The Anti-Inflammatory Effect of KS23, A Novel Peptide Derived From Globular Adiponectin, on Endotoxin-Induced Uveitis in Rats

Engineering a novel water-in-oil biocompatible microemulsion system for the ocular delivery of dexamethasone sodium phosphate in the treatment of acute uveitis

Due to their unique characteristics, microemulsions (ME) represent one of the most promising delivery systems which can conquer poor ocular drug bioavailability providing long residence time. Development of a ME system, relying on the use of a safe and non-irritant surfactant combination derived from sustainable resources and which can consolidate the small ME droplets, is the goal of this work. Herein, we report the design and characterization of a novel biocompatible, eco-friendly ME system loaded with the hydrophilic dexamethasone sodium phosphate (DEXP) using a novel surfactant mixture composed of D-α-tocopherol polyethylene glycol succinate (TPGS) and Plantacare® (coco-Glycosides). Capryol™ PGMC and double-distilled water were used as the respective oil and aqueous phases and the MEs were prepared by the water titration method, suitable for scaling up. Optimization of ME formulae was conducted by varying Plantacare® grades, TPGS to Plantacare® mass ratios and drug loading. The formulae were characterized in terms of physical appearance, droplet size (PS), size distribution (PDI), zeta potential (ZP), and stability. The optimized DEXP-loaded ME formula attained acceptable PS, PDI, and ZP values of 43 ± 5 nm, 0.35 ± 0.07, -12 ± 4 mV, respectively. TEM images confirmed a small PS ≤ 100 nm. The in vivo safety of ME was proved by the Draize test. The ME formula prompted excellent mucoadhesion and transcorneal permeation. The confocal studies showed deep penetration into the rabbits' corneas. In vivo studies using endotoxin-induced uveitis showed high ocular efficacy and a significant reduction in inflammatory cells, including interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). The obtained results elect the novel engineered ME system as a promising tool for the ocular delivery of hydrophilic moieties in the management of various ophthalmic diseases.

Identification of the key mechanisms of action of Si-Ni-San in uveitis using bioinformatics and network pharmacology

BACKGROUND

Uveitis is an eye disease with a high rate of blindness, whose pathogenesis is not completely understood. Si-Ni-San (SNS) has been used as a traditional medicine to treat uveitis in China. However, its mechanism of action remains unclear. This study explored the potential mechanisms of SNS in the treatment of uveitis through network pharmacology and bioinformatics.

METHODS

Using R language and Perl software, the active components and predicted targets of SNS, as well as the related gene targets of uveitis, were mined through the Traditional Chinese Medicine Systems Pharmacology, Therapeutic Target, Gene Expression Omnibus, GeneCards, and DrugBank databases. The network diagram of active components and intersection targets was constructed using Cytoscape software and the String database. The CytoNCA plug-in was used to conduct topological analysis on the network diagram and screen out the core compounds and key targets. The genes were analyzed for Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment. Chemoffice, Pymol, AutoDock, and Vina were used to analyze the molecular docking of key targets and core compounds of diseases through the PubChem database.

RESULTS

JUN, RELA, and MAPK may play important roles in the treatment of uveitis by SNS. Kyoto encyclopedia of genes and genomes pathway enrichment analysis showed that core genes were mainly concentrated in MAPK, toll-like receptor, tumor necrosis factor, and nucleotide oligomerization domain-like receptor signaling pathways. In addition, molecular docking results showed that the bioactive compounds (kaempferol, luteolin, naringin, and quercetin) exhibited good binding ability to JUN, RELA, and MAPK.

CONCLUSION

Based on these findings, SNS exhibits multi-component and multi-target synergistic action in the treatment of uveitis, and its mechanism may be related to anti-inflammatory and immune regulation.

