Dried extracts of Encholirium spectabile (Bromeliaceae) present antioxidant and photoprotective activities in vitro

The antioxidant and photoprotective activities of dried extracts from the leaves of Encholirium spectabile were investigated. It was also evaluated the total phenolic and flavonoid contents by the FolineCiocalteu and aluminum chloride methods, respectively. Antioxidant activities of the extracts were evaluated by using of 2,2-diphenyl-1-picrylhydrazil (DPPH) radical scavenging and β-caroteneelinoleic acid bleaching and compared with ascorbic acid, butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) used as reference compounds. The photoprotective effect was evaluated by the spectrophotometric method. The most significant total phenolic and flavonoid contents was of 188.50 ± 27.50 mg of gallic acid equivalent/g and 129.70 ± 4.59 mg of catechin equivalent/g, respectively, for chloroform fraction (Es-CHCl₃). The Es-CHCl₃ also presented the best antioxidant activity (IC50 25.35 4.35 mg/ml) for DPPH scavenging. The ethanol extract (Es-EtOH), Es-CHCl₃ and the fraction ethyl acetate (Es-AcOEt) showed characteristic absorption bands in regions UVB and UVA in a concentration-dependent manner. Es-CHCl₃ presented the highest sun protection factor SPF (8.89 ± 2.11). It shows the possibility to use this extract as sunscreen in pharmaceutical preparations.

Key words: Antioxidant properties, Bromeliaceae, Encholirium spectabile, Medicinal plants, Photoprotection.