In vitro antioxidant activity and solar protection factor of blackberry and raspberry extracts in topical formulation

Abstract

Background: Berries are known for their antioxidant activity due to the presence of flavonoids. Antioxidants' usage guarantees skin protection against free radicals and, flavonoids, especially, can act as sunscreen. The aim of this paper was to evaluate solar protection factor (SPF) and antioxidant activity in vitro of blackberry and raspberry extracts incorporated in topical formulation and study their stability.

Results: Raspberry presented 29.93 mg of anthocyanins/100 g of fruit and blackberry 65.58 mg of anthocyanins/100 g of fruit. In vitro solar protection factor was 54.57 to blackberry and 37.32 to raspberry. When incorporated in O/W emulsions, final formulations showed light pink color, creamy aspect, and typical fruity odor. Formulations submitted to indirect light and stove showed odor and color alterations.

Conclusions: Based on the results, formulations containing extracts should be kept under refrigeration in opaque package to ensure stability due to the presence of flavonoids. In addition, blackberry and raspberry extracts are potential natural alternatives to be used as sunscreen and to prevent skin aging.

Keywords: antioxidant; blackberry; flavonoids; raspberry; solar protection factor.