The effect of topical sunscreen plus antioxidant against the visible light biologic effects.

Background: Visible light (VL) has been shown to induce erythema, pigmentation, and photodamage. Sunscreens effective against VL contain inorganic filters, but are often cosmetically unacceptable in darker skin tones. Antioxidants possess photoprotective properties and may serve as an alternative. Objective: To investigate the synergistic effect of sunscreen plus antioxidant (SA) against the visible light biologic effects. Methods: 29 subjects with Fitzpatrick skin type IV-VI had topical application of sunscreen plus antioxidant (SA), topical sunscreen containing physical blockers (SP), and topical antioxidant (A) before VL exposure. The pigmentation response was compared with subject’s baseline VL response. Investigator’s global assessment scores, photography, and diffuse reflectance spectroscopy were performed immediately after VL exposure to assess immediate pigment darkening (IPD), at 24 hours to assess persistent pigment darkening (PPD), and 7 days after to assess delayed tanning (DT). Results: Clinically, a decrease in IGA score for pigmentation was observed for sites treated with SA, and for SP compared with that of the control, although statistical significance was not reached. Spectroscopic data showed a statistically significant decrease in IPD, PPD, and DT response after application of SP compared with control ( P \u3c .05). In addition, SA reduced PPD ( P \u3c .05) but not DT. Conclusions: A combination product of SA or SP appears to be effective in decreasing the VL-induced persistent pigment darkening response. In addition, SP was able to reduce pigmentation at the IPD and DT time points based on spectroscopic results, suggesting protection offered against VL-induced effects