Volatile compounds of Lamiaceae exhibit a synergistic antibacterial activity with streptomycin

Abstract

Bacterial infections cause thousands of deaths in the world every year. In most cases, infections are more serious because the patient is already weakened, and often, the bacteria are already resistant to the antibiotics used. Counterparting this negative scenario, the interest in medicinal plants as an alternative to the synthetic antimicrobial drugs is blossoming worldwide. In the present work, we identified the volatile compounds of ethanol extracts of Melissa officinalis, Mentha sp., Ocimum basilicum, Plectranthus barbatus, and Rosmarinus officinalis by gas chromatography/mass spectrometry (GC/MS). Also was evaluated antimicrobial activity of ethanol extracts against 6 bacteria of clinical interest, and was tested the interaction of these extracts with a commercial antibiotic streptomycin. Phytol was a compound identified in all extracts by GC/MS, being majoritary component in Plectranthus barbatus and Rosmarinus officinalis. The Gram-positive bacteria were more sensitive to ethanol extracts, and Plectranthus barbatus and Rosmarinus officinalis were the most active extracts. Ethanol extracts exhibited a synergetic effect with streptomycin. These results encourage additional studies, in order to evaluate the possibilities of using ethanol extracts of Lamiaceae family as natural source for antibacterial activity.

Synergism of Plant Compound With Traditional Antimicrobials Against Streptococcus spp. Isolated From Bovine Mastitis

“…Other studies have also been conducted seeking the synergism between compounds or plant extracts and traditional antimicrobial order to help fight against microbial emerging drug resistance ( Araújo et al, 2014 ; Biasi-Garbin et al, 2015 ; Moussaoui and Alaoui, 2016 ; Wikaningtyas and Sukandar, 2016 ; Sanhueza et al, 2017 ). But many of them work with human isolates and reference strains.…”

Medicinal plants of the family Lamiaceae as functional foods - a review

“…The Sharma and Bhadange (2013) study showed that basil (ocimum gratissimum L. and ocimum kilimandscharicum Baker ex Gürke) and Pogostemon benghalensis Kuntze possess antimicrobial activity against bacterial (e. coli, S. aureus, S. typhimurium) and fungal (C. albicans and a. niger) strains. Lemon balm, mint, basil, Brazilian boldo (Plectranthus barbatus Andrews), and rosemary were the subject of the Araújo et al (2014) study and they have shown antibacterial activity to Gram-positive and Gram-negative bacterial strains (e. faecalis, S. aureus, S. mutans, e. coli, K. pneumoniae, and P. aeruginosa (Naguib et al 2012); antibacterial, antifungal, antioxidant (Formisano et al 2011) leaves 25 ocimum americanum L.…”

In Vitro Antimicrobial effects of Extracts from Leaves of Medicinal Herbs and Native Brazilian Plants

“…18 Rosemary is a plant from the Lamiaceae family that presents camphor and verbenone as major components in its extract determined by GC/MS. 49,50 It was confirmed that these two compounds were responsible for the antibacterial effect 51 against S. aureus and Escherichia coli. In this study, we confirmed the action of these two compounds as main responsible for the antimicrobial action of rosemary.…”