A Novel Integrated Active Herbal Formulation Ameliorates Dry Eye Syndrome by Inhibiting Inflammation and Oxidative Stress and Enhancing Glycosylated Phosphoproteins in Rats

Investigating a novel therapeutic composition for dry eye syndrome management: In vitro and in vivo studies

Dry eye syndrome (DES) presents a significant challenge in ophthalmic care, necessitating innovative approaches for effective management. This research article introduces a multifaceted strategy to address DES through the development of ocular inserts utilizing advanced technologies such as hot-melt extrusion (HME) and the CaliCut post-extrusion system. The formulation includes key ingredients targeting different layers of the tear film and associated inflammation, including hydroxypropyl cellulose (HPC), polyethylene glycol (PEG), castor oil, and dexamethasone. The study incorporates a Design of Experiments (DoE) approach, integrating HME and the precise stretching and cutting technique of CaliCut for manufacturing consistency and dimensional control of the inserts. The developed insert(s) have been systematically characterized for their physicochemical properties, release profile, and in vivo efficacy. In silico molecular docking studies have also been conducted to assess the binding affinities of formulation components with ocular mucin, elucidating their binding affinities. Preliminary results demonstrate promising potential for the developed insert in managing DES, offering preservative-free treatment, sustained drug delivery, and improved patient compliance. This study highlights the integration of advanced technologies and formulation strategies in ocular drug delivery for effective DES management.

Protective Effects of Dietary Vitamin D3, Turmeric Powder, and Their Combination against Gasoline Intoxication in Rats

The inhalation of gasoline vapors (GV) is associated with developing various pathologies. Particularly, oil refinery and gas station workers are at a greater risk of developing lung cancer, kidney cancer, bladder cancer, and hematological disorders, including acute myeloid leukemia. Therefore, preventing the harmful effects of GV and alleviating their consequences appear to be important and timely issues. In this study, we investigated the potential of vitamin D3, turmeric powder, and their combination to ameliorate the toxicity of gasoline fumes in rats. Separate groups of animals fed with a standard rodent diet, with or without the supplementation of vitamin D3 (750 IU/kg body weight) and/or turmeric powder (0.5%, w/w, in food), were untreated or treated with GV (11.5 ± 1.3 cm3/h/m3/day) for 30, 60, or 90 days. Changes in the body weight were monitored weekly. Histological, biochemical, and hematological parameters were determined at the end of each treatment period. While the exposure of rats to GV resulted in a time-dependent reduction in body weight, supplementation with vitamin D3, but not with turmeric root powder or their combination, partially prevented weight loss. Macroscopical and histological analyses showed pronounced time-dependent changes in the organs and tissues of GV-treated rats. These included alveolar wall collapse in the lungs, the destruction of the lobular structure and hepatocytolysis in the liver, the shrinkage and fragmentation of glomeruli in the kidneys, and the disorganization of the lymphoid follicles in the spleen. However, co-treatment with the nutritional supplements tested, especially vitamin D3, noticeably alleviated the above conditions. This was accompanied by a significant improvement in the blood chemistry and hematological parameters. Collectively, our results demonstrate that the harmful effects of environmental exposure to GV can be reduced upon supplementation of vitamin D3. The fact that the protective activity of vitamin D3 alone was higher than that of turmeric root powder or the combined treatment suggests that combinations of these supplements may not always be more beneficial than each agent applied separately.

A novel multi-ingredient supplement significantly improves ocular symptom severity and tear production in patients with dry eye disease: results from a randomized, placebo-controlled clinical trial

Introduction

Dry eye disease (DED) is multifactorial and characterized by a loss of tear film homeostasis that causes a cycle of tear film instability, tear hyperosmolarity, and inflammation. While artificial tears are the traditional mainstay of treatment, addressing the underlying pathophysiology could relieve symptoms and prevent progression. Increasing evidence indicates a role for oral nutritional supplementation in multiple ophthalmic diseases, including DED. Lutein, zeaxanthin, curcumin, and vitamin D3 have demonstrated protective and anti-inflammatory properties in ocular models. This prospective, randomized, double-blind, parallel, placebo-controlled study evaluated the efficacy and safety of a proprietary blend of lutein, zeaxanthin isomers, curcumin, and vitamin D3 (LCD) as a daily supplement in adult participants with DED.

