Nutritional antioxidants and age-related cataract and maculopathy

A role for YAP/FOXM1/Nrf2 axis in oxidative stress and apoptosis of cataract induced by UVB irradiation

This study aims to investigate the hypothesis that Yes-associated protein (YAP) significantly regulates antioxidant potential and anti-apoptosis in UVB-induced cataract by exploring the underlying molecular mechanisms. To investigate the association between YAP and cataract, various experimental techniques were employed, including cell viability assessment, Annexin V FITC/PI assay, measurement of ROS production, RT-PCR, Western blot assay, and Immunoprecipitation. UVB exposure on human lens epithelium cells (HLECs) reduced total and nuclear YAP protein expression, increased cleaved/pro-caspase 3 ratios, decreased cell viability, and elevated ROS levels compared to controls. Similar Western blot results were observed in in vivo experiments involving UVB-treated mice. YAP knockdown in vitro demonstrated a decrease in the protein expression of FOXM1, Nrf2, and HO-1, which correlated with the mRNA expression, accompanied by an increase in cell apoptosis, caspase 3 activation, and the release of ROS. Conversely, YAP overexpression mitigated these effects induced by UVB irradiation. Immunoprecipitation revealed a FOXM1-YAP interaction. Notably, inhibiting FOXM1 decreased Nrf2 and HO-1, activating caspase 3. Additionally, administering the ROS inhibitor N-acetyl-L-cysteine (NAC) effectively mitigated the apoptotic effects induced by oxidative stress from UVB irradiation, rescuing the protein expression levels of YAP, FOXM1, Nrf2, and HO-1. The initial findings of our study demonstrate the existence of a feedback loop involving YAP, FOXM1, Nrf2, and ROS that significantly influences the cell apoptosis in HLECs under UVB-induced oxidative stress.

Myopia and Nutrient Associations with Age-Related Eye Diseases in Korean Adults: A Cross-Sectional KNHANES Study

This study assessed the prevalence of myopia, cataracts, glaucoma, and macular degeneration among Koreans over 40, utilizing data from the 7th Korea National Health and Nutrition Examination Survey (KNHANES VII, 2018). We analyzed 204,973 adults (44% men, 56% women; mean age 58.70 ± 10.75 years), exploring the association between myopia and these eye diseases through multivariate logistic regression, adjusting for confounders and calculating adjusted odds ratios (ORs) with 95% confidence intervals (CIs). Results showed a myopia prevalence of 44.6%, cataracts at 19.4%, macular degeneration at 16.2%, and glaucoma at 2.3%, with significant differences across ages and genders. A potential link was found between myopia and an increased risk of cataracts and macular degeneration, but not with glaucoma. Additionally, a higher dietary intake of carbohydrates, polyunsaturated and n-6 fatty acids, vitamins, and minerals correlated with lower risks of these diseases, underscoring the importance of the diet in managing and preventing age-related eye conditions. These findings highlight the need for dietary considerations in public health strategies and confirm myopia as a significant risk factor for specific eye diseases in the aging Korean population.

Swimming exercise reverses transcriptomic changes in aging mouse lens

BACKGROUND

The benefits of physical activity for the overall well-being of elderly individuals are well-established, the precise mechanisms through which exercise improves pathological changes in the aging lens have yet to be fully understood.

METHODS

3-month-old C57BL/6J mice comprised young sedentary (YS) group, while aging mice (18-month-old) were divided into aging sedentary (AS) group and aging exercising (AE) group. Mice in AE groups underwent sequential stages of swimming exercise. H&E staining was employed to observe alterations in lens morphology. RNA-seq analysis was utilized to examine transcriptomic changes. Furthermore, qPCR and immunohistochemistry were employed for validation of the results.

RESULTS

AE group showed alleviation of histopathological aging changes in AS group. By GSEA analysis of the transcriptomic changes, swimming exercise significantly downregulated approximately half of the pathways that underwent alterations upon aging, where notable improvements were 'calcium signaling pathway', 'neuroactive ligand receptor interaction' and 'cell adhesion molecules'. Furthermore, we revealed a total of 92 differentially expressed genes between the YS and AS groups, of which 10 genes were observed to be mitigated by swimming exercise. The result of qPCR was in consistent with the transcriptome data. We conducted immunohistochemical analysis on Ciart, which was of particular interest due to its dual association as a common aging gene and its significant responsiveness to exercise. The Protein-protein Interaction network of Ciart showed the involvement of the regulation of Rorb and Sptbn5 during the process.

CONCLUSION

The known benefits of exercise could extend to the aging lens and support further investigation into the specific roles of Ciart-related pathways in aging lens.

Redox Regulation in Age-Related Cataracts: Roles for Glutathione, Vitamin C, and the NRF2 Signaling Pathway

Age is the biggest risk factor for cataracts, and aberrant oxidative modifications are correlated with age-related cataracts, suggesting that proper redox regulation is important for lens clarity. The lens has very high levels of antioxidants, including ascorbate and glutathione that aid in keeping the lens clear, at least in young animals and humans. We summarize current functional and genetic data supporting the hypothesis that impaired regulation of oxidative stress leads to redox dysregulation and cataract. We will focus on the essential endogenous antioxidant glutathione and the exogenous antioxidant vitamin C/ascorbate. Additionally, gene expression in response to oxidative stress is regulated in part by the transcription factor NRF2 (nuclear factor erythroid 2-related factor 2 [NFE2L2]), thus we will summarize our data regarding cataracts in Nrf2-/- mice. In this work, we discuss the function and integration of these capacities with the objective of maintaining lens clarity.

Chronic Antioxidant Capacity Loss in Anterior Chamber Environment After Iridectomy

Purpose

To compare the ascorbic acid concentration and total antioxidant capacity in the aqueous humor of pigmented Rex rabbits after sham operation (control), iridectomy, and trabeculectomy.

Methods

Pigmented Rex rabbits were divided into control, iridectomy, and trabeculectomy groups and followed up for 12 months after surgery. Ascorbic acid concentration and total antioxidant capacity in the aqueous humor, intraocular pressure, and the occurrence of cataracts were examined in each group.

Results

The ascorbic acid concentration and total antioxidant capacity after iridectomy and trabeculectomy were significantly lower at one week and at one, six, and 12 months after operation than those in the control group (P ≤ 0.03). Ascorbic acid concentration was positively and significantly correlated with total antioxidant capacity in the aqueous humor (P < 0.01). Compared to the control and the iridectomy groups, intraocular pressure in the trabeculectomy group was significantly lower at one week and at one and six months after surgery (one week: P < 0.01 and P < 0.01, respectively; one month: P < 0.01 and P = 0.03, respectively; six months: P = 0.03). Histological findings in the iridectomy and trabeculectomy groups included the appearance of vacuoles in the lens at six and 12 months after surgery.

