Caucasian facial L* shifts may communicate anti-ageing efficacy

An ageing study was conducted to capture skin colour parameters in the CIELab system from Caucasians of both genders and all available adult ages. This study produced a linear correlation between L* and age for a Caucasian population between 20 and 59 years of age as follows: (L* value) = -0.13 × (Age in years) + 63.01. Previous studies have addressed age-related changes in skin colour. This work presents a novel consumer correlated quantitative linear model of skin brightness by which to communicate age-related changes. Two product assessment studies are also presented here, demonstrating the ability of anti-ageing products to deliver on objective and subjective improvements in skin brightness. It was determined to be possible to use the fundamental Caucasian L*-age correlation to describe product benefits in a novel quantitative and consumer-relevant fashion, through the depiction of a 'years back' calculation.     

An updated review of clinical methods in the assessment of ageing skin – New perspectives and evaluation for claims support

With the advancement of skin research, today's consumer has increased access to an informed understanding of ageing skin and its appendages, together with a plethora of targeted products to meet such needs. In recent years, increased legislative demands for quality evidential claims support have led not only to the development and validation of clinical methods to measure and quantify ageing skin, but also a clearer understanding of the skin ageing process–especially the impact of both its internal and external environments–as well as a tougher stance on clearly unjustifiable claims. Traditional testing methods used to research and evaluate anti‐ageing products claim to employ sophisticated instruments. Today, however, since the term anti‐ageing can be considered a misnomer, intelligent use of combined more advanced clinical methods has enabled the development of technologically improved consumer products providing enhanced efficacy and targeted performance. Non‐invasive methods for the assessment and quantification of the causes of ageing skin provide tools to the clinical researcher as defined by key clinically observed ageing parameters. Where evidence requires additional support, a number of clinical procedures evaluating ageing skin and hair products are combined with invasive procedures, thus enabling an added value to product claims. As discussed herein, given the enhanced understanding of ageing, we provide an update to our previous reviews of clinical methods used in the assessment of skin ageing, to include the wider aspects of environmental exposure; skin pigmentation; microbiome disturbance; surface topography; colour, radiance, and pH; and structural integrity–all requiring a disciplined approach to their use in dermatological investigations and product claims evidence.     

Intrinsic and extrinsic factors in skin ageing: a review

As the proportion of the ageing population in industrialized countries continues to increase, the dermatological concerns of the aged grow in medical importance. Intrinsic structural changes occur as a natural consequence of ageing and are genetically determined. The rate of ageing is significantly different among different populations, as well as among different anatomical sites even within a single individual. The intrinsic rate of skin ageing in any individual can also be dramatically influenced by personal and environmental factors, particularly the amount of exposure to ultraviolet light. Photodamage, which considerably accelerates the visible ageing of skin, also greatly increases the risk of cutaneous neoplasms. As the population ages, dermatological focus must shift from ameliorating the cosmetic consequences of skin ageing to decreasing the genuine morbidity associated with problems of the ageing skin. A better understanding of both the intrinsic and extrinsic influences on the ageing of the skin, as well as distinguishing the retractable aspects of cutaneous ageing (primarily hormonal and lifestyle influences) from the irretractable (primarily intrinsic ageing), is crucial to this endeavour.     

A review of ageing and an examination of clinical methods in the assessment of ageing skin. Part 2: Clinical perspectives and clinical methods in the evaluation of ageing skin

With the advancement of skin research, today's consumer has increased access to technological information about ageing skin and hair care products. As a result, there is a rapidly increasing demand for proof of efficacy of these products. Recognizing these demands has led to the development and validation of many clinical methods to measure and quantify ageing skin and the effects of anti-ageing treatments. Many of the current testing methods used to research and evaluate anti-ageing product claim to employ sophisticated instruments alongside more traditional clinical methods. Intelligent use of combined clinical methods has enabled the development of technologically advanced consumer products providing enhanced efficacy and performance. Of non-invasive methods for the assessment and quantification of ageing skin, there is a plethora of tools available to the clinical researcher as defined by key clinically observed ageing parameters: skin roughness and surface texture; fine lines and wrinkles; skin pigmentation; skin colour; firmness and elasticity; hair loss; and proliferative lesions. Furthermore, many clinical procedures for the evaluation of ageing skin treatments are combined with invasive procedures, which enable added-value to claims (such as identification and alteration of biochemical markers), particularly in those cases where perception of product effect needs additional support. As discussed herein, clinical methods used in the assessment of skin ageing are many and require a disciplined approach to their use in such investigations.     