Methods

Participants were randomized to receive one LCD supplement capsule (lutein 20 mg, zeaxanthin isomers 4 mg, curcumin 200 mg curcuminoids, and vitamin D3 600 IU) or placebo per day for 8 weeks (LCD, n=77; placebo, n=78). Primary outcomes were changes in tear volume (Schirmer's test) and ocular symptoms (Ocular Surface Disease Index [OSDI]).

Results

The study met its primary endpoints: the LCD group demonstrated significantly better Schirmer's test scores and improvement in overall OSDI score, versus placebo, at Day 56 (p<0.001 for both). Scores for total OSDI, and symptoms and vision domains, significantly improved by Day 14 for LCD versus placebo, (p<0.05 for all) and were maintained to Day 56 (p<0.001). In addition, the LCD group demonstrated significantly improved tear film break-up time (TBUT) and tear film osmolarity, versus placebo, by Day 56 (p<0.001), along with significant improvements in corneal and conjunctival staining (p<0.001 for both), and inflammation (matrix metalloproteinase-9; p<0.001 for each eye). Total Standard Patient Evaluation of Eye Dryness (SPEED) score, and scores for the frequency and severity domains, were significantly improved by Day 14 for LCD versus placebo (p<0.05 for all) and maintained to Day 56 (p<0.001). There was no difference between groups for artificial tear usage. The supplement was well-tolerated.

Discussion

Once-daily LCD supplementation significantly improved tear production, stability and quality, reduced ocular surface damage and inflammation, and improved participants' symptoms. LCD supplementation could offer a useful adjunct to artificial tears for patients with DED (NCT05481450).

Evaluation of curcumin-based ophthalmic nano-emulsion on atropine-induced dry eye in mice

Background

One of the most efficient treatments for dry eye syndrome (DES) is to use nanocarriers as a potential delivery system. We aim to evaluate curcumin in a nano emulsion formulation.

Methods

A new formulation containing 5.5% curcuminoid was used. DLS, Zeta potential, TEM, and HPLC tests were performed to determine the size and morphology. First, 30 mice were selected as atropine-induced dry eye models. Next, 25 mice in 5 groups were treated with the nano emulsion at different doses, and corneal tissues were separated for evaluation.

Results

The DLS test results were indicative of the particles' stability. Nano curcumin appeared to be thoroughly effective in all groups, with the highest dose showing the most similarity to the healthy control group.

Conclusions

Curcumin-based nano emulsion eye drop is a promising candidate for DES management. However, further investigation is required to evaluate the possible risks in humans.

Potential New Target for Dry Eye Disease-Oxidative Stress

Dry eye disease (DED) is a multifactorial condition affecting the ocular surface. It is characterized by loss of tear film homeostasis and accompanied by ocular symptoms that may potentially result in damage to the ocular surface and even vision loss. Unmodifiable risk factors for DED mainly include aging, hormonal changes, and lifestyle issues such as reduced sleep duration, increased screen exposure, smoking, and ethanol consumption. As its prevalence continues to rise, DED has garnered considerable attention, prompting the exploration of potential new therapeutic targets. Recent studies have found that when the production of ROS exceeds the capacity of the antioxidant defense system on the ocular surface, oxidative stress ensues, leading to cellular apoptosis and further oxidative damage. These events can exacerbate inflammation and cellular stress responses, further increasing ROS levels and promoting a vicious cycle of oxidative stress in DED. Therefore, given the central role of reactive oxygen species in the vicious cycle of inflammation in DED, strategies involving antioxidants have emerged as a novel approach for its treatment. This review aims to enhance our understanding of the intricate relationship between oxidative stress and DED, thereby providing directions to explore innovative therapeutic approaches for this complex ocular disorder.

