Benzoyl peroxide is far from a new chemical ingredient that scientists are just learning about. Discovered in the 19th century and first used medically around 1930, the ingredient later took off as a critical component of acne treatments.
Now, scientists at the University of California, Los Angeles have new research into how benzoyl peroxide works its magic in acne. The findings, released Friday, could have larger implications for how drug developers consider interactions between skin cells and the immune system. But before understanding how the ingredient works, the team delved into acne on a molecular level.
The skin condition affects roughly 10% of the global population and is the result of hair follicles interacting with oil and bacteria. Those follicles may get irritated or inflamed, producing pimples, or they can get clogged up with oil and bacteria, producing blackheads. But what’s happening behind the scenes? Using RNA sequencing and spatial transcriptomics, a team led by Tran Do, Ph.D., investigated acne lesions and found they had a specific macrophage that displayed a surface protein marker called TREM2.
Those macrophages were also shown to be filled with lipids, particularly squalene, which were unable to kill off the acne bacteria Cutibacterium acnes via in vitro testing. Further testing pinpointed squalene as a potential culprit for the ineffectiveness, showing that when added to other macrophages, differentiation was promoted that limited their ability to fight the bacteria.
The findings provide further clarity into how benzoyl peroxide is successful, showing that it can kill off bacteria through oxidation when TREM2 macrophages are handcuffed.
“It really opens the field up to thinking how the skin environment influences the types of immune cells present and how those interactions trigger certain diseases,” Do said in a release.
The researchers aren't the only ones drawn to the secrets of benzoyl peroxide. Sol-Gel and Galderma nabbed FDA approval in April for their cream to treat rosacea, a skin disease marked by pimplelike breakouts and red patches. Cutanea’s med Aktipak, meanwhile, also uses benzoyl peroxide in its acne gel, combining the ingredient with erythromycin.