异甘草素抗鳜蛙虹彩病毒的效应分析OA

Mandarinfish ranavirus(MRV)is a double-stranded DNA virus,belonging to the family Iridoviridae and the genus Ranavirus.It causes severe economic losses in mandarin fish and largemouth bass,with a mortality rate as high as 100%.Due to the lack of effective treatments,there is an urgent need for developing novel antiviral strategies.Consequently,the herbal components have garnered increasing research interest.This study focuses on the flavonoid isoliquiritigenin(ISL),which is known for its antioxidant,anti-inflammatory,and broad-spectrum antiviral activities.To assess the efficacy and underlying mechanisms of ISL against MRV,we conducted both in vitro and in vivo experiments utilizing a combination of qPCR,immunofluorescence,flow cytometry,and histopathological analysis.Then we evaluated the effects of ISL on viral proliferation,apoptosis,reactive oxygen species(ROS)levels,tissue damage and host survival rates.In vitro,the maximum safe concentration of ISL was determined to be 12.5 μmol/L in mandarinfish brain(SCB3)cells,while the CC50 and EC50 were found to be 24.49 μmol/L and 3.08 μmol/L,respectively.Therapeutic administration achieved optimal efficacy,inhibiting MRV replication by 99.99%and reducing virus-induced apoptosis from 28%to 12%.In vivo challenge experiments demonstrated a dose-dependent protection in largemouth bass,where oral administration of 40 mg/kg ISL increased the survival rate from 30%to 80%,and significantly reduced viral loads in the spleen and kidney.Mechanistically,ISL down-regulated the expression of apoptosis-related genes(bad and caspase-3)and pro-inflammatory factors(IL-6 and TNF-α),concurrently reducing splenic ROS levels,diminishing melanomacrophage centre formation,and alleviating tissue damage.This study demonstrates that the antiviral effect of ISL against MRV is primarily mediated through its anti-inflammatory and anti-apoptotic actions,as evidenced by both in vitro and in vivo models.These findings confirm the potential of ISL as a therapeutic agent against MRV and provide a foundation for developing novel antiviral strategies.