Evaluation of Skin Whitening Effect of Artocarpus Lakoocha Extract, Niacinamide, Lactic Acid, Tranexamic Acid, and Their Combinations in Guinea Pigs and Human Volunteers

Abstract

The skin whitening efficacy of Artocarpus Lakoocha extract (Puag-Haad) and its combinations with other whitening agents such as niacinamide, lactic acid, and tranexamic acid were studied in guinea pigs and humans. After 4-week daily application to the back of guinea pigs, solution containing 0.25% Puag-Haad and 1% niacinamide in propylene glycol was found to give the fastest onset of whitening action (one week). Its extent of melanin reduction was also the highest (34.33) although the value did not differ significantly from other whitening agents. Puag-Haad and its combinations were further studied in 84 human volunteers. The results showed that lotions containing 0.25% Puag-Haad alone (A), 1% niacinamide alone (B), 2.5% tranexamic acid alone (C), and Puag-Haad plus niacinamide (D), gave small but significant whitening effect after 12-week application, which was equivalent to a reference commercial product (F). On the other hand, Puag-Haad plus tranexamic acid failed to show significant whitening effect at all weeks. The small extent and slow onset of whitening efficacy was mainly due to poor subject compliance. To obtain more reliable results, an extra 8-week study with tighter control of experiments was conducted in 42 female vlunteers. The data agreed with the animal study in that combination between 0.25% Puag-Haad and 1% niacinamid produced the highest rate and extent of skin whitening, with the onset observed after 6 weeks and the highest extent of melanin reduction (17.29) after 8 weeks. All subjects did not experience any serious skin reactions. Only two subjects dropped out from hypersentivity to niacinamide and lotion base. Therefore, the Therefore, the results indicated a promising potential of the natural plant extract Puag-Haad as a novel and effective whitening agent, which can be formulated into lotion, either alone or with other substances, to obtain safe and effective whitening products for cosmetic and medical applications.