Development of whitening skin lotion from selected medicinal plants and its antityrosinase activity

In Thailand, herbal cosmetics are becoming more popular especially for nourishing and whitening skin. In this study, Artocarpus lakoocha Roxb. (AL), Glycyrrhiza glabra Linn. (GG) and Bombyx mori Linn. (BM) were extracted and formulated as a herbal whitening skin lotion. Antityrosinase activity of each extract and of the lotion preparation were tested using the dopamine method [1]. Additionally, the stability study; tyrosinase inhibitory activity, TLC, colour and odour of the formulation kept at different temperatures (4–8, 25–28 and 45°C) for 4 weeks were studied. The percentage of tyrosinase inhibition of AL, GG and BM at concentration of 1mg/mL were found to be 87.88±0.31 (IC₅₀ =50µg/mL), 74.24±0.62 (IC₅₀=140µg/mL) and 5.19±0.61 (IC₅₀>1000µg/mL), respectively, while the activity of a reference standard kojic acid at the same concentration was 83.30±0.51% (IC₅₀=130µg/mL). The whitening skin lotion containing 1.03% of AL, 0.42% of GG and 0.20%w/w of BM, exhibited antityrosinase activity at 98.60±045%. During 4 weeks of storage at 4°C, the antityrosinase activity, TLC, colour and odour of the lotion were not changed. Thus, the preparation containing AL, GG and BM which promoted high antityrosinase activity was appropriate as a herbal whitening skin lotion and should be stored at 4°C for good stability.

Acknowledgements: This study was granted by Thailand Research Fund for Industrial and Research Projects for Undergraduate Students (IRPUS) (No. I350A02003).

References: 1. Kubo, I., Kinst-Hori, I. (1999) Planta Med 65: 19.9.