Spasmolytic, bronchodilatory and antioxidant activities of Erythrina superosa Roxb.

The present study was undertaken to explore the possible antioxidant, spasmolytic, bronchodilator and antioxidant activities of Erythrina suberosa Roxb. flowers. The crude aqueous methanolic extract of Erythrina suberosa Roxb. flowers (Es.Cr), on application to isolated rabbit jejunum preparations, caused con- centration dependent relaxation of the spontaneous contractions as well as inhibition of K + (80 mM)-induced contractions, suggested that Es.Cr exhibited spasmolytic activity may possibly be mediated through Ca 2+ chan- nel blocking effect. This was confirmed further as Es.Cr treatment of the isolated rabbit jejunum preparations resulted in a rightward shift in the Ca 2+ concentration-response curves in a manner similar to verapamil, a stan- dard calcium channel blocker. Similarly, Es.Cr on application to isolated rabbit tracheal preparations; caused the concentration dependent relaxation of the carbachol (1 µM) and K + (80 mM)-induced contractions indicat- ing its bronchodilator activity in a manner similar to verapamil. The crude methanolic extract of Erythrina suberosa exhibited antioxidant activity as manifested by strong scavenging activity on DPPH free radicals, whereas weaker scavenging activity was shown on NO free radicals in comparison with standard antioxidant quercetin, which is equally potent against both free radicals. It is concluded from this study that the crude aque- ous methanolic extract of the flowers of Erythrina suberosa Roxb. possesses the antioxidant, spasmolytic and bronchodilator activities likely to be mediated through Ca 2+ channel blocking mechanism.