Exploring The Clinical Efficacy And Mechanism Of Total Flavones Of Abelmoschus Manihot In Improving Hyperuricemia-kidney Injury By Targeting HIF-1α-mediated Pyroptosis Pathway And Intestinal Microecology

Observation of clinical efficacy of total flavones of Abelmoschus manihot in improving renal function progression in patients with hyperuricemia-kidney injury:A retrospective study of small sample in single-center[Background/Aims]Increased kidney injury due to hyperuricemia(HUA)is considered to be one of the main causes of disease progression in patients with chronic kidney disease(CKD).Both the 2017 edition of "Practice Guidelines for Diagnosis and Treatment of Hyperuricemia in Kidney Diseases in China" and the 2020 edition of "American College of Rheumatology Guideline for the Management of Gout" clearly recommend that patients with CKD stage 3 and above,who combined with HUA should receive "initial uric acid-lowering therapy(ULT)".However,for patients with CKD stage 3-5,the choice of clinical treatment drugs for ULT has been relatively limited.In recent years,several studies have shown that flavonoids,represented by Total flavones of Abelmoschus manihot(TFA)not only have the effect of lowering serum uric acid(SUA),but also may improve hyperuricemia kidney injury(HUA-KI)and delay the progression of renal function.Therefore,the authors have conducted a single-center,small sample retrospective study to observe the clinical efficacy of TFA on improving renal function progression in patients with HUA-KI.[Methods]The sample size was calculated by PASS software.60 patients with stage 3-4 CKD combined with HUA were collected and included in this study as HUA-KI cases.All cases were divided into two groups according to the different treatment methods,nomoral control group(NC group)and the intervention group(TFA group),each group had 30 cases.The control group was given conventional basic therapy,while the intervention group was given TFA and conventional basic treatment.The treatment period was 12 weeks.Before treatment,the baseline data parameters of the two groups of patients were compared;after treatment,the differences in TCM syndrome grading and quantitative scores,renal function,renal tubular injury indexes,blood lipids and liver function indexes were compared between the two groups.[Results]There were no differences in baseline parameters between the two groups before treatment.After 12 weeks of conventional basic therapy combined with TFA intervention,the TFA group’s TCM syndrome grading and quantitative scores,SUA,Scr,eGFR,URBP,UPRO,UNAG,Tch were significantly improved,and the differences were statistically significant compared with these before treatment(P<0.01,P<0.05).Compared with the NC group after treatment,the TFA group’s TCM syndrome grading and quantitative score,SUA,Scr,eGFR,UPRO,UNAG were improved,and the differences were statistically significant(P<0.01,P<0.05).In addition,there was no significant change in liver function indexes before and after treatment in the two groups.[Conclusions]Conventional basic therapy combined with TFA intervention could improve the quantitative score of TCM syndrome classification,reduce SUA,and improve renal function and renal tubular injury in patients of HUA-KI.Exploring the effects and mechanisms of total flavones of Abelmoschus manihot in improving hyperuricemia-kidney injury by targeting HIF-1α-mediated pyroptosis pathway and intestinal microecology[Background/Aims]Inflammation is the primary factor that induces hyperuricemic kidney injury(HUA-KI),and its pathogenesis is closely related to Nod-like receptor protein 3(NLRP3)inflammasome activation.The latest research showed that in the HUA-induced renal hypoxia environment,the high expression of hypoxia-inducible factor(HIF)-1α regulated the activation of the NLRP3 inflammasome,activated the Caspase-1-dependent classical pyroptosis pathway,promoted the inflammatory response,and exacerbated tubular/interstitial damage at last.On the other hand,disturbance of gut microbial imbalance and gut microbiota was also maybe one of the reasons for aggravating HUA-KI.Therefore,NLRP3/Caspase-1/GSDMD pyroptosis signaling pathway which is mediated by HIF-1α,and the change rule of intestinal microecology,it can not only elucidate