Investigating the Preventive Effect of Lactobacillus plantarum KSFY02 Isolated from Naturally Fermented Yogurt from Xinjiang, China, on D-galactose–induced Oxidative Aging in Mice

Yogurt from Xinjiang, China, is a traditional and naturally fermented food, and abundant
microorganisms are produced during its fermentation process. In this study, we carried out in vivo
animal experiments to explore the effect of a newly isolated lactic acid bacterial strain, Lactobacillus
plantarum KSFY02 (LP-KSFY02), on oxidative aging. We used D-galactose to induce oxidative aging
in mice and analyzed the serum and tissues of those mice using molecular biology detection methods.
The results showed that LP-KSFY02 could inhibit the decreases in the thymic, cerebral, cardiac, liver,
spleen, and kidney indices of mice caused by oxidative aging. The LP-KSFY02 strain increased
activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and glutathione (GSH) and
reduced levels of nitric oxide (NO) and malondialdehyde in the serum, liver, and spleen of the
oxidative aging mice. Pathological observation demonstrated that LP-KSFY02 alleviated damage to
the liver and spleen of oxidative aging mice. Quantitative PCR showed that LP-KSFY02 effectively
upregulated mRNA expression of neuronal nitric oxide synthase (Nos1), endothelial nitric oxide
synthase (Nos3), copper/zinc superoxide dismutase (Sod1), manganese superoxide dismutase
(Sod2), catalase (Cat), heme oxygenase-1 (Hmox1), nuclear factor erythroid 2 related factor 2
(Nfe2l2), γ-glutamylcysteine synthetase (Gclm), and quinone oxidoreductase 1 (Nqo1) in mouse liver
and spleen and downregulated expression of inducible nitric oxide synthase (Nos2). Western blot
analysis revealed that LP-KSFY02 effectively upregulated protein expression of SOD1, SOD2, CAT,
GSH1, and GSH2 in mouse liver and spleen tissues. Therefore, LP-KSFY02 can effectively prevent
D-galactose–induced oxidative aging in mice. Its efficacy was superior to that of Lactobacillus
delbrueckii ssp. bulgaricus (LDSB) and vitamin C, which are commonly used in the medical field as
antioxidants. Thus, LP-KSFY02 is a high-quality strain with probiotic potential. This in vivo animal
experiment preliminarily confirmed that LP-KSFY02 was a high-quality LAB strain that could prevent
oxidative aging, laying the theoretical basis for further in-depth development. However, further
development and utilization of LP-KSFY02 require human experiments, which are the focus of future
research. The specific mechanism underlying the action of LP-KSFY02 in the human body needs to
be explored further.