Potent pigmentation inhibitory activity of incensole-enriched frankincense volatile oil-identification, efficacy and mechanism.

Background: Frankincense volatile oil (FVO) has long been considered a side product in pharmaceutical industry since frankincense of large molecular weight is the prime target. However, the volatile oil recycled in the extract process might contain a series of functional actives, serving as promising ingredients in the cosmetic field.

Methods: Gas chromatography-mass spectrometer was utilized to determine the species and amount of active ingredients in FVO. Subsequently, zebrafish models were used to evaluate pigmentation inhibition, ROS elimination and neutrophil activation. In vitro DPPH test was also conducted to consolidate the anti-oxidation efficacy. Based on the test results, network pharmacology was incorporated, where GO and KEGG enrichment analyses were performed to discover the interrelations between active ingredients.

Results: About 40 actives molecules were identified, including incensole, acetate incensole, and acetate incensole oxide. The FVO demonstrated great depigmentation activity by suppressing melanin synthesis, as well as providing free radical scavenging and anti-inflammation effect. In network pharmacology analysis, 192 intersected targets were identified. By enrichment analysis and network construction, a series of whitening signal pathways, and hub genes, containing STAT3，MAPK3，MAPK1 were identified.

Conclusion: The current study quantified the components of FVO, evaluated its efficacy in skin depigmentation, and give pioneering insights on the possible mechanism. The results confirmed that the FVO could serve as whitening agent in topical uses.