score of TPF (1.003 ± 0.197, 0.620 ± 0.143) was higher than that of control (0.168 ± 0.026, 0.187 ± 0.120), and similar to that of FOS (1.138 ± 0.281, 0.938 ± 0.065) and inulin (0.658 ± 0.181, 0.628 ± 0.160). To investigate the effects of TPF on intestinal barrier integrity, the effect of TPF on tight junction was measured in TNF-α induced Caco-2 cells. The result shows that trans-epithelial electrical resistance of TPF treated group was maintained relatively constant until 72 hr at 70.38%, comparingwith that of control group as 28.07%. In addition, TPF significantly increased the expression of tight junction-related proteins such as ZO-1 and Occludin. Taken together, our study demonstrates the prebiotic activity and protective effect of a polysaccharidefraction of turmeric leaf on intestinal epithelial barrier functions.