Studies on the anti-psoriasis effects and its mechanism of a dual JAK2/FLT3 inhibitor flonoltinib maleate

Natural Product-Derived Compounds Targeting Keratinocytes and Molecular Pathways in Psoriasis Therapeutics

Psoriasis is a chronic autoimmune inflammatory skin disorder that affects approximately 2-3% of the global population due to significant genetic predisposition. It is characterized by an uncontrolled growth and differentiation of keratinocytes, leading to the formation of scaly erythematous plaques. Psoriasis extends beyond dermatological manifestations to impact joints and nails and is often associated with systemic disorders. Although traditional treatments provide relief, their use is limited by potential side effects and the chronic nature of the disease. This review aims to discuss the therapeutic potential of keratinocyte-targeting natural products in psoriasis and highlight their efficacy and safety in comparison with conventional treatments. This review comprehensively examines psoriasis pathogenesis within keratinocytes and the various related signaling pathways (such as JAK-STAT and NF-κB) and cytokines. It presents molecular targets such as high-mobility group box-1 (HMGB1), dual-specificity phosphatase-1 (DUSP1), and the aryl hydrocarbon receptor (AhR) for treating psoriasis. It evaluates the ability of natural compounds such as luteolin, piperine, and glycyrrhizin to modulate psoriasis-related pathways. Finally, it offers insights into alternative and sustainable treatment options with fewer side effects.

Glycyrol Prevents the Progression of Psoriasis-like Skin Inflammation via Immunosuppressive and Anti-Inflammatory Actions

Glycyrol (GC) is one natural active product. Imiquimod-induced psoriasis-like Balb/c mouse models were established. The model mice were intraperitoneally injected with cyclosporine A (CsA) and GC for 8 days followed by a series of biological detections. GC had little toxicity according to the levels of peripheral blood cells, hemoglobin, blood urea nitrogen (BUN), and serum creatinine (CRE), while CsA significantly increased the levels of BUN and CRE. GC decreased the splenic index and reduced the expressions of IL-6, IL-23, and CXCL-3 in the model mice and IL-6, CXCL-1, and CXCL-2 in the inflammatory HaCaT cells. The half inhibition concentration (IC50) of GC on HaCaT cells was 29.72 μmol/L, resulting in improved apoptosis, enhanced expressions of p21, BAX, and BIK, and reduced expressions of BCL-2. GC is an immunosuppressive agent against psoriasis-like symptoms by anti-inflammatory effects, which provides a strategy for the discovery of anti-psoriatic natural products.

4-Octyl itaconate inhibits inflammation to attenuate psoriasis as an agonist of oxeiptosis

Psoriasis is a highly prevalent chronic disease associated with a substantial social and economic burden. Oxeiptosis is a programmed cell death that occurs when cells are in a state of high oxidative stress, which has a potent anti-inflammatory effect. However, there is still no research on oxeiptosis in psoriasis, and the agonists or antagonists of oxeiptosis remain an unclear field. Here, we found that oxeiptosis of keratinocytes was inhibited in psoriasis lesions. KEAP1, as the upstream molecular component of oxeiptosis, is highly expressed in psoriasis lesions. Knockdown of KEAP1 in HaCaT cells caused oxeiptosis in the condition of M5 cocktail stimulation. Next, we found that the cell-permeable derivative of itaconate, 4-octylitaconate (OI) promoted oxeiptosis of keratinocytes by inhibiting KEAP1 and then activating PGAM5 which are two upstream molecular components of oxeiptosis. At the same time, OI can reduce the expression of inflammatory cytokines induced by M5 cocktail stimulation in vitro. Similarly, we found that OI can alleviate IMQ-induced psoriatic lesions in mice and downregulate the levels of inflammatory cytokines in psoriatic lesions. In summary, our findings suggest that oxeiptosis of keratinocytes was inhibited in psoriasis and OI can significantly inhibit inflammation and alleviate psoriasis as an agonist of oxeiptosis, indicating that oxeiptosis may be involved in regulating the progression of psoriasis, which may provide new therapeutic targets for psoriasis treatment.

Preclinical Demonstration of a Novel Treatment with High Efficacy and No Detectable Toxicity for Inflammatory Skin Conditions including Psoriasis

Although the management options for psoriasis have progressed with the use of systemic agents, there are few efficacious nonsteroidal topical therapies for patients with limited or lower grade disease. The effects of allopurinol (Allo) and glutathione (GSH) were examined in two different in vitro models for psoriasis. In the first model, human immortalized keratinocytes (HaCaT) were treated with M5 cocktail (IL-17A, IL-22, oncostatin M, IL-1α, and TNF-α) in four interventional groups (control, Allo, oxypurinol (Oxy), and methotrexate (MTX)). The number of live and dead cells was determined after treatment for 48 and 72 hrs. Allo decreased cell proliferation (total cells) without increasing cell death compared to both its xanthine oxidase inhibiting metabolite Oxy and a standard agent in clinical use, MTX. In the second model, a human psoriatic skin equivalent (PSE) culture system, cells were treated with vehicle control, Allo and GSH (as monotherapies and in combination), and vitamin D (VitD) for 2 and 6 days followed by histological analysis and altered gene expression. The combined exposure to Allo and GSH was equivalent to a standard antipsoriasis agent VitD in the inhibition of both proliferative and replicative markers. Histologic examination of the tissue at 6 days of exposure to VitD resulted in loss of the integrity of the squamous/epithelial continuity whereas tissue integrity was preserved with Allo and GSH exposure. The additional exposure of GSH to Allo reversed the increased thickness of the dermis layer caused by Allo exposure alone. Taken together, this data shows that topical Allo and GSH may have a synergistic effect with low toxicity and constitute a therapeutic advantage over current nonsteroidal therapies in the treatment of inflammatory skin conditions marked by increased cell proliferation such as psoriasis.

Novel Janus-kinase (JAK) Inhibitors in Myelofibrosis

INTRODUCTION

JAK inhibitors (JAKis), used in the treatment of myelofibrosis, have entered standard treatment, providing significant improvements in spleen size and symptom burden. Although splenomegaly provides a reduction and some improvement in cytopenia, there is still a way to go. Novel JAKis are being investigated to overcome barriers to treatment access, such as therapeutic challenges, intolerance, and unresponsiveness.

AREAS COVERED

This review includes the current status of JAKi treatment for myelofibrosis, mainly focusing on investigational JAKis; jaktinib, lestaurtinib, itacitinib, gandotinib, BMS-911543, ilginatinib, TQ05105, and flonoltinib maleate. MEDLINE and clinicaltrials.gov were screened to identify all completed or active studies on this topic. The outcomes of the preclinical studies and clinical trials are presented and discussed for each drug.

EXPERT OPINION

In patients with myelofibrosis, momelotinib was effective in treating anemia, whereas jaktinib was effective in both anemia and Total Symptom Score (TSS). More phase 3 studies are needed to provide more precise evidence. The increasing variety of JAKis will allow for more personalized treatment options for myelofibrosis in the future. The potential impact on disease progression, molecular responses, and the duration of this response will become important parameters for future evaluations of these drugs.