Topically applied KTTKS: a review

Skin ageing is an irreversible process that is caused by both intrinsic and extrinsic factors. The possibility of arresting or delaying skin ageing represents a large research area and has a big potential in the cosmetics sector. Recently, the polypeptide lysine-threonine-threonine-lysine-serine (KTTKS) has attracted a lot of attention and it features in numerous up-market cosmetic products where it has become erroneously associated with the term 'pentapeptide'. In this study, we review in detail KTTKS and its major derivatives, in terms of the limited information in the literature and an appraisal of its physicochemical and theoretical skin permeation properties. There appears to be a sound in vitro basis for its action on fibroblasts due to its stimulatory effect on extracellular matrix synthesis, where the stimulatory effect of KTTKS is specific to collagen types I and III and fibronectin expression. However, there is a surprising absence of in vitro skin penetration data in the literature, and there are relatively few clinical studies using these materials.     

A review of ageing and an examination of clinical methods in the assessment of ageing skin. Part I: Cellular and molecular perspectives of skin ageing

The ageing process is noticeable within all organs of the body and manifests itself visibly in the skin. Skin ageing is influenced by several factors including genetics, environmental exposure, hormonal changes and metabolic processes. Together these factors lead to cumulative alterations of skin structure, function and appearance. The functioning of the central nervous, immune, endocrine and cardiovascular systems, as well as the skin is also impaired with age. Chronologically, aged skin is thin, relatively flattened, dry and unblemished, with some loss of elasticity and age-related loss of architectural regularity. General atrophy of the extracellular matrix is reflected by a decrease in the number of fibroblasts. Reduced levels of collagen and elastin, with impaired organization are primarily because of decreased protein synthesis affecting types I and III collagen in the dermis, with an increased breakdown of extracellular matrix proteins. Oxidative stress is considered of primary importance in driving the ageing process. The original free radical theory of ageing purported that the molecular basis of ageing was derived from a lifetime accumulation of oxidative damage to cells resulting from excess reactive oxygen species (ROS) produced as a consequence of aerobic metabolism. Although the skin possesses extremely efficient anti-oxidant activities, during ageing, ROS levels rise and anti-oxidant activities decline. The ROS are necessary in multiple MAP kinase pathways and the induction of AP-1, in turn, up-regulates expression of matrix-metalloproteinases providing a plausible mechanism for the increased collagen degradation in aged human skin.     

Oral fish cartilage polysaccharides in the treatment of photoageing: biophysical findings

The topically applied cosmetic products can be helpful in improving the aged skin condition. The present study shows how oral fish-cartilage food supplementation can be helpful in improving the treatment of ageing skin. A total of 30 healthy women with signs of skin ageing were studied. Fifteen of the women were treated with a food supplement based on polysaccharides derived from the fish cartilage and a natural mix of antioxidants for 2 months and the other 15 with a placebo. Clinical evaluation and biophysical parameters related to skin function and wrinkle severity, such as silicone replica, skin thickness, mechanical properties, skin colour and capacitance, were measured. The results showed statistically significant changes in the active-treated group in comparison to the placebo. In particular, dermal thickness (treatment: from 1.13 to 1.23 mm; P < 0.001), skin wrinkling (treatment: from 9.5 to 3.5 R(a); P< 0.002), skin colour (treatment: brighter and less pigmented; P < 0.02) and viscoelasticity (treatment: from 0.70 to 0.97%; P < 0.02) showed considerable improvement. Most of these parameters are related to changes occurring within the dermal matrix, which is improved after the treatment, whereas most of the topically applied cosmetic products have a short-term effect on superficial structures. A combination treatment (oral and topical) can be more effective in reducing the signs of skin-ageing.     

A new potent natural antioxidant mixture provides global protection against oxidative skin cell damage

Oxidative stress occurs when there is an over production of free radicals and cells are not able to neutralize them by their own antioxidant mechanisms. These excess of free radicals will attack cellular macromolecules leading to cell damage, function impairment or death. Because of that, antioxidant substances have been largely used in products to offer complementary protection. In this study a new mixture of three known antioxidants (cocoa, green tea and alpha‐tocopherol) was evaluated and its antioxidant protection was assessed focusing on its capacity to protect main cell macromolecules. Results have shown that it has a high antioxidant capacity by protecting lipids, DNA and proteins against oxidative damage. The antioxidant effect of the mixture on cells was also investigated and it was able to reduce oxidative stress generated by lipopolisacharide in human fibroblasts. Finally, as the mixture has proved to be highly antioxidant, its effect on cell senescence was evaluated, and it was demonstrated that fibroblasts in culture had delayed senescence when treated with these actives on a mixture. All results together provide important data about a new antioxidant mixture that uses a small amount of actives and is able to protect cell against oxidative damages in a global way.     