Extract from Aronia melanocarpa, Lonicera caerulea, and Vaccinium myrtillus Improves near Visual Acuity in People with Presbyopia

Presbyopia is a global problem with an estimated 1.3 billion patients worldwide. In the area of functional food applications, dietary supplements or herbs, there are very few reports describing the positive effects of their use. In the available literature, there is a lack of studies in humans as well as on an animal model of extracts containing, simultaneously, compounds from the polyphenol group (in particular, anthocyanins) and iridoids, so we undertook a study of the effects of a preparation composed of these compounds on a condition of the organ of vision. Our previous experience on a rabbit model proved the positive effect of taking an oral extract of Cornus mas in stabilizing the intraocular pressure of the eye. The purpose of this study was to evaluate the effect of an orally administered ternary compound preparation on the status of physiological parameters of the ocular organ. The preparation contained an extract of the chokeberry Aronia melanocarpa, the honeysuckle berry Lonicera caerulea L., and the bilberry Vaccinium myrtillus (hereafter AKB) standardized for anthocyanins and iridoids, as bioactive compounds known from the literature. A randomized, double-blind, cross-over study lasting with a "wash-out" period of 17 weeks evaluated a group of 23 people over the age of 50, who were subjects with presbyopia and burdened by prolonged work in front of screen monitors. The group of volunteers was recruited from people who perform white-collar jobs on a daily basis. The effects of the test substances contained in the preparation on visual acuity for distance and near, sense of contrast for distance and near, intraocular pressure, and conjunctival lubrication, tested by Schirmer test, LIPCOF index and TBUT test, and visual field test were evaluated. Anthocyanins (including cyanidin 3-O-galactoside, delphinidin 3-O-arabinoside, cyanidin 3-O-glucoside, cyanidin 3-O-rutinoside, cyanidin 3-O-arabinoside) and iridoids (including loganin, sweroside, loganic acid) were identified as substances present in the extract obtained by HPLC-MS. The preliminary results showed that the composition of AKB applied orally does not change visual acuity in the first 6 weeks of administration. Only in the next cycle of the study was an improvement in near visual acuity observed in 92.3% of the patients. This may indicate potential to correct near vision in presbyopic patients. On the other hand, an improvement in conjunctival wetting was observed in the Schirmer test at the beginning of week 6 of administration in 80% of patients. This effect was weakened in subsequent weeks of conducting the experiment to 61.5%. The improvement in conjunctival hydration in the Schirmer test shows the potential beneficial effect of the AKB formulation in a group of patients with dry eye syndrome. This is the first study of a preparation based on natural, standardized extracts of chokeberry, honeysuckle berry, and bilberry. Preliminary studies show an improvement in near visual acuity and conjunctival hydration on the Schirmer test, but this needs to be confirmed in further studies.

TFOS Lifestyle: Impact of nutrition on the ocular surface

Nutrients, required by human bodies to perform life-sustaining functions, are obtained from the diet. They are broadly classified into macronutrients (carbohydrates, lipids, and proteins), micronutrients (vitamins and minerals) and water. All nutrients serve as a source of energy, provide structural support to the body and/or regulate the chemical processes of the body. Food and drinks also consist of non-nutrients that may be beneficial (e.g., antioxidants) or harmful (e.g., dyes or preservatives added to processed foods) to the body and the ocular surface. There is also a complex interplay between systemic disorders and an individual's nutritional status. Changes in the gut microbiome may lead to alterations at the ocular surface. Poor nutrition may exacerbate select systemic conditions. Similarly, certain systemic conditions may affect the uptake, processing and distribution of nutrients by the body. These disorders may lead to deficiencies in micro- and macro-nutrients that are important in maintaining ocular surface health. Medications used to treat these conditions may also cause ocular surface changes. The prevalence of nutrition-related chronic diseases is climbing worldwide. This report sought to review the evidence supporting the impact of nutrition on the ocular surface, either directly or as a consequence of the chronic diseases that result. To address a key question, a systematic review investigated the effects of intentional food restriction on ocular surface health; of the 25 included studies, most investigated Ramadan fasting (56%), followed by bariatric surgery (16%), anorexia nervosa (16%), but none were judged to be of high quality, with no randomized-controlled trials.

