Nitric oxide radical scavenging potential of some Elburz medicinal plants

Abstract

Some plants scavenge nitric oxide (NO) with high affinity. For this purpose, forty extracts from 26 medicinal plants, growing extensively in Elburz mountains, were evaluated for their NO scavenging activity. Total phenolic and flavonoid contents of these extracts were also measured by Folin Ciocalteu and AlCl₃ colorimetric assays, respectively. Sambucus ebulus fruit aqueous extract and Pterocarya fraxinifolia leaf methanol extract showed better activity than others with IC₅₀ equal to 29 and 65 g ml^-1, respectively. NO is also implicated in inflammation and other pathological conditions, therefore very powerful scavenging activity of S. ebulus fruit extract may explain its very good anti-inflammatory activity. Phenolic and flavonoids contents of the extracts varied between 10.2 - 200.4 and 2.1 - 90.9 mg g^-1 of extract, respectively. Good correlations could be found between total phenolic contents and NO scavenging activity through linear regression analysis (R² = 0.63). There was also a better correlation between total flavonoids and NO scavenging activity (R² = 0.73). High NO scavenging activity in plants can candidate them for testing their anti-inflammatory property.

Key words: Antiinflammatory, flavonoid contents, medicinal plants, nitric oxide scavenging activity, phenolic contents, Sambucus ebulus, Pterocarya fraxinifolia.