Conclusions

Iridectomy causes a sustained decrease in ascorbic acid concentration, followed by a long-term decrease in the total antioxidant capacity within the aqueous humor.

Translational Relevance

The animal model possibly predicts the vulnerability focusing on the antioxidant level in the anterior chamber environment after trabeculectomy and iridectomy per se in clinical settings.

Redox Homeostasis in Ocular Tissues: Circadian Regulation of Glutathione in the Lens?

Accumulating evidence in tissues suggests an interconnection between circadian clocks and redox regulation. Diurnal variations in antioxidant levels, circadian rhythms of antioxidant enzyme activity, and differences in oxidative stress markers at different times of the day all indicate that oxidative stress responses follow a circadian rhythm. Disruptions of circadian rhythms are linked to a number of age-related diseases, including those in the eye. Typically, ocular tissues contain a robust antioxidant defence system to maintain redox balance and minimise oxidative stress and damage. The lens, in particular, contains remarkably high levels of the antioxidant glutathione (GSH). However, with advancing age, GSH levels deplete, initiating a chain of biochemical events that ultimately result in protein aggregation, light scattering, and age-related cataracts. While there is evidence that the lens exhibits circadian rhythms in the synthesis and release of melatonin, little is known about the regulation or function of timekeeping mechanisms in the lens. Since circadian rhythms are disrupted with age, and the depletion of GSH in the lens is a known initiating factor in the development of age-related cataracts, understanding the mechanisms involved in regulating GSH levels may lead to the future development of approaches to manipulate the clock to restore GSH levels and redox balance in the lens, and protect the lens from cataracts.

Superior Bioavailability of a Novel Lutein and Zeaxanthin Formulation in Healthy Human Subjects

Introduction

Lutein (L) and zeaxanthin (Z) are carotenoids that are found in the macula of the human eye and are known to improve visual functions. However, poor bioavailability of supplemental L and Z poses a challenge to achieving significant benefits after consumption. We developed a novel patented formulation of L and Z (Ocusorb^®) and demonstrated the improved bioavailability in a pharmacokinetic clinical study.

Methods

Ninety adult human volunteers were recruited in this randomized, double-blind, parallel, comparative bioavailability study. Volunteers were randomly assigned to receive single dose of 10 mg lutein and 2 mg zeaxanthin from test (LZO) or reference (LZC) formulations after breakfast. Blood samples were collected pre-dose at − 48, − 24, and 0 h and at 2, 4, 6, 8, 10, 12, 16, 20, 24, 48, and 72 h post-dose. Serum concentrations of L and Z were quantified by using a validated HPLC method. The LZO and LZC formulations were compared for L and Z on the basis of C_max, AUC_0–72, and AUC_0–t.

Results

All 90 subjects completed the study. The LZO group demonstrated significantly higher levels of L and Z in serum at several time points as compared to LZC group. The LZO group showed significantly higher bioavailability for lutein (2.5 times higher C_max, 2.9 times higher AUC_0–72, and 3.2 times higher AUC_0–t) and zeaxanthin (1.8 times higher C_max, 2.2 times higher AUC_0–72, and AUC_0–t) as compared to the LZC group. No safety issues were reported.

Conclusion

The study results show superior bioavailability of lutein and zeaxanthin from our novel LZO formulation as compared to LZC. The enhanced bioavailability from the LZO formulation can be advantageous for individuals looking to quickly improve their L and Z status and enhance their vision performance.

Trial Registration

http://ctri.nic.in/. Identifier: CTRI/2019/11/022082.

Comparative Efficiency of Lutein and Astaxanthin in the Protection of Human Corneal Epithelial Cells In Vitro from Blue-Violet Light Photo-Oxidative Damage

The aim of this study was to compare in vitro the protective and antioxidant properties of lutein and astaxanthin on human primary corneal epithelial cells (HCE-F). To this purpose, HCE-F cells were irradiated with a blue-violet light lamp (415–420 nm) at different energies (20 to 80 J/cm2). Lutein and astaxanthin (50 to 250 μM) were added to HCE-F right before blue-violet light irradiation at 50 J/cm2. Viability was evaluated by the CKK-8 assay while the production of reactive oxygen species (ROS) by the H2DCF-DA assay. Results have shown that the viability of HCE-F cells decreased at light energies from 20 J/cm2 to 80 J/cm2, while ROS production increased at 50 and 80 J/cm2. The presence of lutein or astaxanthin protected the cells from phototoxicity, with lutein slightly more efficient than astaxanthin also on the blunting of ROS, prevention of apoptotic cell death and modulation of the Nrf-2 pathway. The association of lutein and astaxanthin did not give a significant advantage over the use of lutein alone. Taken together, these results suggest that the association of lutein and astaxanthin might be useful to protect cells of the ocular surface from short (lutein) and longer (astaxanthin) wavelengths, as these are the most damaging radiations hitting the eye from many different LED screens and solar light.

Natural Antioxidants from Plant Extracts in Skincare Cosmetics: Recent Applications, Challenges and Perspectives

In recent years, interest in the health effects of natural antioxidants has increased due to their safety and applicability in cosmetic formulation. Nevertheless, efficacy of natural antioxidants in vivo is less documented than their prooxidant properties in vivo. Plant extracts rich in vitamins, flavonoids, and phenolic compounds can induce oxidative damage by reacting with various biomolecules while also providing antioxidant properties. Because the biological activities of natural antioxidants differ, their effectiveness for slowing the aging process remains unclear. This review article focuses on the use of natural antioxidants in skincare and the possible mechanisms underlying their desired effect, along with recent applications in skincare formulation and their limitations.

Multifunctional Redox Modulators Protect Auditory, Visual, and Cognitive Function

Significance: Oxidative stress contributes to vision, hearing and neurodegenerative disorders. Currently, no treatments prevent these disorders; therefore, there is an urgent need for redox modulators that can prevent these disorders. Recent Advances: Oxidative stress is associated with the generation of reactive oxygen species (ROS) and reactive nitrogen species, metal dyshomeostasis, and mitochondrial dysfunction. Here, we discuss the role that oxidative stress and metal dyshomeostasis play in hearing loss, visual impairments, and neurodegeneration and discuss the benefits of a new class of multifunctional redox modulators (MFRMs) that suppress sensory and neural degeneration. MFRMs not only reduce free radicals but also independently bind transition metals associated with the generation of hydroxyl radicals. The MFRMs redistribute zinc from neurotoxic amyloid beta zinc (Aβ:Zn) complexes to the cytoplasm, facilitating the degradation of Aβ plaques by matrix metalloprotease-2 (MMP-2). Although MFRMs bind copper (Cu1+, Cu2+), iron (Fe2+, Fe3+), zinc (Zn2+), and manganese (Mn2+), they do not deplete free cytoplasmic Zn+2 and they protect mitochondria from Mn+2-induced dysfunction. Oral administration of MFRMs reduce ROS-induced cataracts, protect the retina from light-induced degeneration, reduce neurotoxic Aβ:Zn plaque formation, and protect auditory hair cells from noise-induced hearing loss. Critical Issues: Regulation of redox balance is essential for clinical efficacy in maintaining sensory functions. Future Directions: Future use of these MFRMs requires additional pharmacokinetic, pharmacodynamics, and toxicological data to bring them into widespread clinical use. Additional animal studies are also needed to determine whether MFRMs can prevent neurodegeneration, dementia, and other forms of vision and hearing loss.

