Impact of prostaglandin glaucoma drops on platelet-activating factor action: an in vitro study

From Eye Care to Hair Growth: Bimatoprost

BACKGROUND

Bimatoprost has emerged as a significant medication in the field of medicine over the past several decades, with diverse applications in ophthalmology, dermatology, and beyond. Originally developed as an ocular hypotensive agent, it has proven highly effective in treating glaucoma and ocular hypertension. Its ability to reduce intraocular pressure has established it as a first-line treatment option, improving management and preventing vision loss. In dermatology, bimatoprost has shown promising results in the promotion of hair growth, particularly in the treatment of alopecia and hypotrichosis. Its mechanism of action, stimulating the hair cycle and prolonging the growth phase, has led to the development of bimatoprost-containing solutions for enhancing eyelash growth.

AIM

The aim of our review is to provide a brief description, overview, and studies in the current literature regarding the versatile clinical use of bimatoprost in recent years. This can help clinicians determine the most suitable individualized therapy to meet the needs of each patient.

METHODS

Our methods involve a comprehensive review of the latest advancements reported in the literature in bimatoprost formulations, which range from traditional eye drops to sustained-release implants. These innovations offer extended drug delivery, enhance patient compliance, and minimize side effects.

RESULTS

The vast literature published on PubMed has confirmed the clinical usefulness of bimatoprost in lowering intraocular pressure and in managing patients with glaucoma. Numerous studies have shown promising results in dermatology and esthetics in promoting hair growth, particularly in treating alopecia and hypotrichosis. Its mechanism of action involves stimulating the hair cycle and prolonging the growth phase, leading to the development of solutions that enhance eyelash growth. The global use of bimatoprost has expanded significantly, with applications growing beyond its initial indications. Ongoing research is exploring its potential in glaucoma surgery, neuroprotection, and cosmetic procedures.

CONCLUSIONS

Bimatoprost has shown immense potential for addressing a wide range of therapeutic needs through various formulations and advancements. Promising future perspectives include the exploration of novel delivery systems such as contact lenses and microneedles to further enhance drug efficacy and patient comfort. Ongoing research and future perspectives continue to shape its role in medicine, promising further advancements and improved patient outcomes.

PAF-induced inflammatory and immuno-allergic ophthalmic diseases and their mitigation with PAF receptor antagonists: Cell and nuclear effects

Ocular allergies are becoming more prevalent as more airborne pollutants, irritants and microbes pervade our environment. Inflammatory and allergic mediators released by dendritic and mast cells within the conjunctiva cause allergic conjunctivitis (AC), a prevalent ocular surface disorder that affects >40% of the world's human population on a seasonal or perennial basis. Even though histamine is a major culprit, platelet-activating factor (PAF) also contributes to AC, acting either directly or synergistically with histamine and other mediators. PAF receptor-meditated inflammatory reactions, via cell-membrane-bound and nuclear-membrane-bound and nuclear PAF receptors, are also implicated in the etiology of other eye diseases such as uveitis, diabetic retinopathy, corneal and choroidal neovascularization, and age-related macular degeneration which cause serious visual impairment and can lead to blindness. This review highlights the various deleterious elements implicated in the pathological aspects of ocular allergic reactions and inflammation and provides concepts and treatment options to mitigate these eye disorders with a special focus on PAF and PAF receptor antagonists.

Targeted Lipidomic Analysis of Aqueous Humor Reveals Signaling Lipid-Mediated Pathways in Primary Open-Angle Glaucoma

Simple Summary

Analysis of the eye liquids collected from a cohort of primary open-angle glaucoma patients identified signaling lipids, the pattern of which suggests a role of arachidonic acid/platelet activating-factor (PAF)-dependent pathways and oxidative stress in the pathogenesis of the disease and provides novel targets for its diagnostics and treatment.

Abstract

Primary open-angle glaucoma (POAG) is characterized by degeneration of retinal ganglion cells associated with an increase in intraocular pressure (IOP) due to hindered aqueous humor (AH) drainage through the trabecular meshwork and uveoscleral pathway. Polyunsaturated fatty acids and oxylipins are signaling lipids regulating neuroinflammation, neuronal survival and AH outflow. Among them, prostaglandins have been previously implicated in glaucoma and employed for its treatment. This study addressed the role of signaling lipids in glaucoma by determining their changes in AH accompanying IOP growth and progression of the disease. Eye liquids were collected from patients with POAG of different stages and cataract patients without glaucoma. Lipids were identified and quantified by UPLC-MS/MS. The compounds discriminating glaucoma groups were recognized using ANCOVA and PLS-DA statistic approaches and their biosynthetic pathways were predicted by bioinformatics. Among 22 signaling lipids identified in AH, stage/IOP-dependent alterations in glaucoma were provided by a small set of mediators, including 12,13-DiHOME, 9- and 13-HODE/KODE, arachidonic acid and lyso-PAF. These observations correlated with the expression of cytochromes P450 (CYPs) and phospholipases A2 in the ocular tissues. Interestingly, tear fluid exhibited similar lipidomic alterations in POAG. Overall, POAG may involve arachidonic acid/PAF-dependent pathways and oxidative stress as evidenced from an increase in its markers, KODEs and 12,13-DiHOME. The latter is a product of CYPs, one of which, CYP1B1, is known as POAG and primary congenital glaucoma-associated gene. These data provide novel targets for glaucoma treatment. Oxylipin content of tear fluid may have diagnostic value in POAG.

Effect of Cromakalim Prodrug 1 (CKLP1) on Aqueous Humor Dynamics and Feasibility of Combination Therapy With Existing Ocular Hypotensive Agents

Purpose

Cromakalim prodrug 1 (CKLP1) is a water-soluble ATP-sensitive potassium channel opener that has shown ocular hypotensive properties in ex vivo and in vivo experimental models. To determine its mechanism of action, we assessed the effect of CKLP1 on aqueous humor dynamics and in combination therapy with existing ocular hypotensive agents.

Methods

Outflow facility was assessed in C57BL/6 mice by ex vivo eye perfusions and by in vivo constant flow infusion following CKLP1 treatment. Human anterior segments with no trabecular meshwork were evaluated for effect on pressure following CKLP1 treatment. CKLP1 alone and in combination with latanoprost, timolol, and Rho kinase inhibitor Y27632 were evaluated for effect on intraocular pressure in C57BL/6 mice and Dutch-belted pigmented rabbits.

Results

CKLP1 lowered episcleral venous pressure (control: 8.9 ± 0.1 mm Hg versus treated: 6.2 ± 0.1 mm Hg, P < 0.0001) but had no detectable effect on outflow facility, aqueous humor flow rate, or uveoscleral outflow. Treatment with CKLP1 in human anterior segments without the trabecular meshwork resulted in a 50% ± 9% decrease in pressure, suggesting an effect on the distal portion of the conventional outflow pathway. CKLP1 worked additively with latanoprost, timolol, and Y27632 to lower IOP, presumably owing to combined effects on different aspects of aqueous humor dynamics.

Conclusions

CKLP1 lowered intraocular pressure by reducing episcleral venous pressure and lowering distal outflow resistance in the conventional outflow pathway. Owing to this unique mechanism of action, CKLP1 works in an additive manner to lower intraocular pressure with latanoprost, timolol, and Rho kinase inhibitor Y27632.