Compositions and methods for lightening skin and reducing hyperpigmentation

The composition includes a cyclic, unsaturated compound, preferably a polyphenol derivative. It reduces the synthesis of melanin by inhibiting the activity and expression levels of tyrosinase and related proteins, thereby preventing and limiting the content and distribution of melanin in mammalian skin. It also induces autophagy of melanosome, thereby restricting the synthesis, storage and transfer of melanin from melanocyte to keratinocyte. The dual modes of action allow for the efficacy of the composition at low dosage without causing toxicity to lighten skin and treat disorders associated with hyperpigmentation.