Polysacharide of Agaricus blazei gel mitigates bone necrosis in model of the jaws related to bisphosphonate via Wnt signaling.

To investigate de effect of PAb gel on the bone tissue of rats submitted to Bisphosphonate-related osteonecrosis of the jaws (BRONJ). Initially, 54 animals were submitted to BRONJ model by Zoledronic Acid (ZA) (0.1 mg/kg 3x/wk for 9 wk, ip), followed by the 1st upper left molar extraction at the 8th wk. After tooth removal, the animals were divided into 3 groups, ZA that received placebo gel or PAb gel that received 1% PAb gel, inside the dental alveolus. The control Group (CONTROL) received 0.1 mg/kg of 0.9% saline and then placebo gel. Three weeks after tooth extraction, the animals were euthanized, and maxillae were colleted for macroscopic, radiographic, histological and Raman spectomery assays. Additionally, GSK3b, beta-catenin, and Runx2 mRNA expressions were determined. Blood samples were collected for the analysis of Bone-specific alkaline phosphatase (BALP) levels. PAb gel improved mucosal healing, increased the number of viable osteocytes, while it reduced the number of empty lacunae, as well as the amount of bone sequestration. Furthermore, PAb gel positively influenced the number and functionality of osteoblasts by stimulating Wnt signaling, thereby inducing bone remodeling. Additionally, PAb gel contributed to improved bone quality, as evidenced by an increase in bone mineral content, a decrease in bone solubility, and an enhancement in the quality of collagen, particularly type I collagen. PAb gel mitigated bone necrosis by stimulating of bone remodeling through Wnt signaling and concurrently improved bone quality. PAb gel emerges as a promising pharmacological tool for aiding in BRONJ therapy or potentially preventing the development of BRONJ.

Chenopodium Ambrosioides Linn Mitigates Bone Loss in Rats with Periodontitis.

Statement of the Problem: Periodontitis is an inflammatory disease that causes bone loss. Some patients do not respond well to the classic treatment and need therapies that minimize bone loss, the main sequel of the disease. Chenopodium ambrosioides L. has stood out due to its anti-inflammatory and anti-oxidative activities. However, no study has yet investigated its effect on periodontitis. Purpose: This study aimed to evaluate the bone protective effect of Chenopodium ambrosioides L. (CAL) extract on ligature-induced periodontitis model in rats. Materials and Method: For this, a pre-clinical assay was performed, using male Wistar rats divided into 3 groups: Naive (N) (n=6), not submitted to any procedure; Saline (SAL) (n=6), submitted to ligature-induced periodontitis and receiving 2 ml/kg of 0.9% saline solution; and CAL extract, which was subdivided into 3 subgroups (n=6/subgroup) receiving the CAL at 3 (CAL3), 10 (CAL10) or 30 mg/kg (CAL30). All agents were given, by oral gavage, 30 min before periodontitis induction and daily until euthanasia (11th day). By then, maxillae were removed for macroscopic, histological, and histometric analyses. Kidneys, liver, and stomach were collected to evaluate the safety of CAL extract. High-performance liquid chromatography (HPLC) assay was used to investigate the flavonoid content in the extract. Results: Chenopodium ambrosioides L. extract at 30mg/kg showed a reduction by 58% in bone loss marked by an increase (+35%) in the number of osteoblasts and a reduction (-51%) on the number of osteoclasts (p< 0.05). No significant alteration in the liver, kidney, or stomach was seen. Rutin was the main flavonoid found. Conclusion: In summary, it was observed that Chenopodium ambrosioides L. extract has shown important anti-inflammatory and bone anabolic and anti-resorptive properties without causing toxicity in the main organs. Rutin, as the main flavonoid of the extract, seems to be responsible for the beneficial effect of this agent.

Mu and Kappa opioid receptor immunolabeling indicates the prognosis of oropharyngeal squamous cell carcinoma: A cross-sectional observational study.

