Objective:To carry out an overview of systematic reviews on interventions to prevent the recurrence of diabetic foot ulcer (DFU) patients.Methods:Systematic reviews or Meta-analysis on interventions to prevent DFU recurrence were electronically retrieved from databases such as China National Knowledge Infrastructure, WanFang Data, VIP, China Biology Medicine disc, Joanna Briggs Institute (JBI) Evidence-Based Healthcare Center Database, Cochrane Library, PubMed, Embase, CINAHL and Web of Science. The search period was from database establishment to April 20, 2023. Two researchers independently searched and screened literature, and extracted data, and used AMSTAR 2 software and the quality evaluation criteria for systematic review of JBI Evidence-Based Healthcare Center to evaluate the methodological quality of the included literature. GRADE evaluation system was used for quality assessment of outcome indicators (DFU recurrence rate, effectiveness of measures to prevent DFU recurrence) .Results:A total of 24 systematic reviews were included. Studies showed that monitoring and intervention of foot skin temperature, therapeutic shoes or insoles, comprehensive intervention measures, and specific surgical methods could reduce the recurrence rate of DFU, while foot self-care, foot exercise, health education, and psychological intervention had no statistical effect on preventing DFU recurrence. The methodological quality of systematic reviews was generally low. The reports of four articles were relatively complete, 18 articles had certain defects, and two articles had serious defects. The evaluation of evidence quality showed that there were three pieces of moderate-quality evidence, seven pieces of low-quality evidence, and 30 pieces of extremely low-quality evidence.Conclusions:Existing evidence suggests that foot skin temperature monitoring and intervention, therapeutic shoes or insoles, comprehensive intervention measures, and specific surgical methods (such as Achilles tendon lengthening, metatarsophalangeal joint replacement, metatarsal head resection and so on) have a positive impact on preventing DFU recurrence. Rigorous and high standard research is still needed to verify the controversial issues, so as to provide reliable evidence for future clinical practice and studies.

Objective To explore the effects and mechanisms of human umbilical cord mesenchymal stem cell (HUC-MSC)-derived exosomes (Exo) pretreated with Huangkui capsules on renal ischemia-reperfusion injury (IRI). Methods HUC-MSCs were cultured in media containing different concentrations of Huangkui capsules for 24 hours to determine cell viability and select an appropriate concentration for subsequent experiments. HUC-MSCs were pretreated with 50 μg/mL Huangkui capsules for 24 hours, and Exo were extracted using an exosome extraction kit. The morphology was observed under a transmission electron microscope, particle size was measured by nanoparticle tracking analysis, and the expression of exosomal membrane surface marker proteins was detected by Western blot. Human renal tubular epithelial cells (HK-2 cells) were randomly divided into hypoxia/reoxygenation group (M group), hypoxia/reoxygenation + Exo group (E group), and hypoxia/reoxygenation + Huangkui capsules pretreated Exo group (H group). Western blotting was used to measure the expression of endoplasmic reticulum stress (ERS)-related proteins, and real-time fluorescent quantitative reverse transcription polymerase chain reaction was used to measure the expression of ERS-related gene messenger RNA (mRNA). Mice were randomly divided into sham operation group (Sham group), ischemia-reperfusion group (I/R group), ischemia-reperfusion + Exo group (E group), and ischemia-reperfusion + Huangkui capsules pretreated Exo group (H group). Renal histological assessment, serum creatinine (Scr), blood urea nitrogen (BUN) measurement and inflammatory factor detection were performed 24 hours later. Results Both Exo and Huangkui capsules prereated Exo had a bilayer membrane structure and a cup-shaped morphology; their average particle sizes were 116.8 nm and 81.3 nm, respectively. Both expressed CD9, CD63, TSG101. Compared with the M group, the E group had decreased relative expression of transcription factor 6 (ATF6) and protein kinase R-like endoplasmic reticulum kinase (PERK) proteins, increased mRNA relative expression, increased relative expression of C/EBP homologous protein (CHOP) protein, and decreased mRNA relative expression. Compared with the E group, the H group had decreased relative expression of ATF6, PERK, CHOP proteins, and decreased mRNA relative expression of ATF6 and PERK (all P<0.05). Animal experimental results showed that compared with the Sham group, the I/R group had increased renal tubular injury scores, Scr, BUN, interleukin (IL)-1β, IL-10, IL-18, tumor necrosis factor (TNF)-α levels. Compared with the I/R group, the E and H groups had decreased renal tubular injury scores and Scr, BUN, IL-1β, IL-10, IL-18, TNF-α levels. Compared with the E group, the H group had decreased renal tubular injury scores and Scr, BUN, IL-1β, IL-10, IL-18, TNF-α levels (all P<0.05). Conclusions Huangkui capsules pretreatment HUC-MSC-derived Exo may alleviate renal IRI by inhibiting ERS.