The Comparative Study Of Quercetin And 1-5-O-quercetin Glycoside’s Protection For Endothelial Cell Damages Caused By High Glucose

Objective :1、Constructing the model of endotelial cell damage caused by high glucose and detecting the related indexes of oxidative stress.2、Exploring if quercetin and 1-5- O- quercetin glycoside can relieve the degree of endothelial cell damages caused by high glucose through reducing the oxidative stress level and comparing the difference between them.Methods:We culture the endothelial cells in vitro, and select the cells which have a good condition in logarithmic phase. We devided these cells into four groups:(1) normal control group(glucose concentration 5.5 mmol/L + mannitol concentration24.5mmol/L);(2) high glucose injury group(glucose concentration 30 mmo1/L);(3)high glucose + quercetin group(glucose concentration 30 mmo1/L+ 50μmol/L quercetin);(4) high glucose + quercetin glycoside group(glucose concentration for30 mmo1/L+ 50 μmol/L 1-5- O- quercetin glycoside).The medicaments are added to each drug group respectively 2 hours before treatment by high glucose.after training48 hours,we test the following aspects: groups of CCK 8 test endothelial cell activity,the determination of lactate dehydrogenase(LDH), superoxide dismutase(SOD),glutathione peroxidase(GSH-Px) activity and malondialdehyde(MDA)level,DCF-DA test the lever of ROS in endothelial cells,qRT- PCR determination NOX4 mRNA, SODmRNA and CATmRNA expression.Results:(1) Endothelial cell activity :Compared with the normal control group,the activities of the cells which belong to the high glucose group were higher(P < 0.05).However,the quercetin group and 1-5- O- quercetin glycoside’s group cell activities were lower than the high glucose group(P < 0.05), but these two groups have no statistical significance(P > 0.05).(2)Activity of LDH: Compared with the normal control group,the LDH of the cells which belong to the high glucose group were higher(P < 0.05). However,theLDH of quercetin group and 1-5- O- quercetin glycoside group’s cells were lower than the high glucose group(P < 0.05), but these two groups have no statistical significance(P > 0.05).(3)SOD activities:Compared with the normal control group,the SOD activities of the cells which belong to the high glucose group were lower(P < 0.05).However,the total SOD activities of quercetin group and quercetin glycoside group’s cells was higher than the high glucose group(P < 0.05), but these two groups have no statistical significance(P > 0.05).(4)GSH-Px activities:Compared with the normal control group,the GSH-Px activities of the cells which belong to the high glucose group were lower(P < 0.05).However,the GSH-Px activities of quercetin group and 1-5- O- quercetin glycoside group’s cells was higher than the high glucose group(P < 0.05), but these two groups have no statistical significance(P > 0.05).(5)MDA level:Compared with the mormal control group,the MDA level of the cells which belong to the high glucose group were higher(P < 0.05). However,the MDA level of quercetin group and 1-5- O- quercetin glycoside’s group cells was lower than the high glucose group(P < 0.05), but these two groups have no statistical significance(P > 0.05).(6)ROS level:Compared with the normal control group,the ROS level of the cells which belong to the high glucose group were higher(P < 0.05). However,the ROS level of quercetin group and 1-5- O- quercetin glycoside group’s cells were lower than the high glucose group(P < 0.05), but these two groups have no statistical significance(P > 0.05).( 7) SODmRNA level:Compared with the normal control group,the SODmRNA level of the cells which belong to the high glucose group is lower(P <0.05). However,the SODmRNA level of quercetin group and 1-5- O- quercetin glycoside group’s cells was higher than the high glucose group(P < 0.05), but these two groups have no statistical significance(P > 0.05).(8)CATmRNA level:Compared with the normal control group,the CATmRNA level of the cells which belong to the high glucose group is lower(P < 0.05).However,the CATmRNA level of quercetin group and 1-5- O- quercetin glycosidegroup cells was higher than the high glucose group(P < 0.05), but these two groups have no statistical significance(P > 0.05).(9)NOX4mRNA level:Compared with the normal control group,the NOX4 mRNA level of the cells which belong to the high glucose group is higher(P < 0.05).However,the NOX4 mRNA level of quercetin and 1-5- O-quercetin glycoside group’s cells were lower than the high glucose group(P < 0.05), but these two groups have no statistical significance(P > 0.05).Conclusion:(1) Qu and 1-5- O- QG can protect endothelial cell against damages caused by high glucose through regulating the imbalance of oxidant-antioxidant system.(2) The ability of antioxidant removal of oxygen free radicals between Qu and1-5- O- QG has no difference.