Wounding Therapies for Prevention of Photocarcinogenesis

The occurrence of non-melanoma skin cancer (NMSC) is closely linked with advanced age and ultraviolet-B (UVB) exposure. More specifically, the development of NMSC is linked to diminished insulin-like growth factor-1 (IGF-1) signaling from senescent dermal fibroblasts in geriatric skin. Consequently, keratinocyte IGF-1 receptor (IGF-1R) remains inactive, resulting in failure to induce appropriate protective responses including DNA repair and cell cycle checkpoint signaling. This allows UVB-induced DNA damage to proliferate unchecked, which increases the likelihood of malignant transformation. NMSC is estimated to occur in 3.3 million individuals annually. The rising incidence results in increased morbidity and significant healthcare costs, which necessitate identification of effective treatment modalities. In this review, we highlight the pathogenesis of NMSC and discuss the potential of novel preventative therapies. In particular, wounding therapies such as dermabrasion, microneedling, chemical peeling, and fractionated laser resurfacing have been shown to restore IGF-1/IGF-1R signaling in geriatric skin and suppress the propagation of UVB-damaged keratinocytes. This wounding response effectively rejuvenates geriatric skin and decreases the incidence of age-associated NMSC.

In Vitro Photoprotective, Anti-Inflammatory, Moisturizing, and Antimelanogenic Effects of a Methanolic Extract of Chrysophyllum lucentifolium Cronquist

UVB exposure causes DNA mutation and ROS generation, which lead to skin photoaging, skin wrinkling, skin sagging, and uneven skin pigmentation. ROS activate the NF-κB and MAPK signaling pathways leading to production of inflammatory molecules such as COX-2, collagen-degrading proteins such as matrix metalloproteinases (MMPs), and moisture-deficiency-related proteins such as hyaluronidases (HYALs). UVB exposure also induces irregular skin pigmentation though melanin overproduction, related to CREB transcription factor activity and transcription of melanogenesis genes. Here, we demonstrate that Chrysophyllum lucentifolium methanol extract (Cl-ME) has antioxidant activity; it dose-dependently decreased the expression of COX-2, MMP-1, MMP-9, HYAL-1, and HYAL-4 by downregulating the NF-κB (IKKα/β, IκBα) and MAPK (ERK, JNK, and p38) pathways and increased the expression of Col1a1, which encodes a protein important for maintaining skin elasticity. Cl-ME also showed promising antimelanogenic activity by decreasing the expression of CREB, a transcription factor, which in turn inhibited the expression of genes encoding tyrosinase, MITF, TYRP1, and TYRP2. In summary, a methanol extract of C. lucentifolium exhibited antiphotoaging and antimelanogenic activity and could be useful in the cosmeceutical industry.

The Effect of Corncob (Zea mays) Extract Cream on the Number of Melanin Pigments of Guinea Pig Exposed to Ultraviolet

Background: Exposure to Ultraviolet B (UVB) rays on the skin causesmany problems, including pigmentation and aging effect. Hence, protection against it is needed. Purpose: The study aimedto determine the effect of corncob extract cream on the number of melanin pigments in guinea pig skins exposed to UVB rays. Methods: Anexperimental post-test-only control group study was conducted on the 25 guinea pigs. The guinea pigs were divided randomly into five groups: group I without cream, group II cream base, group III hydroquinone cream, group IV 30% corncob extract cream, and group V 40% corncob extract cream. The cream was given daily for 20 minutes before UVB exposure and 4 hours after UVB exposure. The total dose of UVB exposure was 780 mJ / cm2 for 28 days. The amount of melanin pigment was calculated using the CX21 image J. Result: The number of melanin pigment in groups I, II, III, IV, and V were 22.8±0.4 cells, 18±0.3 cells, 6.3±3.1 cells, 13.8±0.2 cells, and 9.4±0.5 cells, respectively. Asignificantlydifferent value of One way ANOVA test was <0.05. Thus, there was a difference in the number of melanin pigments between the five groups. LSD post-hoc test showed differences in each group (p <0.05). Conclusion: 40% corn cobs extract cream effectively decreased the number of melanin pigment in guinea pigs exposed to UVB rays.