BACKGROUND: Opioids are the most effective drugs currently available for cancer pain management. The administration of morphine, in addition to its analgesic effect, can alter tumor development. OBJECTIVE: To characterize the immunoexpression of opioid receptors µ and κ in oropharyngeal squamous cell carcinoma, and correlate it with prognostic factors, proliferation markers, and cell death. MATERIALS AND METHODS: A retrospective, cross-sectional observational study was carried out with 50 patients diagnosed at Haroldo Juaçaba Hospital. Sociodemographic, clinicopathological, and overall survival data were collected, and excisional biopsies were taken for immunohistochemistry using tissue microarrays for opioid receptors µ and κ, Ki-67, and caspase-3. Immunolabeling was evaluated and correlated with other variables using Mann-Whitney, Kruskal-Wallis, Spearman correlation, log-rank (Mantel-Cox), and Cox regression tests. RESULTS: Immunoexpression of opioid receptors µ and κ, Ki-67, and caspase-3 was significantly higher in p16+ and p16- primary tumors and lymph node metastases than in surgical resection margins. The overall survival of patients with p16- tumors was 57.53 ± 8.43 months and that of patients with p16+ tumors was slightly higher at 75.92 ± 11.14 months. Multivariate analysis showed that the expression of opioid receptors µ and κ in the nucleus was directly associated with a lower and higher risk of death, respectively. CONCLUSION: We found increased expression of opioid receptors µ and κ in tumor tissues. The nuclear expression of opioid receptors µ and κ influences overall survival and may be a prognostic factor of oropharyngeal squamous cell carcinoma.

Agaricus blazei Murill polysaccharides/alginate/poly(vinyl alcohol) blend as dressings for wound healing.

Macromolecules with antioxidant properties such as polysaccharides from Agaricus blazei Murill mushroom (PAbs) are an excellent option for manufacturing wound dressings. Based on this, this study aimed to analyze preparation, physicochemical characterization, and assessment of the potential wound-healing activity of films based on sodium alginate and polyvinyl alcohol loaded with PAbs. PAbs did not significantly alter the cell viability of human neutrophils in a concentration range of 1-100 µg mL-1. The Infrared Spectroscopy (FTIR) indicates that the components present in the films (PAbs/Sodium Alginate (SA)/Polyvinyl Alcohol (PVA)) present an increase in hydrogen bonds due to the increase of hydroxyls present in the components. Thermogravimetry (TGA), Differential Scanning Calorimetry (DSC) and X-ray Diffraction (XRD) characterizations indicate a good miscibility between the components where PAbs increasing the amorphous characteristics of the films and that the addition of SA increased the mobility of the chains PVA polymers. The addition of PAbs to films significantly improves properties such as mechanical, thickness, and water vapor permeation. The morphological study evidenced good miscibility between the polymers. The wound healing evaluation indicated that F100 film presented better results from the fourth day onward compared to the other groups. It favored the formation of a thicker dermis (476.8 ± 18.99 µm), with greater collagen deposition and a significant reduction in malondialdehyde and nitrite/nitrate, markers of oxidative stress. These results indicate that PAbs is a candidate for wound dressing.

The beneficial effects of Lacticaseibacillus casei on the small intestine and colon of Swiss mice against the deleterious effects of 5-fluorouracil.

