TITLE:
Quantification of In Vivo Epidermal Keratinocyte Architecture Associated with the Signs of Skin Aging and the Skin Benefit Evaluation by Application of Galactomyces Ferment Filtrate (Pitera)-Containing Skin Care Product
AUTHORS:
Kukizo Miyamoto, Yoko Munakata, Keisuke Fujii, Chenlu Lei, Ley Yang, Suda Sudarsana, Masutaka Furue
KEYWORDS:
Facial Skin Aging, In Vivo Keratinocyte Cellular Architecture, Visual Aging Pa-rameter, Dehydration, Interconnectivity, New Trajectory, Galactomyces Fer-ment Filtrate, PiteraTM, SK-II LXP CreamTM
JOURNAL NAME:
Journal of Cosmetics, Dermatological Sciences and Applications,
Vol.14 No.1,
March
12,
2024
ABSTRACT:
Background: Aged skin exhibits visual alterations such as wrinkles, rough texture,
pore dilation, and dull skin tone, as well as physiological aging, namely,
decreased hydration and increased transepidermal water loss (TEWL). Recent
advances in coherence tomography have also revealed that skin aging affects in vivo epidermal keratinocyte
architecture. However, the interconnectivity between spatial architectural
aging and visual/physiological aging parameters remains largely unknown. Purpose: To elucidate whether the tomographic keratinocyte architectural aging is
correlated with visual and physiological skin aging parameters and to
quantitatively evaluate the improvements of the architectural, visual, and
physiological aging parameters by the daily treatment of the skin care formula
containing Galactomyces Ferment Filtrate (GFF, 8X PiteraTM). Method: We measured the in vivo keratinocyte
cellular architecture with two-photon stereoscopic tomography obtaining
by-layer epidermal section images in 78 Asian females of various ages. Visual
aging parameters were analyzed using a portable image capture system. Hydration
and TEWL were also assessed. The anti-aging effects of GFF-containing skin
moisturizer (SK-II LXP CreamTM) were also examined in two studies
after twice-daily application for 2 (N = 35) and 4 (N = 32) weeks. Results: As for the keratinocyte cellular architecture, skin aging was significantly
associated with decreased cell density and increased cell uniformity. These
architectural aging parameters were significantly correlated with visual and
physiological aging parameters, namely, rough texture, wrinkles, pore dilation,
dull skin tone, dehydration, and increased TEWL. The strong interconnectivity
allowed us to develop formulae to estimate the keratinocyte architecture from
visual aging parameters. Moreover, twice-daily application of SK-II
significantly improved the keratinocyte architecture associated with multiple
skin aging visual and physiological parameters. Conclusion: Skin aging
is a process involving mutual interconnections among epidermal keratinocyte
cellular architecture, visual, and physiological parameters. The GFF-containing
moisturizer SK-II effectively improves spatial architecture of keratinocytes in
epidermis and these evaluated skin aging parameters in a new trajectory over
the course of treatment.