Characterization, antioxidant activity and hepatoprotective effect of purple sweetpotato polysaccharides

Structure-immunomodulatory activity relationships of Hedysarum polysaccharides extracted by a method involving a complex enzyme combined with ultrasonication

A new, more effective and environmentally friendly method involving a complex enzyme combined with ultrasonication was employed to extract and isolate three novel polysaccharides (HPS-MCs: HPS-MC, HPS-MC (50%) and HPS-MC (80%)) of Radix Hedysari. Compared with polysaccharides obtained using a traditional extraction method (hot water extraction, HPS-R), the yields and total carbohydrate contents of HPS-MCs were significantly higher. HPS-MC (80%) exhibited relatively strong immunomodulatory activity and a concentration-dependent dose-response relationship under cyclophosphamide (CP)-induced immunosuppressive conditions in mice models. To more comprehensively investigate the relationships between structural characteristics and immunomodulatory activity, HPS-MC (80%) was fractionated into three major homogeneous polysaccharide fractions (HPS-MC (80%)s: HPS-MC (80%)-1, HPS-MC (80%)-2, and HPS-MC (80%)-3). These three homogeneous polysaccharides had different mass percentages of monosaccharides species (rhamnose, arabinose, mannose, glucose, and galactose) by gas chromatography (GC) and different molecular weights and chain conformations by high-performance gel permeation chromatography coupled with multi-angle laser light scattering (HPGPC-MALLS), and promoted macrophage and splenocyte proliferation to different degrees. These findings indicated that HPS-MC (80%) had a prominent potential immune response, especially HPS-MC (80%)-2 and HPS-MC (80%)-3, and might be suitable candidates for functional foods or potential novel immunomodulators.

Optimization of Ultrasonic-Microwave Assisted Extraction and Hepatoprotective Activities of Polysaccharides from Trametes orientalis

Ultrasonic-microwave assisted extraction (UMAE) of Trametes orientalis polysaccharides was optimized by response surface methodology. Hepatoprotective effects of a purified T. orientalis polysaccharide (TOP-2) were evaluated by alcohol-induced liver injury model mice. The optimal UMAE parameters were indicated as below: ratio of water to raw material 28 mL/g, microwave power 114 W, extraction time 11 min. The polysaccharides yield was 7.52 ± 0.12%, which was well consistent with the predicted value of 7.54%. Pre-treatment with TOP-2 effectively increased the liver index and spleen index in alcohol-treated mice. The elevated serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels of mice after alcohol exposure were inhibited by TOP-2 administration. The liver tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) levels have decreased significantly as a result of alcohol exposure, while pre-treatment with TOP-2 could mitigate these consequences. Furthermore, pre-treatment with TOP-2 could efficiently boost the superoxidase dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities, and observably constrain the malondialdehyde (MDA) level. The findings suggest that TOP-2 might be useful for alleviating the alcohol-induced hepatotoxicity via its antioxidant and anti-inflammatory potential.

Immune-enhancing effects of polysaccharides from purple sweet potato

Immune-enhancing effects of three kinds of purple sweet potato polysaccharides (PSPPs) including water-soluble polysaccharide (WSP), dilute alkali-soluble polysaccharide (DASP) and concentrated alkali-soluble polysaccharide (CASP) were evaluated. Scanning electron microscope analysis showed that all PSPPs could stimulate the formation of microvilli-like structures in cellular surfaces, which was possibly related to activation of macrophages. Neutral red uptake assay showed that PSPPs could increase the phagocytic activity of cells. High dose (400 μg/mL) of PSPPs could notably augment the level of nitric oxide (NO). ELISA analysis revealed that 200 and 400 μg/mL of PSPPs distinctly elevated the production of IL-1β. Cells received 200 and 400 μg/mL of WSP as well as 400 μg/mL of DASP exhibited higher level of IL-6. Results of animal experiments showed that WSP treatment (400 mg/kg) could promote the secretions of IgA, IgG, IgM and sIgA in both normal and immunosuppressed mice. Moreover, CASP treatment (400 mg/kg) elevated the production of IgM in the serum of normal and immunosuppressive mice, while DASP (400 mg/kg) only improved the secretion of IgM in normal mice. In summary, all three polysaccharides can stimulate immune responses of macrophages and positively regulate adaptive immunity by enhancing the production of immunoglobulins in mice.

Antioxidant, anti-hyperlipidemia and hepatic protection of enzyme-assisted Morehella esculenta polysaccharide

The aims of this work were to investigate the antioxidant, anti-hyperlipidemia and hepatic protection of Morehella esculenta polysaccharide (MPS) from fruiting body and its enzyme-assisted MPS (EnMPS). The in vitro scavenging rates of EnMPS at 600 mg/L on superoxide, hydroxyl and 1,1‑diphenyl‑2‑pyrazole hydrazide (DPPH) radicals were 76.92 ± 2.61%, 66.74 ± 2.56% and 75.78 ± 2.4%, higher than those of MPS, respectively. Animals experiments showed that the EnMPS exhibited superior abilities of reducing hepatic lipid levels by monitoring the serum enzyme activities (ALP, ALT, ALB and AST) and serum lipid levels (CK, TC, TG, HDL-C, LDL-C and LDH), enhancing the hepatic antioxidant enzymes (FFA, SOD, CAT and T-AOC) and decreasing the lipid peroxidation (MDA and MPO). The results suggested that the EnMPS can act as a natural candidate for developing drugs to reduce blood lipids, resist oxidation and protect the liver.