Association of lockdowns with the protective role of ultraviolet-B (UVB) radiation in reducing COVID-19 deaths

Nations are imposing unprecedented measures at a large scale to contain the spread of the COVID-19 pandemic. While recent studies show that non-pharmaceutical intervention measures such as lockdowns may have mitigated the spread of COVID-19, those measures also lead to substantial economic and social costs, and might limit exposure to ultraviolet-B radiation (UVB). Emerging observational evidence indicates the protective role of UVB and vitamin D in reducing the severity and mortality of COVID-19 deaths. This observational study empirically outlines the protective roles of lockdown and UVB exposure as measured by the ultraviolet index (UVI). Specifically, we examine whether the severity of lockdown is associated with a reduction in the protective role of UVB exposure. We use a log-linear fixed-effects model on a panel dataset of secondary data of 155 countries from 22 January 2020 until 7 October 2020 (n = 29,327). We use the cumulative number of COVID-19 deaths as the dependent variable and isolate the mitigating influence of lockdown severity on the association between UVI and growth rates of COVID-19 deaths from time-constant country-specific and time-varying country-specific potentially confounding factors. After controlling for time-constant and time-varying factors, we find that a unit increase in UVI and lockdown severity are independently associated with − 0.85 percentage points (p.p) and − 4.7 p.p decline in COVID-19 deaths growth rate, indicating their respective protective roles. The change of UVI over time is typically large (e.g., on average, UVI in New York City increases up to 6 units between January until June), indicating that the protective role of UVI might be substantial. However, the widely utilized and least severe lockdown (governmental recommendation to not leave the house) is associated with the mitigation of the protective role of UVI by 81% (0.76 p.p), which indicates a downside risk associated with its widespread use. We find that lockdown severity and UVI are independently associated with a slowdown in the daily growth rates of cumulative COVID-19 deaths. However, we find evidence that an increase in lockdown severity is associated with significant mitigation in the protective role of UVI in reducing COVID-19 deaths. Our results suggest that lockdowns in conjunction with adequate exposure to UVB radiation might have even reduced the number of COVID-19 deaths more strongly than lockdowns alone. For example, we estimate that there would be 11% fewer deaths on average with sufficient UVB exposure during the period people were recommended not to leave their house. Therefore, our study outlines the importance of considering UVB exposure, especially while implementing lockdowns, and could inspire further clinical studies that may support policy decision-making in countries imposing such measures.

Antiaging and Skin Irritation Potential of Four Main Indonesian Essential Oils

Essential oils possess antiaging properties due to their antioxidant activity. This study aims to determine the antiaging activities of four main Indonesian essential oils and their irritation potential on the skin. The spot yeast and in vivo rat skin with UVB exposure methods were used to analyze the antiaging activity of essential oils on aging triggered by endogenous and exogenous factors, respectively. Meanwhile, patch tests and clinical evaluations were used for the skin irritation potential analysis. The antiaging activity results from the endogenous factor showed that the use of clove, patchouli, nutmeg, and citronella oils increased yeast viability at concentrations of 20, 40, 60, and 100 µg/mL, respectively. Furthermore, nutmeg, cloves, citronella, and patchouli oils decreased the wrinkle score on rat skin after UVB exposure (exogenous factor). The skin irritation potential results of patchouli, nutmeg, citronella, and clove oils were none (0), slightly (0.02), moderately (0.09), and very irritating (0.39), respectively.