Exposure to Porphyromonas gingivalis and Modifiable Risk Factors Modulate Risk for Early Diabetic Retinopathy

Purpose

We hypothesized that exposure to Porphyromonas gingivalis (Pg) increases the risk for early diabetic retinopathy (DR) and that the risk can be modulated.

Methods

We identified 116 early DR cases, and 116 non-DR controls were selected randomly by frequency matching for age, sex, race, and education from the US Third National Health and Nutrition Examination Survey. DR was assessed using non-mydriatic fundus photographs and graded by trained graders using the Modified Airlie House Classification scheme and the Early Treatment for Diabetic Retinopathy Study severity scale. Serum Pg immunoglobulin G (IgG) antibody (Ab) was measured in enzyme-linked immunosorbent assay units. Logistic regression was used to relate serum Pg IgG Ab levels to the risk for early DR.

Results

Per tenfold increase in Pg IgG Ab levels, there was an over 60% increased risk for early DR (odds ratio = 1.64; 95% confidence interval, 1.36–1.97), and a linear trend was noted for the estimated probabilities of early DR at various Pg IgG Ab levels (P for trend = 0.0053). The analysis also suggested that moderate alcohol consumption (less than 12 drinks in the past 12 months; P for interaction = 0.0003) and maintaining a normal serum glycated hemoglobulin level (HbA1c ≤ 5.7%; P for interaction < 0.0001) helped reduce the Pg-related DR risk.

Conclusions

The increased Pg-related DR risk could be alleviated by managing alcohol consumption and maintaining a normal blood glucose level.

Translational Relevance

Findings from this study provide new directions for developing novel therapeutics and prevention strategies for DR.

UV Effect on Human Anterior Lens Capsule Macro-Molecular Composition Studied by Synchrotron-Based FTIR Micro-Spectroscopy

Ultraviolet (UV) irradiation is an important risk factor in cataractogenesis. Lens epithelial cells (LECs), which are a highly metabolically active part of the lens, play an important role in UV-induced cataractogenesis. The purpose of this study was to characterize cell compounds such as nucleic acids, proteins, and lipids in human UV C-irradiated anterior lens capsules (LCs) with LECs, as well as to compare them with the control, non-irradiated LCs of patients without cataract, by using synchrotron radiation-based Fourier transform infrared (SR-FTIR) micro-spectroscopy. In order to understand the effect of the UV C on the LC bio-macromolecules in a context of cataractogenesis, we used the SR-FTIR micro-spectroscopy setup installed on the beamline MIRAS at the Spanish synchrotron light source ALBA, where measurements were set to achieve a single-cell resolution with high spectral stability and high photon flux. UV C irradiation of LCs resulted in a significant effect on protein conformation with protein formation of intramolecular parallel β-sheet structure, lower phosphate and carboxyl bands in fatty acids and amino acids, and oxidative stress markers with significant increase of lipid peroxidation and diminishment of the asymmetric CH₃ band.

Major dietary patterns in relation to age-related cataract

BACKGROUND AND AIMS

Dietary pattern (DP) may play an important role in the formation of Age-related cataract (ARC). The objective of the study was to investigate the association between DP and ARC.

METHODS

Participants (120 cases and 240 controls) aged 50-80 years were selected from the ophthalmology clinic of Urmia Imam Khomeini Educational Hospital in the Northwest of Iran by the simple random sampling method between 2017 and 2018. Participants in matched case-control study were free of diabetes, autoimmune diseases and cancer. Factor analysis method was used to identify the major DPs. The association between participants' DPs and ARC were evaluated using logistic regression analysis in SPSS20.

RESULTS

Four major DPs were found and nominated: "Unhealthy", "Healthy", "Salty foods" and "Mixed" patterns. In continues model the Unhealthy pattern was positively associated with the risk of ARC disease (odds ratio in adjusted model was 5.71; 95% CI: 3.68-8.87, P _trend< 0.001). The Healthy pattern was inversely associated with the ARC (odds ratio in adjusted model was 0.48; 95% CI: 0.34-0.67, P_trend = 0.02). The Salty foods pattern was associated with ARC (odds ratio in adjusted model was 1.45; 95% CI; 1.04-2.02, P_trend = 0.03). The association between ARC disease and Mixed patterns was not statistically significant.

CONCLUSION

The results indicate that Unhealthy and Salty foods patterns were associated with increased risk of ARC. Further prospective studies are needed to confirm such an association.

Vitamin C and the Lens: New Insights into Delaying the Onset of Cataract

Cataracts or clouding of the lens is the leading cause of blindness in the world. Age and diabetes are major risk factors, and with an increasing aging and diabetic population, the burden of cataracts will grow. Cataract surgery is an effective way to restore vision; however, alternatives to cataract surgery are required to reduce the looming cataract epidemic. Since it is well established that oxidative damage plays a major role in the etiology of cataracts, antioxidants have been promoted as therapies to delay and/or prevent cataracts. However, many antioxidant interventions including vitamin C have produced mixed results as anti-cataract therapies. Progress has been made towards our understanding of lens physiology and the mechanisms involved in the delivery and uptake of antioxidants to the lens which may guide future studies aimed at addressing some of the inconsistencies seen in previous animal and human studies. Of interest is the potential for vitamin C based supplements in delaying the onset of cataracts post vitrectomy which occurs in up to 80% of patients within two years. These targeted approaches are required to reduce the burden of cataract on hospitals and improve the quality of life of our aging and diabetic population.

Synchrotron-based FTIR microspectroscopy of protein aggregation and lipids peroxidation changes in human cataractous lens epithelial cells

Cataract is the leading cause of blindness worldwide but the mechanisms involved in the process of cataractogenesis are not yet fully understood. Two most prevalent types of age-related cataracts are nuclear (N) and cortical (C) cataracts. A common environmental factor in most age-related cataracts is believed to be oxidative stress. The lens epithelium, the first physical and biological barrier in the lens, is build from lens epithelial cells (LECs). LECs are important for the maintenance of lens transparency as they control energy production, antioxidative mechanisms and biochemical transport for the whole lens. The purpose of this study is to characterize compounds in LECs originated from N and C cataracts, by using the synchrotron radiation-based Fourier Transform Infrared (SR-FTIR) microspectroscopy, in order to understand the functional importance of their different bio-macromolecules in cataractogenesis. We used the SR-FTIR microspectroscopy setup installed on the beamline MIRAS at the Spanish synchrotron light source ALBA, where measurements were set to achieve single cell resolution, with high spectral stability and high photon flux. The results showed that protein aggregation in form of fibrils was notably pronounced in LECs of N cataracts, while oxidative stress and the lipids peroxidation were more pronounced in LECs of C cataracts.

