Activity of Imidazole Salts on the Microbiome of Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma is often associated with imbalances in the oral microbiome, where interactions with microorganisms such as Candida sp. may promote proliferation and carcinogenic processes, influencing disease progression. Candida sp., particularly Candida albicans, are opportunistic pathogens present in up to 80% of the population, with harmful impact in immunocompromised cancer patients. Identifying new therapeutic compounds is therefore important. Imidazole salts (IS) possess physicochemical properties allowing structural modifications and have recognized medicinal applications. The objective is to investigate IS activity against isolates from the microbiome of oral squamous cell carcinoma. IS C16MImCl, C18MImCl and C18MImMeS were tested at concentrations of 1024–1 µg/mL. Miconazole 4% in DMSO served as control. Four yeast isolates (C. albicans CFP00107, CFP00283, CFP00292 and CFP00895) from oral and orotracheal mucosa were tested. MIC was determined using CLSI M27-A2 and M38A protocols. Inoculum was prepared in 0.85% saline at 10⁶ CFU/mL, confirmed spectrophotometrically (530–540 nm). Serial dilutions were incubated at 37°C for 48 h. Results read at 24 and 48 h. All IS showed MIC of 1 µg/mL for all isolates. Miconazole MIC was 4 µg/mL for CFP00107, CFP00283, and CFP00292, and 2 µg/mL for CFP00895. IS demonstrated strong antifungal activity against Candida sp., outperforming miconazole with lower MIC values. These findings highlight their therapeutic potential for microbiome control and possibly for modulating tumor-related progression in oral squamous cell carcinoma.