Extraction of polysaccharide fraction from cadamba (Neolamarckia cadamba) fruits and evaluation of its in vitro and in vivo antioxidant activities

Abstract

In this study, polysaccharide fraction (PFFNC) derived from Neolamarckia cadamba fruits showed remarkable antioxidant activity. The PFFNC was successfully extracted from the fruits by the hot water extraction process, followed by decolorization, defatting, and deproteinization. The chemical composition of PFFNC was effectively characterized by the use of UV–Vis, FT-IR, CHN, GC–MS, and 13C NMR spectroscopy. The findings indicated that PFFNC had an average molecular weight of 292 kDa and was predominantly composed of carbohydrates (76 %), with notable contributions from uronic acids (37.22 %) and proteins (12.35 %). The primary components of the sugar content were glucose (19.24 %), galactose (10.19 %), mannose (4.09 %), and glucuronic acid (2.8 %). The tertiary structural study verified the existence of a triple-helical structure. PFFNC exhibited a strong reducing power in vitro as determined by ABTS (IC50: 121 ± 0.12 μg/mL), DPPH (IC50: 146.065 ± 0.54 μg/mL), FRAP (677.788 ± 24.189 mM Fe (II)/g), hydroxyl radical scavenging (IC50: 78.736 ± 0.32 μg/mL), and phosphomolybdate assay (90.7 ± 0.43 mg AAE/g). In addition, the PFFNC furthermore showed significant in vivo antioxidant capacity, as determined using the brine shrimp (Bsmp) (Artemia salina Leach) model. The PFFNC exhibits significant antioxidant potential, suggesting broad spectrum applications in pharmaceuticals, nutraceuticals, and oxidative stress-related disorders.