Antimicrobial and Antioxidant Activities of Volatile Oils from Four Citrus Species on Selected Oral Pathogens and GC-MS Identification of Associated Compounds

Josephine Omose Ofeimun; Upe Francisca Babaiwa; Osayemwenre Erharuyi; Blessed Bassey; Alex Ifesinachi  Eze

doi:10.4314/just.v40i3.1387

Dr. Josephine Omose Ofeimun Department of Pharmacognosy, Faculty of Pharmacy, University of Benin https://orcid.org/0000-0002-7282-0337
Dr. Upe Francisca Babaiwa Department of Pharmaceutical Microbiology, Faculty of Pharmacy, University of Benin, Nigeria https://orcid.org/0000-0003-3266-5309
Dr. Osayemwenre Erharuyi Department of Pharmaceutical Chemistry ,Faculty of Pharmacy, University of Benin. https://orcid.org/0000-0002-9667-2439
Bassey Blessed
Dr. Alex Ifesinachi Eze

DOI: https://doi.org/10.4314/just.v40i3.1387

Keywords: Oral pathogens, Antimicrobial, Antioxidant, Citrus peel, Volatile oils

Abstract

This study evaluated the in-vitro antioxidant and antimicrobial activities of peel volatile oils of Citrus aurantifolia, Citrus limon, Citrus paradisi and Citrus sinensis on clinical isolates of Methicillin-resistant Staphylococcus aureus, Methicillin-sensitive Staphylococcus aureus, Ciprofloxacin resistant Escherichia coli, Ciprofloxacin sensitive Escherichia coli and Candida albicans obtained from the oral cavity. Gas chromatography-Mass spectrometric (GC-MS) analysis of the oils was also carried out. The agar well diffusion method was used to determine the antimicrobial activity of the oils while the 2,2-diphenyl-1 picrylhydrazyl (DPPH) radical scavenging method was used to evaluate the antioxidant activity. Total flavonoid and phenol contents of oils were equally determined. The composition of the oils was determined by GC-MS analysis. The volatile oil of C. aurantifolia exhibited the most activity against the test pathogens with a minimum inhibitory concentration (MIC) range of 2 – 4 mg/ml, while C. limon had the least antimicrobial activity as its MIC could not be determined against Methicillin-resistant Staphylococcus aureus, Ciprofloxacin resistant and sensitive Escherichia coli. C. limon and C. paradisi had MICs in the range of 4-16 mg/ml and 4-32 mg/ml respectively.C. sinensis peel oil had the highest DPPH radical scavenging activity of 47.86±2.22% and C. aurantifolia the least with a value of 25.27±1.23%. Methylisobutyl ketone was identified in C. paradisi, C. aurantifolia and C.sinensis. This study revealed that the peel volatile oils of the investigated citrus species possess antioxidant and antimicrobial activities against oral pathogens and have the potential to be used in the management of oral diseases caused by the selected pathogens.

Author Biographies

Dr. Josephine Omose Ofeimun, Department of Pharmacognosy, Faculty of Pharmacy, University of Benin

Dr Ofeimun is an Associate Professor of Pharmacognosy in the Department of Pharmacognosy, Faculty of Pharmacy, University of Benin. Her broad area of interest covers the phytochemistry and biological activities of natural products. Narrowed down, she has undertaken research studies to identify, isolate and characterise specific constituents in plant extracts responsible for various activity which include; anti-microbial, anti-benigh prostate hyperplasia, male infertility and cancer.

Dr. Upe Francisca Babaiwa, Department of Pharmaceutical Microbiology, Faculty of Pharmacy, University of Benin, Nigeria

Upe Babaiwa is Senior Lecturer in the Department of Pharmaceutical Microbiology, Faculty of Pharmacy, University of Benin, Nigeria. Her research is focused on understanding and dealing with issues concerning the detection and control of pathogenic bacteria in the public health space and the general environment. Her particular interest centres on the understanding and evaluation of the genetic bases of bacteria resistance to chemotherapic agents and providing solution to limit such resistance through collaborative research.

Dr. Osayemwenre Erharuyi, Department of Pharmaceutical Chemistry ,Faculty of Pharmacy, University of Benin.

Osayemwenre Erharuyi is a Senior Lecturer in the Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Benin.

Bassey Blessed

Blessed served as a Research Assistant in this study and was involved in the data acquisition and interpretation. His role qualified him to be included as a co-Author even if not a recognised researcher in the broadest sense.