Background: Intestinal mucositis is one of the most common and important side effects of 5-fluorouracil (5-FU). Currently, there are still no specific and effective protocols for its prevention and treatment. The aim of the present study was to evaluate the effect of oral administration of Lacticaseibacillus casei (L. casei) on the progression of 5-FU-induced intestinal mucositis. Methods: L. casei (1x109 CFU/ml) or saline was orally administered to Swiss mice, beginning 15 days before intestinal mucositis induction by single intraperitoneal 5-FU administration (450 mg/kg). Body weight, number of peripheral leukocytes and fecal lactic acid bacteria were monitored. After euthanasia, on day 18, tissue samples from colon and each small intestine segment were collected for histopathology. Jejunal tissues were collected and evaluated for iNOS and TNF-alpha immunoexpression, IL-1-beta, IL-6 and TNF-alpha levels, malonaldehyde (MDA) accumulation, invertase activity and factor nuclear kappa B (NFkB-P65) gene expression, toll like receptor-4 (TLR-4), mucin-2 (MUC-2), occludin and zonula occludens-1 (ZO-1). Results: The positive impact of L. casei on 5-FU-induced leukopenia was observed, but not on 5-FU-induced weight loss in mice. L. casei reduced 5-FU-induced inflammation in the colon and small intestine (p<0.05). Decreased TNF-α, IL-1ß, IL-6 (p<0.05) and MDA (p<0.05) levels, as well as decreased iNOS and TNF-alpha protein expressions (p<0.05) were found in the jejunum from L casei group. In addition, L-casei down-regulated NFKB-P65 (p<0.05) and TLR-4 (p<0.05) gene expressions and up-regulated MUC-2 and mucosal barrier proteins occludin and ZO-1 gene expressions (p<0.05). Furthermore, greater lactic acid bacteria population (p<0.05) was found in the L. casei group when compared to control groups. Conclusion: Oral L. casei administration can protect the intestine of Swiss mice from 5-FU-induced intestinal mucositis, thus contributing to overall health.

Role of Pannexin-1-P2X7R signaling on cell death and pro-inflammatory mediator expression induced by Clostridioides difficile toxins in enteric glia.

Clostridioides difficile (C. difficile) produces toxins A (TcdA) and B (TcdB), both associated with intestinal damage and diarrhea. Pannexin-1 (Panx1) channels allows the passage of messenger molecules, such as adenosine triphosphate (ATP), which in turn activate the P2X7 receptors (P2X7R) that regulate inflammation and cell death in inflammatory bowel diseases. The aim of this study was to verify the effect of C. difficile infection (CDI) in the expression of Panx1 and P2X7R in intestinal tissues of mice, as well as their role in cell death and IL-6 expression induced by TcdA and TcdB in enteric glial cells (EGCs). Male C57BL/6 mice (8 weeks of age) were infected with C. difficile VPI10463, and the control group received only vehicle per gavage. After three days post-infection (p.i.), cecum and colon samples were collected to evaluate the expression of Panx1 by immunohistochemistry. In vitro, EGCs (PK060399egfr) were challenged with TcdA or TcdB, in the presence or absence of the Panx1 inhibitor (10Panx trifluoroacetate) or P2X7R antagonist (A438079), and Panx1 and P2X7R expression, caspase-3/7 activity and phosphatidylserine binding to annexin-V, as well as IL-6 expression were assessed. CDI increased the levels of Panx1 in cecum and colon of mice compared to the control group. Panx1 inhibitor decreased caspase-3/7 activity and phosphatidylserine-annexin-V binding, but not IL-6 gene expression in TcdA and TcdB-challenged EGCs. P2X7 receptor antagonist accentually reduced caspase-3/7 activity, phosphatidylserine-annexin-V binding, and IL-6 gene expression in TcdA and TcdB-challenged EGCs. In conclusion, Panx1 is increased during CDI and plays an important role in the effects of C. difficile toxins in EGCs, participating in cell death induced by both toxins by promoting caspase-3/7 activation via P2X7R, which is also involved in IL-6 expression induced by both toxins.

Milk kefir therapy improves the skeletal response to resistance exercise in rats submitted to glucocorticoid-induced osteoporosis.

