Modulatory activity of ethanol and hexane extracts of Costus cf. arabicus roots on antimicrobial drugs

Abstract

The bacterium Escherichia coli is known to produce enterotoxins causing diarrheal diseases. Some species of Staphylococcus are recognized as etiological agents of many animal and human opportunistic infections. Pseudomonas aeruginosa is the main cause of nosocomial infections, mainly affecting immunocompromised patients. Candidiasis is the most frequent opportunistic mycosis, frequently caused by Candida albicans, C. tropicalis, C. parapsilosis, C. glabrata, and C. krusei. Medicinal plants have been the source of many remedies used in the clinical practice. In this study, the hexane and methanol extracts of Costus cf. arabicus were assayed to the antibacterial activity alone or associated with aminoglycosides and antifungal drugs. Synergism of the ethanol and hexane were verified by the microdilution method. A synergistic effect of the two extracts combined with the aminoglycosides and antifungal agents was demonstrated. It is therefore suggested that the extracts from Costus cf. arabicus could be used as a source of natural products with resistance-modifying antimicrobial activity, providing a new mechanism against the problem of bacterial and fungal resistance to drugs.