This study aims to explore the pharmacodynamics of chelidonine, the active ingredient in greater celandine (Chelidonium majus L.), on in vitro rat bladder and trachea tissue, and evaluate its cell protective effects on primary lung and kidney cell lines. The study was carried out via repeated applications of acetylcholine, atropine, verapamil and oxybutynin, alongside Ca++ in a calcium-free environment, on urinary bladder tissue, and repeated applications of acetylcholine, atropine, carbachol and mecamylamine on trachea tissue. At the same time, cell viability and catalase and superoxide dismutase activity was measured on primary cell lines obtained from lung and kidney tissue samples. The study has shown that chelidonine has a relaxant effect on bladder and trachea tissues, and it may be mentioned that this effect is produced via muscarinic receptors. In addition, chelidonin caused a statistically insignificant increase in cell viability in primary lung and kidney cell lines at increasing doses (1 and 4 mu g/mL), but this increase remained at the control group level. In contrast, chelidonin caused a significant decrease in cell viability at the same cell lines at doses of 8 and 16 mu g/mL. In conclusion, it is suggested that greater celandine, which is used in folk medicine, and its active ingredient chelidonine might have beneficial effects on asthma, urinary incontinence and other urinary tract and respiratory diseases among others.