Ethnopharmacological relevance: Roots of Onosma species are used for the treatment of various disorders such as bronchitis, tonsillitis, hemorrhoids as well as alleviating pains in folk medicine in Turkey.
Aim of the study: The chloroform and ethanol (70%) extracts obtained from the roots of Onosma species (Boraginaceae) growing in Turkey, Onosma aucheranum DC., Onosma isauricum Boiss. and Heldr. (endemic), Onosma sericeum Willd., Onosma tauricum Pallas ex Willd. var. brevifolium DC. (endemic) and Onosma tauricum Pallas ex Willd. var. tauricum (Syn: Onosma velenovskyi Davidov) were evaluated for in vivo anti-inflammatory and antinociceptive activities.
Materials and methods: For the preliminary screening, carrageenan-induced hind paw edema for the anti-inflammatory activity and, p-benzoquinone-induced abdominal constriction test for the antinociceptive activity were used in mice.
Results: The chloroform extracts from Onosma aucheranum and Onosma isauricum and ethanolic extracts from Onosma isauricum and Onosma sericeum demonstrated 28.0%, 34.3%, 24.6% and, 27.5% inhibition in p-benzoquinone-induced abdominal constriction test. The chloroform and ethanol (70%) extracts of Onosma isauricum and ethanol (70%) extract of Onosma sericeum also exhibited marked inhibition, ranging between 12.3-27.3%, 10.5-25.3%, 8.2-22.6%, respectively, in carrageenan-induced hind paw edema model at 100mg/kg dose without gastric damage and the activity was quite comparable to indomethacin (32.0-38.4% inhibition) as a reference sample. Neither death nor gastric bleeding was observed for any of the plant extracts during the acute toxicity evaluation.
Conclusion: The experimental data demonstrated that Onosma aucheranum, Onosma isauricum and Onosma sericeum displayed remarkable anti-inflammatory and antinociceptive activities.