Mechanistic Effects of Baicalein on Aqueous Humor Drainage and Intraocular Pressure

A review of using Traditional Chinese Medicine in the management of glaucoma and cataract

Traditional Chinese Medicine has a long history in ophthalmology in China. Over 250 kinds of Traditional Chinese Medicine have been recorded in ancient books for the management of eye diseases, which may provide an alternative or supplement to current ocular therapies. However, the core holistic philosophy of Traditional Chinese Medicine that makes it attractive can also hinder its understanding from a scientific perspective - in particular, determining true cause and effect. This review focused on how Traditional Chinese Medicine could be applied to two prevalent ocular diseases, glaucoma, and cataract. The literature on preclinical and clinical studies in both English and Chinese on the use of Traditional Chinese Medicine to treat these two diseases was reviewed. The pharmacological effects, safety profile, and drug-herb interaction of selected herbal formulas were also investigated. Finally, key considerations for conducting future Traditional Chinese Medicine studies are discussed.

Regulation of Aqueous Humor Secretion by Melatonin in Porcine Ciliary Epithelium

Secretion of melatonin, a natural hormone whose receptors are present in the ciliary epithelium, displays diurnal variation in the aqueous humor (AH), potentially contributing to the regulation of intraocular pressure. This study aimed to determine the effects of melatonin on AH secretion in porcine ciliary epithelium. The addition of 100 µM melatonin to both sides of the epithelium significantly increased the short-circuit current (Isc) by ~40%. Stromal administration alone had no effect on the Isc, but aqueous application triggered a 40% increase in Isc, similar to that of bilateral application without additive effect. Pre-treatment with niflumic acid abolished melatonin-induced Isc stimulation. More importantly, melatonin stimulated the fluid secretion across the intact ciliary epithelium by ~80% and elicited a sustained increase (~50-60%) in gap junctional permeability between pigmented ciliary epithelial (PE) cells and non-pigmented ciliary epithelial (NPE) cells. The expression of MT3 receptor was found to be >10-fold higher than that of MT1 and MT2 in porcine ciliary epithelium. Aqueous pre-treatment with MT1/MT2 antagonist luzindole failed to inhibit the melatonin-induced Isc response, while MT3 antagonist prazosin pre-treatment abolished the Isc stimulation. We conclude that melatonin facilitates Cl- and fluid movement from PE to NPE cells, thereby stimulating AH secretion via NPE-cell MT3 receptors.

Investigation of the Material Basis of Xiexin Tang to Alleviate Type 2 Diabetes Mellitus Based on Spectrum-Effect Analysis by UPLC-Q-TOF/MS

Xiexin Tang (XXT) is a classic prescription for treating diabetes in clinical practices for thousands of years in China, which has been also proved by a large number of modern pharmacological studies. However, due to its complex composition, the bioactive ingredients of XXT is still unclear. In present researches, spectrum-effect relationship analysis is widely used to explore the material basis of traditional medical herbs, so this method was adopted in this study. Firstly, the extract of XXT was separated and enriched into 5 fractions by macroporous adsorption resin. Then, UPLC-Q-TOF/MS method was used for qualitative identification of components in each eluting part, and efficacy of each fraction was assessed by the T2DM rat model. Based on grey relational analysis and pearson bivariate correlation analysis, it was found that the components such as berberine, gallic acid, catechin, epicatechin, acteoside, berberastine and 1-O-galloyl-β-D-glucose might be the main effective basis of XXT to improve T2DM.