Gastroprotective activity and physicochemical analysis of carboxymethylated gum from Anadenanthera colubrina.

Biotechnological advancements require the physicochemical alteration of molecules to enhance their biological efficacy for the effective treatment of gastric ulcers. The study aimed to produce a polyelectrolytic compound from red angico gum (AG) by carboxymethylation, evaluate its physicochemical characteristics and investigate gastric protection against ethanol-induced ulcers. AG and carboxymethylated angico gum (CAG) were characterized by Fourier transform infrared spectroscopy, determination of the degree of substitution and gel permeation chromatography (GPC) and 13C NMR techniques. The results demonstrated that the modification of the polymer was satisfactory, presenting conformational changes e improving the interaction with the gastric mucosa. AG and CAG reduced macroscopic and microscopic damage such as edema, hemorrhage and cell loss caused by exposure of the mucosa to alcohol. Both demonstrated antioxidant activity in vitro, and in vivo, pretreatment with gums led to the restoration of superoxide dismutase and glutathione levels compared to the injured group. Concurrently, the levels of malondialdehyde and nitrite decreased. Atomic force microscopy showed that CAG presented better conformational properties of affinity and protection with the gastric mucosa compared to AG in the acidic pH. Based on our findings, it is suggested that this compound holds promise as a prospective product for future biotechnological applications.

In vivo evaluation of bone repair guided with biological membrane based on polyhydroxybutyrate and norbixin.

The present work aimed to synthesize and verify the effectiveness of the polyhydroxybutyrate and norbixin membrane as a scaffold in bone defects induced in the tibia of rats. Twenty-four male Rattus norvegicus rats were used, divided into control and membrane groups. After anesthesia, a bone defect was induced in the right tibia, followed by the implantation of the biomaterial at the site of the lesion only in the membrane group, with euthanasia after 15 and 30 days of the experiment. The deposition of organic and inorganic matrix, the quality of newly formed bone tissue and the morphology of the bone defect were measured. After 15 days of the experiment, the biomaterial significantly influenced the deposition of hydroxyapatite crystals, the formation of collagen I matrix and mineralization content in relation to the control group, in addition to the abbreviation of the inflammatory process and superior quality of the newly formed bone tissue. After 30 days, only the membrane group had fully completed its repair process. The biomaterial acted as a scaffold in the regeneration of the guided bone defect by accelerating the synthesis of collagen matrix, mineralization content, density, and maturity when compared to the control group.

Latex proteins from Plumeria pudica reduce ligature-induced periodontitis in rats.

BACKGROUND: Previous studies have shown that latex proteins from Plumeria pudica (LPPp) have anti-inflammatory and antioxidant activity. Therefore, the aim of this study was to evaluate the effects in rats of LPPp on ligature-induced periodontitis, an inflammatory disease. METHODS: The animals were divided into groups: saline (animals without induction of periodontitis), periodontitis (induced periodontitis and untreated) and LPPp (induced periodontitis and treated with 40 mg/kg). The following parameters were evaluated after 20 consecutive days of treatment: gingival bleeding index (GBI), probing pocket depth (PPD), alveolar bone height (ABH) and gingival myeloperoxidase (MPO) activity. In the hepatic tissue, malondialdehyde (MDA), glutathione (GSH) and histopathological alterations were evaluated. Blood levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured. RESULTS: Significant reduction in GBI, PPD and gingival MPO activity and ABH was seen in animals treated with LPPp compared with periodontitis. Values of GSH, MDA, ALT and histopathological evaluation were preserved in animals treated with LPPp. CONCLUSIONS: Treatment with LPPp improved clinical aspects of periodontitis, reduced the blood and hepatic alterations and prevented alveolar bone loss. Data suggest that LPPp have potential for treatment of periodontitis.

Activation of transient receptor potential vanilloid channel 4 contributes to the development of ethanol-induced gastric injury in mice.

The transient receptor potential vanilloid channel 4 (TRPV4) is associated with the development of several pathologies, particularly gastric disorders. However, there are no studies associating this receptor with the pathophysiology of gastric erosions. The aim of this study was to investigate the role of TRPV4 in the development of ethanol-induced gastric damage in vivo. Gastric lesions were induced by ethanol in Swiss mice pretreated with TRPV4 antagonists, GSK2193874 (0.1; 0.3 and 0.9 mg/kg) or Ruthenium red (0.03; 0.1 or 0.3 mg/kg) or its agonist, GSK1016790A (0.9 mg/kg). Gastric mucosal samples were taken for histopathology, immunohistochemistry, atomic force microscopy and evaluation of antioxidant parameters. The gastric mucus content and TRPV4 mRNA expression were analyzed. Ethanol exposure induced upregulation of gastric mRNA and protein expression of TRPV4. TRPV4 blockade promoted gastroprotection against ethanol-induced injury on macro- and microscopic levels, leading to reduced hemorrhage, cell loss and edema and enhanced gastric mucosal integrity. Moreover, an increase in superoxide dismutase (SOD) and glutathione (GSH) activity was observed, followed by a decrease in malondialdehyde (MDA) levels. TRPV4 blockade during alcohol challenge reestablished gastric mucus content. The combination of TRPV4 agonist and ethanol revealed macroscopic exacerbation of gastric damage area. Our results confirmed the association of TRPV4 with the development of gastric injury, showing the importance of this receptor for further investigations in the field of gastrointestinal pathophysiology and pharmacology.

