Anogeissus leiocarpus roots as a promising source of potent antimicrobial and antioxidant agents

Background: Infections pose an increasing health burden in people living with diabetes, and it worsened by antimicrobial resistance.

Objective: This study assessed the antimicrobial and antioxidant properties of Anogeissus leiocarpus.

Materials and methods: Five different bacterial and fungal strains were tested: Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 700603, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 29213, and Candida albicans ATCC 35659.

The Antimicrobial activity of the hydroethanolic extract of Anogeissus leiocarpus roots was determined by agar well diffusion (inhibition zone diameters). The minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MMC) were measured using the broth dilution method. The in vitro antioxidant potential was assessed through the hydroxyl radical scavenging, Nitric oxide scavenging, and iron chelating assays. 

Results: The hydroethanolic extract of Anogeissus leiocarpus roots exhibited broad-spectrum antimicrobial activity with MIC values ranging from 3.91 to 62.5 mg/mL, inhibiting both Gram-positive and Gram-negative bacteria (19.90 - 27.09 mm) and Candida albicans (15.59mm). The extract showed bactericidal and fungicidal activities against the five different bacterial and fungal strains, with MBC/MIC and MFC/MIC ratios ≤ 4. Staphylococcus aureus strain with the lowest MIC (MIC = 3.91 mg/mL) was the most susceptible among the Gram-positive strains. In vitro, it also demonstrated concentration-dependent antioxidant activity by scavenging the NO and OH radicals and chelating Fe ions.

Conclusion: These findings indicate that Anogeissus leiocarpus roots could serve as a natural source of antimicrobial and antioxidant agents, potentially useful in managing infections commonly associated with the diabetic population.