Structural Features of Three Hetero-Galacturonans from Passiflora foetida Fruits and Their in Vitro Immunomodulatory Effects

Abstract

Passiflora foetida is a horticultural plant and vital traditional Chinese herbal medicine. In our previous study, the characterization and immuno-enhancing effect of fruits polysaccharide 1 (PFP1), a water-eluted hetero-mannan from wild Passiflora foetida fruits, were investigated. Herein, another three salt-eluted novel polysaccharides, namely PFP2, PFP3, and PFP4, were obtained and structurally characterized. The results showed that PFP2, PFP3, and PFP4 were three structurally similar hetero-galacturonans with different molecular weights of 6.11 × 10 4 , 4.37 × 10 4 , and 3.48 × 10 5 g/mol, respectively. All three of these hetero-galacturonans are mainly composed of galacturonic acid, galactose, arabinose (75.69%, 80.39%, and 74.30%, respectively), and other monosaccharides including mannose, fucose, glucose, ribose, xylose, and glucuronic acid (24.31%, 19.61, and 25.70%, respectively), although differences in their backbone structure exist. Additionally, immunomodulatory assay indicated that the three hetero-galacturonans possess the ability to promote the production of nitric oxide (NO), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) in RAW264.7 macrophages in a concentration-dependent manner (p < 0.05). Especially, PFP3 displayed a stronger enhancing effect than PFP2 and PFP4 at the minimum effective concentration. Therefore, the results suggested that the obtained three salt-eluted hetero-galacturonans, especially PFP3, could be utilized as immunomodulatory effectivity ingredients in nutritional/pharmaceutical industries.

Immunological Activity and Gut Microbiota Modulation of Pectin from Kiwano (Cucumis metuliferus) Peels

“…The IL-6 secretion ( Figure 4 C) of RAW264.7 increased significantly ( p < 0.01) when treating with 50 µg/mL of CMPP. At the highest concentration of CMPP (50 µg/mL), NO, TNF-α and IL-6 production were all inferior to the LPS group, which suggested a more moderate immune regulation of CMPP than LPS [ 33 ]. Comprehensively, CMPP had better immune-enhancing activity than CMPP-2 (6.25 µg/mL) at the equivalent concentration, and its effect was close to CMPP-1 (0.78 µg/mL) [ 16 ].…”

Immunomodulatory effects of the polysaccharide from Sinonovacula constricta on RAW264.7 macrophage cells

“…Signals within the range of 3.5–5.5 ppm (1H spectra) and 97–102 ppm (13C spectra) showed a typical characteristic of polysaccharide, respectively (Sun et al., 2019). Signals of hydrogen protons on α‐configuration glycoside anomeric carbon generally occurred in the range of δ 5.0–5.8 ppm in 1H NMR spectra, while the isomers of β‐configuration glycosides occurred in the range of δ 4.4–5.0 ppm 1H NMR spectra (Song et al., 2020). As shown in Figure 4, the chemical shifts at δ 5.32 and 4.95 ppm were attributed to two anomeric protons.…”

Spirulina polysaccharide induces the metabolic shifts and gut microbiota change of lung cancer in mice

“…Finally, PSP was obtained after lyophilizing the dialysate. The total sugar content, protein content, relative molecular weight, monosaccharide composition, and functional groups of PSP were measured ( Hao et al, 2019 ; Song et al, 2020 ). These results are shown in Tables S1–S2 and Fig.…”