A comparative investigation on the extraction-function relationship of polysaccharides derived from moringa oleifera...

Owing to the hypoglycemic, anti-inflammatory, and other beneficial bioactivities of Moringa oleifera seeds (MOS), the antioxidant activities and physicochemical characteristics of deproteinized polysaccharides extracted using hot water (MSWP) and alkali (MSAP) from MOS were systematically studied. MSAP exhibited higher antioxidant activity than MSWP in vitro. Subsequently, the antioxidant capacity was evaluated after oral administration of MSAP in diabetic rats. The results demonstrated a statistically significant increase in serum antioxidant parameters. The two polysaccharides were then purified and characterized. The molecular weights of purified fractions MSAP3 and MSWP1 were 4.582 × 10⁴ Da and 1.9058 × 10⁵ Da, respectively; the content of uronic acid in MSAP3 was higher than that in MSWP1; and both compounds presented typical infrared spectral absorption peaks of polysaccharides. In conclusion, MSAP exhibits superior antioxidant properties that depend on its structural characteristics, and this study provides data support for further elucidation of the hypoglycemic mechanism of MSAP.