Evaluation of Lactobacillus rhamnosus Antioxidant Effects on Survival of Human Mesenchymal Stem Cells

ntroduction: Multipotent mesenchymal stromal cells (MSCs) have novel therapeutic potential to treat a wide variety of diseases but they have poor survival in oxidative stress conditions. Probiotics are one of the most effective antioxidant substances in the improvement of cell resistance to oxidative environments. The main purpose of this study was to evaluate the protective effects of Lactobacillus rhamnosus on MSCs viability in stressful conditions. Materials and Methods: The MSCs were exposed to live or killed L. rhamnosus in oxidative-stress conditions to evaluate the expression of antioxidant genes; heme oxygenase (HO1), metallothionein 1 (MT1), superoxide dismutase 1 (SOD1) and 2 (SOD2). Also, the antioxidant activity was assessed. Results: In harmful conditions (H2O2) and serum deprivation, killed L. rhamnosus not only increased the expression of HO-1, MT1, SOD1 and SOD2 genes of the MSCs (P ≤ 0.001) but also enhanced the antioxidant activity of MSCs (P ≤ 0.001), leading to a better survival under oxidative stress conditions. The synergism effect of killed L. rhamnosus increased the antioxidant potential of MSCs to resist oxidative stress conditions. Conclusions: The killed L. rhamnosus has protective effects on the survival of MSCs in stress conditions.