Structural Characterization and Antitumor Activity of Polysaccharides from Kaempferia galanga L.

The water-soluble polysaccharides from Kaempferia galanga L. (KGPs) were extracted and purified, and their structural characteristics and antitumor activity were further investigated. The UV spectrum, high-performance gel permeation chromatography (HPGPC), Fourier-transform infrared spectroscopy (FTIR), and ion chromatography (IC) were employed to evaluate the structural characteristics, and H22 tumor-bearing mice model was established to demonstrate the antitumor activity. Physicochemical analysis and UV spectrum results showed that the proportions of total sugar, protein, and uronic acid in KGPs were 85.23%, 0.54%, and 24.17%, respectively. HPGPC, FTIR, and IC indicated that KGPs were acidic polysaccharides with skeletal modes of pyranose rings and mainly composed of arabinose and galactose with the average molecular weight of 8.5 × 10⁵ Da. The in vivo antitumor experiments showed that KGPs could effectively protect the thymus and spleen of tumor-bearing mice from solid tumors and enhance the immunoregulatory ability of CD4⁺ T cells, the cytotoxic effects of CD8⁺ T cells and NK cells, and finally resulting in the inhibitory effects on H22 solid tumors. This study provided a theoretical foundation for the practical application of KGPs in food and medical industries.