Background: Diabetic retinopathy (DR) is a serious microvascular complication of diabetes and remains the leading cause of blindness in adults. Retinal inflammation is playing a crucial role in the development of DR, and targeting inflammatory mediators is a promising strategy for controlling DR. Here, we investigated compound Chinese medicine Luo Tong formula (LTF) alleviated retinal inflammatory responses in a STZ-induced diabetic rat model. Methods: Sprague–Dawley rats were divided into four groups: control, streptozotocin-induced diabetic, LTF-treated diabetic, and calcium dobesilate (CaD)-treated diabetic rats. Blood samples were collected for blood glucose examination. Hematoxylin–eosin and periodic acid-Schiff staining were conducted for light microscopy observations. Retinal cell apoptosis was detected using the TUNEL assay. Proteins expression was quantified by Western blotting and/or immunohistochemistry, and gene expression was assessed by real-time PCR. Results: Diabetic rats showed significant increases in the expression of tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), monocyte chemotactic protein-1 (MCP-1), intercellular adhesion molecule-1 (ICAM-1), nuclear factor-κB (NF-κB), and the phospho-p38 mitogen-activated protein kinase (p-p38-MAPK)/p38 MAPK ratio compared to control rats. LTF treatment significantly improved both retinal and pancreatic pathological injury, LTF treatment also inhibited inducible the p-p38 MAPK/p38 MAPK ratio and NF-κB activation and decreased the subsequent induction of the retinal expression of proinflammatory mediators TNF-α, IL-1β, MCP-1 and ICAM-1 compared to diabetic rats. LTF also exhibited a protective effect on islet function. Conclusions: LTF before the onset of DR can alleviate retinal pathological injury, LTF may play an anti-inflammatory role by inhibiting p38-MAPK and then inhibiting NF-κB pathway. But further studies are needed to confirm this conclusion. Trial registration This is an animal experiment, trial registration is not necessary.

Yiqi Tongluo Fang (YQTLF) is an effective prescription for the treatment of diabetic retinopathy (DR), but its mechanism of action remains unclear. The content of YQTLF was determined using liquid and gas chromatography-mass spectrometry (LC-MS and GC-MS, respectively). Twenty-five Sprague Dawley (SD) rats were randomly selected as the normal control group. One hundred SD streptozotocin-induced diabetes (type 1) rats were randomly divided into diabetic control, diabetic+insulin+ calcium dobesilate (CaD), and diabetic+insulin+ YQTLF groups, with 25 rats in each group. Bodyweight level was measured every 2 weeks. After 12 weeks of gavage, the glucose levels, lipids, oxidative stress, inflammation, retinal histopathology, and the blood-retinal barrier were assessed in each group. The p38 MAPK pathway was changed to explore its internal mechanism. The measurement data were expressed as mean ± standard deviation, and different statistical methods were used according to a normal distribution, square error, or not. A total of 1024 valid peaks were identified in YQTLF using GC-MS. YQTLF significantly lowered the fasting blood glucose levels in diabetic rats. YQTLF early inhibited changes in retinal histology, capillaries, cells, and tight junction proteins (such as ZO-1, occludin, claudin-5, and VE-cadherin) before the formation and development of DR. These findings correlated with the alleviation of glucolipid metabolism, inflammation, and oxidative stress. The lncRNA MALAT1 and the PRC 2/p38 MAPK-related pathway, such as the expression of EZH2, SUZ12, EED, p38 MAPK, MMP-9, and VEGFR, were also correlated. We have demonstrated the molecular and cellular mechanisms underlying the preventive and delayed development and formation of DR. YQTLF prevents changes in dyslipidemia, retinal histology, capillaries, cells, and tight junction proteins. These protective effects appear to be linked to its antioxidant and anti-inflammatory effects, which prevent the activation of intracellular signaling pathways, such as the lncRNA MALAT1 and PRC 2/p38 MAPK-related pathway.

