-
Molecules (Basel, Switzerland) Jun 2021Catechins are a part of the chemical family of flavonoids, a naturally occurring antioxidant, and a secondary metabolite in certain plants. Green tea catechins are well... (Meta-Analysis)
Meta-Analysis
Catechins are a part of the chemical family of flavonoids, a naturally occurring antioxidant, and a secondary metabolite in certain plants. Green tea catechins are well recognized for their essential anti-inflammatory, photo-protective, antioxidant, and chemo-preventive functions. Ultraviolet radiation is a principal cause of damage to the skin. Studies observed that regular intake of green tea catechins increased the minimal dose of radiation required to induce erythema. The objectives of this systematic review and meta-analysis are to determine the effectiveness of green tea catechins in cutaneous erythema and elucidate whether green tea catechin consumption protects against erythema (sunburn) inflammation. A comprehensive literature search was conducted to identify the relevant studies. Two researchers carried out independent screening, data extraction, and quality assessment according to the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). The pooled effect of green tea catechins on protection against erythema was assessed using approaches fixed-effects or random-effects model to quantify the effectiveness of green tea catechins in the erythema dose-response. Studies not be included in meta-analyses were summarized narratively. Six randomized controlled studies of enrolled studies regularly administrated green tea catechins orally for 6 to 12 weeks involving healthy volunteers comprising a total of 100 participants were included in the analysis. The results revealed green tea catechins have favorable protection against erythema inflammation even at increased minimal erythema dose (MED) of ultraviolet radiation. Meta-analysis results confirm oral supplementation of green tea catechins is highly effective at low-intensity ultraviolet radiation-induced erythema response (MED range; 1.25-1.30) compared to placebo, showing a significant pooling difference ( = 0.002) in erythema index (SMD: -0.35; 95% CI, -0.57 to -0.13; I = 4%, = 0.40) in the random-effects model. The pro-inflammatory signaling pathways through oral supplementation with green tea catechins are an attractive strategy for photo-protection in healthy human subjects and could represent a complementary approach to topical sunscreens. Therefore, studies that involved green tea catechin in topical applications to human subjects were also evaluated separately, and their meta-analysis is presented as a reference. The evidence indicates that regular green tea catechin supplementation is associated with protection against UV-induced damage due to erythema inflammation.
Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Catechin; Erythema; Flavonoids; Humans; Inflammation; Skin; Sunscreening Agents; Tea; Ultraviolet Rays
PubMed: 34204433
DOI: 10.3390/molecules26123702 -
Photodermatology, Photoimmunology &... Nov 2020DNA damage is one of the main factors responsible for photoageing and is predominantly attributed to ultraviolet irradiation (UV-R). Photoprotection by conventional...
BACKGROUND
DNA damage is one of the main factors responsible for photoageing and is predominantly attributed to ultraviolet irradiation (UV-R). Photoprotection by conventional sunscreens is exclusively prophylactic, and of no value, once DNA damage has occurred. As a result, the demand for DNA repair mechanisms inhibiting, reversing or delaying the pathologic events in UV-exposed skin has sparked research on anti-photoageing and strategies to improve the effect of conventional sunscreens. This review provides an overview of recent developments in DNA repair enzymes used in sunscreens and their impact on photoageing.
METHODS
A systematic review of the literature, up to March 2019, was conducted using the electronic databases, PubMed and Web of Science. Quality assessment was carried out using the Newcastle-Ottawa scale (NOS) to ensure inclusion of adequate quality studies only (NOS > 5).
RESULTS
Out of the 352 publications, 52 were considered relevant to the key question and included in the present review. Two major enzymes were found to play a major role in DNA damage repair in sunscreens: photolyase and T4 endonuclease V. These enzymes are capable of identifying and removing UV-R-induced dimeric photoproducts. Clinical studies revealed that sunscreens with liposome-encapsulated types of photolyase and/or T4 endonuclease V can enhance these repair mechanisms.
CONCLUSION
There is a lack of randomized controlled trials demonstrating the efficacy of DNA repair enzymes on photoageing, or a superiority of sunscreens with DNA repair enzymes compared to conventional sunscreens. Further studies are mandatory to further reveal pathogenic factors of photoageing and possible therapeutic strategies against it.
