Purpose: To review the effects of polysaccharides and their proposed mechanisms of action in breast cancer experimental models. Data sources, selection, and extraction: Articles were selected by using PubMed, ScienceDirect, Scopus, and Medline, assessed from 1 May 2019 to 1 July 2020. The systematic review was registered in the International Prospective Register of Systematic Reviews (Prospero) under the number CRD42020169103. Results: Most of the studies explore algae polysaccharides (43.2%), followed by mushrooms (13.5%), plants (13.5%), fruits (10.8%), fungus (2.7%), bacteria, (2.7%), and sea animals (2.7%). A total of 8.1% investigated only in vitro models, 62.1% evaluated only in vivo models, and 29.7% evaluated in vitro and in vivo models. The mechanism of action involves apoptosis, inhibition of cellular proliferation, angiogenesis, and antimetastatic effects through multiple pathways. Conclusions: Findings included here support further investigations on the anti-tumor effect of polysaccharides. Some polysaccharides, such as fucoidan and β-glucans, deserve detailed and structured studies aiming at translational research on breast tumors, since they are already used in the clinical practice of other proposals of human health.

Inflammatory bowel disease (IBD) is a complex inflammatory disorder characterized by chronic and spontaneously relapsing inflammation of the gastrointestinal tract. IBD includes two idiopathic disorders: Crohn’s disease (CD) and ulcerative colitis (UC). In particular, UC causes inflammation and ulceration of the colon and rectum. There is no cure for UC. The pharmacological treatment is aimed at controlling and/or reducing the inflammatory process and promoting disease remission. The present study investigated the possible protective effects of soluble dietary fiber (SDF) isolated from yellow passion fruit peel in the dextran sulfate sodium‐ (DSS‐) induced colitis model in mice, induced by 5% of DSS. The animals were treated with SDF (10, 30, or 100 mg/kg (po)), and the disease activity index was monitored. Colon tissues were collected, measured, and prepared for oxidative stress, inflammation, and histology analysis. SDF improved body weight loss, colon length, and disease activity index and prevented colonic oxidative stress by regulating GSH levels and SOD activity. Furthermore, SDF reduced colonic MPO activity, TNF‐α, and IL‐1β levels and increased IL‐10 and IL‐6 levels. As observed by histological analysis, SDF treatment preserved the colonic tissue, the mucus barrier, and reduced inflammatory cell infiltration. Although this is a preliminary study, taken together, our data indicate that SDF may improve the course of DSS‐UC. More studies are needed to explore and understand how SDF promotes this protection.

Gastrointestinal mucositis is a serious and dose-limiting toxic side effect of oncologic treatment. Interruption of cancer treatment due to gastrointestinal mucositis leads to a significant decrease in cure rates and consequently to the deterioration of a patient’s quality of life. Natural polysaccharides show a variety of beneficial effects, including a gastroprotective effect. Treatment with soluble dietary fiber (SDF) from yellow passion fruit (Passiflora edulis) biomass residues protected the gastric and intestinal mucosa in models of gastrointestinal injury. In this study, we investigated the protective therapeutic effect of SDF on 5-FU-induced mucositis in male and female mice. Oral treatment of the animals with SDF did not prevent weight loss but reduced the disease activity index and preserved normal intestinal function by alleviating diarrhea and altered gastrointestinal transit. SDF preserved the length of the colon and histological damage caused by 5-FU. SDF significantly restored the oxidative stress and inflammation in the intestine and the enlargement and swelling of the spleen induced by 5-FU. In conclusion, SDF may be a promising adjuvant strategy for the prevention and treatment of intestinal mucositis induced by 5-FU.

