The Role of Coenzyme Q10 in Skin Aging and Opportunities for Topical Intervention: A Review.

Background: Coenzyme Q10 (CoQ10) is a naturally produced, lipid-soluble molecule crucial for cellular energy production and antioxidant activity. It diminishes with age and under external stress factors in skin, leading to signs of aging. Beyond its role in cellular energy production within the mitochondria, CoQ10 is vital to skin's defense against oxidative stress, a key contributor to premature aging.

Clinical Evaluation of Next-generation, Multi-weight Hyaluronic Acid Plus Antioxidant Complex-based Topical Formulations with Targeted Delivery to Enhance Skin Rejuvenation.

Introduction: Hyaluronic acid (HA) has become a commonly used ingredient in many topical products due to its strong humectant properties and essential role in skin hydration; however, limitations of delivery of HA to only the surface of skin has hindered leveraging the full capacity of HA biology necessary for skin rejuvenation. Here, we describe the clinical efficacy data of a set of novel next-generation, multi-weight HA plus antioxidant complex-based topical formulations with targeted skin delivery to enhance skin rejuvenation.

Methods: Four multi-weight HA plus antioxidant complex-based formulations: 1) Multi-Weight HA plus Antioxidant Complex Lotion with SPF 30 (Day Lotion); 2) Multi-Weight HA plus Antioxidant Complex Cream (Night Cream); 3) Multi-Weight HA plus Antioxidant Complex Gel Cream; and 4) Multi-Weight HA plus Antioxidant Complex Boost Serum were clinically evaluated for key attributes including moisturization via corneometer, with clinical grading of: dryness, roughness, fine lines and wrinkles, and following daily use of the individual products for up to eight weeks.

Application habits and practices of regular sunscreen users in the United States: Results of an online survey.

A nationwide online survey assessed claimed usage of sunscreen products in 2283 self-identified regular sun protection factor (SPF) consumers (RSPFC) in the United States. Subjects applied sunscreen most frequently when spending more than 3 h in the sun. Sunscreen usage peaks during the summer, with sunny weather prompting 99% usage of beach/recreational SPF products but drops to approximately 50% and 30% on partly cloudy and cloudy days, respectively, regardless of SPF product category.

Evaluation of efficacy of antioxidant-enriched sunscreen prodcuts against long wavelength ultraviolet A1 and visible light.

Objective: The synergistic effects of VL and long wavelength UVA1 (VL + UVA1, 370-700 nm) on inducing pigmentation and erythema in skin have been demonstrated and linked to exacerbation of dermatologic conditions including melasma and post-inflammatory hyperpigmentation. This study aimed to compare the photoprotection of organic sunscreens enriched with antioxidant (AO) combinations against VL + UVA1 induced biologic effects. The efficacy was compared with that offered by a commercially available tinted sunscreen.

Impact of visible light on skin health: The role of antioxidants and free radical quenchers in skin protection.

Until recently, the primary focus of photobiology has centered on the impact of UV radiation on skin health, including DNA damage and oncogenesis; however, the significant effects of visible light (VL) on skin remain grossly underreported. VL has been reported to cause erythema in individuals with light skin (Fitzpatrick skin types [FSTs] I-III) and pigmentary changes in individuals with dark skin types (FSTs IV-VI). These effects have importance in dermatologic diseases and potentially play a role in conditions aggravated by sun exposure, including phototoxicity in patients with FSTs I to III and post-inflammatory hyperpigmentation and melasma in patients with FSTs IV to VI.

Mitigating Visible Light and Long Wavelength UVA1-induced Effects with Topical Antioxidants.

The role of topical antioxidants (AOs) on visible light plus ultraviolet A1 (VL+UVA1)-induced skin changes were evaluated. Twenty subjects with skin phototypes (SPTs) I-VI had placebo and concentrations of an AO blend applied to their back (AO 0.5%, 1.

Multi-laboratory study of hybrid diffuse reflectance spectroscopy to assess sunscreen SPF and UVA-PFs.

