In Vitro Anti-Candida Drug Susceptibility Screening And Anti-Infective Mechanism Of Action Of Common Chinese Medicines

Objective:To screen the in vitro susceptibility of common Chinese herbal medicines against Candida and to investigate the mechanism of action.Methods:To determine the minimum inhibitory concentration(MIC50)of common Chinese medicines against Candida albicans using the microdilution method of RPMI-1640 medium proposed by the Clinical and Laboratory Standards Institute(CLSI).Then,the Chinese medicine Huanglian,which has better anti-C.albicans activity,was selected,berberine hydrochloride,the main monomer of the Chinese medicine Huanglian with good anti-C.albicans activity,was selected for the determination of the minimum inhibitory concentrations(MIC50 and MIC90)of Candida spp.and the changes in the growth degree and mycelium formation of wild strain and fluconazole-resistant C.albicans after treatment with different concentrations of berberine hydrochloride.Finally,the effects and mechanisms of berberine hydrochloride on the inflammatory response of vaginal epithelial cells infected with Candida were initially explored by examining the release of lactate dehydrogenase,cell mitochondria,FITC staining,and the production and changes of inflammatory vesicles NLRP3 after treatment with berberine hydrochloride.Results1.Among the 24 Chinese herbal granules screened,cinnamon,bitter ginseng,pepper,fried cassia seeds,chen pi,rhubarb,rhizoma anemarrhenae,coptis chinensis,scutellaria baicalensis and clove have anti-C.albicans effect with MIC50 of 1-256mg/ml.The anti-C.albicans effects of coptis chinensis and scutellaria baicalensis are more prominent with MIC90 of lmg/ml and 4mg/ml respectively.2.The anti-fluconazole-resistant C.albicans effect of berberine hydrochloride with MIC50 of 4-32μg/ml;but no significant effect was observed against fluconazole-resistant Candida auris with MIC50≥256μg/ml.Berberine hydrochloride significantly inhibited the growth rate and mycelium formation of C.albicans,and the inhibitory effect became stronger with the increase of drug concentration.3.After berberine hydrochloride treatment,vaginal epithelial cells infected with wild strains and fluconazole-resistant C.albicans showed reduced lactate dehydrogenase release,increased mitochondrial membrane potential,reduced fluorescence intensity of FITC and reduced fluorescence intensity of NLRP3 in C.albicans compared with positive controls.Conclusions1.Cinnamon,bitter ginseng,pepper,fried cassia seeds,chen pi,rhubarb,rhizoma anemarrhenae,coptis chinensis,scutellaria baicalensis and clove all have anti-Candida effects,among which coptis chinensis and scutellaria baicalensis have more prominent anti-Candida effects and can be the choice of subsequent anti-Candida treatment.2.Berberine hydrochloride,the main monomer of coptis chinensis has strong in vitro anti-fluconazole-resistant C.albicans effects,while berberine hydrochloride may exert anti-fluconazole-resistant C albicans effects mainly by inhibiting the growth degree and mycelium formation.3.Berberine hydrochloride may exert protective effects on C.albicans-infected vaginal epithelial cells through mechanisms such as stabilization of mitochondrial metabolism and reduction of inflammation levels in host cells.