**8.1 Lavender essential oil**

The lavender EO is used in traditional medicine as well as in cosmetic products; this oil is believed to have sedative, anti-inflammatory, and antimicrobial effects [99]. Lavender EO shows a synergistic effect when combined with piperacillin antibiotic against beta-lactamase-producing *Escherichia coli* under study with fractional inhibitory concentration (FIC) index between 0.26 and 0.5 [97]. This finding shows that it's possible to use the lavender EO as an agent in modifying the antibiotic resistance [97]. Another study which aimed to compare the antimicrobial efficacy of four types of lavender oil on MSSA and MSRA shows that by direct contact the oil inhibits the growth of these microbes [100]. Fusidic acid is one of the compounds within this oil which gives it the antimicrobial activity, the mechanism of which is to cause bacterial cell damage by reducing synthesis of proteins [101].

### **8.2 Cinnamon bark essential oil**

The cinnamon bark EO can be obtained from different parts of the tropical evergreen tree, which is important for human health and agriculture uses [102]. Previously, a study reported that a combination of cinnamon bark EO with piperacillin resulted in a synergistic relationship with FIC ≤ 0.5, and this result indicates the possibility of using cinnamon bark EO as a resistance-modifying agent against MDR bacteria [97, 103]. Cinnamon bark oil contains cinnamaldehyde which is one of the compounds that inhibit the activity of amino acid decarboxylase; this compound with others within the oil gives this oil the ability to inhibit some pathogenic bacteria [104].

### **8.3 Peppermint essential oil**

Peppermint EO is significant in inhibiting the microbial growth and increasing the shelf-life of food by preventing food spoilage [105]. Combination of piperacillin and peppermint EOs with FIC in the range 0.26–0.5 was found showing a synergistic effect that is absent in 31 other combination pairs that were studied, indicating a promising alternative to reduce the use of antibiotic and achieve the reverse betalactam antibiotic resistance [91]. The antibacterial activity for this oil is associated with menthol and ethyl acetate in high concentrations [106].

### **9. Future perspectives**

Research about the reversal antibiotic resistance is important to preserve the healthy microbial ecosystem in the human host. It is imperative to understand the cause of antimicrobial resistance and to find solutions to alleviate the present

**59**

**Author details**

Mariam Aljaafari1

and Swee-Hua Erin Lim1

, Maryam Sultan Alhosani1

1 Health Science Division, Abu Dhabi Women's College, Higher Colleges of

2 Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, University Putra Malaysia, Serdang, Selangor, Malaysia

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

\*

Technology, Abu Dhabi, United Arab Emirates

\*Address all correspondence to: lerin@hct.ac.ae

provided the original work is properly cited.

, Aisha Abushelaibi1

, Kok-Song Lai1,2

*Essential Oils: Partnering with Antibiotics DOI: http://dx.doi.org/10.5772/intechopen.86575*

**Acknowledgements**

**Conflict of interest**

situation. As discussed above, combination therapy between EOs and antibiotic provides a promising alternative to mitigate MDR bacteria, possibly by disrupting the bacterial cell wall. Although EOs have been proven to be useful for mitigating MDR bacteria spread, there is still much to be done in terms of the combination stability, selectivity, definite mechanism of action, chemical nature, availability of these products in human body, optimal dose, and adverse reactions as a treatment. These gaps need to be taken into consideration before applying EOs for clinical usage. In addition, there is also a need for animal study and human trials in the future, if one intends to employ EOs as a therapeutic option in medical settings.

The authors would like to thank the HCT Research Grants from the Higher

Colleges of Technology, UAE for supporting this work.

The authors declare they have no competing interests.

*Essential Oils: Partnering with Antibiotics DOI: http://dx.doi.org/10.5772/intechopen.86575*

situation. As discussed above, combination therapy between EOs and antibiotic provides a promising alternative to mitigate MDR bacteria, possibly by disrupting the bacterial cell wall. Although EOs have been proven to be useful for mitigating MDR bacteria spread, there is still much to be done in terms of the combination stability, selectivity, definite mechanism of action, chemical nature, availability of these products in human body, optimal dose, and adverse reactions as a treatment. These gaps need to be taken into consideration before applying EOs for clinical usage. In addition, there is also a need for animal study and human trials in the future, if one intends to employ EOs as a therapeutic option in medical settings.