Glucocorticoid-induced osteoporosis (GIO) has emerged as a challenge after long-term glucocorticoids (GCs) administration. Exercise has been an important non-pharmacological option, while medications modulate bone remodeling despite adverse effects. In this way, milk Kefir (MK) therapy stands out as a safe alternative to improve bone metabolism. Our study aimed to investigate the effect of MK associated to resistance exercise on bone loss in rats with GIO. For this, sixty male Wistar rats were divided into 2 groups: normal (N) and subjected to GIO, which was subdivided into 4 groups: control (C), milk kefir therapy (K), Exercise (Ex), and Exercise+K (ExK). GIO was induced by dexamethasone (7 mg/kg - i.m.; 1×/wk, 5 wk). MK was administered daily (1×/day; 0.7 ml/animal) and the climb exercise with load was performed 3×/wk; both for 16 wk. Femur was collected for assessment of bone microarchitecture, quality and metabolism. GIO markedly reduced trabecular bone volume density (BV/TV) (-35 %), trabecular thickness (Tb.Th) (-33 %), mineral content of femur (-26 %) as well as bone collagen content (-56 %). Bone strength and its biomechanical properties given by flexural strength (-81 %), fracture load (-80 %), and the number of osteocytes (-84 %) were lowered after GIO. GCs reduced osteoblast number and function while increased osteoclast number, altering bone remodeling (p < 0.05). On the other hand, ExK significantly improved bone microarchitecture and quality, marked by fractal dimension increase (+38 %), cortical volume (+34 %), BV/TV (+34 %), Tb.Th (+33 %), mineral content and collagen maturity, while reduced the space between trabecula (-34 %). The Ex and ExK increased the number of osteocytes (p < 0.05) and they were able to reverse the lower osteoblast number. Both treatments used alone significantly enhanced bone biomechanical properties, but the ExK showed a more significant improvement. ExK ameliorated bone strength and biomechanics (p < 0.05) and stimulated bone formation and modulated bone remodeling (p < 0.05). MK and exercise administered isolated or in association increased the percentage of collagen bone filling after GIO (p < 0.05), but only ExK improved collagen maturity. Our results showed that MK associated to resistance exercise enhanced bone microarchitecture, quality and metabolism, being therefore an interesting tool to improve skeletal response during GIO.

Therapeutic effects of a lipid transfer protein isolated from Morinda citrifolia L. (noni) seeds on irinotecan-induced intestinal mucositis in mice.

This work aimed to evaluate the activity of a lipid transfer protein isolated from Morinda citrifolia L. seeds, McLTP1, on the development of intestinal mucositis following irinotecan administration. McLTP1 (0.5, 2, and 8 mg/kg, i.v.) was injected into mice 1h before irinotecan administration (75 mg/kg, i.p.; 4 days), and then for additional 6 days. Seven days after the first dose of irinotecan, diarrhea was assessed, and the intestine was removed for histological evaluation, assessment of intestinal over-contractility, measurement of myeloperoxidase (MPO), proinflammatory cytokines and chemokine (IL-1, IL-6, and KC levels - a murine homolog of human IL-8 chemokine), analysis of cyclooxygenase 2 (COX-2), nuclear factor kappa B (NF-κB), and nitric oxide synthase (iNOS) expression. At the two highest doses, McLTP1 administration decreased mortality and diarrhea. McLTP1 (8 mg/kg, i.v.) significantly prevented irinotecan-induced intestinal damage and led to a reduction in over-contractility of the intestinal muscle (p < 0.05). Moreover, McLTP1 decreased the MPO, IL-1ß, IL-6, and KC levels by 74.7%, 42%, 92.9%, and 95.9%, respectively. Also, the expression of COX-2, NF-κB, and iNOS was reduced. Our study provides a potential new therapeutic for preventing irinotecan-induced mucositis, improved clinical parameters, and reduced inflammation.

Host and Clostridioides difficile-Response Modulated by Micronutrients and Glutamine: An Overview.

