Platycodon grandiflorum Polysaccharides with Dellifferent Extraction Processes and Their Effects on Oxaliplatin Distribution in Vivo

Objective: To investigate the physicochemical properties of PGP extracted by different processes and the effects of these PGPs on the in vivo distribution of Oxaliplatin (OXA). Methods: In this study, hot water extraction (HW), acetic acid-assisted extraction (CA), ammonia-assisted extraction (KA), and ultrasound-assisted extraction (UA) were used to prepare PGP. The physicochemical properties of the polysaccharides were determined by methods such as infrared spectroscopy, ultraviolet spectroscopy, gel chromatography, and high-performance liquid chromatography. An inductively coupled plasma mass spectrometry (ICP-MS) method was established to analyze the in vivo distribution of OXA in SD rats treated with OXA alone, OXA+PGP-HW, OXA+PGP-CA, OXA+PGP-KA, and OXA+PGP-UA. The expression levels of Oct-2 and Pg-P proteins in lung tissues were measured by Western blot to investigate the mechanism of PGP in modifying the in vivo distribution of OXA. Results: Significant differences existed in the physicochemical properties of the four types of PGPs. Among these four types, PGP-KA had the highest yield. The infrared spectra of all four PGPs exhibited typical absorption peaks characteristic of polysaccharides. The four PGPs consisted primarily of two molecular weights, 7 kDa and 3790 kDa, but the distribution percentages of these molecular weights vary. All four PGPs contained mannose (Man), rhamnose (Rha), galacturonic acid (GalA), glucose (Glu), galactose (Gal), and arabinose (Ara), although their ratios differ. The particle sizes of the four PGPs were mainly concentrated around 300 nm, and all demonstrate good solution stability. Compared with the OXA alone group, the OXA+PGP-CA and OXA+PGP-KA groups increased the lung tissue content of OXA by 36.93% and 35.12%, respectively. The OXA+PGP-KA group also significantly increased the expression level of Oct-2 protein (P<0.05), while there was no significant difference in the expression level of Pg-P protein. Conclusion: The physicochemical properties of PGP extracted by different processes are different. Among them, the combination of PGP-CA and PGP-KA can significantly increase the lung tissue distribution of OXA, which would be related to the increase in Oct-2 expression in lung tissues.