Hirsutanone Isolated from the Bark of Alnus japonica Attenuates Melanogenesis via Dual Inhibition of Tyrosinase Activity and Expression of Melanogenic Proteins

Researchers found that hirsutanone, a natural compound from East Asian alder bark, can reduce skin pigmentation by blocking melanin production through two mechanisms: directly inhibiting the tyrosinase enzyme and suppressing the cellular signals that trigger melanin-producing genes. In laboratory tests with both mouse and human skin cells, hirsutanone proved more effective than a related compound called oregonin at reducing melanin without harming the cells. This discovery suggests hirsutanone could potentially be developed into a treatment for pigmentation problems like age spots and melasma.