<i>Haloxylon ammodendron</i>: Assessing Antioxidant and Antimicrobial Efficacy with Minimum Inhibitory Concentration (MIC) Determination in Bacterial Strains

Background: Haloxylon ammodendron belongs to the genus Haloxylon of the Amaranthaceae family. This study is the first to assess the antibacterial and antifungal properties of H. ammodendron ethanolic extract and provides an analysis of the plant’s antioxidant capacity. Additionally, the research offers insights into the phenolic content of the plant’s ethanolic extract, which is directly linked to its bioactivity. Objectives: The study aimed to evaluate the antioxidant, antibacterial, and antifungal activity and determine the phenolic content of H. ammodendron ethanolic extract. Methods: The maceration method was used to prepare H. ammodendron ethanolic extract. The antibacterial and antifungal activity of this extract was investigated using two strains of gram-positive bacteria (Staphylococcus aureus, Streptococcus mutans), four strains of gram-negative bacteria (Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumannii, and Escherichia coli), and one fungal strain (Candida albicans). The agar well diffusion method was used to evaluate the inhibition of bacterial growth. The phenolic compounds of H. ammodendron were measured by the Folin-Ciocalteu method. Antioxidant activity was determined by the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) method. Results: The results demonstrated that various concentrations of H. ammodendron ethanolic extract exhibit antibacterial effects. The extract showed the most significant inhibitory effect against S. mutans and S. aureus. The lowest inhibitory effect was observed against A. baumannii and E. coli. This plant showed a significant antioxidant effect (IC50: 0.2 mg/mL). Conclusions: In this study, the H. ammodendron species was investigated for the first time. The results showed that the ethanolic extract of H. ammodendron has an excellent inhibitory effect on gram-positive bacteria. Considering the significant antioxidant effect of this plant, further studies are suggested to explore its therapeutic effects on disorders related to oxidative stress.