Sunscreen activity of Punica granatum (Pomegranate) leaf extract

Abstract

This study aimed to evaluate in vitro sunscreen activity of methanol and aqueous extracts of Punica granatum leaves and formulate an effective sunscreen lotion. The phytochemical screening revealed that both extracts were rich in phenols and flavonoids. The total phenolic contents for methanol and aqueous extracts were 2003.925 ± 31.551 and 1244.212 ± 23.893 mg Gallic acid equivalent (GAE)/100 mg dry weight of the leaves, respectively. The Total flavonoid contents were 524.264 ±12.842 and 360.168 ± 10.403 mg Catechin equivalent (CAE)/100 g dry weight of leaves, respectively. A concentration series of 0.05, 0.1, 0.2, 0.3 mg/ml in methanol was prepared for both P. granatum extracts along with a commercial product, Dermatone® (the reference, SPF 36). The Sun Protection Factor (SPF) was determined at all concentrations and methanolic extract gave a SPF of 30.493 ± 0.058 at 0.3 mg/ml which is significantly higher than Dermatone® at the same concentration. However, 0.3 mg/ml aqueous extract gave the SPF of 19.662 ± 0.033 which is less than the reference. It is established that SPF 15 sunscreening products block roughly 93% UV rays when applied thoroughly. Interestingly, both extracts have exceeded the SPF of 15 at the concentration of 0.3 mg/ml. The UV spectra of both extracts have shown more efficient UV absorption over 250-400 nm range than the reference. Methanol extract was used for the preparation of herbal sunscreen lotion with 3% (F1) and 5% (F2) of the dried extract. The SPF obtained for 0.3 mg/ml solution of F1 and F2 were 1.817 ± 0.025 and 3.172 ± 0.023, respectively. Punica granatum leaves with efficient UV absorbing constituents could be used in sunscreen products as a safe alternative to harmful synthetic compounds.