Anti-tyrosinase activity of Curcuma aromatica ethyl acetate extract: from lead diarylheptanoids to melanogenesis targets

Abstract

Background

Curcuma aromatica (C. aromatica), a traditional medicinal plant, holds promise for addressing oxidative stress and hyperpigmentation through its rich curcuminoid and polyphenol content. Building on our previous identification of five major diarylheptanoids in its extract, this study investigated the ability of C. aromatica to mitigate oxidative stress and modulate melanogenesis with insight into its bioactive compounds’ contributions.

Results

Spectrophotometric analysis of its ethyl acetate extract revealed significantly high phenolic content, with 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays confirming strong antioxidative activity. Using B16 cells, the extract demonstrated non-toxic inhibition of melanin synthesis, reduced tyrosinase activity, and downregulated melanogenic proteins such as tyrosinase, related proteins, and microphthalmia-associated transcription factor (MITF). Gene Ontology and KEGG pathway enrichment analysis (GO-KEGG) along with molecular docking showed that five major diarylheptanoids strongly interacted with these proteins, modulating key pathways involved in pigmentation and beyond.

Conclusions

Together, these findings highlight C. aromatica’s dual action in combating oxidative stress and inhibiting melanogenesis, positioning it as a promising candidate for advancing medicinal chemistry approaches to hyperpigmentation and oxidative damage.