Background: Proof-of-principle studies have established the use of Hybrid Diffuse Reflectance Spectroscopy (HDRS) methods to assess both Ultraviolet-A Protection Factor (UVA-PF) and Sun Protection Factor (SPF) indices in individual laboratories.

Methods: Multiple laboratories evaluated 23 emulsions and two spray sunscreen products to evaluate repeatability and accuracy of assessment of SPF and UVA-PF values, using HDRS test systems from various manufacturers using different designs.

Results: All of the laboratories reported similar SPF and UVA-PF values within a narrow range of values to establish the reliability of the HDRS methodology across laboratories, independent of equipment manufacturer or operator.

Evaluation of sunscreen efficacy over time and re-application using hybrid diffuse reflectance spectroscopy.

Background: In 2007, the FDA added requirements for sunscreens to be labeled "re-apply at least every 2 hours" based on very limited data. This study used hybrid diffuse reflectance spectroscopy (HDRS) to evaluate the persistence of protection by 80 minutes water-resistant sunscreen formulation with and without re-application, and with and without sweat-inducing activity over 6 hours.

Methods: Sunscreens were applied to subject's foreheads and backs, and they remained at rest or exercised to induce sweating in a heated environment.

Long-wavelength Ultraviolet A1 and Visible Light Photoprotection: A Multimodality Assessment of Dose and Response.

Human skin is exposed to visible light (VL; 400-700 nm) and long-wavelength ultraviolet A1 (UVA1) radiation (370-400 nm) after the application of organic broad-spectrum sunscreens. The biologic effects of these wavelengths have been demonstrated; however, a dose-response has not been investigated. Ten subjects with Fitzpatrick skin phototype IV-VI were enrolled.

Impact of Long-Wavelength Ultraviolet A1 and Visible Light on Light-Skinned Individuals.

Solar radiation is known to be a major contributor to the development of skin cancer. Most sunscreen formulations, including those with broad spectrum, offer minimal protection in long-wavelength ultraviolet A1 (UVA1; 370-400 nm) and visible light (VL; 400-700 nm) domain. There is limited information regarding the impact of this broad waveband (VL + UVA1, 370-700 nm) on those with light skin.

UV fluorescence excitation spectroscopy as a noninvasive predictor of epidermal proliferation and clinical performance of cosmetic formulations.

Background: The epidermis is the outermost layer of skin and is composed of cells primarily containing keratin. It consists of about ten layers of living cells (keratinocytes) and ten layers of dead cells (corneocytes). Thinning of the epidermis and decreased proliferation of its cells are associated with aging related changes in skin, including wrinkling and laxity.

Photoprotection against visible light-induced pigmentation.

Objective: This paper presents in vivo an in vitro studies demonstrating the induction of pigmentation in human skin by visible light which can be blocked by using formulation containing the correct amount of yellow iron oxide (YIO).

Methods: An in vitro absorption method was developed to determine the protection provided by a test formulation containing 4.5% YIO using an IPD UVA-VIS action spectrum.

The Kollias legacy: Skin autofluorescence and beyond.

In a paper published at the J Invest Dermatol in 1998 Nik Kollias and coworkers described distinct changes in skin native fluorescence associated with skin aging and photoaging, using in vivo fluorescence excitation spectroscopy. The assignment of the 295 nm band to tryptophan fluorescence had a profound significance influencing many later studies from multiple groups. The reproducible changes in skin native fluorescence suggested that aging causes predictable alterations in both the epidermis and the dermis, whereas chronic UV exposure induces the appearance of new fluorophores.

Water-Holding and Transport Properties of Skin Stratum Corneum of Infants and Toddlers Are Different from Those of Adults: Studies in Three Geographical Regions and Four Ethnic Groups.

Background/objective: Epidermal structure, function, and composition are different in white infants and adults. We investigated whether ethnicity and location contribute to differences in functional and clinical measurements of skin barrier function during the first years of life and in adults.

