In Vitro Antioxidant, Antibacterial, and Cholinesterase-Inhibitory Properties of an Aqueous Euphorbia macroclada Root Extract Obtained by Ultrasound-Assisted Extraction.

In the present study, the aqueous extract obtained from the roots of Euphorbia macroclada via ultrasound-assisted extraction (Ult-ER) was evaluated for its anticholinesterase (AChE and BChE), antioxidant, and antibacterial activities. While the extract exhibited weak inhibition against AChE (IC50: 507.69 ± 17.95 mg/mL), it showed relatively greater inhibitory activity against BChE (IC50: 22.41 ± 0.49 mg/mL). In antioxidant assays, Ult-ER exhibited measurable antioxidant responses, with DPPH and ABTS+ radical-scavenging capacities of 18.33 ± 0.49 and 119.59 ± 1.86 mg TE/L, respectively. Its Fe3 + and Cu2 + reducing capacities were 128.51 ± 12.57 and 670.33 ± 11.59 mg TE/L, respectively. The total phenolic and flavonoid contents were 84.80 ± 3.31 mg GAE/g and 60.67 ± 2.29 mg QE/g, while the total antioxidant capacity was 9.78 ± 0.44 mg TE/g and 15.62 ± 1.85 mg BHAE/g. In the antibacterial evaluation, Ult-ER at the highest tested concentration of 8 mg/mL exhibited inhibitory activity against all tested strains, including Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 27853, whereas no detectable inhibition was observed at lower concentrations.