Chapter 9 Cosmeceutical Vitamins: Vitamin B
NIACINAMIDE
• Topical cosmeceutical effects
BARRIER AND IRRITATION
Topical niacinamide reduced transepidermal water loss (TEWL), indicating improved barrier function. The treated skin was found to be significantly more resistant to damage by barrier-destructive agents such as the surfactant sodium lauryl sulfate (SLS) and trans-retinoic acid. This translates into less irritation and facial red blotchiness (Fig. 9.1).
YELLOWING (SALLOWNESS)
With topical niacinamide, yellowing was significantly prevented (Figs 9.2 and 9.3). The mechanism for this may involve antioxidancy via NAD(P)H, specifically prevention of protein glycation (Maillard reaction), the end products of which are cross-linked yellow-brown proteins (Amedori products) that accumulate in skin. Niacinamide has been reported to have antiglycation properties.
Fig. 9.2 Anti-yellowing effect in Chinese facial skin by topical 3.5% niacinamide: (A) baseline; (B) 4 weeks