CPW partially attenuates DSS-induced ulcerative colitis in mice

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) of the gastrointestinal tract. The etiology is not fully understood, but environmental, microbial, and immunologic factors, as well as a genetic predisposition, play a role. UC is characterized by episodes of abdominal pain, diarrhea, bloody stools, weight loss, severe colonic inflammation, and ulceration. Despite the increase in the frequency of UC and the deterioration of the quality of life, there are still patients who do not respond well to available treatment options. Against this background, natural products such as polysaccharides are becoming increasingly important as they protect the intestinal mucosa, promote wound healing, relieve inflammation and pain, and restore intestinal motility. In this study, we investigated the effect of a polysaccharide isolated from the biomass of Campomanesia adamantium and Campomanesia pubescens (here referred to as CPW) in an experimental model of acute and chronic ulcerative colitis induced by dextran sulfate sodium (DSS). CPW reversed weight loss, increased disease activity index (DAI), bloody diarrhea, and colon shortening. In addition, CPW reduced visceral mechanical hypersensitivity, controlled oxidative stress and inflammation, and protected the mucosal barrier. CPW is not absorbed in the intestine, does not inhibit cytochrome P450 proteins, and does not exhibit AMES toxicity. These results suggest that CPW attenuates DSS-induced acute and chronic colitis in mice and may be a potential alternative treatment for UC.

Polysaccharides from Passion Fruit Peels: From an Agroindustrial By-Product to a Viable Option for 5-FU-Induced Intestinal Damage

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.

Rodent models for anticancer toxicity studies: contributions to drug development and future perspectives

Antineoplastic treatment induces a type of gastrointestinal toxicity known as mucositis. Findings in animal models are usually easily reproducible, and standardized treatment regimens are often used, thus supporting translational science. Essential characteristics of mucositis, including intestinal permeability, inflammation, immune and oxidative responses, and tissue repair mechanisms, can be easily investigated in these models. Given the effects of mucositis on the quality of life of patients with cancer, and the importance of experimental models in the development of more effective new therapeutic alternatives, this review discusses progress and current challenges in using experimental models of mucositis in translational pharmacology research. Teaser Experimental models for studying gastrointestinal mucositis have provided a wealth of information improving the understanding of antineoplastic toxicity.

Polysaccharide Fraction from Campomanesia adamantium and Campomanesia pubescens Attenuates 5-Fluorouracil-Induced Intestinal Mucosal Inflammation in Mice

Gastrointestinal toxicity, including diarrhea and inflammation, is commonly observed with the use of 5-fluorouracil (5-FU). Several studies have shown that polysaccharides are interesting bioactive macromolecules for the treatment or prevention of gastrointestinal diseases. Therefore, in this study, the effect of a polysaccharide fraction from a mixture of two Guavira species (Campomanesia adamantium and Campomanesia pubescens), referred to here as CPW, on the development of intestinal mucositis was investigated. Intestinal mucositis was induced by a single injection of 5-FU (450 mg/kg), and various doses of CPW (3-100 mg/kg) were tested. CPW attenuated disease development and prevented small bowel dysmotility and colon shortening. CPW prevented the increase in villi width, crypt depth, and mucosal thickness in the duodenum, but not in the colon. Preservation of mucus, reduction of oxidative stress, inflammation, and prevention of the 5-FU-induced enlargement and swelling of the spleen were observed. In conclusion, this study demonstrated for the first time that CPW alleviates the intestinal damage induced by 5-FU and could be used as an adjuvant strategy during chemotherapy.

An overview of the gut side of the SARS-CoV-2 infection

In late 2019, an outbreak of pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) initiated in Wuhan, Hubei province, China. The major clinical symptoms described for coronavirus disease (COVID-19) include respiratory distress and pneumonia in severe cases, and some patients may experience gastrointestinal impairments. In accordance, viral RNA or live infectious virus have been detected in feces of patients with COVID-19. Binding of SARS-CoV-2 to the angiotensin-converting enzyme 2 (ACE2) is a vital pathway for the virus entry into human cells, including those of the respiratory mucosa, esophageal epithelium as well as the absorptive enterocytes from ileum and colon. The interaction between SARS-CoV-2 and ACE2 receptor may decrease the receptor expression and disrupt the function of B0AT1 transporter influencing the diarrhea observed in COVID-19 patients. In this context, a fecal-oral transmission route has been considered and points out a role for the digestive tract in disease transmission and severity. Here, in order to further understand the impact of COVID-19 in human physiology, the cellular and molecular mechanisms of SARS-CoV-2 infection and disease severity are discussed in the context of gastrointestinal disturbances.