5-ALA/SFC Ameliorates Endotoxin-Induced Ocular Inflammation in Rats by Inhibiting the NF-κB Signaling Pathway and Activating the HO-1/Nrf2 Signaling Pathway

Sodium ferrous citrate (SFC) is involved in the metabolism of 5-aminolevulinic acid (5-ALA) and enhances its anti-inflammatory effects. The effects of 5-ALA/SFC on inflammation in rats with endotoxin-induced uveitis (EIU) have yet to be elucidated. In this study, during lipopolysaccharide injection, 5-ALA/SFC (10 mg/kg 5-ALA plus 15.7 mg/kg SFC) or 5-ALA (10 or 100 mg/kg) was administered via gastric gavage, wherein we saw that 5-ALA/SFC ameliorated ocular inflammation in EIU rats by suppressing clinical scores; by infiltrating cell counts, aqueous humor protein, and inflammatory cytokine levels; and by improving histopathological scores to the same extent as 100 mg/kg 5-ALA. Immunohistochemistry showed that 5-ALA/SFC suppressed iNOS and COX-2 expression, NF-κB activation, IκB-α degradation, and p-IKKα/β expression, and activated HO-1 and Nrf2 expression. Therefore, this study has investigated how 5-ALA/SFC reduces inflammation and revealed the pathways involved in EIU rats. 5-ALA/SFC is shown to inhibit ocular inflammation in EIU rats by inhibiting NF-κB and activating the HO-1/Nrf2 pathways.

Effects of Oral 5-Aminolevulinic Acid on Lipopolysaccharide-Induced Ocular Inflammation in Rats

This study aimed to investigate the anti-inflammatory effect of 5-aminolevulinic acid (5-ALA) on endotoxin-induced uveitis (EIU) in rats. EIU was induced in male Sprague Dawley rats by the subcutaneous injection of lipopolysaccharide (LPS). During LPS injection, 5-ALA diluted with saline was administered via gastric gavage. After 24 h, clinical scores were assessed after which aqueous humor (AqH) samples were obtained. The number of infiltrating cells, protein concentration, and levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), nitric oxide (NO), and prostaglandin E2 (PGE2) in AqH were measured. For histological examination, both eyes of some rats were enucleated. In vitro, a mouse macrophage cell line (RAW264.7 cells) was stimulated by LPS with or without 5-ALA. Western blot was used to analyze the expression of inducible NO synthase (iNOS) and cyclooxygenase-2. 5-ALA suppressed the EIU clinical scores, infiltrating cell number, and protein concentration while improving the histopathologic scores. In particular, 100 mg/kg 5-ALA reduced the concentrations of NO, PGE2, TNF-α, and IL-6 in AqH, similar to 1 mg/kg prednisolone. In addition, 5-ALA suppressed iNOS upregulation in LPS-stimulated RAW264.7 cells. Therefore, 5-ALA has an anti-inflammatory effect on EIU through the inhibition of the upregulation of inflammatory mediators.

Insight Into Polysaccharides From Panax ginseng C. A. Meyer in Improving Intestinal Inflammation: Modulating Intestinal Microbiota and Autophagy

Polysaccharides from Panax ginseng C. A. Meyer (P. ginseng) are the main active component of P. ginseng and exhibit significant intestinal anti-inflammatory activity. However, the therapeutic mechanism of the ginseng polysaccharide is unclear, and this hinders the application for medicine or functional food. In this study, a polysaccharide was isolated from P. ginseng (GP). The primary structure and morphology of the GP were studied by HPLC, FT-IR spectroscopy, and scanning electron microscopy (SEM). Further, its intestinal anti-inflammatory activity and its mechanism of function were evaluated in experimental systems using DSS-induced rats, fecal microbiota transplantation (FMT), and LPS-stimulated HT-29 cells. Results showed that GP modulated the structure of gut microbiota and restored mTOR-dependent autophagic dysfunction. Consequently, active autophagy suppressed inflammation through the inhibition of NF-κB, oxidative stress, and the release of cytokines. Therefore, our research provides a rationale for future investigations into the relationship between microbiota and autophagy and revealed the therapeutic potential of GP for inflammatory bowel disease.