Changes in intestinal microbiota are integral to development of Clostridioides difficile (C. difficile)-associated nosocomial diarrhea. Certain diets, especially Western diets, increase susceptibility to C. difficile infection (CDI). Here, we discuss recent findings regarding how nutrients modulate response of the host and C. difficile during infection. Calcium has a role in the sporulation and germination process. Selenium is effective in reducing the total amount of C. difficile toxin A (TcdA) and toxin B (TcdB) and in decreasing its cytotoxicity. In addition, selenium phosphate synthetase deficiency reduces C. difficile growth and spore production. On the other hand, iron has a dual role in C. difficile growth. For instance, high intracellular levels can generate reactive hydroxyl radicals, whereas low levels can reduce its growth. In humans, zinc deficiency appears to be related to the recurrence of CDI, in contrast, in the CDI model in mice a diet rich in zinc increased the toxin's activity. Low vitamin D levels contribute to C. difficile colonization, toxin production, and inflammation. Furthermore, glutamine appears to protect intestinal epithelial cells from the deleterious effects of TcdA and TcdB. In conclusion, nutrients play an important role in modulating host and pathogen response. However, further studies are needed to better understand the mechanisms and address some controversies.

Successful Pre-Clinical Management of Irinotecan-Debilitated Animals: A Protein- Based Accessory Phytomedicine.

BACKGROUND: Calotropis procera is a laticiferous plant (Apocynaceae) found in tropical regions all over the world. The ultrastructural characteristics of laticifers, their restricted distribution among different taxonomic groups, and in some species in each clade, as peptidases from latex, make them very attractive for biological analysis. OBJECTIVE: The study aims to investigate the effects of LP-PII-IAA (laticifer protein (LP) sub-fraction II (PII) of C. procera presenting an iodoacetamide-inhibited cysteine proteinase activity) on irinotecan-induced intestinal mucositis, a serious adverse effect of this medicine for the treatment of cancer. METHODS: LP-PII-IAA is composed of closely related isoforms (90%) of peptidases derived from catalysis and an osmotin protein (5%). Animals receiving co-administration of LP-PII-IAA presented a significant decrease in mortality, absence of diarrhea, histological preservation, and normalization of intestinal functions. RESULTS: Clinical homeostasis was accompanied by a reduction in MPO activity and declined levels of IL-1ß, IL-6 and KC, while the IL-10 level increased in LP-PII-IAA-treated animals. COX-2 and NF-kB immunostaining was reduced and the levels of oxidative markers (GSH, MDA) were normalized in animals that received LP-PII-IAA. CONCLUSION: We suggest that peptidases from the latex of Calotropis procera were instrumental in the suppression of the adverse clinical and physiological effects of irinotecan.

Improved microvascular reactivity after aged garlic extract intake is not mediated by hydrogen sulfide in older adults at risk for cardiovascular disease: a randomized clinical trial.

PURPOSE: This study aimed to investigate the effects of AGE on microvascular reactivity, systolic blood pressure (SBP), and diastolic blood pressure (DBP) in older individuals at high risk for cardiovascular disease (CVD). Urinary thiosulfate was also investigated as an indirect marker of endogenous hydrogen sulfide (H2S) synthesis. The study was conducted in a randomized, double-blind, crossover, and placebo-controlled way. METHODS: Twenty-eight participants (14 male), 67 ± 6 years old with CVD risk factors, ingested 2.4 g of AGE or placebo (PLA). Near-infrared spectroscopy evaluated tissue oxygen saturation (StO2) during a vascular occlusion test (30 s baseline, 5 min occlusion, and 2 min reperfusion). The upslope of StO2 signal after cuff release was calculated to measure microvascular reactivity. Urinary thiosulfate levels were measured using a high-performance liquid chromatography system. RESULTS: The upslope of StO2 was significantly faster after AGE (1.01 ± 0.37% s-1) intake compared to PLA (0.83 ± 0.35% s-1; P < 0.001; d = 0.50). Relative changes in Δ% SBP from pre- to post-AGE intake (- 5.17 ± 5.77%) was significantly different compared to Δ% PLA (0.32 ± 5.99%; P = 0.001; d = 0.93). No significant changes in urinary thiosulfate concentrations were observed between interventions. Moreover, no significant gender effect in any parameter assessed was found. CONCLUSION: This study demonstrated that a single dose of AGE improved microvascular reactivity in older adults at risk of CVD despite such an effect was not linked with urinary thiosulfate levels. This trial was registered at clinicaltrials.gov as NCT04008693 (May 19, 2020).

