Dragendorff's reagent was prepared by mixing 1.7 g of Bismuth subnitrate, 20 ml of glacial acetic acid, 80 ml of millipore water and 50% solution of potassium iodide (50 g in 100 ml). Out of this Dragendorff's stock solution, 10 ml was missed with 20 ml of glacial acetic acid and the final volume was constituted up to 100 ml with millipore water. This solution was used as the working solution for the further experiments. 0.25 ml of the plant extract was then mixed with 0.5 ml of Dragendorff's reagent working solution and was kept at room temperature for 45 min. The absorbance of the reaction was measured at 700 nm. The concentration of the total alkaloid was determined as mg of atropine equivalent (AE) per gram of tissue using an equation obtained from the atropine calibration curve.