Spasmolytic effects of Scrophularia nodosa extract on isolated rabbit intestine

Scrophularia nodosa (figwort), an indigenous medicinal plant grows in moist and cultivated waste ground. It contains saponins, cardioactive glycosides, flavonoids, resin, sugar and organic acids. It is traditionally used for anti-inflammatory purpose and in skin disorders. It has diuretic and cardiac stimulant properties. The present studies were carried out on crude extract of Scrophularia nodosa and its n-hexane, chloroform, ethyl acetate, n-butanol and aqueous fractions. During phytochemical studies seven known compounds of flavonoid nature were isolated from the chloroform fraction of crude extract of S. nodosa. The structures of these compounds were elucidated by spectroscopic (UV, IR, Mass (EIMS, HREIMS) and NMR ((1)H-NMR, (13)C-NMR, DEPT, and (1)H-(1)H, COSY, HMQC, HMBC and NOESY) techniques. Compound 1 was identified as 5, 4`-hydroxy-3, 6, 7-trimethoxyflavone, compound 2 as 5-hydroxy-3,6,7,4'-tetramethoxyflavone, compound 3 as Centaurein, compound 4 as 5-hydroxy-7,8,2',3',4'-pentamethoxyflavone (Serpyllin), compound 5 as Kaempferol 7-O-α-L-rhamnopyranoside, compound 6 as sakuranetin 4'-O (6''-O-α-L-rhamnopyranosyl)-β-D-glucopyranoside (Vitexoside) and compound 7 as Spinoside. Crude extract and its fractions were tested on isolated rabbit intestine (in vitro) for their effects. The results of crude extract and its fractions in different doses showed the decrease in normal movement of the smooth muscles of rabbit intestine (jejunum). The chloroform fraction showed maximum relaxant effect (77.37%) at 15mg/ml dose and aqueous fraction showed 38.56% spasmogenic response which was not present in the crude extract. Further study was carried out on different fractions to investigate the possible mechanism of action of S. nodosa extract. For this purpose spasmolytic effect of different fractions were compared with agonist and antagonist activities of standard drugs including adrenaline, atropine andacetylcholine (1x10(-2), 1x10(-4) and 10(-6) M conc.). It is concluded that the chemical constituents present in S. nodosa having spasmolytic action are possibly acting through muscarinic receptors.