Enhancing anti-diabetic activity and reducing cytotoxicity of T. crispa extracts through sustainable approach of pressurized hot water extraction and micelle-mediated separation

In this study, pressurized hot water extraction (PHWE) was evaluated for the recovery of anti-diabetic borapetoside C (BPC) from T. crispa stems. The maximum BPC extraction efficiency obtained at 100 ˚C, 2.5 MPa and 5.0 mL/min was considerably higher than that obtained by the conventional methods. Under optimized conditions, one-site kinetic desorption model could most accurately describe the PHWE behavior, suggesting an intra-particle diffusion-controlled mechanism. The undesirable compounds in the extract were further removed by micelle-mediated separation (MMS), in which Tween 80 was added, followed by NaCl addition and slight temperature increase to induce phase separation. At the most suitable MMS condition, with 0.028 mM Tween 80, 0.4 M NaCl, at 85 ˚C, the majority (87 %) of BPC could be recovered in the aqueous phase after 40 min. After MMS, the resulting extract exhibited low cytotoxicity against L6 and HepG2 cells while maintaining significant α-glucosidase and α-amylase inhibition activities.