Effect of aqueous extract of Origanum vulgare and Melilotus officinalis on production of nitric oxide (NO) in cultured vascular endothelial cells (mouse endothelioma F-2 cell line)

Background and During recent years, nitric oxide (NO) has been considered as a molecule involved in migraine headaches. This free radical involves in initiation of migraine headaches via NO/cGMP signaling pathway and vascular relaxation specially big intracranial arteries. Therefore, we studied the effects of aqueous extract of Origanum vulgare and Melilotus officinalis prescribed in migraine treatment in traditional & modern medicine, on NO level in cultured endothelial cells. Each crude herb (25g) was mixed with 200 ml distilled water. End extract obtained after filtering and drying. Endothelial cells propagated in DMEM medium containing 10% FCS and 1-2% penicillin-streptomycin. The nitrite concentration was measured as an indicator of nitric oxide production according to the Griess reaction and with ELISA in 540 nm. Concentrations of 100, 200 and 400 g/ml of Origanum vulgare, reduced NO levels compared with control to 13.1 % (p<0.05), 25.8% (p<0.01) and 33.9% (p<0.001) respectively. However, despite our expectation melilotus officinalis increased NO level. The concentrations of 100, 200 and 400 g/ml of the herb, increased NO levels to 12.7 (p<0.05), 36.5% (p<0.001) & 72.9% (p<0.001) respectively. We concluded that aqueous extract of Origanum vulgare probably decreases migraine headaches by reducing NO and aqueous extract of Melilotus officinalis does not act through this mechanism.