Comparative biofilm-forming ability between Clostridioides difficile strains isolated in Latin America and the epidemic NAP1/027 strain.

Introduction: One of the challenges in treating Clostridioides difficile infection (CDI) is that the bacterium forms biofilms, a critical virulence mechanism known to promote antibiotic resistance and, as a result, consequently, a higher recurrence of the disease. The goal of this study was to compare the ability of three MLST Clade 2 strains to form a biofilm in vitro: ICC-45 (ribotype SLO231/UK[CE]821), a ST41 toxinotype IXb isolated in Brazil; and two epidemic NAP1/027/ST01 strains: NAP1/027/ST01 (LIBA5756), isolated during a 2010 outbreak in Costa Rica and the reference epidemic strain NAP1/027/ST01 (R20291); and ATCC700057, a non-toxigenic strain. Methods: The ability of strains to form biofilm was evaluated using crystal violet staining. In addition, samples were stained with the Film Tracer biofilm matrix (Invitrogen®) and the biofilm matrix thickness was measured using confocal microscopy. The matrix architecture was determined using Scanning electron microscop. Confocal microscopy was used to detect the presence of toxin A (tcdA) using an anti-Clostridioides difficile TcdA antibody. The expression of virulence genes (tcdA, tcdB, tcdC, cdtB, spo0A, slpA, cwp66 and cwp84) was examined, as well as the effect of antibiotics metronidazole (MTZ) and vancomycin (VAN) on biofilm growth. Results: All of the strains tested formed a moderate biofilm with 1.1 3.5. After 72h, biofilm biomass of the NAP1/027/ST01 epidemic strains (LIBA5756 and R20291) was significantly higher than ICC-45 and ATCC 700057 biofilms, as confirmed by electron and confocal microscopy. At 120h, the LIBA5756 biofilm biomass decreased compared to other strains. The toxigenic strains R20291 or LIBA 5756 had higher expression of genes tcdA, tcdB, tcdC, cdtA, slpA and spo0A than ICC-45, but there were no significant differences in the expression levels of cdtB, cwp66 and cwp84. In epidemic strains, VAN and MTZ inhibited biofilm formation; however, in the ICC-45 strain, MIC concentrations of VAN and MIC and 4MIC of MTZ did not inhibit biofilm formation. Conclusion: The three MLST Clade 2 isolated from different rybotipes, two of which were isolated from Latin America, are competent biofilm-forming bacteria, indicating their ability to induce C. difficile infection recurrence, making treatment difficult.

Increased Oxidative Stress in Gastric Cancer Patients and Their First-Degree Relatives: A Prospective Study from Northeastern Brazil.

