Revealing the exceptional antioxidant activity of phosphorylated polysaccharides from medicinal Abrus cantoniensis Hance.

Abrus cantoniensis Polysaccharides (ACP) exhibit antioxidant activity and immune-regulatory functions. Abrus cantoniensis Hance widely distributed in the Guangdong and Guangxi regions of China. In this study, this research investigated the impact of phosphorylation modification on the biological activity of ACP, aiming to provide theoretical insights for its development. This research modified ACP through phosphorylation and evaluated changes in its in vitro antioxidant capacity, including free radical scavenging and resistance to cellular oxidative damage. Additionally, this research administered both native ACP and phosphorylated ACP (P-ACP) to mice to assess their protective effects against acute ethanol-induced oxidative injury. This research explored whether these effects were mediated through the Keap1-Nrf2 signaling pathway and their influence on gut microbiota. Results revealed that phosphorylation significantly enhanced ACP's antioxidant capacity and protective effects (p < 0.05). P-ACP improved mice resistance to acute oxidative injury, mitigating the adverse effects of 50 % ethanol (p < 0.05). Moreover, both ACP and P-ACP are involved in modulating the expression of the Keap1-Nrf2 signaling pathway and, to some extent, alter the composition of the gut microbiota in mice. In summary, phosphorylation modification effectively enhances ACP's antioxidant capacity and provides better protection against acute oxidative injury in mice.

Carboxymethylated Abrus cantoniensis polysaccharide prevents CTX-induced immunosuppression and intestinal damage by regulating intestinal flora and butyric acid content.

As a Chinese folk health product, Abrus cantoniensis exhibits good immunomodulatory activity because of its polysaccharide components (ACP), and carboxymethylation of polysaccharides can often further improve the biological activity of polysaccharides. In this study, we explored the impact of prophylactic administration of carboxymethylated Abrus cantoniensis polysaccharide (CM-ACP) on immunosuppression and intestinal damage induced by cyclophosphamide (CTX) in mice. Our findings demonstrated that CM-ACP exhibited a more potent immunomodulatory activity compared to ACP. Additionally, CM-ACP effectively enhanced the abundance of short-chain fatty acid (SCFA)-producing bacteria in immunosuppressed mice and regulated the gene expression of STAT6 and STAT3 mediated pathway signals. In order to further explore the relationship among polysaccharides, intestinal immunity and intestinal flora, we performed a pseudo-sterile mouse validation experiment and fecal microbiota transplantation (FMT) experiment. The findings suggest that CM-FMT and butyrate attenuate CTX-induced immunosuppression and intestinal injury. CM-FMT and butyrate show superior immunomodulatory ability, and may effectively regulate intestinal cell metabolism and repair the damaged intestine by activating STAT6 and STAT3-mediated pathways. These findings offer new insights into the mechanisms by which CM-ACP functions as functional food or drug, facilitating immune response regulation and maintaining intestinal health.

Characterization and macrophages immunomodulatory activity of two water-soluble polysaccharides from Abrus cantoniensis.

The study aims to elucidate the physicochemical properties and immunomodulatory activity of two polysaccharides (ACP t0 and ACP t2) from Abrus cantoniensis. Results revealed that ACP t0 with a molecular weight of 26.0 kDa, was mainly composed of glucose (83.1%) and galactose (6.1%), and that ACP t2 with a molecular weight of 145.6/8.9 kDa, consisted of galactose (25.6%), galacturonic acid (22.2%), arabinos (16.6%) and galactose (11.0%) respectively. AFM and Congo red experiments suggested that ACP t0 and ACP t2 might be spherical particles with triple-helix conformation in aqueous solution. ACP t0 and ACP t2 exhibited immunomodulatory activity by promoting the proliferation, augmenting pinocytic and phagocytic capacities, releasing immunoactive molecules such as ROS, NO, iNOS, TNF-α, IL-6 and IL-1ß, upregulation of the mRNA levels of corresponding cytokines in macrophages. Moreover, ACP t0 and ACP t2 were recognized by toll-like receptor 4 (TLR4) and exerted immunomodulatory effects via activating Myeloid differentiation factor 88 (MyD88), mitogen-activated protein kinases (MAPKs) and serine/threonine kinase (Akt) signaling pathways in macrophages. Notably, ACP t2 had higher immunomodulatory activity than ACP t0. Based on the present findings, ACP t0 and ACP t2 could be explored as an active component of immunomodulators in the food and pharmaceutical fields.

The Protective Effects of Three Polysaccharides From Abrus cantoniensis Against Cyclophosphamide-Induced Immunosuppression and Oxidative Damage.

This study was designed to systematically elucidate the immunomodulatory and antioxidant effects of three polysaccharide fractions (ACP60, ACP80, and ACPt2) from Abrus cantoniensis on cyclophosphamide (CTX)-induced immunosuppressive mice. The experimental mice were divided into 12 groups, then modeled and administrated with different doses of three polysaccharides (50, 150, 300 mg/kg/day) by gavage. The results showed that ACP could markedly recover the CTX-induced decline in immune organ and hemocytes indexes and promote proliferation of splenocytes, earlap swelling rate, secretion of cytokines (TNF-α, IFN-γ, IL-1ß, IL-6), and immunoglobulin (Ig-M and Ig-G). Additionally, ACP improved the enzymatic activities of T-SOD and GSH-PX greatly, while the level of MDA was significantly decreased in the liver. In particular, ACPt2 had higher immunomodulatory and antioxidant activities than ACP60 and ACP80. Based on the present findings, ACP could be utilized as an efficacious candidate for immunomodulators and antioxidants, which provide a new application prospect in the food and pharmaceutical industries.