The potential health benefits of dietary natural plant products in age related eye diseases

In the past decade, there has been a tremendous increase in the number of cases of age-related eye diseases such as age-related macular degeneration (AMD), cataract, diabetic retinopathy and glaucoma. These diseases are the leading causes of visual impairment and blindness all over the world and are associated with many pathological risk factors such as aging, pollution, high levels of glucose (hyperglycaemia), high metabolic rates, and light exposure. These risk factors lead to the generation of uncontrollable reactive oxygen species (ROS), which causes oxidative stress. Oxidative stress plays a crucial role in the pathogenesis of age-related eye diseases through the activation of nuclear factor kappa B (NF-κB), vascular endothelial growth factor (VEGF), and lipid peroxidation, which leads to the production of inflammatory cytokines, angiogenesis, protein and DNA damages, apoptosis that causes macular degeneration (AMD), cataract, diabetic retinopathy and glaucoma. This review provides updated information on the beneficial effects of dietary natural plant products (DPNPs) against age-related eye diseases. In this review, supplementation of DPNPs demonstrated preventive and therapeutic effects on people at risk of or with age-related eye diseases due to their capacity to scavenge free radicals, ameliorate inflammatory molecules, neutralize the oxidation reaction that occurs in photoreceptor cells, decrease vascular endothelial growth factor and the blood-retinal barrier and increase the antioxidant defence system. However, further experiments and clinical trials are required to establish the daily doses of DPNPs that will safely and effectively prevent age-related eye diseases.

Association between dietary glycemic index and glycemic load, insulin index and load with incidence of age-related cataract: Results from a case-control study

AIM

To identify the association between the dietary carbohydrate indexes, such as dietary glycemic index (DGI) and load (DGL), dietary insulin index (DII) and load (DIL), with the possibility of cataract.

METHOD

This case-control study consisted of 101 new cases of cataract and 202 controls. DGI and DGL were computed through DGI values previously published. DII was also calculated based on dietary insulin index data published previously.

RESULTS

There was a significant positive association between the highest quartiles of DGI (OR = 6.56; 95% CI = 2.67-16.06; P < 0.001), DGL (OR = 6.17; 95% CI = 1.93-19.37; P = 0.002) and DIL (OR = 4.17; 95% CI = 1.41-12.27; P = 0.004) with risk of cataract, compared to those on the lowest quartile, but not for DII (OR = 0.85; 95% CI = 0.39-1.86; P = 0.82). Furthermore, after stratifying groups by BMI, a significant direct association between highest quartile of DGI (OR = 6.76; 95% CI = 2.49-18.38; P < 0.001) and DGL (OR = 3.45; 95% CI = 0.96-12.37; P = 0.05) with risk of cataract was evident in individuals with elevated BMI (BMI≥25).

CONCLUSION

We found a significant, direct, relationship between DGI, DGL and DIL with risk of cataract. However, the association between DII and the risk of cataract was not significant, even after adjusting for related confounders.

Nutrition and Eye Health

Diet is a key lifestyle factor that can have long-term effects on ocular health [...].

Functional Analysis of the Marigold (Tagetes erecta) Lycopene ε-cyclase (TeLCYe) Promoter in Transgenic Tobacco

Lycopene ε-cyclases (LCYEs) are key enzymes in carotenoid biosynthesis converting red lycopene to downstream lutein. The flowers of marigold (Tagetes erecta) have been superior sources to supply lutein. However, the transcriptional regulatory mechanisms of LCYe in lutein synthesis are still unclear in marigold. In this work, the expression pattern of the TeLCYe gene in marigold indicated that TeLCYe mainly expressed in floral organs. To gain a better understanding of the expression and regulatory mechanism of TeLCYe gene, the TeLCYe promoter was isolated, sequenced, and analyzed through bioinformatics tools. The results suggested that the sequence of TeLCYe promoter contained various putative cis-acting elements responsive to exogenous and endogenous factors. The full-length TeLCYe promoter and three 5'-deletion fragments were fused to the GUS reporter gene and transferred into tobacco to test the promoter activities. A strong GUS activity was observed in stems of seedlings, leaves of seedlings, middle stems, top leaves, petals, stamens, and stigmas in transgenic tobacco containing full-length TeLCYe promoter LP0-2086. Deletion of - 910 to - 429 bp 5' to ATG significantly increased the GUS activity in chloroplast-rich tissues and floral organs, while deletion occurring from 1170 to 910 bp upstream ATG decreased the TeLCYe promoter strength in stems of seedlings, leaves of seedlings, top leaves and sepals. Functional characterization of the full-length TeLCYe promoter and its' deletion fragments in stable transgenic tobacco indicated that the LP0-2086 contains some specific cis-acting elements, which might result in the high-level expression of in floral organs, and LP2-910 might contain some specific cis-acting elements which improved GUS activities in vegetable tissues.

Effects of a novel isoflavonoid from the stem bark of Alstonia scholaris against fructose-induced experimental cataract

OBJECTIVE

The present study investigated the anticataract activity of a novel isoflavonoid, isolated from stem bark of Alstonia scholaris, against fructose-induced experimental cataract.

METHODS

The bioactivity of fractions extracted from A. scholaris, an isolated isoflavonoid (ASII) was screened using in vitro (goat lens) and in vivo (albino rats) experimental cataract models. For the in vivo evaluation, albino rats (12-15 weeks old) were divided into five groups (n = 6). Group I (normal) received 0.3% carboxymethyl cellulose solution (10 mL/[kg·d], p.o.). Group II (control) received 10% (w/v) fructose solution in their drinking water. Groups III-V received ASII at three different doses, 0.1, 1.0 and 10 mg/(kg·d), concurrently with 10% (w/v) fructose solution. Treatment was given daily for 8 consecutive weeks. During the protocol, systolic blood pressure, diastolic blood pressure, blood glucose level and lenticular opacity were monitored at 2-week intervals. Pathophysiological markers (catalase, superoxide dismutase, glutathione peroxidase, reduced glutathione and malondialdehyde) in eye lenses were examined at the end of the 8-week treatment period.