TO DETERMINE THE PREVALENCE AND OCCURANCE OF VISUAL MORBIDITY IN PATIENTS OF PTERYGIUM ATTENDING EYE OPD IN A TERTIARY CARE CENTRE OF EASTERN INDIA

To determine the prevalence and occurrence of visual morbidity in patients of pterygium attending eye opd in a tertiary care centre of Bihar. Methods: In this observational study a total of 193 patients, diagnosed with pterygium, underwent complete ocular examination by an ophthalmologist. Epidemiological trends including age, sex, occupation, effect of living condition and socioeconomic status were analyzed. Results: There is a male preponderance of 58.03%. The age incidence of the group showed that the incidence of pterygium was 10.36% in the age group of less than 30 years. It rises to a maximum of 29.53% in the age of 41-50 years and then gradually declines.. The incidence was found to be maximum among farmers(39.86%) followed by miners(31%). Conclusion: People who work outdoors are at a greater risk because they are subjected to involuntary UVB exposure. The highest exposure occurs during the two hours on either side of noon. Workers must be aware and should take appropriate measures like wearing protective glasses, caps, etc

(−)-Loliolide Isolated from Sargassum horneri Abate UVB-Induced Oxidative Damage in Human Dermal Fibroblasts and Subside ECM Degradation

Ultraviolet (UV) B exposure is a prominent cause of skin aging and a contemporary subject of interest. The effects are progressing through the generation of reactive oxygen species (ROS) that alter cell signaling pathways related to inflammatory responses. The present study evaluates the protective effects of (7aR)-6-hydroxy-4,4,7a-trimethyl-6,7-dihydro-5H-1-benzofuran-2-one (HTT) isolated from the edible brown algae Sargassum horneri against UVB protective effects in human dermal fibroblasts (HDFs). HTT treatment dose-dependently suppressed intracellular ROS generation in HDFs with an IC50 of 62.43 ± 3.22 µM. HTT abated UVB-induced mitochondrial hyperpolarization and apoptotic body formation. Furthermore, UVB-induced activation of key nuclear factor (NF)-κB and mitogen-activated protein kinase signaling proteins were suppressed in HTT treated cells while downregulating pro-inflammatory cytokines (interleukin-1β, 6, 8, 33 and tumor necrosis factor-α). Moreover, HTT treatment downregulated matrix metalloproteinase1, 2, 3, 8, 9 and 13 that was further confirmed by the inhibition of collagenase and elastase activity. The evidence implies that HTT delivers protective effects against premature skin aging caused by UVB exposure via suppressing inflammatory responses and degradation of extracellular matrix (ECM) components. Extensive research in this regard will raise perspectives for using HTT as an ingredient in UV protective ointments.

The Safety of Oral Telomerase Activator in UV-Induced Skin Cancer with A Review of Telomerase in Aging and Skin Carcinogenesis

The supplement telomerase activator TA-65 (purified from Astragalus membranaceus) has been shown to retard cellular senescence, boost the aging immune system, and retard age-related symptoms. Lengthened telomeres retard aging, but because cancers often maintain longevity by lengthening telomeres, dietary telomerase activator might possibly increase tumorigenesis. This study investigated whether oral TA-65 effects the timing of onset and/or the incidence of skin cancers induced by UVB-irradiation and whether that possible effect is different if the oral supplementation is begun only after tumors are first detected clinically or if supplementation is begun before initiation of tumors as well as during and after the inciting UVB exposure. Three groups of ten Skh:1 hairless, nonpigmented mice exposed to UVB for twenty weeks were given (1) no supplementation, (2) TA-65 supplementation starting when the first UV-induced skin cancers were clinically observed, after which the UV exposure was terminated, and (3) TA-65 supplementation before, during, and after UV exposure (as more tumors subsequently appeared). Except for two time points when Group 3 had borderline or statistically more tumors ≥ 2mm per mouse, overall, there was no statistically significant difference in the time of onset, the incidence, or the tumor load of skin cancers with TA-65 with either timing, confirming the safety of this anti-aging supplement in this model of the most frequent human malignancy.