Efficient purification of flavonoids from bamboo shoot residues of Phyllostachys edulis by macroporous resin and their hypoglycemic activity

The adsorption/desorption process of flavonoids obtained from bamboo shoots residues of Phyllostachys edulis (RPEFs) was established by resin screening, adsorption isotherms, adsorption kinetics and dynamic tests. Results indicated the Langmuir equation fairly fitted the isotherms data and the pseudo-second-order model accurately described its kinetic adsorption on HPD-500 resin. The optimal process was as follows: 2 mg/mL of solution, 2.8 BV feed volume under 2 BV/h flow rate for adsorption; 5 BV volume of 70 % ethanol with a flow rate of 2 BV/h for desorption. After enrichment, the flavonoids in RPEFs increased from 1.39 % to 37.34 %. The analysis of UPLC-TOF-MS/MS uncovered that the purified RPEFs were composed of four major flavonoids. It had potent hypoglycemic activity via PI3K/AKT pathway by upregulating the protein expression of PI3K, AKT, IRS-1, and GLUT4 in a dose-dependent manner based on HepG2-IR cells. Those results provide possible utilization of Phyllostachys edulis by-products in food additives.

Automated summary

This study established the adsorption/desorption process of flavonoids from bamboo shoot residues using resin screening, adsorption isotherms, adsorption kinetics, and dynamic tests. The Langmuir equation and pseudo-second-order model were found to accurately describe the adsorption process. The optimal conditions for adsorption were a solution concentration of 2 mg/mL, a feed volume of 2.8 BV, and a flow rate of 2 BV/h, while for desorption, a 70% ethanol solution at a volume of 5 BV and a flow rate of 2 BV/h were used. After enrichment, the flavonoid content in the residues increased from 1.39% to 37.34%. Analysis also revealed that the purified residues were composed of four major flavonoids. The study found that the residues exhibited potent hypoglycemic activity via the PI3K/AKT pathway. These findings suggest the potential use of bamboo shoot residues as food additives.