Effects of <i>Coleus amboinicus</i> L. Essential Oil and Ethanolic Extracts on Planktonic Cells and Biofilm Formation of <i>Microsporum canis</i> Isolated from Feline Dermatophytosis

• Main Authors: Arpron Leesombun (Author), Karnchanarat Thanapakdeechaikul (Author), Jiraporn Suwannawiang (Author), Pipada Mukto (Author), Sivapong Sungpradit (Author), Norasuthi Bangphoomi (Author), Tanasak Changbunjong (Author), Orathai Thongjuy (Author), Thekhawet Weluwanarak (Author), Sookruetai Boonmasawai (Author)
• Format: Book
• Published: MDPI AG, 2022-12-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 10.3390/antibiotics11121734; 2079-6382
• Keywords: <i>Microsporum canis</i>; <i>Coleus amboinicus</i>; essential oil; ethanolic extracts; antifungal; biofilm formation; Therapeutics. Pharmacology; RM1-950
• Source: Antibiotics, Vol 11, Iss 12, p 1734 (2022)

<i>Microsporum canis</i> is an important zoonotic fungus that causes dermatophytosis in domestic animals and their owners. Domestic cats are the primary reservoir for <i>M. canis</i>. Antifungal drugs frequently produce adverse effects on the host animal, increasing the demand for novel alternative treatments derived from nature. We evaluated the antifungal activity of <i>Coleus amboinicus</i> essential oil (CEO) and ethanolic extracts (CEE) against <i>M. canis</i> in planktonic and biofilm growth. Twelve clinical isolates of <i>M. canis</i> were identified in feline dermatophyte samples. Using GC-MS, 18 compounds were identified in CEO, with carvacrol being the major constituent. HPLC analysis of CEE revealed that it contained rosmarinic acid, apigenin, and caffeic acid. The planktonic growth of all <i>M. canis</i> isolates was inhibited by <i>C. amboinicus</i> extracts. The minimum inhibitory concentration at which ≥50% of the isolates were inhibited (MIC₅₀) was 128 µg/mL (32-256 µg/mL) for both CEO and CEE. The MIC₉₀ values of CEO and CEE were 128 and 256 µg/mL, respectively. CEO at MIC (128 µg/mL) and 2× MIC (256 µg/mL) significantly inhibited the biofilm formation of weak, moderate, and strong biofilm-producing <i>M. canis</i>. CEE at 2× MIC (256 µg/mL) significantly inhibited the biofilm formation of all isolates. Overall, <i>C. amboinicus</i> extracts inhibited planktonic growth and exhibited a significant antibiofilm effect against <i>M. canis</i>. Thus, <i>C. amboinicus</i> is a potential source of natural antifungal compounds.