Kissper: a peptide of kiwi fruit with anti-inflammatory and anti-oxidant properties for the colonic mucosa.

Introduction Kiwi fruit is a food with many different effects on human health. Kissper is a 39-residue peptide isolated in good yield from the edible part of kiwi fruit 1. The high amount of kissper found in ripe kiwi fruit and its resistance to proteolysis suggests that it may have an impact on gastrointestinal physiology. Method The aim of this study is to analyze the potential antioxidant and anti-inflammatory proprieties of kissper using two in vitro models. Intestinal epithelial Caco-2 cells and colonic mucosa from 14 patients with Crohn's disease (CD) were challenged with or without Lipopolysaccharide from Escherichia Coli (EC-LPS, 1mg/ml) in presence or absence of kissper pre-treatment (10mg/ml) for 4 and 24 h. The effects of kissper on oxidative stress, intracellular calcium levels, mitochondrial permeability and mucosal inflammation were investigated by western blot analysis and confocal microscopy. For simultaneous measurement of [Ca2]i and mitochondrial permeability, rhodamine (Rh) 123 was added into the cultures during the last 15 min of the Fura-2 loading period. For measurement of rates of ROS generation, cells were incubated with 20 mM 2,7 dichlorodihydrofluorescein diacetate ( DCF). The inflammatory response were monitored through TG2 (calcium related protein), p65-NF-KB, COX2, and ICAM 1 expression in Caco2 cells and CD colonic mucosa Result We show that kissper controls EC-LPS mediated reactive oxygen species (ROS) increase, expressed as percent of DCF positive cells. Kissper also decreases EC-LPS induced [Ca2+] levels and simultaneously it controls mitochondrial depolarization and cytochrome c release. Our results show that kissper peptide reduces the TG2 expression and p65-NF-kB nuclear translocation. Moreover Kissper decreases the COX2 and ICAM 1 mucosal expression. Conclusion These results suggest that kissper is able to control oxidative stress modulating intracellular ROS over-production and calcium increase, and it prevents mitochondrial damage. Moreover kissper shows an anti-inflammatory effect reducing inflammatory markers expression consequent to EC-LPS treatment. Our data suggest that kissper is a constituent of a functional food with anti-inflammatory property and its effects can be further studied in clinical trials in some inflammatory diseases.