The Pomegranate Flower Water Extract Negatively Regulates Melanogenesis by Suppressing MITF Expression and Its Target Enzymes.

BACKGROUND: The aesthetic issues caused by pigmentation are increasing people's demand for skin whitening. Considering its long-term use, it is very important for searching safe and effective agents. Pomegranate flower, a kind of traditional Chinese medicine, has shown promising anti-inflammatory, antioxidant, and antidiabetic properties, but its potential skin-lightening effects have not been well explored. AIMS: We investigated the effect of pomegranate flower water extract (PFE) on skin lightening and elucidated its underlying mechanisms. METHODS: The radical scavenging capacity was measured by ABTS and DPPH assays, and the mechanism of lightening was detected by Western blot. RESULTS: PFE could obviously inhibit tyrosinase activity, which its inhibition IC(50) value was lower than the positive control, kojic acid. Meanwhile, the radical scavenging capacity was also better than vitamin C (VC). Then the synthesis ability of melanin was measured in B16F10 cells; we found that PFE, in its safe concentrations, could reduce the synthesis of melanin resulting from inhibiting TYR activities. The expression of the main melanogenesis enzymes TYR, TRP-1, and TRP-2 was sharply reduced. Interestingly, MITF, a transcription factor of TYR, was obviously decreased its expression when treated with PFE at 50, 100, and 150 μg/mL, which was even significantly lower than the downregulation by kojic acid. CONCLUSION: Pomegranate flower extract possessed a strong antimelanogenesis effect, which resulted from inhibiting the expression of MITF and its downstream target enzymes involved in melanin synthesis. These findings provide a strong scientific basis for the use of PFE as a safe and effective skin-lightening ingredient in the cosmetic industry.