Potentiation of the Activity of Antibiotics against ATCC and MDR Bacterial Strains with (+)-α-Pinene and (-)-Borneol

Abstract

The increasing rates of antimicrobial resistance have demanded the development of new drugs as conventional antibiotics have become significantly less effective. Evidence has identified a variety of phytocompounds with the potential to be used in the combat of infections caused by multidrug-resistant (MDR) bacteria. Considering the verification that terpenes are promising antibacterial compounds, the present research aimed to evaluate the antibacterial and antibiotic-modulating activity of (+)-α-pinene and (-)-borneol against MDR bacterial strains. The broth microdilution method was used to determine the minimum inhibitory concentration (MIC) of the compounds and antibiotics and further evaluate the intrinsic and associated antibiotic activity. These analyses revealed that (+)-α-pinene showed significant antibacterial activity only against E. coli ( MIC = 512 μ g . m L − 1 ), while no significant inhibition of S. aureus and P. aeruginosa growth was observed ( MIC ≥ 1024 μ g m L − 1 ). However, when combined with antibiotics, this compound induced a significant improvement in the activity of conventional antibiotics, as observed for ciprofloxacin, amikacin, and gentamicin against Staphylococcus aureus, as well as for amikacin and gentamicin against Escherichia coli, and amikacin against Pseudomonas aeruginosa. On the other hand, (-)-borneol was found to inhibit the growth of E. coli and enhance the antibiotic activity of ciprofloxacin and gentamicin against S. aureus. The present findings indicate that (+)-α-pinene and (-)-borneol are phytocompounds with the potential to be used in the combat of antibacterial resistance.

Synthesis of novel sulphamethoxazole derivatives and exploration of their anticancer and antimicrobial properties

“…Activity of compound 16b was higher against S . aureus compared to its original structural component–sulfamethoxazole, which is still used nowadays in combination with trimethoprim [ 63 ]. Considering the fact that most gram-negative microorganisms are not sensitive to sulfamethoxazole, it could be possible to explain the selectivity of 16b towards gram-positive bacteria [ 64 ].…”

“…trimethoprim [63]. Considering the fact that most gram-negative microorganisms are not sensitive to sulfamethoxazole, it could be possible to explain the selectivity of 16b towards grampositive bacteria [64].…”

Neutrophil Immunomodulatory Activity of (−)-Borneol, a Major Component of Essential Oils Extracted from Grindelia squarrosa

“…The biological activity of (−)-borneol was also reported previously. For example, (−)-borneol was recently reported to exhibit antibacterial activity [ 69 ]. (−)-Borneol was also reported to have neuroprotective effects in a middle cerebral artery occlusion (MCAO) model [ 70 , 71 ], as well as vasorelaxant properties, which may be attributed to Ca 2+ influx blockade through voltage-gated Ca 2+ channels, Ca 2+ mobilization from intracellular stores, and activation of K + channels [ 72 , 73 , 74 ].…”

In Vitro Antibacterial Activity and in Silico Analysis of the Bioactivity of Major Compounds Obtained from the Essential Oil of Virola surinamensis Warb (Myristicaceae)

“…e chemical composition of all collected samples of V. surinamensis essential oils was characterized by a high percentage of α-pinene (>33%) and β-pinene (>13%), which probably influenced their antibacterial activities. Studies have demonstrated that these two compounds in the isolated form show antibacterial activity against different bacterial species [55][56][57]. Furthermore, essential oils with high content of α-pinene and β-pinene have been reported by antibacterial activity against strains of P. aeruginosa [58], E. coli [59], and S. aureus [60].…”