RESULTS

The results of in vitro study showed that A. scholaris extract and the active fraction (A₃) reduced the lenticular opacity as compared to toxic control group. The in vivo study showed that 8-week administration of ASII (0.1, 1.0 and 10 mg/[kg·d], p.o.) led to significant reduction in blood pressure and blood glucose level and retarded the initiation and evolution of cataractogenesis, compared to the fructose-induced cataract model control. Additionally, ASII treatment led to significant improvement in lens antioxidants (catalase, superoxide dismutase, glutathione peroxidase and reduced glutathione) and decreased lens malondialdehyde, compared to the control group (group II).

CONCLUSION

Results revealed that administration of ASII played a crucial role in the reduction of cataract formation in diabetic and hypertensive models.

Crude and standardized prevalences of cataract and related factors in the elderly people in Northern Iran

Purpose:

This study aims to estimate the crude and standardized prevalences of cataract and its related factors among old people in northern parts of Iran.

Methods:

This cross-sectional study was carried out among 397 people aged 60 and older in northern Iran. Required information about treated and nontreated cataract was collected using a standard checklist. The World Standard Population was applied for direct standardization.

Results:

The standardized prevalence (95% confidence interval) of cataract among men, women, and all people were 27.5% (21.2–33.8), 30.9% (24.5–37.4), and 29.1% (24.6–33.6), respectively. Based on multivariate logistic regression models, age over 75 years (OR = 3.03, 95% CI: 1.21–7.59), living alone (OR = 4.89, 95% CI: 1.86‒12.86), diabetes mellitus (odds ratio = 19.10, 95% confidence interval: 8.13–44.89), rheumatoid arthritis (OR = 7.76, 95% CI: 2.32–25.99), history of infectious diseases (OR = 4.02, 95% CI: 1.35‒11.98), hypertension (OR = 3.19, 95% CI: 1.59–6.42), history of ophthalmic surgery (OR = 2.83, 95% CI: 1.29–6.16), history of sedative drug use (OR = 2.71, 95% CI: 1.35–5.47), history of vitamin supplementation use (OR = 0.21, 95% CI: 0.08–0.55), and familial history of cataract (OR = 2.81, 95% confidence interval: 1.38–5.72) increased the odds of cataract. Our multiple logistic regression model explained 53% of the variation in developing cataract.

Conclusion:

Our study showed that the prevalence of cataract in the study population was relatively high. We also found that aging, living alone, diabetes mellitus, rheumatoid arthritis, hypertension, infectious diseases, ophthalmic surgery, sedative drugs and familial history of cataract were the risk factors of cataract and vitamin supplementations were its protective factors.

Potential of Microalgae Carotenoids for Industrial Application

Microalgae cultivation, when compared to the growth of higher plants, presents many advantages such as faster growth, higher biomass productivity, and smaller land area requirement for cultivation. For this reason, microalgae are an alternative platform for carotenoid production when compared to the traditional sources. Currently, commercial microalgae production is not well developed but, fortunately, there are several studies aiming to make the large-scale production feasible by, for example, employing different cultivation systems. This review focuses on the main carotenoids from microalgae, comparing them to the traditional sources, as well as a critical analysis about different microalgae cultivation regimes that are currently available and applicable for carotenoid accumulation. Throughout this review paper, we present relevant information about the main commercial microalgae carotenoid producers; the comparison between carotenoid content from food, vegetables, fruits, and microalgae; and the great importance and impact of these molecule applications, such as in food (nutraceuticals and functional foods), cosmetics and pharmaceutical industries, feed (colorants and additives), and healthcare area. Lastly, the different operating systems applied to these photosynthetic cultivations are critically discussed, and conclusions and perspectives are made concerning the best operating system for acquiring high cell densities and, consequently, high carotenoid accumulation.

Transcriptomic changes triggered by carotenoid biosynthesis inhibitors and role of Citrus sinensis phosphate transporter 4;2 (CsPHT4;2) in enhancing carotenoid accumulation

Carotenoid accumulation and chromoplast development in orange were perturbed by carotenoid inhibitors, and candidate genes were identified via transcriptomic analysis. The role of CsPHT4;2 in enhancing carotenoid accumulation was revealed. Carotenoids are important plant pigments and their accumulation can be affected by biosynthesis inhibitors, but the genes involved were largely unknown. Here, application of norflurazon (NFZ), 2-(4-chlorophenylthio)-triethylamine hydrochloride (CPTA) and clomazone for 30 days to in vitro cultured sweet orange juice vesicles caused over-accumulation of phytoene (over 1000-fold), lycopene (2.92 μg g^-1 FW, none in control), and deficiency in total carotenoids (reduced to 22%), respectively. Increased carotenoids were associated with bigger chromoplasts with enlarged plastoglobules or a differently crystalline structure in NFZ, and CPTA-treated juice vesicles, respectively. Global transcriptomic changes following inhibitor treatments were profiled. Induced expression of 1-deoxy-D-xylulose 5-phosphate synthase 1 by CPTA, hydroxymethylbutenyl 4-diphosphate reductase by both NFZ and CPTA, and reduced expression of chromoplast-specific lycopene β-cyclase by CPTA, as well as several downstream genes by at least one of the three inhibitors were observed. Expression of fibrillin 11 (CsFBN11) was induced following both NFZ and CPTA treatments. Using weighted correlation network analysis, a plastid-type phosphate transporter 4;2 (CsPHT4;2) was identified as closely correlated with high-lycopene accumulation induced by CPTA. Transient over-expression of CsPHT4;2 significantly enhanced carotenoid accumulation over tenfold in 'Cara Cara' sweet orange juice vesicle-derived callus. The study provides a valuable overview of the underlying mechanisms for altered carotenoid accumulation and chromoplast development following carotenoid inhibitor treatments and sheds light on the relationship between carotenoid accumulation and chromoplast development.

Nutritional effect on age-related cataract formation and progression

PURPOSE OF REVIEW

To provide a comprehensive summary of the latest evidence-based data on nutrients linked to the pathogenesis of cataract formation and progression.

RECENT FINDINGS

This summary of peer-reviewed publications emphasizes the ongoing effort to modulate the cataractogenous process through nutrition, and points at an only weak evidence for the contribution of a specific nutrient to this process. Although observational studies successfully demonstrated a positive correlation between specific nutrients intake and age-related cataract, such evidence was usually lacking in following interventional studies. Three metanalyses point towards a beneficial effect of high intake of vitamin C, vitamin E and vitamin A on the risk of age-related cataract. New studies point at a protective effect of a high intake of vitamin K1 and vitamin D but negate the influence of Mediterranean diet or an overall high dairy consumption on the progression of cataract in a subgroup of patients. Sterols are candidate nutrients for future investigation.

SUMMARY

Nutrition rich in fruits and vegetables, and a high dietary intake of vitamins A, C, D, E and K1 may be inversely associated with the risk of age-related cataract. More studies involving patients in a wide range of nutritional status are required to establish the long-term benefit of nutritional supplements.

