Effect of α-linolenic acid-rich diacylglycerol oil on protein kinase C activation in the rat digestive tract and lingual mucosa

Abstract

1,2-Diacylglycerol with short chain fatty acids is an endogenous activator of protein kinase C (PKC), which involved in multiple cellular processes implicated in cancer. The aim of the present study was to assess the effects of dietary α-linolenic acid-rich diacylglycerol (ALA-DAG) oil on PKC activation in the rat digestive tract and lingual mucosa in comparison with the effects of α-linolenic acid-rich triacylglycerol (ALA-TAG) oil, and common dietary oil. Membranous PKC activity in the lingual mucosa of male Wistar rats was significantly activated by treatment of the tongue with 1,2-tetradecarnoylphorbol-13-acetate (100 μM) twice in 1 day. In contrast, animals consuming a diet containing either ALA-DAG oil (7.5% or 30%), ALA-TAG oil (7.5% or 30%), or rapeseed oil (30%) for 4 weeks exhibited no significant differences in the cytosolic and membrane PKC activity in the lingual, esophageal, gastric, small intestinal, and colonic mucosa. Dose-related increases in PKC activity were not observed in the ALA-DAG oil-fed groups. Thus, the effects of dietary ALA-DAG oil on PKC activation in the digestive tract and lingual mucosa was similar to those of the ALA-TAG and rapeseed oils. These findings suggest that replacement of common dietary oil with ALA-DAG oil would not increase the risk of carcinogenesis.