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.