Therapeutic effect of molecular hydrogen in corneal UVB-induced oxidative stress and corneal photodamage

The aim of this study is to examine whether molecular hydrogen (H₂) is able to reduce oxidative stress after corneal damage induced by UVB irradiation. We previously found that UVB irradiation of the cornea caused the imbalance between the antioxidant and prooxidant enzymes in the corneal epithelium, followed by the imbalance between metalloproteinases and their physiological inhibitors (imbalances in favour of prooxidants and metalloproteinases) contributing to oxidative stress and development of the intracorneal inflammation. Here we investigate the effect of H₂ dissolved in PBS in the concentration 0.5 ppm wt/vol, applied on rabbit corneas during UVB irradiation and healing (UVB doses 1.01 J/cm² once daily for four days). Some irradiated corneas remained untreated or buffer treated. In these corneas the oxidative stress appeared, followed by the excessive inflammation. Malondiladehyde and peroxynitrite expressions were present. The corneas healed with scar formation and neovascularization. In contrast, in H₂ treated irradiated corneas oxidative stress was suppressed and malondiladehyde and peroxynitrite expressions were absent. The corneas healed with the restoration of transparency. The study provides the first evidence of the role of H₂ in prevention of oxidative and nitrosative stress in UVB irradiated corneas, which may represent a novel prophylactic approach to corneal photodamage.

Gene expression levels of the insulin-like growth factor family in patients with AMD before and after ranibizumab intravitreal injections

Purpose

The present study focused on the assessment of the mRNA levels of the insulin-like growth factor (IGF) family in patients with the exudative form of age-related macular degeneration (AMD) before and after ranibizumab intravitreal injections.

Patients and methods

An analysis of the expression profile of the IGF family of genes in patients with AMD was carried out using the oligonucleotide microarray and quantitative reverse transcriptase polymerase chain reaction (RT-qPCR) methods.

Results

In the peripheral blood mononuclear cells (PBMCs) obtained from AMD group receiving ranibizumab compared to the peripheral blood mononuclear cells from AMD group before ranibizumab treatment using oligonucleotide microarray technique, six statistically significant differentially expressed transcripts related to the IGF family were detected (unpaired t-test, p<0.05, fold change >1.5). Moreover, analysis using the real-time RT-qPCR technique revealed statistically significant differences in the IGF2 and IGF2R mRNA levels (Mann–Whitney U test, p<0.05) between the two groups that were studied. Statistical analyses of both oligonucleotide microarray and real-time RT-qPCR results demonstrated a significant decreased expression only for IGF2 mRNA.

Conclusion

Our results revealed a changed expression of IGF2 mRNA after ranibizumab treatment.

Age-related cataracts: Role of unfolded protein response, Ca2+ mobilization, epigenetic DNA modifications, and loss of Nrf2/Keap1 dependent cytoprotection

Age-related cataracts are closely associated with lens chronological aging, oxidation, calcium imbalance, hydration and crystallin modifications. Accumulating evidence indicates that misfolded proteins are generated in the endoplasmic reticulum (ER) by most cataractogenic stresses. To eliminate misfolded proteins from cells before they can induce senescence, the cells activate a clean-up machinery called the ER stress/unfolded protein response (UPR). The UPR also activates the nuclear factor-erythroid-2-related factor 2 (Nrf2), a central transcriptional factor for cytoprotection against stress. Nrf2 activates nearly 600 cytoprotective target genes. However, if ER stress reaches critically high levels, the UPR activates destructive outputs to trigger programmed cell death. The UPR activates mobilization of ER-Ca2+ to the cytoplasm and results in activation of Ca2+-dependent proteases to cleave various enzymes and proteins which cause the loss of normal lens function. The UPR also enhances the overproduction of reactive oxygen species (ROS), which damage lens constituents and induce failure of the Nrf2 dependent cytoprotection. Kelch-like ECH-associated protein 1 (Keap1) is an oxygen sensor protein and regulates the levels of Nrf2 by the proteasomal degradation. A significant loss of DNA methylation in diabetic cataracts was found in the Keap1 promoter, which overexpresses the Keap1 protein. Overexpressed Keap1 significantly decreases the levels of Nrf2. Lower levels of Nrf2 induces loss of the redox balance toward to oxidative stress thereby leading to failure of lens cytoprotection. Here, this review summarizes the overall view of ER stress, increases in Ca2+ levels, protein cleavage, and loss of the well-established stress protection in somatic lens cells.

An epidemiological investigation of age-related macular degeneration in aged population in China: the Hainan study

Purpose

The aim of this study was to investigate the prevalence of age-related macular degeneration (AMD) and the risk factors in the residents aged ≥50 years in Hainan Province.

Methods

Random sampling was carried out in four separated cities in Hainan Province in 2015. All the subjects accomplished the standard questionnaire and ocular examinations. The diagnosis of AMD was performed based on the criteria proposed by Beckman Initiative for Macular Research Classification Committee.

Results

Three hundred and fifty-seven subjects (15.6%) were diagnosed with AMD, including 267 (11.7%) of early AMD, 64 (2.80%) of intermediate AMD and 24 (1.1%) of late AMD, respectively. The factors associated with the prevalence of AMD included age, educational level, smoking, outdoor activities and diet. The prevalence of AMD increased with age, lower educational level, smoking or less outdoor activities. The prevalence of AMD in those with a diet of meat or eggs was higher compared with a diet of vegetables or fish. The prevalence of early, intermediate and late AMD in the aged population in Hainan Province was 11.7, 2.8 and 1.1%, respectively.

Conclusions

Age and smoking were the risk factors for AMD, while the educational level and outdoor activities were the protective factors. Early AMD mostly occurred in those aged 50–59 years and 60–69 years, while intermediate and late AMD occurred in 70–79 years and older than 80 years.

The Effect of a Mediterranean Diet on the Incidence of Cataract Surgery

BACKGROUND

Cataract is a leading cause of vision impairment worldwide, and surgery is the only available treatment. The process that initiates lens opacification is dependent on the oxidative stress experienced by the lens components. A healthy overall dietary pattern, with the potential to reduce oxidative stress, has been suggested as a means to decrease the risk of developing cataract. We aimed to investigate the hypothesis that an intervention with a Mediterranean diet (MedDiet) rather than a low-fat diet could decrease the incidence of cataract surgery in elderly subjects.

METHODS

We included 5802 men and women (age range: 55-80 years) from the Prevención con Dieta Mediterránea study (multicenter, parallel-group, randomized controlled clinical trial) who had not undergone cataract surgery. They were randomly assigned to one of three intervention groups: (1) a MedDiet enriched with extra-virgin olive oil (EVOO) (n = 1998); (2) a MedDiet enriched with nuts (n = 1914), and a control group recommended to follow a low-fat diet (n = 1890). The incidence of cataract surgery was recorded yearly during follow-up clinical evaluations. Primary analyses were performed on an intention-to-treat basis. Cox regression analyses were used to assess the relationship between the nutritional intervention and the incidence of cataract surgery.