the pathogenesis of HUA-KI,but also explore the therapeutic targets of Chinese and Western medicines point.In recent years,the flowers of Abelmoschus manihot(AM)and their extract,total flavones of Abelmoschus manihot(TFA),have been widely used in the clinical treatment of CKD in China.In clinical studies,the authors found that TFA could reduce serum uric acid(SUA)and delayed the progression of renal function in HUA-KI patients.However,its vivo mechanism of action still has not yet been elucidated.In this study,the author used a modified HUA-KI rat model and compared with the classic uric acid-lowering drug,febuxostat(FEB),to explore the effect and mechanism of TFA in improving HUA-KI by targeting HIF-1α-mediated NLRP3/Caspase-1/GSDMD signaling pathway,and provided pharmacological evidence for the secondary development and application of classic traditional Chinese medicine for treating kidney in the field of metabolic nephropathy.[Methods]The modified HUA-KI rat model was established by "unilateral nephrectomy+potassium oxonate gavage+high purine diet",they were randomly divided into 3 groups:model group(n=7),FEB group(n=8),TFA group(n=8);at the same time,a normal group(n=5)was set up as a control.Rats in normal group and model group were given distilled water by gavage,FEB group and TFA group were given FEB suspension and TFA suspension by gavage respectively,and the intervention period was 10 weeks.Before the intervention and at 5 and 10 weeks after the intervention,blood was collected from the orbital vein and 24-hour urine was collected from the metabolic cage to detect SUA and renal injury indicators.After 10 weeks of intervention,all rats were killed,and the serum,liver,kidney and feces were collected.Firstly,those samples were used to observe the general condition of the model rats,serum uric acid and kidney injury,inflammatory factors,renal tubular/interstitial pathological damage,changes of uric acid metabolism indexes,and the intervention effects of TFA and FEB.Secondly,those samples were also used to explore the expression level of HIF-1α protein in the kidney of model mice,the change characteristics of the activation of the "first signal" and "second signal"pathways of the NLRP3 inflammasome,and the intervention effects of TFA and FEB were also analyzed.In addition,the change characteristics of the gut microbiota of the model mice and the intervention effects of TFA and FEB were also observed and analyzed.[Results]①TFA and FEB could improve general condition,reduce kidney swelling and the deposition of uric acid crystals on the kidney surface;② Both TFA and FEB could reduce SUA and renal injury indicators,and FEB had a better effect on reducing UA,while TFA could improve 24hUPRO;③Both TFA and FEB could decrease the level of inflammatory factors;④Both TFA and FEB could improve renal tubular/interstitial injury;⑤Both TFA and FEB could reduce the activity of hepatic XOD and inhibit the production of UA;⑥TFA and FEB could down-regulate the expression of HIF-1α,TLR4,NF-κB(p65),NLRP3,ASC,Caspase-1(Pro),Caspase-1(p20),GSDMD(FL),GSDMD(N),IL-1β(Pro)and IL-1β proteins,among which,TFA had a better effect on down-regulating protein expression levels of NLRP3,ASC,GSDMD(FL),IL-1β(Pro)and IL-1β.⑦In addition,There were differences in the distribution of gut microbiota in the four groups of rats,mainly concentrated in "Bacteroides,Clostridium,Trichococcus,Lactobacillus",in which,the differences in "Bacteroides,Lactobacillus" were more Obviously;Bacteroides were reflected at the level of "phylum,class and order",while Lactobacillus was reflected at the level of "family and genus".The surprising finding was that after the intervention of TFA and FEB,the abundance of Bacteroides and Lactobacillus species in the gut microbiota of HUA-KI model mice were adjusted.[Conclusions]In this study,using the modified rat models with HUA-KI,the authors demonstrated that ①TFA can reduce renal inflammatory response and improve renal tubular/interstitial injury by regulating the HIF-1α-mediated pyroptosis pathway;②The mechanism of TFA lowering uric acid is mainly related to its inhibition of XOD activation.In addition,the authors also found that TFA can improve gut microbiota disturbance,which may be related to delaying HUA-KI progression.