An Assessment of the Antioxidant, Antimicrobial, and Anti-inflammatory Properties of Eleutherine bulbosa (Mill.) Urb. Extract

Eleutherine bulbosa is a medicinal plant known for its rich content of bioactive compounds, particularly polyphenols and flavonoids, which contribute to its notable antioxidant, antibacterial, and anti-inflammatory properties. In this study, ultrasound-assisted extraction of E. bulbosa tubers was performed using 96% ethanol (EtOH_96), water (W), and a 1:1 ethanol-water mixture (EtOH_96:W). The extracts were assessed for biological activities through 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2 '-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging assays, agar well diffusion, minimum inhibitory concentration (MIC), and anti-inflammatory tests. Among the solvents, EtOH_96 yielded the highest antioxidant activity, with IC₅₀ values of 202.2 ± 17.6 µg/mL (DPPH) and 250.8 ± 7.8 µg/mL (ABTS). These effects corresponded to elevated levels of polyphenols (94.9 ± 4.0 mg gallic acid equivalent (GAE)/g dry weight (DW)) and flavonoids (119.3 ± 17.1 mg quercetin equivalent (QE)/g dry weight (DW)). Additionally, the EtOH_96 extract displayed antibacterial activity against Staphylococcus aureus and Escherichia coli with MIC values of 6.25 mg/mL and suppressed heat-induced protein denaturation with an IC₅₀ value of 86.0 µg/mL, highlighting E. bulbosa tubers as a credible source of phytotherapeutics for both animal and human use.