Results from in vitro and ex vivo skin aging models assessing the antiglycation and anti-elastase MMP-12 potential of glycylglycine oleamide

Fenugreek seed ethanolic extract inhibited formation of advanced glycation end products via scavenging reactive carbonyl intermediates

Senescence is a natural phenomenon of growing old. It accelerates under certain conditions like diabetes mellitus resulting in early decline of bodily functions, which can be avoided by many claimed functional foods. The present study aims to investigate the anti-aging ability of Fenugreek seeds (Trigonellafoenum-graecum); a common ingredient of Indo-Pak cuisines. Briefly, the Fenugreek seeds extract (FgSE) in concentrationsof0.1, 0.5 and 1 mg/ml inhibited the formation of Advanced Glycation End products (AGEs) and fructosamine adducts in Bovine serum albumin (BSA)/fructose model in vitro. The BSA conformational analysis via Circular Dichorism and Congo red assays showed that it preserves secondary structure of BSA in aforementioned model. Although mechanistic studies revealed insignificant lysine blocking ability of Fenugreek by OPA assay, however carbonyl entrapping was found to be 24%, 34% and 42% at 0.1, 0.5 and 1 mg/ml, respectively. In vivo model of High Fructose diet (HFD) induced glycation, FgSE treatment in doses of 10, 25 & 50 mg/kg markedly improved Escape latency (p < 0.01) and preserved cognition in Morris Water Maze. Our data further exhibits significant decrease of CML (Nε-carboxymethyl lysine) levels in serum and hippocampus byFgSE treatment in comparison with HFD group. Therefore, we deduced that FgSE prevents glycation-induced memory decline via entrapping the reactive carbonyl intermediates, formed during production of AGEs. Hence, as a promising functional food it slows down the harmful process of glycation and aging associated morbidities.

Tracing skin aging process: a mini- review of in vitro approaches

Skin is a rather complex, yet useful organ of our body. Besides, skin aging is a complicated process that gains a growing interest as mediates many molecular processes in our body. Thus, an efficient skin model is important to understand skin aging function as well as to develop an effective innovative product for skin aging treatment. In this mini review, we present in vitro methods for assessments of skin aging in an attempt to pinpoint basic molecular mechanisms behind this process achieving both a better understanding of aging function and an effective  evaluation of potential products or ingredients that counteract aging. Specifically, this study presents in vitro assays such as 2D or 3D skin models, to evaluate skin aging-related processes such as skin moisturization, photoaging, wound healing, menopause, and skin microbiome as novel efforts in the designing of efficacy assessments in the development of skincare products.

The Ex Vivo Skin Model as an Alternative Tool for the Efficacy and Safety Evaluation of Topical Products

The development of alternative approaches for safety and efficacy testing that avoid the use of animals is a worldwide trend, which relies on the improvement of current models and tools so that they better reproduce human biology. Human skin from elective plastic surgery is a promising experimental model to test the effects of topically applied products. As the structure of native skin is maintained, including cell population (keratinocytes, melanocytes, Langerhans cells and fibroblasts) and dermal matrix (containing collagen, elastin, glycosaminoglycans, etc.), it most closely matches the effects of substances on in vivo human skin. In this review, we present a collection of results that our group has generated over the last years, involving the use of human skin and scalp explants, demonstrating the feasibility of this model. The development of a test system with ex vivo skin explants, of standard size and thickness, and cultured at the air–liquid interface, can provide an important tool for understanding the mechanisms involved in several cutaneous disorders.

Revisiting the effects of menopause on the skin: Functional changes, clinical studies, in vitro models and therapeutic alternatives

Menopause is a stage in a woman's life characterized by twelve months of amenorrhoea. This transition happens due to changes in ovarian follicular activity, leading to endocrine, biological and clinical modifications. The main hormones related to these changes and symptoms are oestradiol, LH, FSH, AMH, Inhibin B and GnRH. It is important to point out that the skin is very affected by all these hormone changes, leading to a decrease in collagen content, water content, elasticity, thickness and impacting on all skin layers quality. Aiming to help women go through this period of their lifetimes with a better quality of life, cosmetic and pharmaceutical industries have studied formulations to improve skin quality. In order to study the safety and efficacy of these products, in vitro methods have been developed in order to mimic menopause and aged skin. In addition to that, many clinical methodologies for skin features assessment have also been improved and applied to evaluate the efficacy of treatments or compounds for menopause. Studying and improving skin models and skin evaluation methodologies may help in the identification of therapeutic targets, treatments, drugs and cosmetics along with new insights for future research in the dermatology field.

Novel Facial Cream Containing Carnosine Inhibits Formation of Advanced Glycation End-Products in Human Skin

BACKGROUND

Accumulation of advanced glycation end-products (AGEs) in skin has been associated with skin aging. Inhibition of glycation of proteins of extracellular matrix may help skin texture and appearance. The objective of the study was to demonstrate the antiglycation activity of topically applied carnosine and novel facial cream (FC) containing carnosine in human skin explants ex vivo.

