Essential oil of Seseli tortuosum L. from Portugal: safety and anti-inflammatory potential evaluation

Several Seseli L. (Apiaceae) species are used in folk medicine for several healing effects, namely herbal remedy for human inflammation, swelling, rheumatism, pain and common cold. In Portugal, there are two taxa usually used in traditional medicine: Seseli tortuosum L. and Seseli montanum subsp. peixotoanum (Samp.). The aim of the present research was to evaluate the anti-inflammatory activity of S. tortuosum and to assess their safety profile in several mammalian cell types at concentrations presenting strong bioactivity. This oil is characterized by high percentage of α-pinene (21.1%), β-pinene (22.6%) and cis-β-ocimene (11.8). The anti-inflammatory potential was investigated in lipopolysaccharide (LPS)-triggered nitric oxide (NO) production by macrophages and microglia concomitantly treated with S. tortuosum essential oil. Our results demonstrated a significant decrease of LPS-induced NO production at concentrations up to 0.16 μL/mL, without affecting cell viability. Our findings confirm the safety of S. tortuosum oil in doses with anti-inflammatory activity. These results support further studies envisaging the use of S. tortuosum oil in pharmaceutical formulations for inhalation, topical application or oral administration