ABSTRACT The aim of this study was to evaluate the antioxidant, antidiabetic, anti-inflammatory and antimicrobial activities of three edible seaweed extracts from Chilean coasts: Pyropia orbicularis, Ulva spp, and Durvillaea antarctica. Seaweed extracts in methanol and 70% acetone were performed to evaluate antioxidant and antidiabetic activities, whereas 60% methanol was used to measure anti-inflammatory and antimicrobial activities. Acetone extracts from D. antarctica had the highest total phenolic content and consequently exhibited the strongest antioxidant activity, while methanol extract of this seaweed presented the highest α-glucosidase inhibition (IC50= 0.004 mg mL-1). In the tests against E. coli and Penicillium sp., the extracts obtained from Ulva spp. were the most effective and exhibited the maximum anti-inflammatory effect against phorbol 12-myristate 13-acetate irritant agent (61.8% inhibition) in mice. Results indicated that all evaluated Chilean seaweed extracts are promising candidates for application in functional foods and in the pharmaceutical industry.

RESUMEN El objetivo de este estudio fue evaluar las actividades antioxidantes, antidiabéticas, antiinflamatorias y antimicrobianas de los extractos de tres algas marinas comestibles de las costas Chilenas (Pyropia orbicularis, Ulva spp. y Durvillaea antarctica). Se realizaron extractos de algas marinas en metanol y acetona al 70% para evaluar las actividades antioxidantes y antidiabéticas, mientras que el metanol al 60% se usó para actividades antiinflamatorias y antimicrobianas. Los extractos de acetona de D. antarctica tuvieron el mayor contenido de fenoles totales (TPC) y, en consecuencia, exhibieron la mayor actividad antioxidante, mientras que el extracto metanólico de estas algas presentó la mayor inhibición de la α-glucosidasa (IC50= 0,004 mg mL-1). En las pruebas contra E. coli y Penicillium sp., los extractos obtenidos de Ulva spp., actuaron como los más efectivos y exhibieron el máximo efecto antiinflamatorio contra el agente irritante de forbol 12-miristato 13-acetato (TPA) (inhibición del 61,8%) en ratones. Por lo tanto, los resultados indican que todos los extractos de algas chilenas evaluados pueden ser candidatos prometedores para su aplicación en alimentos funcionales y en las industrias farmacéuticas.

A cromatografia do extrato resinoso das partes aéreas de Haplopappus remyanus conduziu ao isolamento do ácido 18-acetoxilabda-7,13E-dien-15-óico, assim como dos derivados monoterpênicos 9-hidróxi-α-terpineol, 9-benzoilóxi-α-terpineol, 7-hidróxi-9-benzoilóxi-α-terpineole 9-benzoilóxi-(1-formil)-α-terpineol. As estruturas para os novos compostos foram propostas com base em evidências espectroscópicas. A presença de quercetina e de outros cinco flavonóides conhecidos e identificados neste estudo pode ser responsável pela alta atividade antioxidante descrita e pelo moderado efeito tópico anti-inflamatório sobre edema de orelha induzido. Uma avaliação MTT com células tumorais CCRF-CEM mostrou 50% da atividade citotóxica exibida pela doxorubicina nas mesmas condições. Diferenças quantitativas na composição química foram detectadas em comparação com estudos prévios com a mesma espécie, as quais podem ser atribuídas a fatores ambientais.

Chromatography on the resinous extract of aerial parts of Haplopappus remyanus led to the isolation of 18-acetoxy-labda-7,13E-dien-15-oic acid along with the monoterpene derivatives 9-hydroxy-α-terpineol, 9-benzoyloxy-α-terpineol,7-hydroxy-9-benzoyloxy-α-terpineoland 9-benzoyloxy-(1-formyl)-α-terpineol. Structures for the new compounds are proposed on spectroscopic evidence. The presence of quercetin and five other known flavonoids identified in this study could account for the reported high antioxidant activity and the moderate topic anti-inflammatory effect on induced ear oedema. MTT assay with CCRF-CEM tumor cells showed 50% of the cytotoxic activity displayed by doxorubicin under the same conditions. Quantitative differences in chemical composition were detected in comparison with previous studies of the species that could be attributed to environmental factors.