The antioxidant capacity related to the phenolic composition of monospecific honeybee-collected pollen extract from the mesquite tree (Prosopis juliflora) from Durango, Mexico, was evaluated in an in vitro-biological system (as inhibitor of lipid peroxidation on mouse hepatic microsomal preparations) and in an in vivo system (on homogenized liver of bromobenzene-intoxicated mice) by quantification of thiobarbituric acid-reactive substances (TBARS). The comparison of results obtained from these two different systems was also made. The results obtained suggest that pollen of P. juliflora is an important source of flavonoids, which can be considered as natural antioxidants. Mesquite pollen extracts showed antioxidant activity related to the flavonol concentration in both the in vitro-biological system and the in vivo system with a lower activity in the latter of these systems. Under in vivo conditions and in those in which a state of oxidation in not induced, a high concentration of flavonols in the extract of mesquite pollen can have a pro-oxidant effect. r

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The family Verbenaceae hosts important species used in traditional medicine of many countries. The taxonomic controversies concerning the specific delimitation of several of its species make it difficult to guarantee the botanical origin of herbal preparations based on species of this family. To contribute to the development of both specific chemomarkers and a quality control tool to authenticate the botanical origin of herbal preparations of Verbenacea species, we determined the foliar HPLC-DAD phenolic profiles and the antioxidant properties of 10 wild species of this family occurring in Mexico. The contents of phenols and flavonoids varied significantly among species. Priva mexicana showed the highest levels of total phenolics (53.4 mg g -1 dry tissue) and Verbena carolina had the highest levels of flavonoids (17.89 mg g -1 dry tissue). Relevant antioxidant properties revealed by antiradical and reducing power were found for the analyzed species. These properties varied significantly in a species-dependent manner. The phenolic compounds accumulated were flavones and phenolic acids. Flavones were the only type of flavonoids found. The results of a cluster analysis showed that the compounds were accumulated in species-specific profiles. The phenolic profiles are proposed as valuable chemomarkers that can become a useful tool for the quality control concerning the botanical origin of herbal medicinal preparations based on the species analyzed. In addition, phenolic profiles could contribute importantly to solve the taxonomic controversies concerning species delimitation in the family Verbenaceae.Keywords: Verbenacea, antioxidant activity, chemomarkers, flavones, phenolic profiles. Compostos fenólicos das folhas de dez especies selvagem de Verbenaceae como antioxidantes e quimiomarcadores específicos ResumoA família Verbenaceae compreende importantes espécies utilizadas na medicina popular de muitos países. As dificuldades taxonômicas relativas à delimitação específica de muitas das suas espécies face difícil a verificar a origem botânico das preparações herbales baseadas nas espécies desta família. Para fazer uma contribuição ao desenvolvimento de indicadores taxonômicos e dum método de controle de qualidade para verificar a origem botânico de preparações herbales das espécies de Verbenaceae, os perfis fenólicos, obtidos pares HPLC-DAD, e as atividades antioxidantes das folhas de 10 espécies selvagens Mexicanas desta família foram determinados. Os conteúdos dos compostos fenólicos totais e dos flavonoides foram significativamente diferentes entre as espécies. Priva mexicana apresentou a maior quantidade de compostos fenólicos totais (53.4 mg g -1 amostra seca) e Verbena carolina apresentou a maior quantidade de flavonoides (17.89 mg g -1 amostra seca). Verifica-se importantes propriedades antioxidantes, como os resultados dos ensaios da capacidade antiradical e do poder redutor indicaram. As propriedades antioxidantes foram significativamente diferentes entre as espécies. Verificou-se que os compostos fe...

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Abstract:The pollen flavonoid/phenolic acid composition of 14 individual of Stenocactus multicostatus subsp. zacatecasensis (Britton et Rose) U. Guzmán et Vázquez-Benitez, comb. et stat. nov., 11 of Echinocereus enneacanthus Engelmann, 8 of Echinocereus pectinatus (Scheidweiler) Engelmann and 12 of Mammillaria heyderi sensu lato (all belonging to Cactaceae) was analyzed by HPLC/DAD with the aim of determining the role of pollen profiles of flavonoid/phenolic acid as valuable markers in those taxa. The flavonoid/phenolic acid composition of pollen was evaluated within and among the taxa analyzed. The results suggest that (a) the flavonoid/phenolic acid profiles of these species are among the most complex reported, (b) that quercetin, kaempferol and herbacetin glycoside derivatives are the major phenols found in the pollen of these species of cactus, (c) that some intrapopulation variability is present in all four species and (d) that these pollen flavonoid/phenolic acid profiles tend to be species-specific, so that they can represent important taxonomic markers in Cactaceae.