Microbial resistance and oxidative stress are two significant health issues associated with chronic illnesses and therapy failures. The antioxidant and antibacterial properties of Euphorbia cuneata Vahl. aerial component extracts made with various polarity solvents were assessed in this work.

Disc diffusion and minimum inhibitory concentration (MIC) tests were used to evaluate the 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, total phenolic and flavonoid contents, and antimicrobial activity of n-hexane, toluene, ethanolic, and aqueous extracts against specific ESKAPE pathogens (Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida tropicalis). High-performance liquid chromatography and gas chromatography-mass spectrometry were used to further characterize the most active extract.

Compared to the aqueous (IC₅₀ = 51.61 µg/mL), toluene (IC₅₀ = 30.57 µg/mL), and n-hexane (IC₅₀ = 128.15 µg/mL) extracts, the ethanolic extract demonstrated the greatest 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity (97.90 ± 0.8%; IC₅₀ = 28.52 µg/mL). Additionally, it has the highest levels of flavonoids (40.5 ± 1.5 mg luteolin equivalents/g) and phenolic (80.0 ± 0.2 mg gallic acid equivalents/g). While gas chromatography-mass spectrometry found methyl 12-hydroxy-9-octadecenoate (44.39%) as the main volatile molecule, high-performance liquid chromatography analysis identified caffeic acid, pyrogallol, rutin, and 7-hydroxyflavone as important ingredients. The ethanolic extract showed antifungal activity against C. tropicalis (MIC = 6.25 mg/mL) and moderate antibacterial activity with the lowest MIC values against S. aureus (450 µg/mL) and E. coli (500 µg/mL).

The ethanolic extract of Euphorbia cuneata demonstrated potent in vitro antioxidant activity and moderate antimicrobial effects, primarily attributable to its high phenolic and flavonoid content. These results support its potential as a natural source of bioactive compounds for further development.