Structural characterization, acute toxicity assessment and protective effects of selenylated apple pectin on dextran sulfate sodium-induced ulcerative colitis

Physicochemical properties, structural characterization, and antidiabetic activity of selenylated low molecular weight apple pectin in HFD/STZ-induced type 2 diabetic mice

A novel selenylated low molecular weight apple pectin (Se-LMWAP) was prepared through enzymatic modification combined with selenylation. The physicochemical properties, the structural characterization of Se-LMWAP were evaluated by FT-IR, NMR and SEM. Moreover, the antidiabetic activity and potential mechanism of Se-LMWAP were investigated using high-fat diet (HFD)/streptozotocin (STZ)-induced type 2 diabetic mice. The results revealed that the physicochemical properties of Se-LMWAP were distinctly improved after modifications, and the primary structure was not altered significantly compared to apple pectin and low molecular weight apple pectin. Se-LMWAP had a relative molecular weight of 8.91 × 103 Da (accounted for 61.3 %) and total selenium content of 148.3 ± 2.0 μgselenium/gsample. It consisted of Rha, Ara, Gal, Glc, Xyl and GalA at a molar ratio of 0.093:0.014:0.132:0.020:0.118:0.622, with the selenium substitution occurred at the C-6 position. Se-LMWAP was able to significantly reduce weight loss, hyperglycemia, oxidative stress and liver, kidney and pancreas damage. Additionally, improved glucose tolerance, relieved lipid metabolism disorders, elevated hepatic glycogen content and ameliorated insulin resistance were observed in the Se-LMWAP group. Overall, Se-LMWAP can be used as a promising dietary selenium supplement to exert -antidiabetic effect through modulating hepatic glucose metabolism and liver insulin-signaling transduction and oxidative stress.

Deciphering Pectin: A Comprehensive Overview of Its Origins, Processing, and Promising Utility

Pectin is an acidic heteropolysaccharide, a natural high molecular weight compound primarily found in higher plants. It consists of four major structural domains: homogalacturonan (HG), rhamnogalacturonan II (RG-II), rhamnogalacturonan I (RG-I), and xylogalacturonan (XGA). Various methods are currently employed for pectin extraction, including acid extraction, microbial fermentation, microwave-assisted extraction, and ion extraction, each with unique advantages and disadvantages. Pectin is sourced from fruits and vegetables, such as citrus fruits, apples, beets, and carrots. In terms of regulating human health, pectin enhances antioxidant activity, promotes beneficial microorganisms, and stimulates the production of short-chain fatty acids (SCFAs) through microbial metabolism. Additionally, pectin interacts directly with the mucosa, inhibits Toll-like receptor 2 (TLR2) signaling, and modifies the glycosylation of intestinal mucosal proteins. In disease models, pectin shows preventive and therapeutic effects in inflammatory bowel disease, type 2 diabetes, obesity, cardiovascular disease, and cancer. This review covers recent research, summarizing the sources and extraction methods of pectin, and emphasizes its role as a modulator of human health.

The double-layer emulsions loaded with bitter melon (Momordica charantia L.) seed oil protect against dextran sulfate sodium-induced ulcerative colitis in mice

In this study, a whey protein isolate (WPI)-chitooligosaccharide (COS) stabilized bitter melon (Momordica charantia L.) seed oil emulsions (WC-BSOE) were prepared using the electrostatic layer-by-layer self-assembly technique, and their modulating effects on ulcerative colitis (UC) were investigated in dextran sulfate sodium (DSS)-induced UC mice model. The stability and releasing ability of WC-BSOE under simulated gastrointestinal digestion condition and their acute toxicity were also investigated. The results showed that WC-BSOE was stable to droplet aggregation in the simulated gastric and intestinal fluids and exhibited sustained release profile during gastrointestinal transit, evidenced by the measurement of particle size, polydispersity index, zeta-potential and released free fatty acids contents. Moreover, WC-BSOE had no toxic effects on BALB/c mice within the dose range of 40,000 mg/kg body weight (BW), and treatment with WC-BSOE at a dosage of 15 mg/kg BW effectively relieved DSS-induced UC symptoms in mice. Furthermore, WC-BSOE could improve the IL-4 and IgA contents in serum, as well as up-regulate the occludin and ZO-1 expressions and down-regulate MPO, MDA and ROS levels in colon tissues of colitis mice, and it also elevated the diversity and relative abundances of Firmicutes, Bacteroides, and Lactobacillus in the intestinal microbiota. These findings indicated that WC-BSOE exerted protective effects in UC through decreasing proinflammatory cytokines, increasing tight junction proteins, suppressing oxidative stress, and regulating intestinal microbiota. Collectively, this study suggested WC-BSOE might be developed as a promising dietary supplement for UC protection.