Protective Effect of Allyl Isothiocyanate in an Experimentally Induced Rat Model for Dry Eye Syndrome

PURPOSE/AIM OF THE STUDY

Growing evidence emphasizes the role of inflammation and oxidative stress in the pathogenesis of Dry Eye Syndrome (DES). Concordantly, the importance of agents targeting the inflammatory cascade and oxidative stress in the treatment is also progressively increasing. Herein, the study has investigated the protective effects and underlying mechanism of allyl isothiocyanate (AITC) on the ocular surface in a benzalkonium chloride (BAC)-induced dry eye rat model.

MATERIALS AND METHODS

A total of twenty-one Wistar albino rats were used to form the following three groups: Control, BAC, BAC + AITC. DES was established by topical application of BAC (four times daily for two weeks) in two groups, of which one group was treated with AITC (10 mg/kg BW daily oral dosage) for four weeks. Rats were monitored by dry eye diagnostic tests during the study period, and eventually, corneal tissues were used to evaluate for histopathologic analyzes and inflammatory and oxidative status.

RESULTS

A significant improvement was observed in various histopathologic and ophthalmologic findings, including tear volume, tear film integrity, ocular surface damage, ocular inflammatory signs, corneal thickness, and edema through AITC supplementation. AITC prominently balanced the inflammatory status and oxidative stress by lowering key proinflammatory mediators (NF-κB, TNF-α, IL-1β, IL-6, and IL-8) and increasing the activities of antioxidant enzymes (SOD, GSH-Px). Also, levels of protective tear proteins, including Muc1, Muc4, and Muc5 were recovered with AITC supplementation.

CONCLUSION

AITC alleviates clinical and histopathologic signs related to DES. Antioxidative and anti-inflammatory properties of AITC play a significant role in the mechanism of action.

The Pathomechanism, Antioxidant Biomarkers, and Treatment of Oxidative Stress-Related Eye Diseases

Oxidative stress is an important pathomechanism found in numerous ocular degenerative diseases. To provide a better understanding of the mechanism and treatment of oxidant/antioxidant imbalance-induced ocular diseases, this article summarizes and provides updates on the relevant research. We review the oxidative damage (e.g., lipid peroxidation, DNA lesions, autophagy, and apoptosis) that occurs in different areas of the eye (e.g., cornea, anterior chamber, lens, retina, and optic nerve). We then introduce the antioxidant mechanisms present in the eye, as well as the ocular diseases that occur as a result of antioxidant imbalances (e.g., keratoconus, cataracts, age-related macular degeneration, and glaucoma), the relevant antioxidant biomarkers, and the potential of predictive diagnostics. Finally, we discuss natural antioxidant therapies for oxidative stress-related ocular diseases.

Development of Lutein-Containing Eye Drops for the Treatment of Dry Eye Syndrome

Dry eye syndrome (DES) is a common ophthalmological disease that decreases tear secretion and causes dryness, photophobia, pain, severe corneal rupture, and even blindness. Ocular and lacrimal gland inflammation is one of the pathological mechanisms underlying DES. Therefore, effective suppression of inflammation is a crucial strategy for the treatment of DES. Lutein, commonly found in healthy foods, has anti-inflammatory effects in corneal or retina-related cells and may be a potential therapy for DES. The addition of lutein to artificial tears (AT) as an eye-drop formulation for DES treatment in a mouse model was studied in the present work. Polyvinyl alcohol (PVA) was used as a thickener to increase the viscosity of eye drops to prolong drug retention on the ocular surface. A WST-8 assay in human corneal epithelial cells (HCE-2) showed that a concentration of <5 μM lutein (L5) and <1% PVA (P1) maintained the cell viability at 80%. A real-time PCR showed that the inflamed human corneal epithelial cells (HCECs) cocultured with L5P1 had downregulated expression of inflammatory genes such as IL-1β, IL-6, and TNF-α. In a benzalkonium chloride- (BAC) induced DES mouse model, AT/L5P1 could repair damaged corneas, elevate tear secretion, increase the number of goblet cells, and inhibit the production of inflammatory cytokines, such as IL-1β, IL-6, and TNF-α, in the cornea. In conclusion, we demonstrate that lutein/PVA as eye drops could prolong the drug ocular retention time and effectively to decrease inflammation in DES mice. Therefore, lutein, obtained from eye drops, has a potential therapeutic role for DES.

