Evaluation of medicinal plants from Central Kalimantan for antimelanogenesis

In the course of searching for new materials to use as whitening agents, we screened 19 methanol extracts prepared from 14 medicinal plants from Central Kalimantan province, Indonesia. The screening methods used were the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging assay, a tyrosinase inhibition assay, and a melanin formation inhibition assay using B16 melanoma cells. The extracts of Willughbeia coriacea (bark part of aerial root), Phyllanthus urinaria (root), Eleutherine palmifolia (bulb), Eusideroxylon zwageri (seed), Dendrophthoe petandra (aerial root), Passiflora foetida (stem), and Vitex pinnata (root) showed DPPH radical-scavenging activity of more than 70% at 100 μg/ml. The extracts of W. coriacea (bark part of aerial root), P. urinaria (root), and D. petandra (aerial root) showed tyrosinase inhibitory activity of more than 40% using l-tyrosine as a substrate at 500 μg/ml. The extracts of W. coriacea (bark part of aerial root) and D. petandra (aerial root) showed tyrosinase inhibitory activity of more than 40% using l-DOPA as a substrate at 500 μg/ml. The extracts of W. coriacea (bark part of aerial root, 200 μg/ml), Glochidion philippcum (aerial root, 200 and 300 μg/ml), E. palmifolia (bulb, 50 μg/ml), E. zwageri (seed, 100 μg/ml), D. petandra (aerial root, 200 μg/ml), Lansium domesticum (bark, 25 μg/ml), P. foetida (stem, fruit, 300 μg/ml), and Solanum torvum (root, 300 μg/ml) strongly inhibited the melanin production of B16 melanoma cells without significant cytotoxicity. These findings indicate that some medicinal plants from Central Kalimantan are potential ingredients for skin-whitening cosmetics if their safety can be confirmed.