Hypopigmentation can occur in severe genetic forms such as oculocutaneous albinism (OCA) as well as in inflammatory conditions that damage pigment-producing cells. Without melanin’s natural protection from ultraviolet radiation and its antioxidant role, patients may face higher skin cancer risk, vision problems related to impaired retinal development, and significant quality-of-life challenges.

The research, published June 18 in JCI Insight, focuses on stimulating tyrosinase, the key enzyme driving melanin synthesis. While tyrosinase inhibitors are common in skin-lightening products, reliably activating tyrosinase has been far more difficult—largely because practical experimental systems capable of testing activation in a high-throughput manner have been limited.

To overcome this barrier, the team developed a soluble, catalytically active form of human tyrosinase. This enabled purification of functional enzyme and the creation of a high-throughput chemical-optical assay, which screened more than 34,000 compounds for modulators of tyrosinase activity.

The screen highlighted candidate activators and inhibitors, including multiple novel molecules. After more rigorous follow-up, ampyrone stood out as the most promising activator. It increased tyrosinase catalytic activity in both normal enzyme and OCA-causing mutant variants.

Beyond enzyme activity, ampyrone boosted melanin production in cell-based models and in a 3D human skin model. Importantly, the researchers did not observe toxicity signals after up to three weeks in some testing conditions, consistent with ampyrone’s origin as a derivative of aminopyrine, a compound known for a favorable safety profile.

Using a new LC-MS-based approach to quantify immediate changes in melanin synthesis, the team found ampyrone could induce new melanin production within an hour. This rapid response underscores the compound’s potency and also suggests the assay could be broadly useful for screening pigment-modulating drugs inside cells.

The study concludes that ampyrone can serve as a lead compound for developing tyrosinase activator therapeutics aimed at correcting hypopigmentation. The investigators are now using it to guide the next stage of drug development.

Subject of Research: Not applicable
Article Title: Ampyrone is a direct agonist of human tyrosinase and a potential therapeutic for hypopigmentation disorders
News Publication Date: 18-Jun-2026
Web References: https://insight.jci.org/articles/view/202947/pdf
References: JCI Insight (June 18, 2026)
Image Credits: Dr. Jonathan Zippin

Keywords: ampyrone, melanin, hypopigmentation, tyrosinase, oculocutaneous albinism, LC-MS, JCI Insight, skin pigmentation, NSAID derivative, preclinical drug discovery