Study On Anti-asthma Mechanism Of Scoparone

AIMBronchial asthma is a chronic disease that seriously damages the health of human being. Its morbidity and mortality show a tendency to gradually rise. Thus, It is a important subject in the medicine field to study pathological mechanism of asthma and develop effective drugs. Scoparone (Sco) that is a extract from Chinese traditional herb is potential to be develop an effective anti-asthma drug. This study investigated the method and rate of output of extracting Sco from Artemisia scoparia Waldst. Et Kit growing in Shenyang. Also, pathological mechanism of bronchial asthma and the effect of Sco on it was explored in the pathway of ryanodin e-mediated calcium release and Thl/Th2 misbalance theory.METHODSExtraction of Sco Flower, fruits or all of Artemisia scoparia Waldst. Et Kit growing in Shenyang were dried and cut into pieces, then soaked in 40 C -80 C water or organic solvent for two times (4h, 3h). The solution from soak was combined and concentrated. The concentrated solution was extracted by chloroform. The extracted solution was concentrated to minimum, and then the carboxylic acid and phenol constituents were removed respectively by 5% N^ C03 and 2% NaOH. At last, extract was washed by water and gradually become dry by retrieving chloroform. The remainder was heated and dissolved in carbi-nol, then cooled. The white crystal separated out from the carbinol containing the remainder is Sco.Drug treatment of animals Healthy guinea pigs ( male and female)weihting 150-200g were individed into three groups at random; control, asthma, Sco groups. Guinea pigs from Sco group were treated by Sco (0.034% w/v in 0.9% NaCl) for two minutes every day from beginning of experiment to the 28' day. The others were treated by 0.9% NaCl in the same way.Producing asthma guinea pig model The guinea pigs from asthma and Sco groups were sensitized by injecting ovalbumin (OA) 1ml ( 10% w/v in 0.9% NaCl, intraperitoneally). After two weeks, they were challenged by exposure to aerosolized OA (1% w/v in 0. 9% NaCl) for two minutes one time per day to induce asthma, by total two weeks. The responsiveness of animals was observed when they were challenged. Take deep and fast breath, ventral twitch, etc. as positive responsiveness which suggests; successful model. Dead and unsuccessful animals were fell in disuse. The guinea pigs from control were given 0. 9% NaCl in the same way. The animals were killed for experiments within 24 hours after the last challenge.Tracheal ring preparation and tension measurement The animals were killed by heating head, the lungs were rapidly excised and placed in cold, oxygenated (95% 02, 5%CO2) Krebs-Henseleit (K-H) solution. The main trachea were cleaned of all connective tissue and rings were cut (3-5 mm ). Tracheal rings were suspended in organ chambers (10ml) maintained at 37 0. 5C and perfused with normal gas mixture (95% O2, 5%C02; pH =7.4). The rings were mounted on two tungsten triangles suspended between stainless steel wire hooks, one of which was anchored to the organ bath, and the other was connected to a forces transducer. Tension was continuously recorded with a pen recorder using a force displacement transducer,. Before the beginning of each experiment , tracheal rings were allowed to equilibrate for 2 hours during which the tissues were washed with fresh standard K-H solution at 20 min intervals. Also during the equilibration period, a resting tension of 2g was applied to each ring. The rings were then repetitively challenged with 60mM KC1 until stable contractile responses were obtained. Ryanodine and KC1 were used as agonist for RyR and voltage-depended calcium channel ( VDCC) respectively.Identification of RyR isoforms on tracheal smooth muscle cells ( TSMC) of guinea pigs by RT-PCR The guinea pigs were killed by heating head. In ster-ile condition, lungs from the animals were dissected and placed in cold saline vehicle. Main tracheas were carefully cleaned of fat, connective tissues. The tracheas were cut longitudinally through the cartilage, the...