Antispasmodic activity of Teucrium stocksianum Boiss.

The aim of the study was to explore the traditional antispasmodic use of Teucrium stocksianum on scientific grounds, and preliminary screen the specie for phytochemical constituents. Crude methanolic extract of aerial parts of Teucrium stocksianum (Ts.Cr) was studied for possible relaxant effects on spontaneous rabbits' jejunum preparations at concentrations of 0.01, 0.03, 0.1, 0.3, 3.0, 5.0 and 10.0 mg/ml. Effects of Ts.Cr was also studied on 80 mM KCl-induced contractions to find out possible mechanism as antispasmodic. Calcium chloride curves were constructed in the presence and absence of Ts.Cr at different concentrations in decalcified rabbits' jejunum preparations and were compared with curves of verapamil. Plant was also screened for different classes of phytochemicals. The plant gave positive tests for the presence of different classes of phytochemicals like carbohydrates, proteins and amino acids, saponins, tannins, flavonoids and sterols. It gave negative tests for alkaloids, anthraquinone glycosides and cardiac glycosides. Ts.Cr caused 100% relaxation of the spontaneous rabbit's jejunum preparations at dose of 5.0 mg/ml (EC50=1.98 mg/ml±0.07, n=6). Contractions induced by 80 mM potassium chloride (KCl) were also relaxed 100% by Ts.Cr at dose of 5.0 mg/ml. When tested for possible calcium channel blockade in calcium free K+-rich medium, Ts.Cr at concentration of 0.3 mg/ml produced a right shift in the calcium chloride curves vs. control (log EC50=-1.78±0.03 [Ca++] M vs. control log EC50=-2.57±0.07 [Ca++] M). In similar fashion, a right shift was observed for the calcium chloride curves in the tissues treated with 0.1 μM verapamil. When tested on histamine and barium chloride induced contractions, the extract produced no significant effect. The results confirm the folkloric use of Teucrium stocksianum as antispasmodic possibly through the calcium channel blocking mechanism.