ABSTRACT Passiflora edulis Sims var. flavicarpa O. Deg. (Yellow-passion fruit) is the native plant species most used by juice industries in Brazil while its leaf extracts are widely employed in folk medicine. This study evaluated the phenolic content of leaves, roots, fruit shells and pulp of plants of P. edulis in juvenile, flowering and fruiting stages. The extent of scavenging and/or degradation of reactive nitrogen and oxygen species by plant extracts was also investigated. Leaves were the organs that most accumulated phenolics/flavonoids, regardless of plant developmental stage. Leaf extracts efficiently scavenged DPPH by up to 67 % while root and fruit shell extracts effectively captured up to 80 % O2 -. Maximum activity of catalase (51.6 mmol H2O2 min-1 mg prot-1) and ascorbate peroxidase (2.2 mmol ascorbate min-1 mg prot-1) was recorded in leaf extracts from plants in the fruiting stage. Superoxide dismutase activity reached its highest levels (37.5 U min-1 mg prot-1, on average) in plant leaves of both juvenile and fruiting plants. Overall, these results suggest that, for therapeutic purposes, parts of P. edulis should be harvested when plants are in the fruiting stage due to the excellent antioxidant properties of their extracts and their accumulation of phenolic compounds.

Ageratum conyzoides (mentrasto) tem valor sócio-econômico-cultural inestimável sendo utilizada como hortaliça não convencional na tradicional culinária de Minas Gerais. Na medicina popular é usada como purgativa, febrífuga, antiemética, em cólicas, úlceras e problemas uterinos. O objetivo deste trabalho foi quantificar o teor de compostos fenólicos, flavonoides e atividade antioxidante em extratos etanólicos de mentrasto, como etapa para validação analítica e bioanalítica do uso como medicamento fitoterápico e/ou como alimento funcional. Assim, nos extratos etanólicos de folhas (EF), flores (EFL) e raízes (ER) de mentrasto fizeram-se análises dos teores de compostos fenólicos, flavonoides e atividade antioxidante (% AAT). O doseamento de compostos fenólicos, em EF, EFL e ER, foi realizado pelo método de Folin-Ciocalteu. Na determinação do teor de flavonoides, nos extratos, utilizou-se vanilina em meio ácido e na avaliação antioxidante, a metodologia do sequestro do radical 2,2-difenil-1-picrilhidrazil (DPPH). O delineamento experimental foi em blocos casualizados; todas as análises foram feitas com quatro repetições, os dados submetidos à análise de variância e teste de média a 1% de significância. ER teve maior concentração de compostos fenólicos (23,333 mg/mL), seguido de EFL (19,254 mg/mL) e EF (14,722 mg/mL). O teor mais elevado de flavonoides foi em EF (5,726 µg/mL), seguido de EFL (5,463 µg/mL) e ER (4,805 µg/mL). A atividade antioxidante de EFL (87,62%) foi semelhante ao controle positivo indicando a potencial ação desta espécie como alimento funcional e o desenvolvimento de formulação fitoterápica padronizada que possa ser utilizada na prevenção de doenças degenerativas e no combate ao envelhecimento celular.

Ageratum conyzoides (mentrasto or goat weed) has invaluable socio-economic-cultural importante being used as unconventional vegetable in traditional cuisine of Minas Gerais state, Brazil. In folk medicine it is used as a purgative, febrifuge, antiemetic and against colic, ulcers and uterine problems. The objective of this study was to quantify the concentration of phenolic compounds, flavonoids and antioxidant activity in ethanol extracts of goat weed, as a step towards analytical and bioanalytical validation of its use as aherbal and/or medication as functional food. Thus, analysis of the levels of phenolic, flavonoids and antioxidant activity (AAT %) were made in ethanol extracts of leaves (EF), flowers (EFL) and roots (ER) of goat weed. Measuring phenolic compounds in EF, ER and EFL, was carried out by the Folin-Ciocalteu method. The content of flavonoids in the extracts was determined using vanillin in acid medium. For the antioxidant evaluation we used the methodology of 2,2-diphenyl-1-picryl-hydrazyl (DPPH) free radical scavenging method. The experimental design was randomized blocks design, all analyzes being performed with four replications. Data were submitted to analysis of variance and to test at 1% significance. ER had a higher concentration of phenolic compound (23.33 mg/mL), followed by EFL (19.254 mg/mL) and PE (14.722 mg/mL). The highest content of flavonoids was EF (5.726 µg/mL), followed by EFL (5.463 µg/mL) and ER (4.805 µg/mL). The antioxidant activity of EFL (87.62%) was similar to the positive control validating the potential of this species as a functional food and the development of standardized herbal formulation that can be used for preventing of degenerative diseases and cellular aging.