Comparative in vitro assessment of oak (Quercus infectoria) and Carob (Ceratonia siliqua) extracts as natural alternatives to metronidazole against Trichomonas gallinae.

Objectives: Trichomonas gallinae, a protozoan parasite, is responsible for avian trichomoniasis, leading to significant morbidity and mortality, particularly among juvenile pigeons. Although metronidazole is the standard treatment, its potential for inducing resistance has prompted exploration of herbal extracts as alternative therapeutic options. This study aims to compare metronidazole's antitrichomonal effects with oak (Quercus infectoria) extracts and carob (Ceratonia siliqua) on T. gallinae in vitro.

Methods: T. gallinae samples were collected from infected pigeons. For the in vitro study, multiwell plates were used with different concentrations (5, 10, 25, 50, and 100 µg/mL).

Results: The minimum inhibitory concentration (MIC) after 24 hr for Q. infectoria was 25 µg/mL, while for C. siliqua it was 50 µg/mL. In comparison, the MIC of metronidazole was also found to be 50 µg/mL.

Conclusions: Findings suggest that Q. infectoria and C. siliqua extracts exhibit potent antitrichomonal activity, comparable to metronidazole, in inhibiting T. gallinae trophozoite growth in vitro, making them viable natural alternatives.