Abstract:The effects of Auricularia auricula fermented by a mixture of Lactobacillus casei and Lactobacillus plantarum on high glucose-induced oxidative damage in H9c2 cardiomyocytes were investigated. A cell model of high glucose-induced oxidative damage in H9c2 cardiomyocytes was established to simulate the pathological state of cardiomyocytes in a high glucose environment. Subsequently， the thiazolyl blue [3-（4，5-dimethylthiazol-2-yl）-2，5-diphenyltetrazolium bromide， MTT] method was used to determine the effective concentration of fermented A. auricula extract（with the main component being melanin）. Moreover， the effects of the extract on cell viability， oxidative stress indicators [superoxide dismutase （SOD）， glutathione peroxidase （GSH-Px），malondialdehyde （MDA）， and glutathione （GSH）]， myocardial injury indicators [lactate dehydrogenase （LDH），creatine kinase （CK）， and troponin Ⅰ]， and levels of inflammatory cytokines [interleukin-1β （IL-1β）， interleukin-6 （IL-6）， and tumor necrosis factor-α（TNF-α）] were evaluated. The results showed that compared with the high glucose group， the application of probiotic-fermented A. auricula extract to H9c2 cardiomyocytes resulted in increased cell viability and activities of SOD and GSH-Px， decreased content of MDA along with increased content of GSH， and reduced levels of LDH， CK， and troponin Ⅰ and inflammatory cytokines. In conclusion， the probiotic-fermented A. auricula extract can improve the viability and reduce the oxidative damage of H9c2 cardiomyocytes exposed to high glucose.