Background: Diabetic retinopathy (DR) is a common microvascular complication of diabetes. Luo Tong formula (LTF), a classical traditional Chinese medicine (TCM) prescription, consists of four plants that have been widely and effectively used to treat DR. Previous work in our laboratory has confirmed that LTF can effectively ameliorate DR. However, the potential mechanism underlying the therapeutic effect of LTF on DR has not been fully elucidated. To explore the potential mechanism of action through which LTF prevents and alleviates DR from an inflammation and gut microbiota perspective. Materials and methods: Metabolite profiling of LTF was performed using liquid chromatography–mass spectrometry (LC–MS) and gas chromatography–mass spectrometry (GC–MS). Type 1 diabetes was induced in male Sprague Dawley (SD) rats via tail vein injection of 45 mg/kg streptozotocin. Next, 100 SD rats were randomly divided into four groups, normal control; diabetic control; diabetic + insulin + calcium dobesilate; and diabetic + insulin + LTF. After 12 weeks of treatment, glucose metabolism, fundus oculi, blood-retinal barrier permeability, retinal thickness, microvascular damage, as well as cell junction expression in retinas were measured and the changes observed in different groups were compared. Finally, the alteration in gut microbiota and inflammatory cytokine expression in serum and tissues were monitored, and their correlation was analyzed. Results: A total of 1024 valid peaks were obtained for LTF using GC–MS. The HbA1c and fasting blood glucose (FBG) levels in the LTF group were slightly decreased. LTF exerted protective effects on fundus oculi and the retina structure to different degrees. LTF attenuated systemic and local retinal inflammation by significantly decreasing the levels of seven pro-inflammatory cytokines, including ICAM-1, IL-6, IL-8, MCP-1, VCAM-1, VEGF, and IL-1β. LTF restored the intestinal microbiota of diabetic rats to levels that were similar to those of normal rats. Further analysis revealed that Enterobacteriales, Prevotellaceae, Enterobacteriaceae, Bacteroides, and Klebsiella were significantly and positively correlated with the inflammatory factors in DR after LTF treatment. Conclusions: Our results revealed the mechanisms underlying the preventive effects of LTF on DR development and progression. LTF inhibited pathological changes in retinal histopathology, cell composition, and cell junction proteins while effectively ameliorating systemic and local retinal inflammation via regulating pivotal gut microbiota.

The blood-retinal barrier (BRB) comprises the inner blood-retinal barrier (iBRB) and the outer blood-retinal barrier (oBRB). The integrity of the BRB is essential to maintaining stability of the retinal microenvironment. Mitophagy plays a crucial role in maintaining organellar integrity by regulating mitochondrial quality and quantity. High glucose-induced mitophagy dysfunction contributes to diabetic retinopathy (DR) by damaging the BRB. This review presents mitophagy mechanisms under physiological conditions and examines changes across different cell types under DR-related pathological conditions that damage the BRB. It also summarizes drugs and targets that regulate mitophagy to stabilize the BRB and alleviate DR, offering new therapeutic insights.

Metabolic dysfunction-associated steatotic liver disease (MASLD) has emerged as the most prevalent chronic liver condition globally. Studies have revealed distinct differences in the gut microbiota (GM) composition between healthy individuals and MASLD patients, suggesting a crucial role of GM in disease initiation and progression. This review summarizes characteristic gut microbial alterations in MASLD, examines the relationship between GM and their metabolites in MASLD pathogenesis, and discusses potential mechanistic pathways. Furthermore, we summarize the possible therapeutic applications of probiotics, fecal microbiota transplantation (FMT), and natural products in managing MASLD through GM modulation. Although current evidence indicates these interventions may slow or prevent MASLD progression, most research remains limited to animal experiments and small-scale clinical studies. The scarcity of high-quality clinical evidence has created a significant gap between theoretical research and clinical application. Therefore, this article aims to summarize existing findings, explore the prospects of GM-targeted strategies for MASLD treatment, and propose future research directions in this field.

Icariin (ICA), the principal flavonoid from Epimedii Folium, aligns with traditional Chinese medicine indications of tonifying kidney-yang and strengthening bone. Prior reviews mostly catalog ICA’s preclinical neuroprotective, anti-fibrotic, anti-tumor, and osteoprotective effects, but lack evidence stratification. Here, we establish an evidence-stratified framework to evaluate ICA’s structure–activity relationships, pharmacokinetics, and safety profiles, explicitly distinguishing preclinical pharmacological actions from unproven clinical efficacy. We delineate translational barriers including interspecies pharmacokinetic gaps, poor bioavailability, and flawed trial designs, and assess delivery systems to address these limitations. This work bridges traditional Chinese medicine practice with graded modern evidence, providing a translational roadmap to guide ICA’s rational clinical development.