Abstract:  Using ethanol reflux， water decoction or ultrasonic method， extracts of 25 different traditional antipyretic and antidote medicines were obtained. Inhibition zone diameters of above 25 extracts on Helicobacter pylori（Hp） from swine were detected by Oxford cup method. Minimal inhibitory concentration（MIC） were detected by macrodilution broth method， and combined antibacterial effects in vitro of them were also observed. MICs of the extracts obtained from rhizome coptidis， fructus canarii against Hp ranged from 156 to 312 mg·mL-1. MICs of the extracts obtained from flos lonicerae， radix tinosporae， folium isatidis， radix scrophulariae， radix sophorae tonkinensis， radix pulsatillea， herba violae， radix et rhizome rhei and herba taraxaci ranged from 12.50 to 25.00 mg·mL-1. MICs of the extracts obtained from caulis sargentodoxae， rhizome polygoni cuspidati， rhizoma belamcandae， caulis lonicerae， flos chrysanthemi， herba houttuyniae， fructus forsythiae， radix isatidis， herba leonuri， fructus chebulae and radix ampelopsis ranged from 50.00 to 100.00 mg·mL-1. MICs of the extracts obtained from rhizome cimicifugae， rhizome dryopteris crassirhizomatis and radix bupleuri exceeded 200.00 mg·mL-1. The results of pairwise joint bacteriostatic test showed that the fractional inhibitory concentration index （FICI） of the extracts from fructus canarii and radix tinosporea against Hp was less than or equal to 0.5. The FICI of fructus canarii/radix tinosporea with rhizome coptidis were more than 0.5， but less than or equal to 1. The FICI of fructus canarii/radix tinosporea/rhizome coptidis with flos lonicerae were more than 2. It was concluded that fructus canarii， radix tinosporea， rhizome coptidis， flos lonicerae showed a good antibacterial effect against Hp in vitro. The combination of fructus canarii and radix tinosporea was characterized by a synergism effect， whereas the combination of fructus canarii and rhizome coptidis， radix tinosporea and rhizome coptidis， respectively， was characterized by an additive effect. The combination of fructus canarii or radix tinosporea or rhizome coptidis with flos lonicerae showed a antagonism effect.

Key words: swine-derived Helicobacter pylori, traditional Chinese medicine extract, antimicrobial activity, in vitro