Resveratrol, found in grapes and wine, has been shown in the past to stop the formation of free radicals, which cause cell and tissue damage. Benzoyl peroxide is an oxidant that works by creating free radicals that kill the acne bacteria.
"We initially thought that since actions of the two compounds are opposing, the combination should cancel the other out, but they didn't," says Dr Emma Taylor, the study's first author and an assistant clinical professor of medicine in the division of dermatology at the David Geffen School of Medicine at UCLA.
"This study demonstrates that combining an oxidant and an antioxidant may enhance each other and help sustain bacteria-fighting activity over a longer period of time."
Best of both worlds
In their research, the team grew colonies of the bacteria that causes acne and then added various concentrations of resveratrol and benzoyl peroxide both alone and together to see their effect on bacteria growth over a 10-day period.
They found that benzoyl peroxide was able to initially kill the bacteria at all concentration levels, but the effect was short lived and didn't last beyond the first 24 hours.
Resveratrol didn't have a strong killing capability, but it inhibited bacterial growth for a longer period of time. Surprisingly, the two compounds together proved the most effective in reducing bacteria counts.
"It was like combining the best of both worlds and offering a two-pronged attack on the bacteria," says senior author Dr Jenny Kim, professor of clinical medicine in the division of dermatology at the Geffen School.
After this test, the team then wanted to test for toxicity, so they cultured human skin cells and blood cells with the two compounds, finding that benzoyl peroxide was much more toxic than resveratrol, which could help explain what causes skin to become red and irritated when it's used as a topical treatment.
Combining the two compounds allowed for prolonged antibacterial effects on the acne bacteria while minimizing its toxicity to other skin cells. The finding could lead to a more effective and less irritating topical acne therapy.
"We hope that our findings lead to a new class of acne therapies that centre on antioxidants such as resveratrol," Taylor says.
A patent application has been filed for the combination treatment of benzoyl peroxide and resveratrol, which is owned by the University of Calfironia Regents and managed by the UCLA Office of Intellectual Property and Industry Sponsored Research.
The research was published in the current online edition of the journal Dermatology and Therapy.