The coronavirus disease 19 (COVID-19) is caused by the highly transmissible severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has affected the global population despite socioeconomic status and amazed surveillance agencies for its incidence, mortality, and recovery rates. COVID-19 affects all age groups; however, it is suggested to progress into severe disease and cause mortality in over 10% of the confirmed cases, depending on the individual characteristics of the affected population. One of the biggest unanswered questions it is why only some individuals develop into the severe stages of the disease. Current data indicate that most of the critically ill are the elderly or those with comorbidities such as hypertension, diabetes, and asthma. However, it has been noted that, in some populations, severe disease is mostly observed in much younger individuals (<60-years old) with no reported underlying medical conditions. Certainly, many factors may contribute to disease severity including intrinsic host factors such as genetic variants, the expression levels of tissue proteins, among others. Considering all these aspects, this review aims to discuss how the expression levels of tissue proteases and the different profiles of immune responses influence the susceptibility to COVID-19 as well as disease severity and outcome.

Background: Inflammatory bowel diseases, such as ulcerative colitis and Crohn’s disease, affect the gastrointestinal tract. Treatment aims to induce remission and relieve symptoms but may fail or cause side effects. Recent studies suggest that natural polysaccharides can reduce inflammation and promote healing. The polysaccharides of the pulp of tamarillo (Solanum betaceum cav.) have shown beneficial effects, but their potential in colitis is still unexplored. Objective: To investigate the effect of polysaccharides from tamarillo pulp in an animal model of ulcerative colitis. Methods: Polysaccharides from tamarillo pulp (STWA) were extracted and tested in female mice (BALB/c) to investigate their effect on dextran sodium sulfate (DSS)-induced ulcerative colitis. Different doses of the polysaccharides were tested (10 mg/kg, 30 mg/kg, and 100 mg/kg). The course of the disease and the weight of the animals were monitored daily. At the end of the experimental protocol, the large intestine was removed and measured. Markers of oxidative stress and inflammation were then analyzed. Histological analysis was performed to assess microscopic changes. Results: Treatment with STWA (100 mg/kg) prevented weight loss in mice with DSS-induced colitis and reduced the disease activity index. The colon length was preserved, and occult blood in the feces was reduced. Treatment with STWA controlled oxidative stress. Glutathione S-transferase (GST) levels increased, while lipid peroxidation decreased. The inflammatory process was reduced, as indicated by the decrease in myeloperoxidase (MPO), N-acetylglucosamine (NAG), and tumor necrosis factor alpha (TNF-α) levels and the increase in interleukin 10 (IL-10) levels. STWA also improved the colon histology, while preserving the colonic epithelium. Conclusions: The results suggest that STWA has protective potential and reduces inflammation in an experimental model of ulcerative colitis in mice.

Background: Ganoderma lucidum is a medicinal mushroom widely recognized for its high content of bioactive polysaccharides, particularly β-glucans with immunomodulatory properties. This study aimed to optimize polysaccharide extraction conditions to maximize yield and glucan content, and to evaluate the biological activity of the obtained fractions in an experimental model of intestinal mucositis. Methods: Polysaccharides were extracted using a combination of hot-water extraction and ethanol precipitation, optimized by response surface methodology. Optimal conditions (121 °C for 120 min followed by 90% ethanol precipitation) yielded a crude polysaccharide fraction (Poli-GL). A subsequent freeze–thaw process generated a soluble fraction (S-Poli-GL). Structural and compositional characterization was performed using enzymatic assays, monosaccharide profiling, and NMR spectroscopy. The biological effects of Poli-GL and S-Poli-GL were evaluated in a 5-fluorouracil-induced intestinal mucositis model following oral administration at doses of 30, 100, and 300 mg/kg. Results: The optimized extraction protocol enabled efficient recovery of polysaccharides enriched in glucans. S-Poli-GL exhibited a high total glucan content, including 43.3% β-glucans and 3.45% α-glucans, along with minor amounts of galactose and mannose. Structural analysis confirmed the predominance of branched β-(1→3),(1→6)-D-glucans. While Poli-GL did not prevent mucositis development, S-Poli-GL significantly reduced the disease activity index and attenuated intestinal inflammation, indicating enhanced biological activity associated with the soluble glucan-rich fraction. Conclusions: Optimization of extraction and fractionation improves the functional properties of G. lucidum polysaccharides. The soluble glucan-enriched fraction (S-Poli-GL) demonstrated significant protective effects in intestinal mucositis, supporting its potential as a therapeutic candidate and warranting further investigation for clinical application.