Effect of in vitro simulated digestion on sugar content and biological activities of Zehneria maysorensis (Wight & Arn.) Arn. leaf polysaccharides

Cholesterol-Lowering Effect of Polysaccharides from Cyclocarya paliurus In Vitro and in Hypercholesterolemia Mice

In this study, a new component of Cyclocarya paliurus polysaccharides (CPP20) was precipitated by the gradient ethanol method, and the protective effect of CPP20 on hypercholesterolemia mice was investigated. In vitro, CPP20 had the ability to bind bile salts and inhibit cholesterol micelle solubility, and it could effectively clear free radicals (DPPH•, •OH, and ABTS+). In vivo, CPP20 effectively alleviated hypercholesterolemia and liver damage in mice. After CPP20 intervention, the activity of antioxidant enzymes (SOD, CAT, and GSH-Px) and the level of HDL-C in liver and serum were increased, and the activity of aminotransferase (ALT and AST) and the level of MDA, TC, TG, LDL-C, and TBA were decreased. Molecular experiments showed that CPP20 reduced cholesterol by regulating the mRNA expression of antioxidation-related genes (SOD, GSH-Px, and CAT) and genes related to the cholesterol metabolism (CYP7A1, CYP27A1, SREBP-2, HMGCR, and FXR) in liver. In addition, CPP20 alleviated intestinal microbiota disturbances in mice with hypercholesterolemia and increased levels of SCFAs. Therefore, CPP20 alleviates hypercholesterolemia by alleviating oxidative damage, maintaining cholesterol homeostasis, and regulating gut microbiota.

α-Glucosidase, α-amylase inhibition kinetics, in vitro gastro-intestinal digestion, and apoptosis inducing abilities of Ficus microcarpa L. f. and Ficus racemosa L. fruit polysaccharides

A rich source of nutrients, figs have a number of clinically validated benefits. This study aimed to evaluate the in vitro simulated gastrointestinal digestion, and the antidiabetic and anticancer activity of Ficus microcarpa (FMP) and F. racemosa (FRP) fruits polysaccharides. The pre-digested FMP revealed higher sugar content (721 ± 14.81 mg glucose equivalents/g sample) than FRP. After in vitro digestion, isolated fruit polysaccharides showed effective uptake with over 80% sugar loss. Free radicals and enzymatic inhibition after gastric digestion have been significantly modified, demonstrating the effective absorption of FMP and FRP through the intestine. Conversely, after the continuous digestion, the nutritional content of the isolated polysaccharides was gradually decreased compared to the pre-digested sample. At 30 µg/mL concentration of FMP and FRP was inhibited by 50% of breast cancer cells. The present study reveals the potential uptake of FMP and FRP as nutritional supplements in the future.

Graphical abstract

Digestive properties and effects of Chimonanthus nitens Oliv polysaccharides on antioxidant effects in vitro and in immunocompromised mice

The study was aimed to investigate the simulated digestion behavior of the bioactive polysaccharides from Chimonanthus nitens Oliv (COP1), antioxidant activity in vitro, and prevention against cyclophosphamide (CP) induced oxidative damage in mice. The results showed that COP1 were 18.843 kDa, and consisted of arabinose (56.6 mol%), galactose (24.9 mol%), xylose (11.1 mol%), and glucose (7.4 mol%). Gastrointestinal digestion significantly improved the radical (DPPH, OH, and ABTS⁺) scavenging activities of COP1. Meanwhile, administration of COP1 (150, 300, and 600 mg/kg, continuous 16 days) prevented hepatotoxicity in CP-induced mice (reducing liver index and transaminase levels, alleviating liver damage). COP1 also attenuated oxidative stress as evident from as shown by reduced levels of MDA and enhanced activity of antioxidant enzymes (CAT, SOD, and GSH-Px). In addition, COP1 regulated the Nrf2/Keap1 signaling pathway in CP-treated mice, decreasing the upstream factor Keap1 and increasing the upstream factor Nrf2, which in turn enhanced the expression of downstream factors (NQO1, HO-1, GSH-Px, SOD1, and CAT). COP1 also protected the body from CP-induced oxidative damage by down-regulating Bax and caspase3 in the apoptosis pathway and up-regulating Bcl-2 mRNA levels. Overall, COP1 might be harnessed as an effective natural antioxidant for medical and food industries.

Perspective on the Therapeutic Applications of Algal Polysaccharides

Abstract

Algae are an enormous source of polysaccharides and have gained much interest in human flourishing as organic drugs. Algal polysaccharides have aroused interest in the health sector owing to the various bioactivities namely anticancer, antiviral, immunoregulation, antidiabetic and antioxidant effects. The research community has comprehensively described the importance of algal polysaccharides regarding their extraction, purification, and potential use in various sectors. However, regardless of all the intriguing properties and potency in the health sector, these algal polysaccharides deserve detailed investigation. Hence, the present review emphasizes extensively on the previous and latest developments in the extraction, purification, structural properties and therapeutic bioactivities of algal polysaccharides to upgrade the knowledge for further advancement in this area of research. Moreover, the review also addresses the challenges, prospective research gaps and future perspective. We believe this review can provide a boost to upgrade the traditional methods of algal polysaccharide production for the development of efficacious drugs that will promote human welfare.

Graphic Abstract

Hydrogel-Forming Algae Polysaccharides: From Seaweed to Biomedical Applications

With the increasing growth of the algae industry and the development of algae biorefinery, there is a growing need for high-value applications of algae-extracted biopolymers. The utilization of such biopolymers in the biomedical field can be considered as one of the most attractive applications but is challenging to implement. Historically, polysaccharides extracted from seaweed have been used for a long time in biomedical research, for example, agarose gels for electrophoresis and bacterial culture. To overcome the current challenges in polysaccharides and help further the development of high-added-value applications, an overview of the entire polysaccharide journey from seaweed to biomedical applications is needed. This encompasses algae culture, extraction, chemistry, characterization, processing, and an understanding of the interactions of soft matter with living organisms. In this review, we present algae polysaccharides that intrinsically form hydrogels: alginate, carrageenan, ulvan, starch, agarose, porphyran, and (nano)cellulose and classify these by their gelation mechanisms. The focus of this review further lays on the culture and extraction strategies to obtain pure polysaccharides, their structure-properties relationships, the current advances in chemical backbone modifications, and how these modifications can be used to tune the polysaccharide properties. The available techniques to characterize each organization scale of a polysaccharide hydrogel are presented, and the impact on their interactions with biological systems is discussed. Finally, a perspective of the anticipated development of the whole field and how the further utilization of hydrogel-forming polysaccharides extracted from algae can revolutionize the current algae industry are suggested.