Antimicrobial activity and mechanisms of Salvia sclarea essential oil.

Haiying Cui,Hui Zhou,Lin Lin,Chengting Zhao,Xuejing Zhang

doi:10.1186/s40529-015-0096-4

Abstract

BackgroundNowadays, essential oils are recognized as safe substances and can be used as antibacterial additives. Salvia sclarea is one of the most important aromatic plants cultivated world-wide as a source of essential oils. In addition to being flavoring foods, Salvia sclarea essential oil can also act as antimicrobials and preservatives against food spoilage. Understanding more about the antibacterial performance and possible mechanism of Salvia sclarea essential oil will be helpful for its application in the future. But so far few related researches have been reported.ResultsIn our study, Salvia sclarea oil showed obvious antibacterial activity against all tested bacterial strains. Minimum inhibitory concentration (MIC) and minimum bactericide concentration (MBC) of seven pathogens were 0.05 and 0.1 % respectively. In addition, Salvia sclarea oil also exhibited a significant inhibitory effect on the growth of Escherichia coli (E. coli) in phosphate buffer saline (PBS) and meats. After treated with Salvia sclarea oil, Scanning Electron Microscope (SEM) images can clearly see the damage of cell membrane; the intracellular ATP concentrations of E. coli and S. aureus reduced 98.27 and 69.61 % respectively, compared to the control groups; the nuclear DNA content of E. coli and S. aureus was significantly reduced to 48.32 and 50.77 % respectively. In addition, there was massive leakage of cellular material when E. coli and S. aureus were exposed to Salvia sclarea oil.Conclusions Salvia sclarea essential oil damaged the cell membrane and changed the cell membrane permeability, leading to the release of some cytoplasm such as macromolecular substances, ATP and DNA. In general, the antimicrobial action of Salvia sclarea essential oil is not only attributable to a unique pathway, but also involves a series of events both on the cell surface and within the cytoplasm. Therefore, more experiments need to be done to fully understand the antimicrobial mechanism of Salvia sclarea essential oil.

Highlights

Nowadays, essential oils are recognized as safe substances and can be used as antibacterial additives
As a kind of the necessary food in our life, meat and its products are rich in protein, lipids and have suitable moisture content, which makes them to be the ‘natural media’ of microorganisms (Álvarez-Fernández et al 2013), and they can be contaminated by E. coli during animal evisceration after slaughter, through contact with tainted water or during meat handling (Newell et al 2010)
In addition to being flavouring foods, Salvia sclarea essential oil can act as antimicrobials and preservatives against food spoilage (Kozics et al 2013)

Summary

Introduction

Essential oils are recognized as safe substances and can be used as antibacterial additives. Salvia sclarea is one of the most appreciated medicinal herbs native to Mediterranean countries, and widely used in medicine and cooking (Durling et al 2007), as well as in cosmetics, perfumery and the pharmaceutical industry (Kong et al 2010). Plants from this genus are renowned for their biological activities such as antibacterial, antioxidant, antitumor, antidiabetic, antimicrobial, anxiolytic, sedative and anti-inflammatory activities (Rajabia et al 2014).

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