The effect of Malus doumeri leaf flavonoids on oxidative stress injury induced by hydrogen peroxide (H ₂ O ₂) in human embryonic kidney 293 T cells

Background: In this study, Malus doumeri leaf flavonoids (MDLF) were used as the research object to observe their in vitro antioxidant stress ability. Hydrogen peroxide (H₂O₂) was used to induce oxidative stress in 293 T cells.

Methods: MTT, flow cytometry, and qPCR were used to verify the effect of MDLF.

Results: In vitro cell experiments showed that at a concentration of 0-160 μg/mL, MDLF did not affect the normal proliferation of human embryonic kidney 293 T cells (HEK 293 T cells), and MDLF had no cytotoxic effect in this concentration range. It was found that MDLF could maintain the survival of HEK 293 T cells (82.6%) at a high concentration (160 μg/mL). Morphological observation also found that MDLF can inhibit the cell structure imperfection caused by H₂O₂. It was also observed that MDLF could significantly increase the levels of catalase (CAT), superoxide dismutase (SOD), glutathione (GSH), and glutathione peroxidase (GSH-Px) and reduce the level of malondialdehyde (MDA). The results of quantitative polymerase chain reaction (qPCR) showed that MDLF could significantly up-regulate the mRNA expression levels of CAT, SOD, GSH, GSH-Px, B-cell lymphoma-2 (Bcl-2) and downregulate the expression levels of B-cell lymphoma-2 associated x protein (Bax), tumor necrosis factor-alpha (TNF-α), and nuclear factor kappa-B (NF-κB) in oxidative stress-injured cells. The HPLC analysis showed that MDLF contained hyperin, isoquercetin, quercitrin, hesperidin, myricetin, baicalin and quercetin.

Conclusion: From the experimental results, it was observed that MDLF has a strong anti-oxidation ability in vitro, and it can interfere with the oxidative stress damage caused by H₂O₂ in 293 T cells. Therefore, MDLF is a type of natural substance with good anti-oxidant effect, and it has the potential to interfere with many diseases.

Keywords: Flavonoid; Human embryonic kidney 293 T cells; Malus doumeri; Oxidative stress; mRNA.