The Phytochemicals and Antifungal Properties of Several Medicinal Suaeda spp. Halophytes

The halophytic genus Suaeda is traditionally used in Iraq to treat oral bacterial and fungal infections. This study evaluated the phytochemical composition and antifungal efficacy of aqueous, ethanolic, and acetonic extracts from four species: S. aegyptiaca, S. altissima, S. carnosissima, and S. fruticosa against Candida albicans, C. dubliniensis, C. krusei, and C. tropicalis fungi. Phytochemical profiles were determined via chemical analysis, while antifungal activity was assessed using agar well diffusion and broth microdilution methods to determine the Minimum Inhibitory Concentrations (MIC) and Minimum Fungicidal Concentrations (MFC). Results showed that the acetone extract of S. altissima contained the highest concentrations of alkaloids, tannins, riboflavin, carbohydrates, and phosphorous (1.218, 2.501, 0.019, 9.733, and 0.534 mg/g, respectively). Conversely, the acetone extract of S. aegyptiaca yielded the highest polyphenol (66.16 mg/g) and flavonoid (40.25 mg/g) content. Compared to the reference antifungal Nystatin, all extracts demonstrated efficacy against the tested fungal strains. Notably, the S. aegyptiaca acetone extract exhibited the strongest activity against C. krusei (29 mm inhibition zone), with MIC and MFC values of 2.5 mg/mL and 5.0 mg/mL, respectively.