Methods: Children (n = 397, ages 3-49 mos) and women (n = 117, mean age 31 yrs) were enrolled at independent centers in Beijing, China (ethnic Chinese), Skillman, New Jersey (white, African American), and Mumbai, India (ethnic South Asian).

Visible Light Induces Melanogenesis in Human Skin through a Photoadaptive Response.

Visible light (400-700 nm) lies outside of the spectral range of what photobiologists define as deleterious radiation and as a result few studies have studied the effects of visible light range of wavelengths on skin. This oversight is important considering that during outdoors activities skin is exposed to the full solar spectrum, including visible light, and to multiple exposures at different times and doses. Although the contribution of the UV component of sunlight to skin damage has been established, few studies have examined the effects of non-UV solar radiation on skin physiology in terms of inflammation, and limited information is available regarding the role of visible light on pigmentation.

Evaluation of Seasonal Changes in Facial Skin With and Without Acne.

The objective of this study was to compare facial skin of adolescent males with (acne) and without acne (non-acne) over the course of 1 year. At study entry, presence of acne was determined by clinical image analysis (acne n=7, non-acne n=10). Monthly evaluations of skin condition were made using standard and fluorescent imaging, fluorescence spectroscopic analysis, sebum analysis, skin high frequency conductivity (moisture content), transepidermal water loss (TEWL), and sampling of skin bacteria (aerobic and anaerobic).

IL-11, IL-1α, IL-6, and TNF-α are induced by solar radiation in vitro and may be involved in facial subcutaneous fat loss in vivo.

Background: The loss of subcutaneous (sc) fat is associated with aging. Inflammatory cytokines, such as interleukin-1 α (IL-1α), interleukin-11 (IL-11) and tumor necrosis factor-α (TNF-α), are known to inhibit the differentiation of preadipocytes.

Objective: This study investigated the potential role of inflammatory cytokines in solar-radiation-induced facial fat loss.

Irradiation of skin with visible light induces reactive oxygen species and matrix-degrading enzymes.

Daily skin exposure to solar radiation causes cells to produce reactive oxygen species (ROS), which are a primary factor in skin damage. Although the contribution of the UV component to skin damage has been established, few studies have examined the effects of non-UV solar radiation on skin physiology. Solar radiation comprises <10% of UV, and thus the purpose of this study was to examine the physiological response of skin to visible light (400-700 nm).

The value of the ratio of UVA to UVB in sunlight.

The objective of this communication is to present the calculated ratio between UVA and UVB irradiance from sunrise to sunset and under a number of weather conditions. UVA plays an important role in the sun spectrum and a lot of attention has been paid lately regarding the protection of people from UVA. Solar spectra were collected in Kuwait City located at 29.

Impact of long-wavelength UVA and visible light on melanocompetent skin.

The purpose of this study was to determine the effect of visible light on the immediate pigmentation and delayed tanning of melanocompetent skin; the results were compared with those induced by long-wavelength UVA (UVA1). Two electromagnetic radiation sources were used to irradiate the lower back of 20 volunteers with skin types IV-VI: UVA1 (340-400 nm) and visible light (400-700 nm). Pigmentation was assessed by visual examination, digital photography with a cross-polarized filter, and diffused reflectance spectroscopy at 7 time points over a 2-week period.

Diffuse reflectance spectroscopy for ultraviolet A protection factor measurement: correlation studies between in vitro and in vivo measurements.

Background/purpose: Assessing the ultraviolet (UVA) protection factor of sunscreen formulations has been discussed for the past 20 years. The purpose of this study is to correlate the measurements of the UVA protection factor value (PFA value) via in vivo diffuse reflectance spectroscopy (DRS) and to compare this method with the in vitro method of measuring the PFA value, as well as with the in vivo persistent pigment darkening (PPD) and PFA methodologies.

Methods: The UVA protection factor via DRS technique was assessed in two clinical studies.