Phytochemical screening, acute toxicity, and anticandidal efficacy of Guiera senegalensis leaf extract against oral Candida albicans

Abstract

The emergence of resistance among fungal pathogens has stimulated interest in medicinal plants as alternative sources of antifungal agents. This study investigated the phytochemical constituents, anticandidal activity, and acute toxicity profile of aqueous leaf extract of Guiera senegalensis against oral isolates of Candida albicans. Clinical isolates obtained from oral thrush samples were identified using colony characteristics, germ tube test, lactophenol cotton blue staining, and Chromagar Candida. The powdered leaves were extracted by cold maceration using distilled water at a 1:5 (w/v) ratio. Qualitative phytochemical analysis was performed using standard procedures, while antifungal activity was evaluated using agar disc diffusion and broth dilution techniques. Acute oral toxicity was assessed in mice according to OECD guideline 423. The extract contained tannins, saponins, flavonoids, alkaloids, phenolic compounds, terpenoids, and carbohydrates, whereas glycosides and anthraquinones were absent. Antifungal activity increased with concentration, producing inhibition zones of 10.00 ± 0.00 mm, 14.33 ± 0.57 mm, and 17.67 ± 0.57 mm at 62.5, 125, and 250 mg/mL, respectively. Fluconazole produced a mean inhibition zone of 19.00 ± 1.00 mm. The MIC and MFC values were 15.625 mg/mL and 250 mg/mL, respectively. No mortality was observed up to 4000 mg/kg body weight, although one animal died at 8000 mg/kg. The findings indicate that G. senegalensis possesses bioactive constituents with considerable anticandidal activity and relatively low acute toxicity, supporting its potential application in the development of plant-derived antifungal agents.