Antioxidant capacity of soymilk yogurt and exopolysaccharides produced by lactic acid bacteria

Abstract

Reactive oxygen species (ROS), such as hydroxyl and superoxide anion radicals, are highly reactive molecules derived from the metabolism of oxygen. ROS play positive roles in cell physiology, but they may also damage cell membranes and DNA, inducing oxidation that causes membrane lipid peroxidation and decreases membrane fluidity. Soymilk yogurt, which is soymilk fermented using lactic acid bacteria (LAB), is an excellent food item with numerous functional substances with antioxidant effects. In this study, the antioxidative activities of soymilk yogurt were investigated. Sixteen of the 26 tested LAB strains solidified soymilk. In antioxidant capacity tests for bacterial cells, Leuconostoc mesenteroides MYU 60 and Pediococcus pentosaceus MYU 759 showed the highest values in the oxygen radical antioxidant capacity (ORAC) and hydroxyl radical antioxidant capacity (HORAC) tests, respectively. The supernatant of soymilk yogurt made with Lactobacillus gasseri MYU 1 showed the highest ORAC and HORAC values. L. mesenteroides MYU 60, Lactobacillus plantarum MYU 74, Lactobacillus reuteri MYU 220, and P. pentosaceus MYU 759 showed significantly high N-acetylcysteine equivalent values compared with the control in a total ROS reducing assay (p<0.05). These strains were selected, and a comet assay was performed, which exhibited decreased values in all selected strains compared with the control, indicating DNA protection. An acidic exopolysaccharide produced by P. pentosaceus MYU 759 showed high antioxidant capacity. The antioxidant substances produced by LAB fermentation may be exopolysaccharides, antioxidant peptides, and isoflavone aglycones. Soymilk yogurt can be used as a functional food useful for various diseases related to oxidation.

Oxidative stress tolerance and antioxidant capacity of lactic acid bacteria as probiotic: a systematic review

“…191 The prevention of oxidative stressinduced DNA damage by Lactobacillus has been evaluated in different mammalian cells (Caco-2 cells, HCT 116 cells, HT-29 cells, and lymphocytes) using a single-cell gel electrophoresis assay (Comet assay), which was developed based on DNA migration. [192][193][194][195] The DNA-protective capacity of probiotic LAB can also be detected by molecular biology techniques to estimate oxidative stress protection. 196 Nowak and colleagues used the DNA repair enzymes endonuclease III and formamidopyrimidine-DNA glycosylase to evaluate the antioxidant capacity of Lactobacillus toward H 2 O 2 and several human carcinogens based on the recognition of oxidized DNA bases by DNA repair enzymes.…”

Pediococcus pentosaceus, a future additive or probiotic candidate

“…Some strains of P. pentosaceus are adept at scavenging hydrogen peroxide, such as P. pentosaceus Be1 (collected from fermented food) [ 38 ] and P. pentosaceus S-SU6 (collected from the gut of blue mackerel) [ 39 ]. P. pentosaceus MYU 759 was found to have hydroxyl radical antioxidant capacity (HORAC) due to the secretion of acidic EPS, which is highly beneficial in its isolation from soymilk yogurt as an antioxidant product [ 40 ]. Additionally, P. pentosaceus AR243, an isolated LAB from Chinese fermented foods, had significant scavenging abilities for hydroxyl radicals and DPPH free radicals, resulting in further inhibition of lipid peroxidation [ 41 ].…”

Oxidative Damage in Sporadic Colorectal Cancer: Molecular Mapping of Base Excision Repair Glycosylases in Colorectal Cancer Patients

“…For example, fruit consumption has been suggested to increase DNA repair capacity and decrease DNA damage, likely due to antioxidants and bioactive compounds in fruits [13]. Soymilk in a form of yogurt also exerts substantial antioxidant potential [116]. Experimental and observational evidence indicate that sub-optimal dietary intakes of selenium may contribute to increased risk for several tumors including CRC, through oxidative and inflammatory response selenoproteins which require selenium for their biosynthesis [14,117].…”