Enhancing bioactive recovery from <i>Codonopsis javanica</i> tuber via ultrasound-assisted extraction: effects of extraction parameters and antioxidant evaluation

Codonopsis javanica ( C. javanica) is an indigenous medicinal plant of Vietnam that possesses various valuable bioactive compounds with potential applications in multiple fields. In this study, the extraction of C. javanica tuber was carried out using ultrasound-assisted extraction with ethanol as the solvent. The effects of the solid-to-solvent ratio, extraction time, and temperature on the saponin content of the extract were investigated. The results indicated that the optimal extraction conditions were a solid-to-solvent ratio of 1:40, an extraction time of 45 min, a temperature of 50 °C, and four extraction cycles. Under these conditions, the extract exhibited a saponin content of 32.7 ± 2.5 mg/g, along with other bioactive compounds, including polyphenols (6.14 ± 0.045 mg GAE/g), flavonoids (1.906 ± 0.006 mg/g), proteins (38.78 ± 0.085 mg/g), reducing sugars (122.6 ± 0.2 mg/g), and polysaccharides (907.4 ± 2.5 mg/g). The antioxidant activity of the extract was evaluated using DPPH and ABTS assays, yielding IC 50 values of 40.34 µg/mL and 228.39 µg/mL, respectively. These results demonstrate that the extract from C. javanica tuber exhibits significant antioxidant activity and has promising potential as a natural source of bioactive compounds for pharmaceutical and cosmetic applications.