Biopolymer Extracted from Anadenanthera colubrina (Red Angico Gum) Exerts Therapeutic Potential in Mice: Antidiarrheal Activity and Safety Assessment.

Anadenanthera colubrina var. cebil (Griseb.) Altschul (Fabaceae family), commonly known as the red angico tree, is a medicinal plant found throughout Brazil's semi-arid area. In this study, a chemical analysis was performed to investigate the antidiarrheal activity and safety profile of red angico gum (RAG), a biopolymer extracted from the trunk exudate of A. colubrina. Upon FT-IR spectroscopy, RAG showed bands in the regions of 1608 cm-1, 1368 cm-1, and 1029 cm-1, which relate to the vibration of O-H water molecules, deformation vibration of C-O bands, and vibration of the polysaccharide C-O band, respectively, all of which are relevant to glycosidic bonds. The peak molar mass of RAG was 1.89 × 105 g/mol, with the zeta potential indicating electronegativity. RAG demonstrated high yield and solubility with a low degree of impurity. Pre-treatment with RAG reduced the total diarrheal stool and enteropooling. RAG also enhanced Na+/K+-ATPase activity and reduced gastrointestinal transit, and thereby inhibited intestinal smooth muscle contractions. Enzyme-Linked Immunosorbent Assay (ELISA) demonstrated that RAG can interact with GM1 receptors and can also reduce E. coli-induced diarrhea in vivo. Moreover, RAG did not induce any signs of toxicity in mice. These results suggest that RAG is a possible candidate for the treatment of diarrheal diseases.

Alendronate-induced gastric damage in normoglycemic and hyperglycemic rats is reversed by metformin.

Alendronate is a bisphosphonate widely used for the treatment of osteoporosis; however, one of its main adverse reactions is gastric ulcer. Metformin is an oral antihyperglycemic agent that has several beneficial effects, including healing, gastroprotective and anti-tumoral action. This study aimed to evaluate the gastroprotective activity of metformin in alendronate-induced gastric damage in normoglycemic and hyperglycemic rats. The treatment with 100 mg/kg of metformin showed a significant gastroprotective effect in damage induced by alendronate (50 mg/kg) in macroscopic analysis and the analysis of light microscopy and atomic force microscopy. The results suggested metformin decreased the inflammatory response by reducing the expression of proinflammatory cytokines (TNF-α, IL-1ß and IL-6), myeloperoxidase activity, and malondialdehyde levels. Also, the results suggested that metformin induces the maintenance of basal levels of collagen and increase the production of mucus. Interestingly, with the presence of the AMPK inhibitor (Compound C), metformin presented impairment of its gastroprotective action. The gastroprotective effect of metformin might be related to the activation of the AMPK pathway. These findings revealed that metformin has a gastroprotective action and may be considered a therapeutic potential for the prevention and treatment of gastric lesions induced by alendronate.

Relationship between Experimental Diet in Rats and Nonalcoholic Hepatic Disease: Review of Literature.

BACKGROUND: The pathophysiology of nonalcoholic fatty liver disease (NAFLD) is related to unhealthy lifestyles that combine sedentary lifestyle, hypercaloric diets, excessive saturated fats, refined carbohydrates, and high intake of fructose as a food additive to various processed products. Both the broader recognition of the disease and the additional efforts to elucidate the NAFLD pathogenesis have led to an increase in animal models in recent years. Objective. This review was performed to provide better understanding of the association between the NAFLD and animal models. METHODS: The search in the literature occurred before May of 2018 in the PUBMED database. RESULTS: Most studies investigating the influence of diet on liver fat content have been performed using a high-calorie diet that leads to a significant increase in fat content in the liver. CONCLUSION: The findings of this review show that diet is one of the factors that predisposes to the appearance of NAFLD and that the studies presented a wide variety of designs.

Orabase formulation with cashew gum polysaccharide decreases inflammatory and bone loss hallmarks in experimental periodontitis.

