Biological activities of α-pinene and β-pinene enantiomers.
The antimicrobial activities of the isomers and enantiomers of pinene were evaluated against bacterial and fungal cells. The agar diffusion test showed that only the positive enantiomers of the α- and β-isomers of pinene were active. The minimal inhibitory concentration (MIC) and minimal microbicidal concentration (MMC) of these monoterpenes were also determined, confirming that the positive enantiomers exhibited microbicidal activity against all fungi and bacteria tested with MICs ranging from 117 to 4,150 μg/mL. However, no antimicrobial activity was detected with the negative enantiomers up to 20 mg/mL. Time-kill curves showed that (+)-α-pinene and (+)-β-pinene were highly toxic to Candida albicans, killing 100% of inoculum within 60 min. By contrast, the bactericidal effect occurred after 6 h in methicillin-resistant Staphylococcus aureus (MRSA). In combination with commercial antimicrobials, ciprofloxacin plus (+)-α-pinene or (+)-β-pinene presented synergistic activity against MRSA whereas an indifferent effect against all fungi was detected when amphotericin B was combined with the positive enantiomers of pinene. The potential of (+)-α-pinene and (+)-β-pinene to inhibit phospholipase and esterase activities was also evaluated, and the best inhibition results were obtained with Cryptococcus neoformans. C. albicans biofilm formation was prevented with the MIC concentration of (+)-α-pinene and twice the MIC value of (+)-β-pinene. Finally, the cytotoxicity of the positive enantiomers of pinene to murine macrophages was evaluated, and 250 μg/mL of (+)-α-pinene and (+)-β-pinene reduced the cell viability to 66.8% and 57.7%, respectively.
Institute of Microbiology Paulo de Góes, Federal University of Rio de Janeiro-IMPG-UFRJ, CCS, Ilha do Fundão, Rio de Janeiro, RJ 21941-590, Brazil.
Ana Cristina
AC
Rivas da Silva
Paula Monteiro
PM
Lopes
Mariana Maria
MM
Barros de Azevedo
Danielle Cristina Machado
DC
Costa
Celuta Sales
CS
Alviano
Daniela Sales
DS
Alviano
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology*; D000935:Antifungal Agents / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects / Q000378:metabolism; D000081008:Bicyclic Monoterpenes; D018441:Biofilms / Q000187:drug effects; D001643:Bridged Bicyclo Compounds / Q000737:chemistry / Q000494:pharmacology*; D004357:Drug Synergism; D004950:Esterases / Q000037:antagonists & inhibitors; D005658:Fungi / Q000187:drug effects / Q000378:metabolism; D008264:Macrophages / Q000187:drug effects; D051379:Mice; D008826:Microbial Sensitivity Tests; D039821:Monoterpenes / Q000737:chemistry / Q000494:pharmacology*; D010740:Phospholipases / Q000037:antagonists & inhibitors
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D000935:Antifungal Agents; D000081008:Bicyclic Monoterpenes; D001643:Bridged Bicyclo Compounds; D039821:Monoterpenes; C010789:beta-pinene; D004950:Esterases; D010740:Phospholipases; C005451:alpha-pinene