Sustainable ultrasound-assisted extraction from Curcuma zedoaria: Antioxidative activity and life cycle assessment

• Optimized Curcuma zedoaria rhizome extraction process • Curcuma zedoaria rhizomes extract showed the presence of curcumin • The optimal extract had strong anti-oxidative stress • Life cycle assessment confirmed low environmental impacts Curcuma zedoaria (Zingiberaceae) is a globally distributed medicinal plant; however, its bioactive potential remains underutilized. This study optimized a sustainable extraction process for flavonoids using Response Surface Methodology (RSM) coupled with Ultrasound-Assisted Extraction (UAE). Under the optimal conditions (49.24°C, 15.19 min, 79.12% ethanol, and a 1:10 solid-to-solvent ratio), the process yielded a total flavonoid content of 15.58 mg QE/g, with the model demonstrating high reliability and predictive accuracy. The optimized extract exhibited potent in vitro biological activities, including anti-cholesterol effects (IC 50 = 9.76 ± 0.22 µg/mL) and significant inhibition of pancreatic lipase (IC 50 = 7.53 ± 0.22 µg/mL), α-amylase (IC 50 = 7.62 ± 0.39 µg/mL), and α-glucosidase (IC 50 = 5.74 ± 0.14 µg/mL). Additionally, antioxidant capacity, assessed via four assays, showed IC 50 values ranging from 9.69 ± 0.19 to 17.62 ± 0.58 µg/mL. Antibacterial assays against Enterobacter cloacae revealed inhibition zones of 14.37–20.83 mm and MIC/MBC values of 250/500 µg/mL. Furthermore, Life Cycle Assessment (LCA) indicated that the optimized UAE process had significantly lower environmental impacts compared to reflux extraction, particularly regarding global warming potential, carcinogenicity, and ecotoxicity. These findings highlight C. zedoaria as a promising bioresource and validate the feasibility of a scalable, eco-friendly extraction method for health-related product development.