Ramine Parsa

Low-level red LED light inhibits hyperkeratinization and inflammation induced by unsaturated fatty acid in an in vitro model mimicking acne: RED LIGHT DELIVERS ACNE-RELEVANT BENEFITS IN VITRO

Acne vulgaris is a chronic inflammatory disease of the pilosebaceous units (PSU), associated with increased sebum production, abnormal follicular keratinization (hyperkeratinization), follicular overgrowth of Propionibacterium acnes (P. acnes), and increased inflammatory mediator release. Light therapy has attracted medical interests as a safe alternative treatment for acne. Both blue and red light therapies at high doses >10 J/cm2 have demonstrated marked effects on inflammatory acne lesions. However, few studies have investigated the effects of lower doses of light. The aim of this study is to investigate the biological effects of lower doses of red light at 0.2–1.2 J/cm2 for acne using an in vitro model previously developed to mimic the inflammation and hyperkeratinization observed clinically in acne.

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

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.