The anti-inflammatory activity of flavonoids and alkaloids from Sophora flavescens alleviates psoriasiform lesions: Prenylation and methoxylation beneficially enhance bioactivity and skin targeting

Kurarinone regulates Th17/Treg balance and ameliorates autoimmune uveitis via Rac1 inhibition

INTRODUCTION

Autoimmune uveitis (AU) is a severe intraocular autoimmune disorder with a chronic disease course and a high rate of blindness. Kurarinone (KU), a major component of the traditional Chinese medicine Sophorae Flavescentis Radix, possesses a wide spectrum of activities and has been used to treat several inflammation-related diseases.

OBJECTIVE

We aimed to investigate the effects of KU on AU and its modulatory mechanisms.

METHODS

We used an experimental autoimmune uveitis (EAU) animal model and characterized the comprehensive immune landscape of KU-treated EAU mice using single-cell RNA sequencing (scRNA-seq). The retina and lymph nodes were analyzed. The siRNAs and selective inhibitors were used to study the signaling pathway. The effect of KU on peripheral blood mononuclear cells (PBMCs) from uveitis patients was also examined.

RESULTS

We found that KU relieved chorioretinal lesions and immune cell infiltration in EAU model mice. Subsequent single-cell analysis revealed that KU downregulated the EAU-upregulated expression of inflammatory and autoimmune-related genes and suppressed pathways associated with immune cell differentiation, activation, and migration in a cell-specific manner. KU was implicated in restoring T helper 17 (Th17)/regulatory T (Treg) cell balance by alleviating inflammatory injury and elevating the expression of modulatory mediators in Tregs, while simultaneously ameliorating excessive inflammation by Th17 cells. Furthermore, Rac1 and the Id2/Pim1 axis potentiated the pathogenicity of Th17 cells during EAU, which was inhibited by KU treatment, contributing to the amelioration of EAU-induced inflammation and treatment of AU. In addition, KU suppressed inflammatory cytokine production in activated human PBMCs by inhibiting Rac1. Integration of the glucocorticoid-treated transcriptome suggests that KU has immunomodulatory effects on lymphocytes.

CONCLUSION

Our study constructed a high-resolution atlas of the immunoregulatory effects of KU treatment on EAU and identified its potential therapeutic mechanisms, which hold great promise in treating autoimmune disorders.

Advances in Pharmacological Research on Icaritin: A Comprehensive Review

Epimedium has been widely used in traditional Chinese medicine for several thousands of years. This plant is known for tonifying kidney Yang, strengthening muscles and bones, and dispelling wind and dampness. It is worth noting that icaritin, a prenylated flavonoid isolated from Epimedium, has received increasing attention in recent years due to its wide range of pharmacological activities. Icaritin exhibits significant therapeutic potential against various diseases, such as osteoporosis, tumors (hepatocellular carcinoma, stomach cancer, breast cancer, and glioblastoma), cerebral ischemia skin injury, thrombocytopenia, and systemic lupus erythematosus. We review the pharmacological activities of icaritin and its potential molecular mechanisms for the treatment of related diseases. The data suggest that icaritin can have the pharmacological effects of mediating Wnt/[Formula: see text]-catenin, IL-6/JAK2/STAT3, AMPK/mTOR, PTEN/AKT, MAPK, NF-[Formula: see text]B, and other signaling pathways. This paper also discusses the progress of clinical trials of icaritin. Icaritin was approved by the State Food and Drug Administration in January 2022 for the treatment of advanced HCC, and has various clinical drug prospects. Although it has some disadvantages, including poor solubility, and low bioavailability, icaritin is still a prospective candidate for the development of naturally derived drugs, especially in the treatment of tumors and inflammatory diseases. This review aims to update and deepen the understanding of icaritin, and provide a theoretical basis for its further study.

Therapeutic Potential of Prenylated Flavonoids of the Fabaceae Family in Medicinal Chemistry: An Updated Review

Much attention has been paid to the potential biological activities of prenylated flavonoids (PFs) in various plant families over the last decade. They have enormous potential for biological activities, such as anti-cancer, anti-diabetic, antimicrobial, anti-inflammatory, anti-Alzheimer's, and neuroprotective activities. Medicinal chemists have recently shown a strong interest in PFs, as they are critical to the development of new medicines. PFs have been rapidly prepared by isolation and semi- or full synthesis, demonstrating their significant utility in medicinal chemistry research. This study encompasses the research progress on PFs in the last decade, including their pharmacological activities in the Fabaceae family. This information demonstrates the bioactive potential of PF compounds and their role in the control and treatment of various human health problems.

Macrophage Functions in Psoriasis: Lessons from Mouse Models

Psoriasis is a systemic autoimmune/autoinflammatory disease that can be well studied in established mouse models. Skin-resident macrophages are classified into epidermal Langerhans cells and dermal macrophages and are involved in innate immunity, orchestration of adaptive immunity, and maintenance of tissue homeostasis due to their ability to constantly shift their phenotype and adapt to the current microenvironment. Consequently, both macrophage populations play dual roles in psoriasis. In some circumstances, pro-inflammatory activated macrophages and Langerhans cells trigger psoriatic inflammation, while in other cases their anti-inflammatory stimulation results in amelioration of the disease. These features make macrophages interesting candidates for modern therapeutic strategies. Owing to the significant progress in knowledge, our review article summarizes current achievements and indicates future research directions to better understand the function of macrophages in psoriasis.