Topics: Animals; DNA Damage; DNA Repair; Deoxyribodipyrimidine Photo-Lyase; Deoxyribonuclease (Pyrimidine Dimer); Humans; Skin Aging; Sunscreening Agents; Ultraviolet Rays; Viral Proteins
PubMed: 32772409
DOI: 10.1111/phpp.12597 -
Molecules (Basel, Switzerland) Jul 2020Sun overexposure is associated with the development of diseases that primarily affect the skin, which can lead to skin cancer. Among the main measures of photoprotection... (Meta-Analysis)
Meta-Analysis
Sun overexposure is associated with the development of diseases that primarily affect the skin, which can lead to skin cancer. Among the main measures of photoprotection is the use of sunscreens. However, there is currently concern about the reported harmful effects to both humans and the environment due to several of the sunscreen ingredients available on the market. For this reason, the search for and development of new agents with photoprotective properties is required. In searching for these metabolites, researchers have turned their attention to microbial sources, especially the microbiota in unusual hostile environments. Among the diverse microorganisms available in nature, Actinobacteria and specifically , have been shown to be a source of metabolites with various biological activities of interest, such as antimicrobial, antitumor and immunomodulator activities. Herein, we present the results of a systematic review of the literature in which isolates were studied as a source of compounds with photoprotective properties. A meta-analysis of the structure-property and structure-activity relationships of those metabolites identified in the qualitative analysis phase was also carried out. These findings indicate that are a source of metabolites with potential applications in the development of new, safe and more eco-friendly sunscreens.
Topics: Antioxidants; Biological Products; Humans; Secondary Metabolism; Streptomyces; Structure-Activity Relationship; Sunscreening Agents; Ultraviolet Rays
PubMed: 32679651
DOI: 10.3390/molecules25143221 -
JAMA Ophthalmology Jun 2019Cataract surgery, with intraocular lens (IOL) implantation, is the most common ocular surgical procedure worldwide. It has been suggested that IOLs that selectively...
IMPORTANCE
Cataract surgery, with intraocular lens (IOL) implantation, is the most common ocular surgical procedure worldwide. It has been suggested that IOLs that selectively attenuate short wavelength visible light (blue light-filtering IOLs) may be beneficial for macular health. Whether blue light-filtering IOLs impart retinal photoprotection is of public health relevance, particularly in the context of aging demographics and the increasing global prevalence of age-related macular degeneration. This review analyzes and interprets the key findings, including consideration of the implications for practice and future research, of a 2018 Cochrane systematic review that evaluated the efficacy and safety of blue light-filtering IOLs for providing protection to macular health and function.
OBSERVATIONS
The Cochrane systematic review included 51 randomized controlled trials that were performed in 17 countries. The trials involved adults undergoing cataract surgery in which a blue light-filtering IOL was compared with an equivalent non-blue light-filtering IOL. Study follow-up periods ranged from 1 month to 5 years. Together, these studies considered clinical outcomes in more than 5000 eyes. There was limited ability to combine data across trials (to draw overall conclusions) because of the use of different measurement techniques for outcomes, incomplete reporting of data, and/or varied follow-up periods. We identified substantial shortcomings in the internal validity of many of the included studies, particularly regarding trial design, conduct, and reporting. We propose several avenues for improving the rigor of potential future research in the field, including developing a core set of outcome measures, the inclusion of sample size calculations, the masking of trial participants and outcome assessors, and prospective clinical trial registration.
CONCLUSIONS AND RELEVANCE
Using blue light-filtering IOLs to impart benefits to the macula is currently not supported by the best available clinical research evidence, and it is important that clinicians are mindful of this evidence limitation when adopting these devices in clinical practice.
Topics: Cataract Extraction; Filtration; Humans; Lens Implantation, Intraocular; Lenses, Intraocular; Light; Prospective Studies; Radiation Injuries; Radiation Protection; Retina
PubMed: 30789642
DOI: 10.1001/jamaophthalmol.2019.0019 -
Frontiers in Bioengineering and... 2020Titanium dioxide nanoparticles (TiO NPs) are regularly used in sunscreens because of their photoprotective capacity. The advantage of using TiO on the nanometer scale is...
Titanium dioxide nanoparticles (TiO NPs) are regularly used in sunscreens because of their photoprotective capacity. The advantage of using TiO on the nanometer scale is due to its transparency and better UV blocking efficiency. Due to the greater surface area/volume ratio, NPs become more (bio)-reactive giving rise to concerns about their potential toxicity. To evaluate the irritation and corrosion of cosmetics, 3D skin models have been used as an alternative method to animal experimentation. However, it is not known if this model is appropriate to study skin irritation, corrosion and phototoxicity of nanomaterials such as TiO NPs. This systematic review (SR) proposed the following question: Can the toxicity of TiO nanoparticles be evaluated in a 3D skin model? This SR was conducted according to the Preliminary Report on Systematic Review and Meta-Analysis (PRISMA). The protocol was registered in CAMARADES and the ToxRTool evaluation was performed in order to increase the quality and transparency of this search. In this SR, 7 articles were selected, and it was concluded that the 3D skin model has shown to be promising to evaluate the toxicity of TiO NPs. However, most studies have used biological assays that have already been described as interfering with these NPs, demonstrating that misinterpretations can be obtained. This review will focus in the possible efforts that should be done in order to avoid interference of NPs with biological assays applied in 3D culture.
PubMed: 32587852
DOI: 10.3389/fbioe.2020.00575