Topical stabilized retinol treatment induces the expression of HAS genes and HA production in human skin in vitro and in vivo

Abstract

Skin Aging manifests primarily with wrinkles, dyspigmentations, texture changes, and loss of elasticity. During the skin aging process, there is a loss of moisture and elasticity in skin resulting in loss of firmness finally leading to skin sagging. The key molecule involved in skin moisture is hyaluronic acid (HA), which has a significant water-binding capacity. HA levels in skin decline with age resulting in decrease in skin moisture, which may contribute to loss of firmness. Clinical trials have shown that topically applied ROL effectively reduces wrinkles and helps retain youthful appearance. In the current study, ROL was shown to induce HA production and stimulates the gene expression of all three forms of hyaluronic acid synthases (HAS) in normal human epidermal keratinocytes monolayer cultures. Moreover, in human skin equivalent tissues and in human skin explants, topical treatment of tissues with a stabilized-ROL formulation significantly induced the gene expression of HAS mRNA concomitant with an increased HA production. Finally, in a vehicle-controlled human clinical study, histochemical analysis confirmed increased HA accumulation in the epidermis in ROL-treated human skin as compared to vehicle. These results show that ROL increases skin expression of HA, a significant contributing factor responsible for wrinkle formation and skin moisture, which decrease during aging. Taken together with the activity to increase collagen, elastin, and cell proliferation, these studies establish that retinol provides multi-functional activity for photodamaged skin.

Age‐related biophysical changes of the epidermal and dermal skin in Korean women

“…Age‐related changes in the epidermis and dermis of the skin have been demonstrated previously by several in vitro studies. Skin hydration in relation to skin aging refers to the loss of water content from the skin, which affects the firmness and roughness of skin . Hyaluronic acid (HA) demonstrates excellent water retention properties and thus is an effective moisturizer providing increased skin firmness.…”

“…Skin hydration in relation to skin aging refers to the loss of water content from the skin, which affects the firmness and roughness of skin. 8 Hyaluronic acid (HA) demonstrates excellent water retention properties and thus is an effective moisturizer providing increased skin firmness. Reportedly, HA content of the epidermis is reduced during the process of intrinsic aging.…”

Topical retinol attenuates stress‐induced ageing signs in human skin ex vivo, throughEGFR activation viaEGF, but notERK andAP‐1 activation

“…In clinical studies, topical retinol is capable of increasing epidermal thickness and gene expression of collagen type 1 and reducing collagenase synthesis and fine wrinkling in aged human skin . In human skin explants, topical retinol increases epidermal thickness, cellular proliferation, collagen deposition, elastin fibre formation and hyaluronic acid expression . The topical application of retinoids also reduces fine wrinkling in photodamaged human skin .…”

“…Skin ageing is a complex biological phenomenon that is induced by chronological metabolic processes and by external insults such as solar radiation, smoking and pollution . Aged skin presents a reduction in epidermal thickness and an increased degradation of collagen and elastic fibres, which results in wrinkling, sagging and skin roughness .…”

A blackberry–dill extract combination synergistically increases skin elasticity

“…A blackberry (Rubus fruticosus) leaf extract previously described as an elastase inhibitor (e.g. matrix metalloproteinases-MMPs) in dermal fibroblast [16] was selected and was also found to be a tropoelastin inducer. Additionally, this extract exhibited potent radical scavenging activity [17].…”