Insights into the impact of modification methods on the structural characteristics and health functions of pectin: A comprehensive review

Pectin is a complex polysaccharide that is widely present in plant cells and has multiple physiological functions. However, most pectin exists in the form of protopectin, which has a large molecular weight and cannot be fully absorbed and utilized in the human gut to exert its effects. The significant differences in the structure of different sources of pectin also limited their application in the food and medical fields. In order to achieve greater development and utilization of pectin functions, this paper reviewed several commonly used methods for pectin modification from physical, chemical, and biological perspectives, and elaborated on the relationship between these modification methods and the structure and functional properties of pectin. At the same time, the functional characteristics of modified pectin and its application in medical health, such as regulating intestinal health, anticancer, anti-inflammatory, and drug transport, were reviewed, so as to provide a theoretical basis for targeted modification of pectin and the development of new modified pectin products.

Recent advances in natural polysaccharides against hepatocellular carcinoma: A review

Hepatocellular carcinoma (HCC) is a malignant tumor of the digestive system that poses a serious threat to human life and health. Chemotherapeutic drugs commonly used in the clinic have limited efficacy and heavy adverse effects. Therefore, it is imperative to find effective and safe alternatives, and natural polysaccharides (NPs) fit the bill. This paper summarizes in detail the anti-HCC activity of NPs in vitro, animal and clinical trials. Furthermore, the addition of NPs can reduce the deleterious effects of chemotherapeutic drugs such as immunotoxicity, bone marrow suppression, oxidative stress, etc. The potential mechanisms are related to induction of apoptosis and cell cycle arrest, block of angiogenesis, invasion and metastasis, stimulation of immune activity and targeting of MircoRNA. And on this basis, we further elucidate that the anti-HCC activity may be related to the monosaccharide composition, molecular weight (Mw), conformational features and structural modifications of NPs. In addition, due to its good physicochemical properties, it is widely used as a drug carrier in the delivery of chemotherapeutic drugs and small molecule components. This review provides a favorable theoretical basis for the application of the anti-HCC activity of NPs.

Recent progress in plant-derived polysaccharides with prebiotic potential for intestinal health by targeting gut microbiota: a review

Natural products of plant origin are of high interest and widely used, especially in the food industry, due to their low toxicity and wide range of bioactive properties. Compared to other plant components, the safety of polysaccharides has been generally recognized. As dietary fibers, plant-derived polysaccharides are mostly degraded in the intestine by polysaccharide-degrading enzymes secreted by gut microbiota, and have potential prebiotic activity in both non-disease and disease states, which should not be overlooked, especially in terms of their involvement in the treatment of intestinal diseases and the promotion of intestinal health. This review elucidates the regulatory effects of plant-derived polysaccharides on gut microbiota and summarizes the mechanisms involved in targeting gut microbiota for the treatment of intestinal diseases. Further, the structure-activity relationships between different structural types of plant-derived polysaccharides and the occurrence of their prebiotic activity are further explored. Finally, the practical applications of plant-derived polysaccharides in food production and food packaging are summarized and discussed, providing important references for expanding the application of plant-derived polysaccharides in the food industry or developing functional dietary supplements.

The Preparation and Potential Bioactivities of Modified Pectins: A Review

Pectins are complex polysaccharides that are widely found in plant cells and have a variety of bioactivities. However, the high molecular weights (Mw) and complex structures of natural pectins mean that they are difficult for organisms to absorb and utilize, limiting their beneficial effects. The modification of pectins is considered to be an effective method for improving the structural characteristics and promoting the bioactivities of pectins, and even adding new bioactivities to natural pectins. This article reviews the modification methods, including chemical, physical, and enzymatic methods, for natural pectins from the perspective of their basic information, influencing factors, and product identification. Furthermore, the changes caused by modifications to the bioactivities of pectins are elucidated, including their anti-coagulant, anti-oxidant, anti-tumor, immunomodulatory, anti-inflammatory, hypoglycemic, and anti-bacterial activities and the ability to regulate the intestinal environment. Finally, suggestions and perspectives regarding the development of pectin modification are provided.