RESULTS

During a follow-up period of 7.0 years (mean follow-up period: 5.7 years; median: 5.9 years), 559 subjects underwent cataract surgery. Two hundred and six participants from the MedDiet + EVOO group, 174 from the MedDiet + Nuts group, and 179 from the control group underwent cataract surgery. We did not observe a reduction in the incidence of cataract surgery in the MedDiet groups compared to the control group. The multivariable adjusted hazard ratios were 1.03 (95% confidence interval [CI]: 0.84-1.26, p = 0.79) for the control group versus the MedDiet + EVOO group and 1.06 (95% CI: 0.86-1.31, p = 0.58) for the control group versus the MedDiet + Nuts group.

CONCLUSIONS

To our knowledge, this is the first large randomized trial assessing the role of a MedDiet on the incidence of cataract surgery. Our results showed that the incidence of cataract surgery was similar in the MedDiet with EVOO, MedDiet with nuts, and low-fat diet groups. Further studies are necessary to investigate whether a MedDiet could have a preventive role in cataract surgery.

Nutrient patterns and risk of cataract: a case-control study

AIM

To assess the relation between nutrient patterns and cataract risk.

METHODS

This is a hospital-based case-control study with 97 cataract patients and 198 matched controls. Dietary consumption was collected through a valid food frequency questionnaire (FFQ). Nutrient patterns were detected by applying factor analysis. Unconditional logistic regression models were used to estimate odds ratio (ORs) and 95%CIs.

RESULTS

We extracted 5 main nutrient patterns. Factor 1 included niacin, thiamin, carbohydrates, protein, zinc, vitamin B6 and sodium (sodium pattern). Factor 2 was characterized by oleic acid, monounsaturated fats, polyunsaturated fats, linoleic acid, trans fatty acid, linolenic acid, vitamin E and saturated fats (fatty acid pattern). The third factor represented high intake of vitamin B12, vitamin D, cholesterol and calcium (mixed pattern). The 4^th pattern was high in intake of beta and alpha carotene, vitamin A and vitamin C (antioxidant pattern). Finally, the 5^th pattern loaded heavily on docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) (omega-3 pattern). In crude and multivariate analysis, the sodium pattern was associated with increased risk of cataract (OR=1.97, 95%CI: 1.09-3.96). The fatty acid pattern elevated the risk of cataract (OR=1.94, 95%CI: 1.1-3.86). Antioxidant pattern was associated with a significant 79% reduced risk (2^nd category compared with the 1^st). Omega-3 pattern was significantly negatively associated with risk of cataract (P=0.04).

CONCLUSION

These findings imply that nutrient patterns reflecting a combined consumption of nutrients might be important in the etiology of cataract. Additional studies with more efficient designs are warranted to confirm our findings.

Genetic and Dietary Factors Influencing the Progression of Nuclear Cataract

Purpose

To determine the heritability of nuclear cataract progression and to explore prospectively the effect of dietary micronutrients on the progression of nuclear cataract.

Design

Prospective cohort study.

Participants

Cross-sectional nuclear cataract and dietary measurements were available for 2054 white female twins from the TwinsUK cohort. Follow-up cataract measurements were available for 324 of the twins (151 monozygotic and 173 dizygotic twins).

Methods

Nuclear cataract was measured using a quantitative measure of nuclear density obtained from digital Scheimpflug images. Dietary data were available from EPIC food frequency questionnaires. Heritability was modeled using maximum likelihood structural equation twin modeling. Association between nuclear cataract change and micronutrients was investigated using linear and multinomial regression analysis. The mean interval between baseline and follow-up examination was 9.4 years.

Main Outcome Measures

Nuclear cataract progression.

Results

The best-fitting model estimated that the heritability of nuclear cataract progression was 35% (95% confidence interval [CI], 13–54), and individual environmental factors explained the remaining 65% (95% CI, 46–87) of variance. Dietary vitamin C was protective against both nuclear cataract at baseline and nuclear cataract progression (β = −0.0002, P = 0.01 and β = −0.001, P = 0.03, respectively), whereas manganese and intake of micronutrient supplements were protective against nuclear cataract at baseline only (β = −0.009, P = 0.03 and β = −0.03, P = 0.01, respectively).

Conclusions

Genetic factors explained 35% of the variation in progression of nuclear cataract over a 10-year period. Environmental factors accounted for the remaining variance, and in particular, dietary vitamin C protected against cataract progression assessed approximately 10 years after baseline.

Folic Acid, Vitamin B6, and Vitamin B12 in Combination and Age-Related Cataract in a Randomized Trial of Women

PURPOSE

To examine the incidence of cataract and cataract extraction in a trial of folic acid and vitamins B6 and B12.

METHODS

In a randomized, double-masked, placebo-controlled trial, 5442 female health professionals aged 40 years or older with preexisting cardiovascular disease (CVD) or three or more CVD risk factors were randomly assigned to receive a combination of folic acid (2.5 mg/day), vitamin B6 (50 mg/day), and vitamin B12 (1 mg/day), or placebo. A total of 3925 of these women did not have a diagnosis of cataract at baseline and were included in this analysis. The primary endpoint was age-related cataract, defined as an incident age-related lens opacity, responsible for a reduction in best-corrected visual acuity to 20/30 or worse, based on self-report confirmed by medical record review. Extraction of incident age-related cataract was a secondary endpoint of the trial.

RESULTS

During an average of 7.3 years of treatment and follow-up, 408 cataracts and 275 cataract extractions were documented. There were 215 cataracts in the combination treatment group and 193 in the placebo group (hazard ratio, HR, 1.10, 95% confidence interval, CI, 0.90-1.33; p = 0.36). For the secondary endpoint of cataract extraction, there were 155 in the combination treatment group and 120 in the placebo group (HR 1.28, 95% CI 1.01-1.63; p = 0.04).

CONCLUSIONS

In this large-scale randomized trial of women at high risk of CVD, daily supplementation with a combination of folic acid, vitamin B6, and vitamin B12 had no significant effect on cataract, but may have increased the risk of cataract extraction.

Carotenoids in Microalgae

Carotenoids are a class of isoprenoids synthesized by all photosynthetic organisms as well as by some non-photosynthetic bacteria and fungi with broad applications in food, feed and cosmetics, and also in the nutraceutical and pharmaceutical industries. Microalgae represent an important source of high-value products, which include carotenoids, among others. Carotenoids play key roles in light harvesting and energy transfer during photosynthesis and in the protection of the photosynthetic apparatus against photooxidative damage. Carotenoids are generally divided into carotenes and xanthophyls, but accumulation in microalgae can also be classified as primary (essential for survival) and secondary (by exposure to specific stimuli).In this chapter, we outline the high value carotenoids produced by commercially important microalgae, their production pathways, the improved production rates that can be achieved by genetic engineering as well as their biotechnological applications.

