ABSTRACT
With the appearance of the disadvantages of traditional tumor treatment, immunotherapy has entered people′s horizons as modern emerging treatment strategies, among which plant polysaccharides have received much more attention due to their antitumor activity and significant immunomodulatory effects. Tumor-associated macrophages (TAMs), as a component of tumor microenvironment, are important factors affecting tumors, and the regulation of TAMs by plant polysaccharides is one of the effective immunotherapy to treat tumor. In this review, we mainly described the regulation of TAMs by plant polysaccharides and the underlying mechanisms, and then gave an outlook on the research interests and the development of plant polysaccharides as immune adjuvants, aiming to provide reference for the study of plant polysaccharides in the immunotherapy for tumors.
ABSTRACT
Abstract Ximenia americana L., Olacaceae, barks are utilized in folk medicine as analgesic and anti-inflammatory. The objective was to evaluate the toxicity and antinociceptive effect of polysaccharides rich fractions from X. americana barks. The fractions were obtained by extraction with NaOH, followed by precipitation with ethanol and fractionation by ion exchange chromatography. They were administered i.v. or p.o. before nociception tests (writhing, formalin, carragenan-induced hypernociception, hot plate), or during 14 days for toxicity assay. The total polysaccharides fraction (TPL-Xa: 8.1% yield) presented 43% carbohydrate (21% uronic acid) and resulted in two main fractions after chromatography (FI: 12%, FII: 22% yield). FII showed better homogeneity/purity, content of 44% carbohydrate, including 39% uronic acid, arabinose and galactose as major monosaccharides, and infrared spectra with peaks in carbohydrate range for COO- groups of uronic acid. TPL-Xa (10 mg/kg) and FII (0.1 and 1 mg/kg) presented inhibitory effect in behavior tests that evaluate nociception induced by chemical and mechanical, but not thermal stimuli. TPL-Xa did not alter parameters of systemic toxicity. In conclusion, polysaccharides rich fractions of X. americana barks inhibit peripheral inflammatory nociception, being well tolerated by animals.
ABSTRACT
Plant polysaccharides have a variety of biological activities and have become the focus of many fields such as the areas of medicine and food for the features of safety, high efficiency and low toxicity. The chemical structure of plant polysaccharides is the foundation for the biological activity. Polysaccharides with different chemical structures have great differences in biological activity. The exploration of the structure-activity relationship of plant polysaccharides has guiding significance for the development of new drugs and the health care products of saccharides. Many biological activities of plant polysaccharides such as anti-hepatic injury, antineoplastic, antiviral, hypoglycemia, anticoagulation, anti-oxidation and immunoregulation have been discovered. Therefore, this paper focuses on the bioactivity as the main line, and summarizes the studies on structure-activity relationship and mechanism of plant polysaccharides at home and abroad in recent years. The key point is the structure-activity relationship between plant polysaccharides and the anti-hepatic injury, antineoplastic, antiviral, hypoglycemia, and anticoagulation activities, providing reference for intensive study and exploration of structure-activity relationship of plant polysaccharides as well as development and application of polysaccharides products.
ABSTRACT
Objective: To study the characteristics of partial acid hydrolysis in five different plant polysaccharides and the composition of their hydrolysic products. Methods: Polysaccharides were partially hydrolyzed with trifluoroacetic acid (TFA) at different concentration (0.05, 0.2, and 0.5 mol/L), respectively, and the hydrolytic characteristics were studied by ultra-performance liquid chromatography (UPLC) coupled with multivariate statistricts. Results: The characteristic structural segments of ephedra polysaccharide were the contents of glucuronic acid in trapped fluid hydrolyzed with 0.05 mol/L TFA (X1GlcUA), arabinose in permeation fluid hydrolyzed with 0.05 mol/L TFA (X2Ara), arabinose in trapped fluid hydrolyzed with 0.2 and 0.5 mol/L TFA (Y1Ara and Z1Ara), and galacturonic acid in the permeation fluid hydrolyzed with 0.2 mol/L TFA (Y2GalUA), which could distinguish other plant polysaccharide samples. Conclusion: The proposed method is precise and practical for the analysis on monosaccharide compositon in Chinese materia medica by UPLC coupled with multivariate statistics and partial acid hydrolytic reaction, which further provides the basis for the quality control of the plant polysaccharides.