Anti-bacterial effects of silibinin on Pseudomonas aeruginosa

Introduction: Pseudomonas aeruginosa is one of the most common antibiotic resistant bacteria leading cause of nosocomial infections.Silibinin as a herbal drug exhibits various biological activities such as anti-bacterial and anti-inflammatory and anti-cancer activities .In this study, some clinical isolates of Pseudomonas aeruginosa from Guilan hospital were treated by Silibinin in combination with ciprofloxacin.Material&methode: in this study we isolated ciprofloxacin resistant Pseudomonas aeruginosa from patients in Guilan province. After MIC determination, isolates were treated by ciprofloxacin only and in the combination with silibinin. After 48h, antimicrobial activity of silibinin was evaluated by calculating OD600. Then, mexX gene expression in the treated cells was evaluated by Q-RT-PCR.Result: The MICs of ciprofloxacin against the strains ranged from 64 to 1024 μg/ml. Our analysis showed that a combined silibinin and ciprofloxacin treatment reduced the bacterial counts below the lowest detectable limit after 48 h. Q-RT-PCR analysis showed that mexX expression in cells treated by silibinin and ciprofloxacin was decreased relative to cells treated by ciprofloxacin only.Discussion: This study suggested that silibinin reduced the MICs of ciprofloxacin and through decrease of mexX expression . Also, it seems that silibinin in combination with ciprofloxacin could lead to the development of new combination of antibiotics against antibiotic resistant resistant Pseudomonas aeruginosa infection

Keywords:

Ciprofloxacin , mexX , MIC , Pseudomonas aeruginosa , Silibinin