Response surface methodology was used to optimize the extraction conditions for ultrasonic-assisted extraction of polysaccharides from mango pomace. The Optimum extraction conditions consisted of extraction temperature of 74 °C, ultrasonic power of 170 W, extraction time of 100 min, and raw material-to-water ratio of 1:40 g/mL. Under these conditions, the extraction yield was 3.71 ± 0.07%. Three novel polysaccharide fractions, MG-1, MG-2 and MG-3 were purified from the crude polysaccharides by using DEAE-52 cellulose and Sephadex G-100 column chromatography. The molecular weight and monosaccharide composition of polysaccharide fractions (MPFs) were analyzed by high performance liquid gel permeation chromatography (HPGPC) and HPLC analysis, respectively. The characterizations of MPFs were conducted with FT-IR, 1H NMR and SEM. Furthermore, the anticancer activities of the polysaccharide fractions were also investigated in vitro. Results showed that MG-1, MG-2 and MG-3 exhibited significant anticancer activities against HepG2, MCF-7, A549, HeLa, A2780, HCT-116 and BGC-823 cells in a dose-dependent manner. MPFs were also showed to promote apoptosis as seen in the nuclear morphological examination study using calcein acetyl methoxy methyl easter (calcein-AM) and propidium iodide (PI) staining. This research could serve as a theoretical reference for the efficient utilization of MPFs in biomedical and functional food.
Keywords: Anticancer activity; Characterization; Mango pomace; Polysaccharides; Response surface methodology; Ultrasonic-assisted extraction.
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