Anti-Inflammatory and Anticancer Effects of Microalgal Carotenoids

Acute inflammation is a key component of the immune system's response to pathogens, toxic agents, or tissue injury, involving the stimulation of defense mechanisms aimed to removing pathogenic factors and restoring tissue homeostasis. However, uncontrolled acute inflammatory response may lead to chronic inflammation, which is involved in the development of many diseases, including cancer. Nowadays, the need to find new potential therapeutic compounds has raised the worldwide scientific interest to study the marine environment. Specifically, microalgae are considered rich sources of bioactive molecules, such as carotenoids, which are natural isoprenoid pigments with important beneficial effects for health due to their biological activities. Carotenoids are essential nutrients for mammals, but they are unable to synthesize them; instead, a dietary intake of these compounds is required. Carotenoids are classified as carotenes (hydrocarbon carotenoids), such as α- and β-carotene, and xanthophylls (oxygenate derivatives) including zeaxanthin, astaxanthin, fucoxanthin, lutein, α- and β-cryptoxanthin, and canthaxanthin. This review summarizes the present up-to-date knowledge of the anti-inflammatory and anticancer activities of microalgal carotenoids both in vitro and in vivo, as well as the latest status of human studies for their potential use in prevention and treatment of inflammatory diseases and cancer.

Curcumin enhances the membrane trafficking of the sodium iodide symporter and augments radioiodine uptake in dedifferentiated thyroid cancer cells via suppression of the PI3K-AKT signaling pathway

Radioactive iodine (RAI) is commonly used to treat differentiated thyroid cancer (DTC). A major challenge is the dedifferentiation of DTC with the loss of radioiodine uptake. Patients with distant metastases have persistent or recurrent disease and develop resistance to RAI therapy due to tumor dedifferentiation. Hence, tumor redifferentiation to restore sensitivity to RAI therapy is considered a promising strategy to overcome RAI resistance. In the present study, curcumin, a natural polyphenolic compound, was found to re-induce cell differentiation and increase the expression of thyroid-specific transcription factors, TTF-1, TTF-2 and transcriptional factor paired box 8 (PAX8), and iodide-metabolizing proteins, including thyroid stimulating hormone receptor (TSHR), thyroid peroxidase (TPO) and sodium iodide symporter (NIS) in dedifferentiated thyroid cancer cell lines, BCPAP and KTC-1. Importantly, curcumin enhanced NIS glycosylation and its membrane trafficking, resulting in a significant improvement of radioiodine uptake in vitro. Additionally, AKT knockdown phenocopied the restoration of thyroid-specific gene expression; however, ectopic expressed AKT inhibited curcumin-induced up-regulation of NIS protein, demonstrating that curcumin might improve radioiodine sensitivity via the inhibition of the PI3K-AKT-mTOR signaling pathway. Our study demonstrates that curcumin could represent a promising adjunctive therapy for restoring iodide avidity and improve radioiodine therapeutic efficacy in patients with RAI-refractory thyroid carcinoma.

Evidence of Polyphenols Efficacy against Dry Eye Disease

Dry eye disease is a multifactorial pathology compromising the quality of life of patients, resulting in significant damage of the ocular surface and discomfort. The current therapeutical strategies are not able to definitively resolve the underlying causes and stop the symptoms. Polyphenols are promising natural molecules that are receiving increasing attention for their activity/effects in counteracting the main pathologic mechanisms of dry eye disease and reducing its symptoms. In the present review, a deep literature search focusing on the main polyphenols tested against dry eye disease was conducted, analyzing related in vitro, in vivo, and clinical studies to provide a comprehensive and current review on the state of the art. Polyphenols present multiple effects against dry eye diseases-related ocular surface injury. In particular, the observed beneficial effects of polyphenols on corneal cells are the reduction of the pathological processes of inflammation, oxidative stress, and apoptosis and modulation of the tear film. Due to numerous studies reporting that polyphenols are effective and safe for treating the pathological mechanisms of this ocular surface disease, we believe that future studies should confirm and extend the evidence of polyphenols efficacy in clinical practice against dry eye disease and help to develop new ophthalmic drug(s).