Biological activities of extracts of plants grown in Portugal

The antioxidant properties of herbs and spices are important in the prevention of several diseases. Extracts from Foeniculum vulgare (Apiaceae), Dittrichia viscosa (Asteraceae), Origanum vulgare, Salvia officinalis, Thymbra capitata, Thymus camphoratus, Thymus carnosus and Thymus mastichina (Lamiaceae) were investigated for their antioxidant and anti-inflammatory activities. Some extracts were studied for the first time. Deodorized-, organic- and water-solvent extracts of dried and ground plant material were prepared using solvents of different polarity. The antioxidant activity was assessed by the diphenylpycrylhydrazyl (DPPH) radical method and scavenging of the superoxide anion radicals through an enzymatic hypoxanthine/xanthine oxidase system. The anti-inflammatory activity was evaluated by inhibition of 5-lipoxygenase. Total phenolic content was quantified by the Folin-Ciocalteu method. S. officinalis extracts were the best in scavenging DPPH radicals and superoxide anion radicals. O. vulgare and T. mastichina extracts were also effective as DPPH and superoxide scavengers, respectively. Deodorized chloroformic extracts from T. mastichina, T. camphoratus, T. carnosus, O. vulgare, F. vulgare and S. officinalis exhibited high ability for inhibiting lipoxygenase. Only in very few cases, a weak-moderate positive correlation was detected between the total phenol content and antioxidant activity. For 5-lipoxygenase inhibition, a negative correlation was detected in the majority of the extracts. (C) 2010 Elsevier B.V. All rights reserved.