The Photobiology of Lutein and Zeaxanthin in the Eye

Lutein and zeaxanthin are antioxidants found in the human retina and macula. Recent clinical trials have determined that age- and diet-related loss of lutein and zeaxanthin enhances phototoxic damage to the human eye and that supplementation of these carotenoids has a protective effect against photoinduced damage to the lens and the retina. Two of the major mechanisms of protection offered by lutein and zeaxanthin against age-related blue light damage are the quenching of singlet oxygen and other reactive oxygen species and the absorption of blue light. Determining the specific reactive intermediate(s) produced by a particular phototoxic ocular chromophore not only defines the mechanism of toxicity but can also later be used as a tool to prevent damage.

Plant-Derived Flavonoids in Ocular Angiopathy

Encouraging reports of flavonoid activity, mainly coming from in vitro or ex vivo experimental evidence, should be replicated in randomized controlled trials, to examine their ability to prevent angiopathy.

Lutein dietary supplementation attenuates streptozotocin-induced testicular damage and oxidative stress in diabetic rats

Background

Diabetes mellitus with the successive generation of reactive oxygen species signifies a major risk factor for testicular dysfunction. Antioxidant supplements are one of the best options to prevent such disorder. In the present study, lutein as dietary supplement has been used to explore its potential protective effects against diabetes-induced oxidative stress in testicular cells.

Methods

Diabetes was induced using a single IP injection of streptozotocin (STZ). Lutein was mixed with rat chow powder and supplemented to diabetic rats for 5 weeks. Serum testosterone levels were estimated. In testicular cells, thiobarbituric acid reactive substances (TBARS), total sulfhydryl groups (T-GSH), non-protein sulfhydryl groups (NP-SH), superoxide dismutase (SOD) and catalase (CAT) activities were measured. Pro-inflammatory mediators like tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) were measured in the testis. Nucleic acids and total protein (TP) levels were also estimated in testicular cells. Histopathological changes were evaluated in testis.

Results

Serum testosterone level was significantly decreased in diabetic animals compared to controls. Diabetes markedly reduced T-GSH, NP-SH, CAT and SOD, while TBARS, TNF-α and IL-1β levels were increased in the diabetic testis compared to non-diabetic controls. Lutein supplementation, significantly and dose dependently increased the serum testosterone level. The elevated TBARS levels were significantly decreased compared to diabetic group, while the decreased levels of T-GSH and NP-SH and activities of CAT and SOD were found increased by lutein treatments in dose dependent manner. Lutein pretreatment also inhibited the TNF-α and IL-1β levels compared to diabetic group. The decreased values of nucleic acids and total protein in diabetic group were also significantly increased in lutein supplemented groups. The histopathological evaluation revealed protection the damaged testicular cells in the diabetic rats by lutein supplementation.

Conclusion

These findings showed that lutein has potential beneficial effects in diabetes-induced testicular damage, probably through its antioxidant and anti-inflammatory properties.

Hypercholesterolemia-induced ocular disorder: Ameliorating role of phytotherapy

The ocular region is a complex structure that allows conscious light perception and vision. It is of ecto-mesodermal origin. Cholesterol and polyunsaturated fatty acids are involved in retinal cell function; however, hypercholesterolemia and diabetes impair its function. Retinal damage, neovascularization, and cataracts are the main complications of cholesterol overload. Dietary supplementation of selected plant products can lead to the scavenging of free reactive oxygen species, thereby protecting the ocular regions from the damage of hypercholesterolemia. This review illustrates the dramatic effects of increased cholesterol levels on the ocular regions. The effect of phytotherapy is discussed in relation to the different regions of the eye, including the retina, cornea, and lens.

Topical nutraceutical Optixcare EH ameliorates experimental ocular oxidative stress in rats

PURPOSE

Based on the hypothesis that oral nutraceuticals do not adequately reach all ocular tissues in the anterior segment, we evaluated the ability of a 3% concentration of the ingredients in a topical nutraceutical antioxidant formulation called Optixcare Eye Health (Optixcare EH) to ameliorate oxidative stress in rat models of age-related ocular diseases.

METHODS

Diabetes was induced by tail-vein injection of streptozotocin, and the development of cataracts was monitored by slit lamp. Young rats were exposed to ultraviolet (UV) light, and the reduction in lens glutathione (GSH) levels and increase in 4-hydroxynonenol (4-HNE) were measured. Oxidative stress in the neural retina was generated by exposure of dark-adapted rats to 1,000 lx of light, and oxidative stress markers were measured. Dry eye was induced in rats by twice daily (b.i.d.) subcutaneous scopolamine injections. Topical Optixcare EH was administered b.i.d. and compared in select experiments to the multifunctional antioxidant JHX-4, the topical aldose reductase inhibitor (ARI) Kinostat™, oral Ocu-GLO™, and the topical ocular comfort agents Optixcare Eye Lube, Optixcare Eye Lube + Hyaluron, and Idrop Vet Plus hyaluronic acid.

RESULTS

In diabetic rats, topical ARI treatment prevented cataract formation while the nutraceuticals delayed their development with Optixcare EH>Ocu-GLO. In UV-exposed rats, the reduction of GSH and increase in 4-HNE in the lens were normalized in order JHX-4>Optixcare EH>Ocu-GLO. In the retina, oxidative stress markers were reduced better by oral JHX-4 compared with topical Optixcare EH. In the scopolamine-induced dry-eye rats, tear flow was maintained by Optixcare EH treatment, while none of the comfort agents examined altered tear flow.

CONCLUSIONS

Topical administration of a 3% concentration of the ingredients in Optixcare EH reduces experimentally induced reactive oxygen species in rats exposed to several sources of ocular oxidative stress. In addition, Optixcare EH maintains tear volume in scopolamine-induced dry eye. This suggests that in the anterior segment, the ingredients in Optixcare EH may have clinical potential against ocular oxidative stress.

Lutein production from biomass: marigold flowers versus microalgae

Microalgae have faster growth rates and more free lutein than marigold flowers, the current source of lutein. However, no commercial lutein production uses microalgae. This review compares lutein content, cultivation, harvesting, cell disruption, and extraction stages of lutein production using marigold flowers and those using microalgae as feedstock. The lutein production rate of microalgae is 3-6 times higher than that of marigold flowers. To produce 1 kg of pure lutein, marigolds need more land and water, but require less nutrients (N, P, K) and less energy than microalgae. Since lutein is tightly bound in microalgae and microalgae are small, cell disruption and subsequent extraction stages consume a considerable amount of energy. Research and development of affordable lutein production from microalgae are discussed.