Isolation of lactic acid bacteria capable of reducing environmental alkyl and fatty acid hydroperoxides, and the effect of their oral administration on oxidative-stressed nematodes and rats.

Akio Watanabe,Masataka Uchino,Akira Abe,Sanae Okada,Kaeko Murota,Naoto Tanaka,Junji Terao,Naoaki Ishii,Youichi Niimura,Tomonori Suzuki,Shinya Kimata,Takuro Yamaguchi

doi:10.1371/journal.pone.0215113

Abstract

Reinforcement of the hydroperoxide-eliminating activity in the small and large intestines should prevent associated diseases. We previously isolated a lactic acid bacterium, Pediococcus pentosaceus Be1 that facilitates a 2-electron reduction of hydrogen peroxide to water. In this study, we successfully isolated an alternative lactic acid bacterium, Lactobacillus plantarum P1-2, that can efficiently reduce environmental alkyl hydroperoxides and fatty acid hydroperoxides to their corresponding hydroxyl derivatives through a 2-electron reduction. Each strain exhibited a wide concentration range with regard to the environmental reducing activity for each hydroperoxide. Given this, the two lactic acid bacteria were orally administered to an oxygen-sensitive short-lived nematode mutant, and this resulted in a significant expansion of its lifespan. This observation suggests that P. pentosaceus Be1 and L. plantarum P1-2 inhibit internal oxidative stress. To determine the specific organs involved in this response, we performed a similar experiment in rats, involving induced lipid peroxidation by iron-overloading. We observed that only L. plantarum P1-2 inhibited colonic mucosa lipid peroxidation in rats with induced oxidative stress.

Highlights

The small and large intestines are key areas for the employment of defense mechanisms against various types of diseases and stresses are employed
We investigated the effects resulting from the administration of these two isolated lactic acid bacteria strains capable of reducing environmental hydrogen peroxide (P. pentosaceus Be1 strain, S1 Fig) and fatty acid hydroperoxide (L. plantarum P1-2 strain, Fig 1B)
Distinct inhibitory effects were observed from both strains, and on the basis of these observations, we investigated the effects of the L. plantarum P1-2 and P. pentosaceus Be1 strains on major organs in mammals, the small and large intestines in a rat model of oxidative stress

Summary

Introduction

The small and large intestines are key areas for the employment of defense mechanisms against various types of diseases and stresses are employed. The feeding study of lactic acid bacteria to iron overload mice showed that S. thermophilus YIT2001 strain provides the highest inhibitory activity against lipid peroxidation in liposomes among the tested strains and decreases the level of lipid hydroperoxide in the colonic mucosa [7, 8]. These suggest that the strain acts as scavenger of reactive oxygen or free radical and increases the anti-oxidative capacity of intestinal contents [8]. Distinct inhibitory effects were observed from both strains, and on the basis of these observations, we investigated the effects of the L. plantarum P1-2 and P. pentosaceus Be1 strains on major organs in mammals, the small and large intestines in a rat model of oxidative stress

Materials and methods

Results

Discussion