Assessment of Antioxidant Activity of 24 Native Plants Used in Guatemala for Their Potential Application in Natural Product Industry

Antioxidants in plants are considered to mitigate oxidation reactions in the body, as well as slow deterioration due to oxidation of food. The aim of this research was to assess the antioxidant activity of native species used as food, condiments or medicine to determine their potential application. From the rich Mesoamerican biodiversity, 24 species were chosen (Annona cherimola, A. purpurea, A. reticulata, Brosimum alicastrum, Chamaedorea tepejilote, Cnidoscolus chayamansa, Cucurbita argyrosperma, C. pepo, Erythrina berteroana, Fernaldia pandurata, Gliricidia sepium, Lippia graveolens, Litsea guatemalensis, Manilkara sapota, Neurolaena lobata, Ocimum micranthum, Phlebodium pseudoaureum, Pimenta dioica, Piper auritum, Smilax domingensis, Solanum nigrescens, Spondias mombin, Tagetes lucida and Yucca elephantipes). Samples were collected from cropland or management fields and shade-dried at room temperature. Dried materials or fresh fruits were extracted with 95 percent ethanol by percolation, concentrated in a rotary evaporator, and dried in desiccators. For phytochemical screening, standard semi-micro methods were used, as well as thin layer chromatography (TLC). Antioxidant activity was evaluated by macro- and micro-quantification of total phenolics by Folin-Ciocalteu, total antioxidant capacity using DPPH, and iron reducing power. Results were analyzed by SPSS, univariate analysis by student t-test. Important activity was demonstrated by extracts from S. domingensis, T. lucida, L. guatemalensis, P. dioica, P. pseudoaureum and P. auritum. Phytochemical screening by semi-micro methods and TLC demonstrated the presence of flavonoids, anthocyanins, essential oils, and coumarins; though none showed anthraquinones or tannins. Bio-guided fractionations are being conducted to learn more about the chemistry of the extracts, and assess their potential use as a preservative or nutraceutical products for oral or topical application.