OBJECTIVE: To probe into the mechanism of creatine phosphate sodium combined with fructose diphosphate in alleviating pediatric viral myocarditis. METHODS: Totally 120 children from 2 to 6 years old with viral myocarditis admitted into this hospital from Jan. 2018 to Jan. 2020 were divided into the creatine phosphate sodium group

fructose diphosphate group and creatine phosphate sodium+fructose diphosphate group according to different dosage regimens

with 40 cases in each group. The markers of myocardial injury[cardiac troponin T（cTnT） and creatine kinase isoenzyme（CK-MB）]

inflammatory factors[tumor necrosis factor-α（TNF-α） and interleukin-6（IL-6）]

and miRNA expression of three groups were detected before and after treatment. Human cardiac myocytes（HCM） were disposed with coxsackie B

3

Nancy strain（CVB

3

） virus to construct model cells（CVB

3

-HCM）

CCK-8 was used to detect cellular viability

reverse transcription quantitative polymerase chain reaction（RT-qPCR） and Western Blotting were performed to determine the gene expressions

enzyme linked immunosorbent assay（ELISA） was used to detect cytokines secretion

immunofluorescent staining was used to determine protein expression and cellular localization

and dual-luciferase reporter gene assay was performed to validate gene targeting relationship. RESULTS: Compared with before treatment

the cTnT

CK-MB

TNF-α and IL-6 levels of children in the creatine phosphate sodium+fructose diphosphate group decreased significantly after treatment

while the miR-133 b levels increased significantly. Cell level experiment revealed that transfection of miR-133 b mimics into CVB

3

-HCM can significantly decrease ELAVL1 protein levels. In terms of myocardial injury markers

inflammatory factors and pyroptosis

the levels of the above indicators were significantly lower in CVB

3

-HCM cells treated with creatine phosphate sodium+fructose diphosphate

while the levels of the above indicators were even lower in CVB

3

-HCM cells transfected with miR-133 b inhibitor and CVB

3

-HCM cells transfected with pcDNA-ELAVL1 treated with creatine phosphate sodium+fructose diphosphate

which were lower than those of CVB

3

-HCM cells treated with creatine phosphate sodium+fructose diphosphate. CONCLUSIONS: Creatine phosphate sodium combined with fructose diphosphate can effectively alleviate pediatric viral myocarditis

and its mechanism of action may be through the regulation of miR-133 b/ELAVL1 molecular axis to inhibit virus-induced cardiomyocyte injury

inflammatory response and scorching.