Curcumin-sulfobutyl-ether beta cyclodextrin inclusion complex: preparation, spectral characterization, molecular modeling, and antimicrobial activity

Urinary tract infections (UTIs) caused by Gram-negative bacteria E. coli is responsible for 80-90% of uncomplicated cases in women. The increased prevalence of antibiotic resistance has made the management of UTIs more challenging. Plant-derived compounds have long been used to treat various diseases, and constitute an alternative to antibiotic resistance. Curcumin (CUR), a naturally occurring polyphenolic phytoconstituent obtained from Curcuma longa is endowed with diverse medicinal properties. The present study aims to form a complex of CUR with Sulfobutyl ether-beta-cyclodextrin (SBE beta CD) to overcome the poor solubility and bioavailability of CUR and to evaluate the antimicrobial activity of CUR-SBE beta CD. Phase solubility studies and spectral characterization showed the entrapment of CUR in the SBE beta CD cavity. In silico docking studies performed to investigate the complexation process of CUR with SBE beta CD, revealed that the methoxy group and OH group of CUR interacted with SBE beta CD. The cytotoxicity and HET-CAM assays confirmed that CUR-SBE beta CD was non-irritant. The prepared complex investigated with the disc diffusion method showed antimicrobial activity with a zone of inhibition (ZOI) of 13mm against Escherichia coli (E. coli) and 11.5mm against Staphylococcus aureus (S. aureus) whereas CUR alone did not show any ZOI. It can be concluded that prepared CUR-SBE beta CD demonstrated superior antimicrobial activity and therefore can be a promising alternative for the treatment of UTIs. [GRAPHICS] .