Bakuchiol: a retinol-like functional compound revealed by gene expression profiling and clinically proven to have anti-aging effects.

Objective: The study was undertaken to compare the skin care related activities of retinol and bakuchiol, a potential alternative to retinoids. Retinol is a pivotal regulator of differentiation and growth of developing as well as adult skin. Retinoic acid is the major physiologically active metabolite of retinol regulating gene expression through retinoic acid receptor - dependant and independent pathways.
Methods: Comparative gene expression profiling of both substances in the EpiDerm FT full thickness skin substitute model was undertaken. Furthermore, type I, III and IV collagen, as well as aquaporin 3 expression was analyzed by ELISA and/or histochemistry in human dermal fibroblasts and/or Epiderm FT skin substitutes.
Results: Bakuchiol is a meroterpene phenol abundant in seeds and leaves of the plant Psoralea corylifolia. We present evidence that bakuchiol, having no structural resemblance to retinoids, can function as a functional analogue of retinol. Volcano plots showed great overall similarity of retinol and bakuchiol effects on the gene expression profile. This similarity was confirmed by the side-by-side comparison of the modulation of individual genes, as well as on the protein level by ELISA and histochemistry. Retinol-like functionality was further confirmed for the upregulation of types I and IV collagen in DNA microarray study and also show stimulation of type III collagen in the mature fibroblast model. Bakuchiol was also formulated into a finished skin care product and was tested in clinical case study by twice-a-day facial application. The results showed that, after 12 weeks treatment, significant improvement in lines and wrinkles, pigmentation, elasticity, firmness and overall reduction in photo-damage was observed, without usual retinol therapy-associated undesirable effects.
Conclusion: Based on these data, we propose that bakuchiol can function as an anti-ageing compound through retinol-like regulation of gene expression.
(© 2014 Society of Cosmetic Scientists and the Société Française de Cosmétologie.)