In vitro Antimicrobial Activity and Effect on E. Coli Integrity of Cinnamon Essential Oil and Rhubarb Ethanol Extract

Abstract

The objectives of this study were to evaluate the antimicrobial efficacy of cinnamon essential oil (CEO) and rhubarb ethanol extract (REE) against 5 food-related microorganisms and to investigate effect on E. coli integrity. The main chemical components ( > 0.1%) of CEO and REE were analyzed by GC/MS. The major active constituents of CEO were cinnamaldehyde and 2-methoxycinnamaldehyde, and the major active constituents of REE were chrysophanic acid and physcion. The antimicrobial efficacy of combination of CEO and REE was investigated by analysis of the fractional inhibitory concentration index. The combination showed additive efficacy against all tested microorganisms. Furthermore, the scanning electron microscope observations and the K + concentration change in broth confirmed the physical damage and considerable morphological alteration to the E. coli treated with CEO, REE and combination of them. Thus, our study demonstrated that CEO and REE can be considered potential alternatives to control pathogens and microbial spoilage issues.Keywords: antimicrobial activity, cell integrity, rhubarb, cinnamon essential oil *To whom correspondence should be addressed. E-mail: jianqw@tust.edu.cn IntroductionThe growth of spoilage microorganisms and food-borne pathogens is one of the main causes of food degradation (Viuda-Martos et al., 2011). Despite modern improvements in slaughter hygiene and food production techniques, food safety is an increasingly important public health issue. It has been estimated that as many as 30% of people in industrialized countries suffer from a food-borne disease each year (Burt, 2004). Strong consumer demand for safe, high-quality foods can be attributed in part to the widespread availability and accessibility of quality health information. There are also new concerns about food safety due to the increasing occurrence of new food-borne disease outbreaks caused by pathogenic microorganisms. This presents considerable challenges to food producers and manufacturers, particularly since there is increasing unease regarding the use of chemical preservatives and artificial antimicrobials to inactivate or inhibit the growth of spoilage and pathogenic microorganisms (Arques et al., 2008;Aslim and Yucel, 2007).As a consequence, natural antimicrobials are receiving more attentions in the context of a number of microorganism control issues and have been shown to reduce the need for antibiotics, control microbial contamination in food, improve shelf-life extension technologies to eliminate undesirable pathogens and/or delay microbial spoilage, decrease the development of antibiotic resistance by pathogenic microorganisms, and strengthen immune cells in humans (Tajkarimi et al., 2010). The ability of some plant extracts and essential oils (EOs) to protect foods against pathogenic and spoilage microorganisms has been reported by some researchers (LisBalchin et al., 1997;Nelson, 1997;Hao et al.,1998;Burt and Reinders, 2003;Rojas-Graü et al., 2007), with small terpenoids and phenolic compounds appearing to...

Constituents of the Essential Oils of Garlic and Citronella and Their Vapor-phase Inhibition Mechanism against <i>S.aureus</i>

“…The antimicrobial effects of the essential oil combinations were evaluated based on their FICI values. FICI serves as a simple mathematical approach to quantitatively describe interactions (de Medeiros Barbosa et al, 2016;Han et al, 2013), and it was calculated as Eq. 1:…”

Inhibitory Effects of Cinnamaldehyde Derivatives on Biofilm Formation and Virulence Factors in Vibrio Species

“…Cinnamaldehyde (CNMA) is a nontoxic synthetic flavoring agent with a range of powerful pharmacological functions that are generally recognized as safe [20]. Previous studies on its microbiological activities have documented marked antimicrobial efficacy against food-related pathogens [21,22]. CNMA and its derivatives inhibit planktonic cell growth, biofilm production, and help eradicate microbial persister cells [23].…”

Polyketide-Derived Alkaloids and Anthraquinones in Aloe Plants and Cell Cultures

“…The compound is also present in roots of A. gariepensis and A. viguieri. Chrysarobin, an anthrone, is found from the stem of Cassia singueana [68] and Chinese rhubarb [69]. There is no previous report of this compound in Aloe.…”