The objective of this study was to evaluate the antibacterial activity of Cinnamomum cassia (cinnamon) essential oil (EO) alone and in combination with some classical antibiotics against three multidrug-resistant bacteria, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa, to search a possible synergy. The antibacterial activity of all tested compounds was determined by agar disc diffusion and minimum inhibitory concentration assays. The checkerboard method was used to quantify the efficacy of cinnamon EO in combination with these antibiotics. Fractional inhibitory concentrations were calculated and interpreted as synergy, addition, indifferent, or antagonism. A synergistic interaction was shown against S. aureus with the combination cinnamon EO and ampicillin or chloramphenicol and against E. coli when cinnamon EO was combined with chloramphenicol. However, the combination of cinnamon oil and streptomycin displayed additive effects against all bacteria stains. The combinations of cinnamon EO and antibiotics can be used as an alternative therapeutic application, which can decrease the minimum effective dose of the drugs, thus reducing their possible adverse effects and the costs of treatment.

Antibacterial activity of cinnamon essential oils and their synergistic potential with antibiotics.

Biofilms are dense population of sessile bacterial cells that adhere to the surface, forming a matrix composed of exopolysaccharide, proteins and DNA. This matrix is termed as extracellular polymeric substance and provides stability to the cells adhering to it to form biofilms. It also provides nutrients and thus helps in the pathogenesis of biofilm-associated infections and resistance. Biofilms promote bacterial persistence by resisting host immune responses and antibiotic treatment. Antibiotics are rendered ineffective when biofilms form due to their relative impermeability, the variable physiological status of microorganisms, and subpopulations of persistent strains. Another factor that results in the development of antibiotic resistance within the biofilm is the adaptations that take place within the genes present in the cells dwelling within the biofilm. These adaptations decrease the sensitivity of the bacterial cells toward the antibiotics and develop resistance. Hence, an alternative antimicrobial strategy of making use of plant-based products has been observed to be useful to cure various ailments, as compared to conventional therapy. In this review, we have listed the various biofilm-forming bacteria and the bioactive compounds being produced from the aerial parts of plants having antibiofilm activity and evaluated them against different biofilm-producing bacterial strains.

Elucidating the effect of anti-biofilm activity of bioactive compounds extracted from plants

Essential oils (EO) are complex secondary metabolites, which are produced by aromatic plants and identified by their powerful odors. Present studies on EO and their isolated ingredients have drawn the attention of researchers to screen these natural products and evaluate their effect on the cardiovascular system. Some EO, and their active ingredients, have been reported to improve the cardiovascular system significantly by affecting vaso-relaxation, and decreasing the heart rate and exert a hypotension activity. Several mechanisms have been proposed for the role of EO and their main active components in promoting the health of the cardiovascular system. The objective of this review is to highlight the current state of knowledge on the functional role of EO extracted from plants for reducing the risk of cardiovascular diseases and their mechanisms of action. Research on EO has the potential to identify new bioactive compounds and formulate new functional products for the treatment of cardiovascular diseases such as arterial hypertension, angina pectoris, heart failure, and myocardial infarction.

The effects of food essential oils on cardiovascular diseases: A review.

Phytochemistry, antioxidant and antibacterial activities of two Moroccan Teucrium polium L. subspecies: Preventive approach against nosocomial infections

Solvent-free microwave extraction of essential oils from Thymus vulgaris L. and Melissa officinalis L.

Abstract Objective To determine the phytochemical characterization and antibacterial activity of Melissa officinalis essential oil against bacteria responsible for nosocomial infections. Methods The phytochemical characterization of essential oil was evaluated using gas chromatography-flame ionization detector and gas chromatography-mass spectrometer analysis. Antibacterial activity of the oil was tested against four bacterial strains responsible for nosocomial infections: Pseudomonas aeruginosa , Klebsiella pneumonia , Staphylococcus aureus and Citrobacter koseri using disc diffusion method. Results Thirty three components were identified representing 89.30% of the total oil composition. The yield of essential oil was 0.4% and the predominant components were citronellal (14.40%), isogeraniol (6.40%), geraniol acetate (10.20%), nerol acetate (5.10%), caryophyllene (8.10%) and β-caryophyllene oxide (11.00%). Antibacterial activity of the oil showed the higher activity against all bacterial strains tested. Conclusions The essential oil extracted from lemon balm can be used to clean the environment of reanimation polyvalent and anaesthesia service.

A. Abdellaoui

Papers

Phytochemistry of the essential oil of Mellisa officinalis L. growing wild in Morocco: preventive approach against nosocomial infection.