In Vitro Antibacterial and Antioxidant Activities of Extracts of Turnera diffusa Willd. Ex Schult and Its Polyphenol Profile

Research confirms the antibacterial and antioxidant properties of Turnera diffusa, a plant traditionally used in Mexico's Tehuacán-Cuicatlán Valley for treating infections. The study found that acetone extracts of T. diffusa exhibited strong bactericidal effects against Gram-negative (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa) and Gram-positive bacteria (Staphylococcus aureus, S. epidermidis), with minimal inhibitory concentrations as low as 2.0 mg/mL. Methanol extracts showed significant antioxidant activity, particularly in scavenging DPPH and ABTS radicals, and reducing ferric ions, likely due to their high polyphenol content (6.052%). The study used diffusion and agar dilution assays for antibacterial testing, microbial survival curves, and colorimetric/HPLC analyses for chemical profiling. These findings validate the plant's medicinal use and highlight its potential in treating infectious diseases and oxidative stress.

Serrano-Parrales, R., Aguilera-Ramírez, C. U., Carrillo-Servin, D. N., Nolasco-Ontiveros, E., & Bárcenas-Correa, J. D. (2026). In Vitro Antibacterial and Antioxidant Activities of Extracts of Turnera diffusa Willd. Ex Schult and Its Polyphenol Profile. American Journal of Plant Sciences, 17(01), 1–17. https://doi.org/10.4236/ajps.2026.171001