Abstract:
The purposes of this study were to evaluate the in vivo skin whitening efficacy and irritation potential of the extracts of artocarpus lakoocha heartwood (Puag-Haad) and A. gomezianus root (Haadnun) in guinea pigs and human volunteers. After 4 week-daily application of the two substances to the shaved areas of the guinea pig back skin, 0.5% Puag-Haad was found to be the most effective whitening agent giving the overall whitening of 7.59%, which was significantly greater than 3% kojic acid (5.38%), 3% Haadnun (5.27%) and propylene glycol (3.26%). Thus, Puag-Haad was chosen for further studies in human subjects. Eighty female volunteers participated in a parallel clinical trial with self-control to evaluate the skin whitening activity of 0.5%, 0.25% Puag-Haad, 0.25% licorice extract and 3% kojic acid. After daily application, 0.25% Puag-Haad was the most effective agent, giving the shortest onset time to detect significantly whitening effect at only after 4 weeks. The physical and biochemical stability of Puag-Haad aqueous solution, with and without antioxidants, were also studied. The best antioxidant combination that provided optimum protection against loss in % inhibition of mushroom tyrosinase and against changes in color was the mixture of sodium metabisulfite and butylated hydroxyanisole. These results suggested that Puag-Haad possessed potent tyrosinase inhibitory activity which was superior to licorice extract and kojic acid. Its irritation potential is also low since none of the subjects receiving 0.25% Puag-Haad complained of any serious skin reactions. Thus, the good safety and efficacy of Puag-Haad, coujpled with the more economical price and availability, have made Puag-Haad a very promising alternative as a skin whitening agen or skin depigmenting agent in cosmetic and pharmaceutical industry.
Chulalongkorn University. Office of Academic Resources