Ischemia is a common pathological condition present in many neurodegenerative diseases, including ischemic stroke, retinal vascular occlusion, diabetic retinopathy, and glaucoma, threatening the sight and lives of millions of people globally. Ischemia can trigger excessive oxidative stress, inflammation, and vascular dysfunction, leading to the disruption of tissue homeostasis and, ultimately, cell death. Current therapies are very limited and have a narrow time window for effective treatment. Thus, there is an urgent need to develop more effective therapeutic options for ischemia‐induced neural injuries. With emerging reports on the pharmacological properties of natural flavonoids, these compounds present potent antioxidative, anti‐inflammatory, and antiapoptotic agents for the treatment of ischemic insults. Three major active flavonoids, baicalein, baicalin, and wogonin, have been extracted from Scutellaria baicalensis Georgi (S. baicalensis); all of which are reported to have low cytotoxicity. They have been demonstrated to exert promising pharmacological capabilities in preventing cell and tissue damage. This review focuses on the therapeutic potentials of these flavonoids against ischemia‐induced neurotoxicity and damage in the brain and retina. The bioactivity and bioavailability of baicalein, baicalin, and wogonin are also discussed. It is with hope that the therapeutic potential of these flavonoids can be utilized and developed as natural treatments for ischemia‐induced injuries of the central nervous system (CNS).
1 October 2014 in Journal of Ocular Pharmacology and Therapeutics
Ocular diseases such as cataract, glaucoma, age-related macular degeneration (AMD), and diabetic retinopathy are the leading causes of blindness. The elderly population is at particular risk of developing one or more of these age-related ocular diseases. By virtue of multiple bioactivities, effort has been made to develop dietary flavonoids as complimentary therapies for ocular disorders. Dietary intake of flavonoids has been reported to reduce the risk of cataract and AMD. This review focuses on the main flavones baicalein, baicalin, and wogonin isolated from the Chinese medicinal herb, Scutellariae radix (SR), which has been widely used in Asian countries for the treatment of many diseases. Interest in SR has grown recently following new findings that suggest multiple routes of therapeutic action. This review will summarize the diverse pharmacological properties, therapeutic roles, and mechanisms of these flavones of SR in cellular and animal models of ocular diseases.
Nearly all children and teens in Hong Kong own a smartphone. There is currently no validated instrument that measures whether they use their phone too much. This study tested the psychometric properties of a translated Chinese version of the Smartphone Addiction Scale-Short Version (SAS-SV) and examined the demographic correlates of smartphone addiction among Hong Kong children and adolescents. A total of 1,901 primary school children and secondary school pupils were recruited from 15 Hong Kong schools. Furthermore, 1,797 primary caregivers were asked to complete a self-administered questionnaire on their socioeconomic status and educational attainment. The study used exploratory factor analysis (EFA) to identify the factor structure of SAS-SV for half the participants (n = 951), while confirmatory factor analysis (CFA) was used to assessed the goodness-of-fit of EFA models for the remaining half (n = 951). Spearman correlations were used to assess the convergent validity of the SAS-SV, taking account of time spent by subjects on phones per day, the Smart Device Addiction Screening Tool (SDAST), the Pittsburgh Sleep Quality Index (PSQI), the Multidimensional Scale of Perceived Social Support (MSPSS), and the Center for Epidemiological Studies Depression Scale for Children (CES-DC). EFA generated a three-factor model (with factors labeled “dependency,” the incidence of a “problem,” and “time spent”). CFA confirmed this model yielded an acceptable goodness-of-fit (Comparative Fit Index = 0.96, Tucker Lewis Index = 0.95, and root-mean-square error of approximation = 0.06). SAS-SV was positively correlated with SDAST (ρ = 0.59), PSQI (ρ = 0.29), and CES-D (ρ = 0.35), and negatively correlated with MSPSS (ρ = −0.10). A linear regression model showed that female adolescents, those with highly educated caregivers and those who spent more time using smartphones on their holidays, had on average higher SAS-SV scores, meaning they showed greater vulnerability to becoming addicted. The study found that SAS-SV is a valid scale for estimating excessive smartphone use among Hong Kong children and adolescents.
1 June 2014 in Investigative Ophthalmology & Visual Science
Purpose.: Although glaucoma treatments alter aqueous humor (AH) dynamics to lower intraocular pressure, the regulatory mechanisms of AH circulation and their contributions to the pathogenesis of ocular hypertension and glaucoma remain unclear. We hypothesized that gadolinium-enhanced magnetic resonance imaging (Gd-MRI) can visualize and assess AH dynamics upon sustained intraocular pressure elevation and pharmacologic interventions. Methods.: Gadolinium contrast agent was systemically administered to adult rats to mimic soluble AH components entering the anterior chamber (AC) via blood–aqueous barrier. Dynamic Gd-MRI was applied to examine the signal enhancement in AC and vitreous body upon microbead-induced ocular hypertension and unilateral topical applications of latanoprost, timolol maleate, and brimonidine tartrate to healthy eyes. Results.: Gadolinium signal time courses in microbead-induced hypertensive eyes possessed faster initial gadolinium uptake and higher peak signals in AC than control eyes, reflective of reduced gadolinium clearance upon microbead occlusion. Opposite trends were observed in latanoprost- and timolol-treated eyes, indicative of their respective drug actions on increased uveoscleral outflow and reduced AH production. The slowest initial gadolinium uptake but strongest peak signals were found in AC of both brimonidine-treated and untreated fellow eyes. These findings drew attention to the systemic effects of topical hypotensive drug treatment. Gadolinium leaked into the vitreous of microbead-induced hypertensive eyes and brimonidine-treated and untreated fellow eyes, suggestive of a compromise of aqueous–vitreous or blood–ocular barrier integrity. Conclusions.: Gadolinium-enhanced MRI allows spatiotemporal and quantitative evaluation of altered AH dynamics and ocular tissue permeability for better understanding the physiological mechanisms of ocular hypertension and the efficacy of antiglaucoma drug treatments.