METHODS

Glycation was induced in human skin explants by methylglyoxal (MG) in culture media. FC containing carnosine (FC-CARN) or carnosine in aqueous solution (AQ-CARN) was applied topically on skin explants. Levels of AGEs carboxymethyl-lysine (CML) and pentosidine were determined in the epidermis and dermis of skin sections and were used to calculate antiglycation activity.

RESULTS

Exposure to MG led to increases in CML and pentosidine in skin explants. Antiglycation effect for AQ-CARN was CML: -64 and -41%, pentosidine: -48 and 42% in epidermis and reticular dermis respectively. Antiglycation effect for FC-CARN was CML: -150 and -122%, pentosidine: -108 and -136%, in epidermis and reticular dermis respectively.

CONCLUSION

Topically applied carnosine protects against the glycation induced by MG. Novel FC-CARN significantly reduced levels of AGEs in both epidermis and reticular dermis in human skin explants.

Antiaging efficacy of a retinaldehyde-based cream compared with glycolic acid peel sessions: A randomized controlled study

BACKGROUND

Glycolic acid (GA) chemical peels are a popular treatment for photoaged skin rejuvenation, but retinaldehyde (RAL)-based cosmetic creams have also demonstrated efficacy in improving photoaging, and are potentially better tolerated than chemical peels.

AIMS

To compare the efficacy and safety of an antiaging cream containing 0.1% RAL associated with Glycylglycine Oleamide (GGO, Relastide^® ) and Pre-tocopheryl^® , to GA peels sessions in the treatment of photoaging.

PATIENTS AND METHODS

Fifty-five women with photoaging were randomized in 2 treatment groups: (1) Daily application of the antiaging cream for 8 weeks or (2) Three sequential GA peels (20%, 50%, and 70%), 2-3 weeks apart. Skin surface texture, length of wrinkles, complexion radiance, and evenness of pigmentation and texture were assessed by profilometry using skin replicas, computer image analysis, and self-assessment.

RESULTS

Efficacy of both treatments was similar in reducing crow's feet wrinkles depth (STm -7.61%, P = .0007 vs -4.34%, P = .0348; P = .3049 intergroup) and volume, crow's feet and periorbital wrinkle length, and number of fine lines and wrinkles at end of treatments. The efficacy of the cream in refining skin texture was superior to the peels (contrast: -5.61%, P = .0025 vs +3.54, P = .08; P intergroup = .0252). The 8-week treatment with the antiaging cream was well tolerated; adverse events were fewer and of milder intensity than with the peels, (12-fold lower incidence of physical signs).

CONCLUSION

A dermocosmetic cream containing 0.1% RAL, GGO (Relastide^® ) and Pre-tocopheryl^® is as effective as 3 sequential GA peels, better tolerated, and is an alternative in the management of photoaged skin.

A new dermocosmetic containing retinaldehyde, delta-tocopherol glucoside and glycylglycine oleamide for managing naturally aged skin: results from in vitro to clinical studies

INTRODUCTION

Natural aging of skin tissues, the addition of the cumulative action of the time and radiation exposure result in skin atrophy, wrinkles and degeneration of the extracellular matrix (ECM). The aim of the study was to investigate the beneficial effect of a combination containing retinaldehyde (RAL), delta-tocopherol glucoside (delta-TC) and glycylglycine ole-amide (GGO) and of a dermocosmetic containing the combination.

MATERIALS AND METHODS

The protective effect of the combination was assessed through in vitro gene expression of ultraviolet (UV)-irradiated fibroblasts. A skin aging assay using UV light on ex vivo skin samples and a clinical study conducted in 36 women aged from 35 to 55 years with a minimum of level 4 to a maximum of level 6 on the crow's feet photoscale assessed the antiaging effect of the dermocosmetic.

RESULTS

When added to UV-irradiated fibroblasts, the combination substantially improved the ECM in activating the elastin fiber production (fibrillin 2, fibulin 1 and 5 and lysyl oxidase-like 2) as well as that of proteins involved in the cellular ECM interactions (integrin b1, paxillin and actin a2). An ex vivo photodamaged human skin model showed that the dermocosmetic formulation containing the combination of the active ingredients protected the elastic network against UV-induced alterations including both elastin and fibrillin-rich fibers in the dermis. A daily application of the dermocosmetic for 2 months on naturally aged skin resulted in a statistically significant improvement (p<0.05) of visible signs of aging comprising crow's feet, wrinkles and periocular fine lines. Finally, the formulation was well tolerated.

CONCLUSION

The dermocosmetic containing RAL, delta-TC and GGO provides a substantial benefit in the daily care of naturally aged skin in women aged 35-55 years.