Methods for assessment of cutaneous ageing

Quantitative assessment of skin ageing is necessary for the evaluation of age modifying treatments. The particular method used must depend on the target of the intended treatment. It should also clearly distinguish between the degree of chronic environmentally-induced trauma to the skin (predominantly photoageing) and the intrinsic ageing process. However, it is clear that no one measure will be adequate to define the extent of cutaneous ageing. Broadly speaking, the techniques available are either invasive or non-invasive. Both have their uses. For example, topically applied retinoic acid 0.05% has been shown to increase epidermal thickness and decrease stratum corneum replacement time, using an invasive technique to determine the value for the first and a non-invasive method to evaluate the second. Virtually all aspects of skin structure and function change with age. However, because of the importance with regard to appearance, some measure of solar elastotic degenerative change should be made. Profilometry techniques and ultrasound determination of skin thickness, as well as measurement of skin colour, may all have their use for this purpose.     

A novel anti‐ageing mechanism for retinol: induction of dermal elastin synthesis and elastin fibre formation

Dermal elastic fibres are extracellular matrix protein complexes produced by fibroblasts and involved in skin elasticity. Elastin fibres decrease with age as a result of reduced synthesis and increased degradation, resulting in skin sagging and reduced skin elasticity. In this study, we show that retinol (ROL), known to enhance dermal collagen production, is also enhancing elastin fibre formation. ROL induced elastin gene expression and elastin fibre formation in cultured human dermal fibroblasts. Topical treatment of cultured human skin explants with a low dose (0.04%) of ROL increased mRNA and protein levels of tropoelastin and of fibrillin‐1, an elastin accessory protein, as documented by QPCR and immunohistochemistry staining. Luna staining confirmed the increased elastin fibre network in the ROL‐treated skin explants, as compared with untreated controls. These data demonstrate that ROL exerts its anti‐ageing benefits not only via enhanced epidermal proliferation and increased collagen production, but also through an increase in elastin production and assembly.     

Combined retinol-lactose-glycolic acid effects on photoaged skin: a double-blind placebo-controlled study

The objective of this study was to assess the efficacy of the combination of retinol, lactose and glycolic acid applied topically on photodamaged skin. Forty female volunteers were enrolled in a double-blind, randomized placebo-controlled clinical study. A cream containing retinol, lactose and glycolic acid was applied on one side of the face and a placebo cream on the other side, twice daily for 12 weeks. Skin photoageing signs were assessed clinically, whereas skin microrelief and moisturization were measured instrumentally. Both the clinical assessment and the objective instrumental measurements revealed that the active-treated side was significantly improved at the end of the study compared with baseline and control-treated side. In conclusion, our results demonstrate that topical application of a combination of retinol, lactose and glycolic acid has significantly improved the appearance of photodamaged skin.     

Distinct locational differences observable in biophysical functions of the facial skin: with special emphasis on the poor functional properties of the stratum corneum of the perioral region

The face is composed of complicated anatomical components, presenting unique portions, such as the eyes, nose and mouth in a relatively narrow area. Moreover, the facial skin is densely populated by the pilosebaceous units and sweat glands, and its stratum corneum (SC) is much thinner than that of the trunk and limbs, although it is always exposed to the environment. Among various portions of the facial skin, some are more easily irritated than others by environmental stimuli, or are more often affected by certain dermatoses. However, the functional aspects of the different portions of the facial skin have not been studied in detail under a strictly controlled environment in sufficiently large numbers of subjects covering different age groups. Thus, we conducted studies in winter with various biophysical techniques, such as transepidermal water loss (TEWL), as a parameter for SC barrier function, high-frequency conductance as that for skin surface hydration state, skin surface lipids, pH, blood flow and skin surface temperature on the forehead, mid-portion of the cheek (cheek in short), nasal tip (nose in short), nasolabial fold and chin of 20 healthy Japanese females aged 22-37 years (average 25 years) in a climate chamber adjusted to 21 degrees C and 50% relative humidity. Thereafter, we studied the influence of ageing on these biophysical parameters by collecting data of TEWL, high-frequency conductance and size of superficial corneocytes on the cheek, nasolabial fold and chin of 303 healthy Japanese female volunteers of different ages. The obtained results showed that the barrier function of the SC was best on the cheek, presenting the lowest TEWL, which was significantly higher on the nasolabial fold and chin than on the cheek. TEWL showed a decrease with age. In contrast, skin hydration state was higher on the nose, but it tended to be lower on the nasolabial fold, showing a mild age-related increase. The corneocytes on the nasolabial fold and chin were smaller than those on the cheek. They revealed a clear increase in size with age. Skin surface lipids were richest on the nose, whereas the superficial pH on the nose was the lowest among the regions tested. The skin temperature was lowest on the cheek than on other areas of the face; although, together with the nose, its blood flow was higher than that of the others. These data indicate great regional differences observable in SC functions on the face. In general, the SC barrier function increases with age, probably because of a decreased epidermal turnover rate as recognized by the increase in corneocyte size. Among the various sites, the skin of the nasolabial fold and chin, whose SC consisted of the smallest corneocytes, showed poorest SC properties in barrier function, suggesting the presence of mild invisible inflammation. It is understandable that this area easily develops not only the complaint of sensitive skin to cosmetics but also dermatitis because of various external agents.