Hydrocinnamic acid and perillyl alcohol are effective against Escherichia coli biofilms when used alone and combined with antibiotics.

AIMS: The use of phytochemicals to improve the effectiveness of antibiotics is a promising strategy for the development of novel antimicrobials. In this study, the antibiofilm activity of perillyl alcohol and hydrocinnamic acid, both phytochemicals present in several plants, and two antibiotics from different classes (amoxicillin and chloramphenicol) was tested, alone and in combination, against Escherichia coli. METHODS AND RESULTS: Each molecule was tested at the minimum inhibitory concentration (MIC), 5 × MIC, and 10 × MIC, and characterized concerning biomass removal, metabolic inactivation, and cellular culturability. The highest percentages of metabolic inactivation (88.5% for 10 × MIC) and biomass reduction (61.7% for 10 × MIC) were obtained with amoxicillin. Interestingly, for 5 × MIC and 10 × MIC, phytochemicals provided a total reduction of colony-forming units (CFUs). Dual and triple combinations of phytochemicals and antibiotics (at MIC and 5 × MIC) demonstrated high efficacy in metabolic inactivation, moderate efficacy in terms of biomass reduction, and total reduction of cellular culturability for 5 × MIC. CONCLUSIONS: The results demonstrated the antibiofilm potential of phytochemicals, highlighting the advantage of phytochemical/antibiotic combinations for biofilm control.

Hydrocinnamic Acid and Perillyl Alcohol Potentiate the Action of Antibiotics against Escherichia coli.

The treatment of bacterial infections has been troubled by the increased resistance to antibiotics, instigating the search for new antimicrobial therapies. Phytochemicals have demonstrated broad-spectrum and effective antibacterial effects as well as antibiotic resistance-modifying activity. In this study, perillyl alcohol and hydrocinnamic acid were characterized for their antimicrobial action against Escherichia coli. Furthermore, dual and triple combinations of these molecules with the antibiotics chloramphenicol and amoxicillin were investigated for the first time. Perillyl alcohol had a minimum inhibitory concentration (MIC) of 256 µg/mL and a minimum bactericidal concentration (MBC) of 512 µg/mL. Hydrocinnamic acid had a MIC of 2048 µg/mL and an MBC > 2048 µg/mL. Checkerboard and time-kill assays demonstrated synergism or additive effects for the dual combinations chloramphenicol/perillyl alcohol, chloramphenicol/hydrocinnamic acid, and amoxicillin/hydrocinnamic acid at low concentrations of both molecules. Combenefit analysis showed synergism for various concentrations of amoxicillin with each phytochemical. Combinations of chloramphenicol with perillyl alcohol and hydrocinnamic acid revealed synergism mainly at low concentrations of antibiotics (up to 2 µg/mL of chloramphenicol with perillyl alcohol; 0.5 µg/mL of chloramphenicol with hydrocinnamic acid). The results highlight the potential of combinatorial therapies for microbial growth control, where phytochemicals can play an important role as potentiators or resistance-modifying agents.

The Montreal Cognitive Assessment (MoCA) as a screening test for cognitive dysfunction in multiple sclerosis.

This study investigates the utility of the Portuguese version of Montreal Cognitive Assessment (MoCA) as a screening-method for identifying cognitive dysfunction (CD) in multiple sclerosis (MS). The 118 participants with comprehensive neuropsychological assessment were divided into two subgroups: (I) MS group (n = 59) and (II) control group (n = 59). The MS patients were classified as cognitively intact (n = 26) or impaired (n = 33, 56%). The results indicated that the MoCA is a psychometrically valid instrument in assessment of MS patients. The Multiple Linear Regression analyses highlighted the significant influence of Modified Fatigue Impact Scale and Irregular Word Reading Test on MoCA performance. The MoCA total score showed a good discriminative capacity between cognitively impaired and cognitively intact subjects. In addition, there were significant differences in MoCA cognitive domain scores between groups. The MoCA total score cut-off point for identifying CD in MS patients was a score below 26 points (AUC = 0.837, CI = 0.736-0.937). A proposed EM-MoCA-Subscore for identifying the MS-related cognitive impairment (max. score = 19 points, cut-off <17 points, AUC = 0.871, CI = 0.784-0.958), can reduce administration time for cognitive screening in clinical settings. The MoCA is a useful and sensitive instrument to identify the MS-related cognitive impairment.