In vitro antioxidant and photoprotective activities of dried extracts from Neoglaziovia variegata (Bromeliaceae).

ABSTRACT

The phytochemical screening, antioxidant and photoprotective activities of dried extracts from the leaves of Neoglaziovia variegata were investigated. It was also evaluated the total phenolic and flavonoid contents by the Folin-Ciocalteu 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-carotene-linoleic 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. Preliminary analysis demonstrated that the extracts were found to be positive for the presence of anthracene derivatives, flavonoids, tannins, mono and diterpenes, naphthoquinones, coumarins, triterpenoids and steroids. The most significant total phenolic and flavonoid contents was of 608.50 ± 14.74 mg of gallic acid equivalent/g and 272.50 ± 9.25 mg of catechin equivalent/g, respectively, for ethyl acetate fraction (Nv-AcOEt). The Nv-AcOEt also presented the best antioxidant activity (IC50 3.51 ± 0.18 μg/ml) for DPPH scavenging. The chloroform fraction (Nv-CHCl3) and Nv-AcOEt showed characteristic absorption bands in regions UVB and UVA in a concentration-dependent manner. Nv-AcOEt presented the highest sun protection factor SPF (27. 68 ± 4.03). It shows the possibility to use this extract as sunscreen in pharmaceutical preparations.