This study aimed to investigate the chemical characteristics and the effects of an orabase gel with Cashew Gum Polysaccharide (CG-P) from Anacardium occidentale L. on alveolar bone loss and relative mRNA expression of TNF-α, IL-1ß, RANK, RANKL, and OPG in the periodontal tissue of Wistar rats (Rattus norvegicus) subjected to ligature-induced periodontitis. Crude cashew gum was collected and purified by chemical processes; then, the CG-P was mixed with orabase gel. Female rats were randomly divided into four groups of six animals each: saline 0.9% (Sal Group); orabase gel (Gel Group); 50mg CG-P/1g orabase gel (CG-P50 Group) and 150mg CG-P/1g orabase gel (CG-P150 Group). Periodontitis was induced in the animals; they were treated for 20days with one daily topical application. The purification process of CG-P presented high yield and resulted in a protein-free product. The treatment with CG-P150 (150mg CG-P/1g orabase gel) significantly reduced alveolar bone loss, decreased the relative mRNA expression of TNF-α, IL-1ß, RANKL and the RANKL/OPG ratio, and caused a significant decrease in myeloperoxidase activity of the gingival tissue. Thus, the CG-P in orabase represents a potential adjuvant drug for the treatment of periodontitis and possible source of new biotechnological discoveries.

Periodontitis changes renal structures by oxidative stress and lipid peroxidation.

OBJECTIVE: The aim of this study was to investigate whether experimental periodontitis cause changes to the renal tissues and imbalance in oxidative stress in kidneys. METHODS: Twenty-two female Wistar rats were separated into two groups: control and periodontitis. We assessed the following parameters: gingival bleeding index (GBI), tooth mobility, gum malondialdehyde (MDA), myeloperoxidase (MPO) activity, probing pocket depth (PPD), alveolar bone loss (ABL) for periodontal tissues; histomorphometric measures associated with renal corpuscle and histopathological aspects (evaluation of brush border) for kidneys; as also blood and urine biomarkers. Finally, we evaluated renal oxidative stress through glutathione (GSH) and MDA respectively. RESULTS: With regard to renal histomorphometry, significant differences were observed in all parameters assessed. In relation periodic acid Schiff (PAS) staining, disruption was observed of brush border in the periodontitis group in the renal tubules in comparison with the control group. The periodontitis group presented significantly higher MDA and lower GSH concentrations in the kidneys compared with animals without periodontitis. CONCLUSION: The induced periodontitis caused histomorphometric changes in renal tissues as well as disruption of the brush border in renal tubules, alterations associated with increase in oxidative stress in kidneys. However, these alterations were not sufficient to cause differences in the renal function markers.

Anti-diarrhoeal therapeutic potential and safety assessment of sulphated polysaccharide fraction from Gracilaria intermedia seaweed in mice.

Sulphated polysaccharides extracted from algae have been extensively studied for their diverse biological activities. Thus, the purpose of this study was to evaluate the chemical composition, the anti-diarrhoeal effect and acute toxicity of a sulphated polysaccharide fraction obtained from Gracilaria intermedia (SP-Gi). Initially, the FT-IR of SP-Gi revealed to be an agaran with sulphation at C-6 of the l-galactosyl residues. The anti-diarrhoeal activity of SP-Gi was evaluated in a castor oil-induced diarrhoea model. The effects of SP-Gi on enteropooling, Na +-K +-ATPase activity, gastrointestinal transit, and gastric emptying were then examined. Subsequently, the effect of SP-Gi on diarrhoea induced by cholera toxin (CT) and Escherichia coli was examined. In addition, an acute toxicity test was conducted in accordance with OECD guideline 423. Pre-treatment with SP-Gi reduces the total faeces, total diarrhoeal faeces, and enteropooling. SP-Gi (30mg/kg p.o.) increased Na+/K+-ATPase activity and reduced gastrointestinal transit through anticholinergic mechanisms. ELISA demonstrated that SP-Gi can interact with GM1 receptors and CT. SP-Gi reduced diarrhoea induced by E. coli and prevented weight loss in the animals. Moreover, SP-Gi did not induce any toxicity signs. These results suggest that SP-Gi is a possible candidate for the treatment of diarrhoeal illnesses.

Effects of simultaneous nicotine and alcohol use in periodontitis progression in rats: A histomorphometric study.

OBJECTIVE: The aim of this study was to evaluate the effects of alcohol and nicotine, when used alone or simultaneously, on the alveolar bone loss area resulting from ligature-induced periodontitis in rats. STUDY DESIGN: Forty adult male rats received a cotton ligature in the first lower molar sulcular area, and the animals were randomly assigned to different treatments (n = 10, each group) including daily peritoneal injections of saline solution (group A), submitted to self-administration of alcohol 25% (group B), nicotine solution in concentration 0.19 µl/ml (group C), and nicotine solution in concentration 0.19 µl/ml plus self-administration of alcohol 25% (group D). Five weeks later, the animals were sacrificed, and the samples were routinely processed for semi-serial decalcified sections. RESULTS: Ligated teeth showed more alveolar bone loss than unligated ones (p < 0.05). Unligated teeth showed no significant differences between each other (p > 0.05). Analyses between the ligated teeth showed that the group C (nicotine) or group B (alcohol 25%) each had increasing alveolar bone loss in the furcation area, and the simultaneous combination alcohol and nicotine (group D) intensified these effects (p < 0.05). CONCLUSION: The results suggest that the simultaneous combination of alcohol and nicotine have a synergistic effect in the progression of periodontitis, evidenced by increased furcation region bone destruction in periodontal disease in rats. Key words:Alveolar bone loss, periodontitis, nicotine, alcohol, rats.

