Neuroprotective effect of luteolin-7-O-β-D-glucuronide in a rat model offocal cerebral ischemia

OBJECTIVE To investigate the neuroprotective effect and possible mechanisms of lute.olin-7-O-β-D-glucuronide(LGU) against focalcerebral ischemic injury.METHODS The focal cerebral ischemic injury model was established by middle cerebral artery occlusion(MCAO).Male Sprague Dawley rats were randomly divided into sham group,model group(MCAO),LGU group(0.24,0.72 and2.16 mg·kg^(-1)) and positive control group(Edaravone at 5 mg·kg^(-1)).LGU was injected intravenously 30 min after MCAO.Neurological severity score,infarct volume and brain water content were detected 24 h after MCAO and the levels of Na+-K+ ATPase,Ca2 + ATPase,TNF-α and IL-1β were detected to explore the possible mechanisms.For the therapeutic time window test,LGU(0.72 mg·kg^(-1)) was injected intrave.nously 0.5,2,4,6,8,10 and 12 h respectively after MCAO.To evaluate motion behavior,LGU were injected intravenously 30 min after MCAO and once per day during detection period.The changes of motor coordination were detected by rotating rod method and grip strength analysis,and the changes of gaits were detected using DigiGait Imaging System.RESULTS LGU improved the neurological severity score,infarct volume ratio and brain water content.The therapeutic time window of LGU for cerebral infarction and brain edema was at least 6 h and for neurological dysfunction was 12 h.LGU also prolonged the latency on rotarod,increased the forelimb tension and improved 8 gait parameters,including stance duration,stride length,stance width,paw area,paw area variability,gait symmetry,ataxia coefficient and tau propulsion.Furthermore,LGU increased Na^+-K^+-ATPase and Ca^(2+)-ATPase levels in the cortex and hippocampus in the ischemic side,reduced the levels of TNF-α and IL-1β in the serum.CONCLUSION LGU has a significant neuroprotective effect against cerebral ischemic injury via improving energy metabolism and reducing inflammation.

Protective effect of luteolin-7-O-β-D-glucuronide against oxygenglucose deprivation-induced H9C2 cardiomyocytes injury

OBJECTIVE To investigate the protective effect and mechanisms of luteolin-7-O-β-dglucuronide(LGU) on oxygen glucose deprivation(OGD)-induced H9C2 cardiomyocytes injury.METH.ODS The protective effect of LGU on OGD-induced H9C2 cardiomyocytes death were investigated by MTT assay.The microfilament change of H9C2 cardiomyocytes was detected by phalloidin staining and the lactate dehydrogenase(LDH) leakage rate was also detected by LDH kit.In order to explore the possible mechanisms of LGU,ATP content,intracellular Ca^(2+) fluorescent intensity and concentra.tion,mitochondrial membrane potential(MMP)and the expressions of apoptosis-related proteins were detected by ATP kit,CLSM(Fluo-3/AM probe),Ca^(2+) kit,CLSM(JC-1 probe) and western blotting meth.od,respectively.RESULTS The inhibition of H9C2 cardiomyocyte survival rate inducedby OGD was improvedby pretreated with LGU in a concentrationdependent manner.The microfilaments injury as well as the increase of LDH leakage rate were also improvedby pretreated with LGU.The ATP content was significantly decreased,intracellular Ca^(2+) fluorescent intensity and concentration were significantly increased and the MMP was significantly decreased 4 hafter OGD.LGU significantly reversed the de.crease of intracellular ATP content,the increase of Ca^(2+) fluorescent intensity and concentration and the decrease of MMP.The release of cytochrome C,the expressionsof caspase-9 and caspase-3 in H9C2 cardiomyocytes were increased 16 h after OGD.LGUsignificantly inhibited the changes of these apop.tosis-related proteins.CONCLUSION LGU has a significant protective effect against OGD-induced H9C2 cardiomyocytes injury through inhibiting calcium overload,increasing ATP content,improving mi.tochondrial function and inhibiting apoptosis.