Abstract:
The polyphenols such as flavonoids are a group of phytochemicals with photoprotection properties. Flavonoids accumulate densely in leaves exposed to excess solar radiation than shade leaves. This study aimed to evaluate the sunscreen activity of extracts of Cocosnucifera leaves with prolonged exposure to sunlight during the day. The extracts were obtained using methanol and water separately. Phytochemical screening revealed the presence of alkaloids, phenols, flavonoids, carbohydrates, terpenoids, and tannins in both extracts while saponins were present only in the aqueous extract. The total phenolic contents were determined by the Folin–Ciocalteu method to be2079.347 ± 41.551 and 680.750 ± 21.893 mg Gallic acid equivalent (GAE)/100 mg dry weight of the leaves for methanol and aqueous extracts, respectively. The total flavonoid contents were determined by aluminum chloride colorimetric assay to be1369.571 ± 11.842 and 494.444 ± 11.403 mg Catechin equivalent (CAE)/100 g dry weight of leaves for methanol and aqueous extracts, respectively. A concentration series of 0.2, 0.3, 0.4, 0.5 mg/ml in methanol were prepared for both extracts along with a commercial lotion, Dermatone® as the reference (SPF 36). The Sun Protection Factor (SPF) was determined by Mansur method at all concentrations. A SPF of 31.288 ± 0 was obtained for methanol extract at 0.5 mg/ml. Also, 0.5 mg/ml aqueous extract has a SPF of 21.893 ± 0.038. Both extracts have exceeded the SPF of 15 at the 0.5 mg/ml concentration indicating their ability to block roughly 93% UV rays when applied thoroughly. The Cocosnucifera leaves with efficient UV absorbing constituents could be used in sunscreen products as a safe alternative to harmful synthetic compounds.
