Investigation of the Antitrichomonal Activity of Cinnamaldehyde, Carvacrol and Thymol and Synergy with Metronidazole

• Published in: Türkiye parazitolojii dergisi Vol. 48; no. 2; pp. 72 - 76
• Main Authors: Özel, Yener, Çavuş, İbrahim, Ünlü, Gülhan, Ünlü, Mehmet, Özbilgin, Ahmet
• Format: Journal Article
• Language: English
• Published: Turkey Türkiye Parazitoloji Derneği 30.06.2024; Galenos Publishing House
• Subjects: Acrolein - analogs & derivatives; Acrolein - pharmacology; Antimicrobial activity; Antimicrobial agents; Antiprotozoal Agents - pharmacology; Biyoloji; Carvacrol; Cinnamaldehyde; Cinnamomum zeylanicum; Cinnamomum zeylanicum - chemistry; Clinical isolates; Cymenes - pharmacology; Disease resistance; Drug Resistance; Drug Synergism; Essential oils; Female; Humans; Metronidazole; Metronidazole - pharmacology; Microbial Sensitivity Tests; Monoterpenes - pharmacology; Oils & fats; Oils, Volatile - pharmacology; Parasite resistance; Parasitic diseases; Thymol; Thymol - pharmacology; Thymus Plant - chemistry; Thymus vulgaris; Tıp; Trichomonas vaginalis; Trichomonas vaginalis - drug effects; Veterinerlik; İzmir; Türkiye; thymol; synergy; T. vaginalis; Checkerboard; metronidazole; carvacrol; cinnamaldehyde; timol; sinerji; sinnamaldehit; karvakrol; metronidazol
• ISSN: 1300-6320; 2146-3077; 2146-3077
• DOI: 10.4274/tpd.galenos.2024.91855

is a sexually transmitted protozoan parasite that usually causes infections in women. Metronidazole is used as the first choice in the treatment of this parasitic disease, but there is a need for new drugs since 1980's with increasing numbers of reported resistance. In this study, it was aimed to determine the antitrichomonal activity of the major components of (cinnamon) and (thyme) essential oils, cinnamaldehyde, carvacrol and thymol against metronidazole resistant and susceptible strains, and to determine their interaction with metronidazole by checkerboard method. Cinnamaldehyde, carvacrol, thymol and metronidazole were obtained commercially. Two clinical isolates and one metronidazole resistant reference strain were used in the study. MIC50 and MLC values of essential oil components and metronidazole were determined by broth microdilution method. The combinations of essential oil components with metronidazole were determined by the checkerboard method. According to activity tests, cinnamaldehyde was determined to be most effective essential oil component. Clinical isolates were susceptible to metronidazole. In combination study, metronidazole showed synergy with cinnamaldehyde and carvacrol, and partial synergy with thymol. It was determined that cinnamaldehyde, carvacrol and thymol, which are known to have high antimicrobial activity, also have strong activity against isolates and show a synergistic interaction with metronidazole. The use of metronidazole at lower doses in the synergistic interaction may contribute to the literature in terms of reducing drug side effects, creating a versatile antimicrobial target, and reducing the rate of resistance development.