Evaluation of the antibacterial and modulatory potential of α-bisabolol, β-cyclodextrin and α-bisabolol/β-cyclodextrin complex

• Published in: Biomedicine & pharmacotherapy 2017-08, Vol.92, p.1111-1118
• Main Authors: Oliveira, Fernanda de Sousa, Freitas, Thiago Sampaio de, Cruz, Rafael Pereira da, Costa, Maria do Socorro, Pereira, Raimundo Luiz Silva, Quintans-Júnior, Lucindo José, Andrade, Tatianny de Araújo, Menezes, Paula dos Passos, Sousa, Bruna Maria Hipólito de, Nunes, Paula Santos, Serafini, Mairim Russo, Menezes, Irwin Rose Alencar de, Araújo, Adriano Antunes de Souza, Coutinho, Henrique Douglas Melo
• Format: Article
• Language: English
• Subjects: alpha-Cyclodextrins - chemistry; alpha-Cyclodextrins - pharmacology; Anti-bacterial agents; Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; beta-Cyclodextrins - chemistry; beta-Cyclodextrins - pharmacology; Drug Compounding; Drug Resistance, Multiple, Bacterial; Drug Synergism; Escherichia coli - drug effects; Escherichia coli - growth & development; Gentamicins - pharmacology; Internal Medicine; Medical Education; Microbial Sensitivity Tests; Natural products; Norfloxacin - pharmacology; Pseudomonas aeruginosa - drug effects; Pseudomonas aeruginosa - growth & development; Sesquiterpenes - chemistry; Sesquiterpenes - pharmacology; Staphylococcus aureus - drug effects; Staphylococcus aureus - growth & development; Terpenes; α-Bisabolol; β-Cyclodextrin
• ISSN: 0753-3322; 1950-6007
• DOI: 10.1016/j.biopha.2017.06.020

Abstract The present study aimed to evaluate the antibacterial and modulatory potential of α-bisabolol, β-cyclodextrin and α-bisabolol/β-cyclodextrin complex. The minimum inhibitory concentration was determined through the broth microdilution technique using the bacterial strains: Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The drugs norfloxacin, imipenem and gentamicin were used in the tests, and the compounds α-bisabolol and β-cyclodextrin; all the compounds were diluted in DMSO. To obtain the minimum inhibitory concentration (MIC) a serial microdilution of the substances in volumes corresponding to the sub-inhibitory concentration (MIC/8), and microdilution with the antibiotic until the penultimate well were performed. The results showed that β-cyclodextrin did not present synergistic effects when combined with the antibiotics. It was found that α-bisabolol presented a synergistic effect against S. aureus , when combined with the antibiotic norfloxacin. Moreover, α-bisabolol presented synergism against E. coli when combined with gentamicin. The results of this study show that α-bisabolol presents a modulatory synergistic effect for some antibiotics, as gentamicin, and this is an interesting result against multidrug resistant bacteria (MDR). By other side, the complexation of α-bisabolol with β-cyclodextrin apparently reduces the modulatory effect, maybe due the polarity enhancement of the polarity of α-bisabolol, affecting the interaction of this compound with the cell membrane bilayer. However, more studies are necessary to demonstrate or not these interactions.