Antimelanogenesis and antioxidant activity of <i>Broussonetia papyrifera</i> leaf extract fermentation broth

<i>Broussonetia papyrifera</i> leaves are a medicinal plant rich in bioactive substances. This study utilized microbial fermentation of <i>B. papyrifera</i> leaf extract (BLE) to screen out <i>Lactobacillus rhamnosus</i> and <i>Bifidobacterium papyrifera</i> as the most suitable fermentation strains. The total phenols, total flavonoids, total tannins and total triterpenoids content increased after fermentation. The fermentation broth of <i>L. rhamnosus</i> and BLE (BLFs) could inhibit the tyrosinase, melanin production and related protein expression of mouse melanoma cell B16-F10. The fermentation broth of <i>B. bifidum</i> and BLE (BBFs) exhibited significant antioxidant effects. It indicates that the fermented BLE has great application potential in the fields of medicine, cosmetics and related areas.