Semi-automatic algorithm for construction of the left ventricular area variation curve over a complete cardiac cycle.

BACKGROUND: Two-dimensional echocardiography (2D-echo) allows the evaluation of cardiac structures and their movements. A wide range of clinical diagnoses are based on the performance of the left ventricle. The evaluation of myocardial function is typically performed by manual segmentation of the ventricular cavity in a series of dynamic images. This process is laborious and operator dependent. The automatic segmentation of the left ventricle in 4-chamber long-axis images during diastole is troublesome, because of the opening of the mitral valve. METHODS: This work presents a method for segmentation of the left ventricle in dynamic 2D-echo 4-chamber long-axis images over the complete cardiac cycle. The proposed algorithm is based on classic image processing techniques, including time-averaging and wavelet-based denoising, edge enhancement filtering, morphological operations, homotopy modification, and watershed segmentation. The proposed method is semi-automatic, requiring a single user intervention for identification of the position of the mitral valve in the first temporal frame of the video sequence. Image segmentation is performed on a set of dynamic 2D-echo images collected from an examination covering two consecutive cardiac cycles. RESULTS: The proposed method is demonstrated and evaluated on twelve healthy volunteers. The results are quantitatively evaluated using four different metrics, in a comparison with contours manually segmented by a specialist, and with four alternative methods from the literature. The method's intra- and inter-operator variabilities are also evaluated. CONCLUSIONS: The proposed method allows the automatic construction of the area variation curve of the left ventricle corresponding to a complete cardiac cycle. This may potentially be used for the identification of several clinical parameters, including the area variation fraction. This parameter could potentially be used for evaluating the global systolic function of the left ventricle.

On the use of motion-based frame rejection in temporal averaging denoising for segmentation of echocardiographic image sequences.

We have recently introduced an algorithm for semi-automatic segmentation of the left ventricular wall in short-axis echocardiographic images (EMBC 30:218-221). In its preprocessing stage, the algorithm uses temporal averaging for image denoising. Motion estimation is used to detect and reject frames that do not correlate well with the set of images being averaged. However, the process of estimating motion vectors is computationally intense, which increases the algorithm's computation time. In this work, we evaluate the viability of replacing the motion estimation stage with less computationally intense approaches. Two alternative techniques are evaluated. The ventricular contours obtained from each of the three algorithm variants were quantitatively and qualitatively compared with contours manually-segmented by a specialist. We show that it is possible to reduce the algorithm's computational load without significantly reducing the segmentation quality. The proposed algorithms are also compared with three other techniques from the literature.

Semi-automatic detection of the left ventricular border.

Two semi-automatic methods for the detection of the left ventricular border in two-dimensional short axis echocardiographic images are presented and compared. In these methods, the left ventricular area variation curve is calculated during a complete cardiac cycle after the segmentation of several frames. This allows the evaluation of the cardiovascular dynamics and the identification of important clinical parameters. The algorithms are proposed as several independent modules. The results are validated through the comparison between the semi-automatic continuous boundaries and manuals boundaries sketched by a medical specialist.

Left ventricle segmentation in echocardiography using a radial-search-based image processing algorithm.

A new left ventricle segmentation method in two-dimensional echocardiography images is proposed. Image processing techniques combined with radial search and temporal information are used to extract the left ventricle boundary. Borders from sequential images are extracted using the proposed method, and a curve illustrating the area variation within a cardiac cycle is presented. Performance evaluation is performed by comparing the borders obtained from the presented method to those manually prescribed by a medical specialist. The new sequential radial search algorithm improved the border extraction from long-axis ultrasound images, specially the ones where the mitral valve was open. Segmentation errors due to low contrast were corrected.

Classification and retrieval of medical images in an integrated healthcare environment.

This work presents a new approach for classification and retrieval of echocardiographic images from textual information of the anatomical structures and diagnosis features. These textual attributes will be acquired from the electronic medical report generated in an integrated healthcare environment. The medical report is provided by a specialist in the area during the analysis of the medical image stored in a PACS environment. Such innovation guarantees a more accurate classifier and a better optimization of the medical work, since the medical report and the attributes for the medical image classifier will be created at the same time. The system is being developed in the University Hospital of the University of Brasilia.