Objective To investigate the effect of acacetin on oxidative stress injury in diabetic cataract(DC)rats and its regulation of sirtuin 1(Sirt1)/adenosine monophosphate-activated protein kinase(AMPK)/nuclear factor-erythroid 2-related factor 2(Nrf2)signaling pathway.Methods Sixty SD rats were randomly divided into the control group,model group,low-dose acacetin group,high-dose acacetin group,and acacetin+Sirt1 inhibitor(EX527)group.DC rat models were constructed except for the control group.Rats in the low-dose and high-dose acacetin groups were injected with 10 mg·kg-1 and 20 mg·kg-1 acacetin subcutaneously through the neck,twice a day,respectively.Rats in the acacetin+EX527 group were injected with 20 mg·kg-1 acacetin subcutaneously through the neck,twice a day;additionally,3.5 mg·kg-1 EX527 was administered subcutaneously through the osmotic micro-pump for 4 weeks.The same amount of nor-mal saline was pumped into rats in the rest groups for 4 weeks.After administration,blood pressure and fasting blood glu-cose(FBG)were measured.The lens opacity was observed under the slit lamp irradiation,and the histopathological chan-ges in the lens were observed after hematoxylin-eosin staining.Enzyme-linked immunosorbent assay was performed to de-termine the serum levels of malondialdehyde(MDA),superoxide dismutase(SOD),glutathione peroxidase(GSH-Px),in-terleukin(IL)-6,and IL-1 β.Western blot was applied to detect the expression levels of Sirt1,phosphorylated AMPK(p-AMPK),AMPK,and Nrf2 proteins.Results Compared with the control group,the lens epithelial cells(LECs)of rats in the model group showed patchy and striped shapes,and migration and aggregation occurred;the systolic blood pres-sure(SBP),FBG,lens opacity score,and the levels of MDA,IL-6 and IL-1 β increased,while the expression levels of SOD,GSH-Px,Sirt1,p-AMPK/AMPK,and Nrf2 proteins decreased(all P＜0.05).Compared with the model group,the migration and aggregation of LECs improved in the low-dose and high-dose acacetin groups,the SBP,FBG,lens opacity score,and the levels of MDA,IL-6 and IL-1 β decreased,while the expression levels of SOD,GSH-Px,Sirt1,p-AMPK/AMPK,and Nrf2 proteins increased(all P＜0.05).Compared with the high-dose acacetin group,the morphological chan-ges and aggregation of LECs in the acacetin+EX527 group were more significant,the SBP,FBG,lens opacity score,and the levels of MDA,IL-6 and IL-1 β increased,while the expression levels of SOD,GSH-Px,Sirt1,p-AMPK/AMPK,and Nrf2 proteins decreased(all P＜0.05).Conclusion Acacetin may protect DC rats from oxidative stress injury by activating the Sirt1/AMPK/Nrf2 pathway.

Objective To investigate the effect of total flavone of Cydonia oblonga on oxidative damage of human lens epithelial cells induced by high glucose and its mechanism.Methods A cell injury model was established by inducing human lens epithelial cells with high glucose.Human lens epithelial cells were cultured in the medium containing 30 mmol·L-1 glucose for 24 h,which was recorded as the high glucose group.Cells in the control group were cultured in a medium con-tainning 5.5 mmol·L-1 glucose for 24 h.Human lens epithelial cells were inoculated into 96-well plates with 5 × 103 cells per well,and treated with mediums containing 10 mmol·L-1,20 mmol·L-1,and 40 mmol·L-1 total flavone of Cydonia ob-longa combined with 30 mmol·L-1 glucose for 24 h.They were recorded as high glucose+low total flavone of Cydonia oblonga group,high glucose+medium total flavone of Cydonia oblonga group,and high glucose+high total flavone of Cydonia oblonga group.Human lens epithelial cells were transfected with anti-miR-NC and anti-miR-370 with Lipo-fectamine2000 transfection reagent,and treated with 30 mmol·L-1 glucose for 24 h,which were recorded as high glucose+anti-miR-NC group and high glucose+anti-miR-370 group.Human lens epithelial cells were transfected with miR-NC and miR-370 mimics,and treated with medium containing 30 mmol·L-1 glucose and 40 mmol·L-1 total flavone of Cydonia oblonga for 24 h,which were labeled as high glucose+total flavone of Cydonia oblonga+miR-NC group and high glucose+total flavone of Cydonia oblonga+miR-370 group.The activities of superoxide dismutase(SOD)and cata-lase(CAT),and the content of malondialdehyde(MDA)were measured by Enzyme-linked immunosorbent assay;flow cy-tometry was applied to detect apoptosis rate;quantitative reverse transcription polymerase chain reaction was applied to detect the expression level of miR-370;Western blot was applied to detect the expression of apoptosis-related proteins.Results Compared with the control group,the activities of SOD and CAT decreased and the content of MDA increased in the human lens epithelial cells of the high glucose group,and the differences were statistically significant(all P＜0.05);compared with the high glucose group,the activities of SOD and CAT significantly increased and the content of MDA signifi-cantly decreased in the high glucose+low total flavone of Cydonia oblonga group,the high glucose+medium total fla-vone of Cydonia oblonga group and the high glucose+high total flavone of Cydonia oblonga group(all P＜0.05).Com-pared with the control group,apoptosis rate,and protein expressions of Caspase-3 and Caspase-9 of human lens epithelial cells in the high glucose group significantly increased(all P＜0.05);compared with the high glucose group,the apoptosis rate,Caspase-3 and Caspase-9 protein expressions of human lens epithelial cells in the high glucose+low total flavone of Cydonia oblonga group,high glucose+medium total flavone of Cydonia oblonga group,and high glucose+high total fla-vone of Cydonia oblonga group significantly decreased(all P＜0.05).The expression levels of miR-370 in human lens epi-thelial cells were 1.00±0.00,4.04±0.36,3.22±0.24,2.42±0.23 and 1.62±0.14 in the control group,high glucose group,high glucose+low total flavone of Cydonia oblonga group,high glucose+medium total flavone of Cydonia oblon-ga group,and high glucose+high total flavone of Cydonia oblonga group,respectively.There was a statistically different significance among the five groups(F=256.138,P＜0.05).Compared with the high glucose+anti-miR-NC group,the ex-pression of miR-370 significantly decreased,the activities of SOD and CAT significantly increased,and the content of MDA significantly decreased in human lens epithelial cells of the high glucose+anti-miR-370 group(all P＜0.001).Compared with the high glucose+anti-miR-NC group,apoptosis rate,and protein expressions of Caspase-3 and Caspase-9 of the hu-man lens epithelial cells in the high glucose+anti-miR-370 group significantly decreased(all P＜0.001).Compared with the high glucose+total flavone of Cydonia oblonga+miR-NC group,the activities of SOD and CAT significantly de-creased,and the content of MDA,apoptosis rate,and protein expressions of Caspase-3 and Caspase-9 significantly in-creased in the human lens epithelial cells of high glucose+total flavone of Cydonia oblonga+miR-370 group(all P＜0.001).Conclusion The expression of miR-370 increases in high glucose-induced human lens epithelial cells.Total fla-vone of Cydonia oblonga can inhibit the oxidative stress and apoptosis of high glucose-induced human lens epithelial cells,and the mechanism may be related to the decreased expression of miR-370.