Chemically Characterized Essential Oils of <i>Citrus reticulata</i> and <i>Thymus vulgaris</i> L. and Their Nanoemulsions Inhibited the Pathogenic Microbes Causing Mastitis in Cattle
Creators: name: Khalaf, Doaa D.
name: Ragab, Tamer I.M.
name: Mansour, Asmaa S.
name: Elshamy, Abdelsamed I.
name: El-Gendy, Abd El-Nasser G.
Publisher: name: Taylor & Francis
Year: 2022
Subjects: subject: Biophysics
subject: Biochemistry
subject: Microbiology
subject: FOS: Biological sciences
subject: Cell Biology
subject: Genetics
subject: Molecular Biology
subject: Pharmacology
subject: Biotechnology
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Ecology
subject: Immunology
subject: FOS: Clinical medicine
subject: 69999 Biological Sciences not elsewhere classified
subject: Developmental Biology
subject: Hematology
subject: 110309 Infectious Diseases
subject: FOS: Health sciences
subject: Plant Biology

description: Essential oils (EOs) of <i>Citrus reticulata</i> (<i>C. reticulata</i>, mandarin) peels and <i>Thymus vulgaris</i> (<i>T. vulgaris</i>) are well known active microbial inhibitors. Nanoemulsion preparation is a modern technique for enhancing antimicrobial potentialities. EOs of both plants were prepared and chemically characterized using gas chromatography/mass spectrometry. Methyl-<i>N</i>-methyl anthranilate (non terpenoidal compound) and monoterpene hydrocarbons are the main components of mandarin peels EO with relative concentrations of 61.07% and 35.15%, respectively. Whereas, <i>T. vulgaris</i> was characterized by abundance of oxygenated monoterpenes and monoterpene hydrocarbons with relative concentrations of 66.89%, and 25.74%, respectively. The antimicrobial potentialities of EOs and their nanoemulsions were assayed. Mandarin EO exhibited strong activities against <i>Citrobacter diversus</i> (ATCC 13315), <i>Proteus vulgaris</i> (ATCC 13315), and <i>Escherichia coli</i> (resis.) with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 12.5 and 25 μg mL<sup>−1</sup>, respectively. On the other hand, mandarin nanoemulsion showed potentialities against all strains with MIC and MBC of 3.13 and 6.25 μg mL<sup>−1</sup>, respectively. <i>T. vulgaris</i> EO showed antibacterial potentialities against <i>C. diversus</i>, <i>P. vulgaris</i>, <i>Staphylococcus aureus</i>, and <i>E. coli</i> (resis.) with MIC of 0.19 μg mL<sup>−1</sup> and a moderate activity against the other strains. Also, its nanoemulsion exhibited better growth inhibition against <i>C. diversus</i>, <i>P. vulgaris</i>, and <i>E. coli</i> (resis.) at 0.19 μg mL<sup>−1</sup>. Mandarin EO possessed significant antifungal activities against <i>Candida albicans</i>, <i>Candida tropicalis</i>, and <i>Candida glabrata</i> with MIC of 0.19, 0.78, and 1.56 μg mL<sup>−1</sup>, respectively. The mandarin nanoemulsion had a significant activity against <i>C. glabrata</i> and <i>C. tropicalis</i> with MIC of 0.39 and 1.56 μg mL<sup>−1</sup>, respectively. <i>T. vulgaris</i> EO and its nanoemulsion are significant antifungals for all strains with MIC of 0.19 and 0.39 μg mL<sup>−1</sup>, respectively. The findings deduced the significant role of EOs of both plants and their nanoformulations as antimicrobial agents in food and pharmaceutical industries.