Polysaccharides with Antitumor Effect in Breast Cancer: A Systematic Review of Non-Clinical Studies

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.

Susceptibility to SARS-CoV-2 infection in patients undergoing chemotherapy and radiation therapy

The outbreak of the new coronavirus disease (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has rapidly become a public health emergency of international concern, especially affecting the elderly people and patients with chronic disease, such as hypertension and respiratory syndromes. Patients undergoing chemotherapy treatment (e.g., bleomycin, cyclophosphamide, methotrexate, monoclonal antibodies, and paclitaxel therapy) are vulnerable to the development of respiratory syndromes induced by chemotherapeutic agents and are also more susceptible to viral infections as they are immunosuppressed. Neutropenia is an important risk factor for increased vulnerability to infections, as a respiratory syndrome involves an array of immune cells maintaining the balance between pathogen clearance and immunopathology. However, the differential diagnosis of pulmonary symptoms in cancer patients is broad, with complications being related to the malignancy itself, treatment toxicity, and infections. The risk factors depend on the specific type of cancer, chemotherapy, patient characteristics, and comorbidities. Thus, this review discusses the main events implicated in immunosuppression caused by chemotherapy and radiation therapy and the association of immunosuppression and other factors with SARS-CoV-2 infection susceptibility in cancer patients; and, importantly, how to deal with this situation in face of the current pandemic scenario.

The GLP-1 analog liraglutide attenuates acute liver injury in mice

INTRODUCTION AND OBJECTIVES

Acute liver injury is a current health problem with few effective treatments. The present study investigated the hepatoprotective and curative potential of the glucagon-like peptide-1 analog liraglutide against carbon tetrachloride (CCl₄)-induced hepatotoxicity.

MATERIALS AND METHODS

Male Swiss mice were subjected to two protocols. The first protocol (Pretreatment) consisted of intraperitoneal (i.p.) treatment with liraglutide (0.057 and 0.118mgkg^-1) or vehicle (distilled water) once daily for 7 days. On days 6 and 7, the animals were challenged with 2% CCl₄ (5mgkg^-1, i.p.). The second protocol (Late treatment) began with an injection of 5% CCl₄ (5mgkg^-1, i.p.) and subsequent treatment with liraglutide (0.057mgkg^-1) or vehicle (distilled water) for 1 day. In both protocols, 24h after the last administration, blood and bile were collected from anesthetized animals, followed by euthanasia and liver collection. Plasma and bile underwent biochemical analyses, and histological, oxidative stress, and metabolic parameters were evaluated in the liver.

RESULTS

Both liraglutide treatment protocols attenuated hepatotoxicity that was induced by CCl₄, decreasing plasma levels of hepatic enzymes, stimulating the hepatic antioxidant system, and decreasing centrilobular necrosis, hepatic glycogen, and lipid accumulation. CCl₄ tended to reduce bile lipid excretion, but liraglutide did not influence this parameter.

CONCLUSIONS

The present results demonstrated the hepatoprotective and therapeutic effects of liraglutide, which may be attributable to a decrease in liver oxidative stress and the preservation of metabolism. Liraglutide may have potential as a complementary therapy for acute liver injury.

Evidence of a Role for the TRPC Subfamily in Mediating Oxidative Stress in Parkinson's Disease

Parkinson's disease (PD) represents one of the most common multifactorial neurodegenerative disorders affecting the elderly population. It is associated with the aggregation of α-synuclein protein and the loss of dopaminergic neurons in the substantia nigra pars compacta of the brain. The disease is mainly represented by motor symptoms, such as resting tremors, postural instability, rigidity, and bradykinesia, that develop slowly over time. Parkinson's disease can also manifest as disturbances in non-motor functions. Although the pathology of PD has not yet been fully understood, it has been suggested that the disruption of the cellular redox status may contribute to cellular oxidative stress and, thus, to cell death. The generation of reactive oxygen species and reactive nitrogen intermediates, as well as the dysfunction of dopamine metabolism, play important roles in the degeneration of dopaminergic neurons. In this context, the transient receptor potential channel canonical (TRPC) sub-family plays an important role in neuronal degeneration. Additionally, PD gene products, including DJ-1, SNCA, UCH-L1, PINK-1, and Parkin, also interfere with mitochondrial function leading to reactive oxygen species production and dopaminergic neuronal vulnerability to oxidative stress. Herein, we discuss the interplay between these various biochemical and molecular events that ultimately lead to dopaminergic signaling disruption, highlighting the recently identified roles of TRPC in PD.