Antimicrobial, antimycobacterial and antibiofilm properties of Couroupita guianensis Aubl. fruit extract

Background: Couroupita guianensis Aubl. (Lecythidaceae) is commonly called Ayahuma and the Cannonball tree. It is distributed in the tropical regions of northern South America and Southern Caribbean. It has several medicinal properties. It is used to treat hypertension, tumours, pain, inflammatory processes, cold, stomach ache, skin diseases, malaria, wounds and toothache. Methods: The fruits of Couroupita guianensis were extracted with chloroform. Antimicrobial, antimycobacterial and antibiofilm forming activities of the chloroform extract were investigated. Quantitative estimation of Indirubin, one of the major constituent, was identified by HPLC. Results: Chloroform extract showed good antimicrobial and antibiofilm forming activities; however it showed low antimycobacterial activity. The zones of inhibition by chloroform extract ranged from 0 to 26 mm. Chloroform extract showed effective antibiofilm activity against Pseudomonas aeruginosa starting from 2 mg/mL BIC, with 52% inhibition of biofilm formation. When the chloroform extract was subjected to HPLC-DAD analysis, along with Indirubin standard, in the same chromatographic conditions, it was found that Indirubin was one of the major compounds in this plant (0.0918% dry weight basis). Conclusions: The chloroform extract showed good antimicrobial and antibiofilm properties. Chloroform extract can be evaluated further in drug development programmes.