Ridolfia segetum (L.) Moris (Apiaceae) from Portugal: A source of safe antioxidant and anti-inflammatory essential oil

Ridolfia segetum (L.) Moris essential oil was obtained by hydrodistillation and analysed by GC and GC-MS. The antioxidant properties were evaluated through the TBARS assay, and the in vitro anti-inflammatory activity was assessed through inhibition of NO production triggered by the toll-like receptor 4 (TLR4) agonist, lipopolysaccharide (LPS), in mouse macrophages. Assessment of cell viability was made through a colorimetric assay using MIT on macrophages, keratinocytes, and hepatocytes. The main compounds are alpha-phellandrene (53.0-63.3%), terpinolene (11.9-8.6%), beta-phellandrene (5.5-6.0%), and dillapiol (1.9-8.0%). The oil demonstrated high antioxidant capacity in the concentrations tested (0.05-0.20 mu L/mL) and significantly inhibited NO production without cytotoxicity in concentrations up to 1.25 mu L/mL. The plants showed a high essential oil yield, which confers an industrial potential interest. Also, the high content of alpha-phellandrene (53.0-63.3%) makes it an important natural source of this compound. These results provide evidence of the therapeutic effects of this oil, and suggest that the anti-inflammatory activity in doses without cytotoxicity on mammalian cells, combined with its antioxidant potential and pleasant smell, could be of great value in the development of new phytopharmaceuticals. (C) 2014 Elsevier B.V. All rights reserved.