Objective To study the effect of hesperetin(HSP)on renal ischemia-reperfusion injury(RIRI)in rats and its mechanism.Methods Fifty male SD rats were randomly divided into five groups:sham group,model group(renal ischemia-reperfusion injury I/R),HSP pretreatment(HSP+I/R)group,all-trans retinoic acid pretreatment(ATRA+I/R)group,HSP and ATRA pretreatment(HSP+ATRA+1/R)group.Each group had 10 rats.The sham group only exposed both kidneys by opening the abdominal cavity.In other groups,the RIRI model was established by occluding the bilateral renal pedicles for 45 min,followed by reperfusion for 24 h.Hematoxylin-eosin staining(HE)was used to ascertain the extent of kidney injury.The microplate method was used to measure serum creatinine(Scr)levels,while the urease method was used to measure blood urea nitrogen(BUN)levels.Enzyme-linked immunosorbent assay(ELISA)was used to detect the contents of interleukin-6(IL-6),interleukin-1β(IL-1 β)and tumor necrosis factor-α(TNF-α)in the serum.The kit method was used to examine the levels of superoxide dismutase(SOD),glutathione(GSH),malondialdehyde(MDA)and catalase(CAT)in kidney tissue.The Western blot analysis was conducted to detect the expression of nuclear factor erythroid 2 related factor 2(Nrf2)and its downstream antioxidant proteins heme oxygenase-1(HO-1)and quinone oxide reductase 1(NQO1)in renal tissues.Results The scores for renal tubule damage in sham,I/R and HSP+I/R groups were 0.20±0.45,4.20±0.84 and 2.40±0.55;Scr contents were(55.52±11.23),(207.10±19.22)and(105.60±18.11)μmol·L-1;IL-6 contents were(33.66±6.83),(172.50±8.09)and(105.40±10.03)pg·mL-1.The SOD levels in sham,I/R,HSP+I/R,ATRA+I/R and HSP+ATRA+I/R groups were(57.04±3.44),(37.29±3.60),(51.61±9.41),(32.55±5.58)and(37.40±3.66)U·mg·prot-1;the relative expression levels of Nrf2 were 0.37±0.24,0.57±0.28,1.31±0.34,0.44±0.17 and 0.77±0.25;the relative expression levels of HO-1 protein were 0.26±0.14,0.57±0.30,1.32±0.61,0.53±0.28 and 0.67±0.50.There was significant difference in renal tubule damage score,Scr,IL-6 and SOD indexes in I/R group compared to sham group(P＜0.05,P＜0.01).The above indexes were statistically significant between HSP+I/R group and I/R group(P＜0.05,P＜0.01).Conclusion The activation of HSP may stimulate the Nrf2-antioxidant response element(ARE)pathway,enhance the expression of downstream antioxidant proteins,mitigate the renal damage caused by oxidative stress,and ultimately improve RIRI.

Aim To study the effect of different hepa- ry.Methods First, heparin derivatives with different rin sulfation patterns on bleomycin induced lung inju- sulfation patterns,6-desulfated heparin (6-DeH) and N-acetvlated heparin ( N-AcH ) , were synthesized.Secondly, the effect of these compounds on BLM-in¬duced bronchial epithelial cell ( BEARS-2B) injury was evaluated via lactate dehydrogenase activity, MTT experiment, Annexin V/ PI staining and Hoechst 33258 staining.Then , immunofluorescence staining and West¬ern blotting were used to investigate the shedding of Svndecan-1 and the activation of c-Met by 6-DeH/Akt j j signaling pathway.Finally, a BLM-induced lung injury mouse model was used to further verify the protective effect of 6-DeH by HE staining, Svndecan-1 immunos- taining,bodv weight change,and survival rate.Results In the BLM-induced BEARS-2B injury model, 6- DeH was selected as the best candidate, which exerted their effect by competitively binding to BLM, thereby reducing the damage of heparan sulfate barrier (Svnde- can-1 ) on cell surface, and improving cell survival by activating the downstream c-Met/Akt pathway.In the BLM-induced lung injury mouse model, it was further confirmed that 6-DeH reduced the shedding of Svnde- can-1 in the early stage, and delayed the lung injury and fibrosis process.Conclusions 6-DeH protects the bronchial epithelial cells against BLM-induced lung in¬jur)' through inhibiting the shedding of Svndecan-1 and activating the c-Met/Akt signaling pathway.