BACKGROUND AND AIMS: First-degree relatives of gastric cancer patients are at increased risk of developing gastric cancer. Increased oxidative stress, including lipid peroxidation, has been associated with gastric carcinogenesis. Whether first-degree relatives of gastric cancer patients have increased oxidative stress remains unknown. We aimed to compare oxidative stress in patients with gastric cancer, their first-degree relatives, and dyspeptic controls. METHODS: A total of 155 patients undergoing upper endoscopy were prospectively enrolled, including 50 with gastric cancer, 49 first-degree relatives of gastric cancer patients, and 56 controls. Serum concentrations of malondialdehyde (MDA) and glutathione) and activities of superoxide dismutase (SOD) and catalase were measured. Multivariate analysis adjusting for sex, age, smoking status, and alcohol consumption was performed. RESULTS: Lipid peroxidation, as measured by concentration of MDA (nmol/mL), was higher (p = 0.04), and glutathione levels were lower (p < 0.001) in the gastric cancer group compared to controls. There was no difference in the catalase activity among the groups. There was no difference in glutathione and MDA concentration or catalase activity between the different stages of gastric cancer based on the TNM classification. Relatives of gastric cancer patients had higher glutathione concentration (µmol/mL) compared to gastric cancer patients (262.5 vs. 144.6; p = 0.018), while there was no difference in MDA concentration. Catalase and superoxide dismutase activity were lower in the gastric cancer group (3.82 vs. 0.91; p < 0.001 and 1.04 vs. 0.6; p < 0.001) compared to their first-degree relatives. Interestingly, MDA concentration in the first-degree relative group was higher than in the control group (7.9 vs. 5.1; p = 0.03). CONCLUSIONS: In this study, similarly to gastric cancer patients, their first-degree relatives were found to have increased oxidative stress compared to controls. Further studies are warranted to validate this observation and to better understand the role of oxidative stress as a possible biomarker in this population.

The Receptor AT1 Appears to Be Important for the Maintenance of Bone Mass and AT2 Receptor Function in Periodontal Bone Loss Appears to Be Regulated by AT1 Receptor.

A large number of experimental studies has demonstrated that angiotensin II (Ang II) is involved in key events of the inflammatory process. This study aimed to evaluate the role of Ang II type 1 (AT1) and Ang II type 2 (AT2) receptors on periodontitis. Methods: Experimental periodontitis was induced by placing a 5.0 nylon thread ligature around the second upper left molar of AT1 mice, no-ligature or ligature (AT1-NL and AT1-L), AT2 (AT2-NL or AT2-L) and wild type (WT-NL or L). Alveolar bone loss was scanned using Micro-CT. Cytokines, peptides and enzymes were analyzed from gingival tissues by Elisa and RT-PCR. Results: The blockade of AT1 receptor resulted in bone loss, even in healthy animals. Ang II receptor blockades did not prevent linear bone loss. Ang II and Ang 1-7 levels were significantly increased in the AT2-L (p < 0.01) group compared to AT2-NL and AT1-L. The genic expression of the Mas receptor was significantly increased in WT-L and AT2-L compared to (WT-NL and AT2-NL, respectively) and in AT1-L. Conclusions: Our data suggest that the receptor AT1 appears to be important for the maintenance of bone mass. AT2 receptor molecular function in periodontitis appears to be regulated by AT1.

Losartan improves intestinal mucositis induced by 5-fluorouracil in mice.

Intestinal mucositis (IM) is a common side effect of 5-fluorouracil (5-FU)-based chemotherapy, which negatively impacts therapeutic outcomes and delays subsequent cycles of chemotherapy resulting in dose reductions and treatment discontinuation. In search of new pharmacological alternatives that minimize your symptoms, this work set out to study the effect of losartan (LOS), a receptor type I (AT1) angiotensin II antagonist, on intestinal mucositis induced by 5-FU. Intestinal mucositis was induced by a single intraperitoneal administration of 5-FU (450 mg/kg) in Swiss mice. Losartan (5, 25 or 50 mg/kg) or saline was orally administered 30 min before 5-FU and daily for 4 days. On 4th day, the animals were euthanized and segments of small intestine were collected to evaluate histopathological alterations (morphometric analysis), concentration of inflammatory cytokines, oxidative stress markers and genic expression of NF-κB p65, Fn-14 and TWEAK. Weight evaluation and changes in leukogram were also analyzed. 5-FU induced intense weight loss, leukopenia and reduction in villus height compared to saline group. Losartan (50 mg/kg) prevented 5-FU-induced inflammation by decreasing in the analyzed parameters compared to the 5-FU group. Our findings suggest that 50 mg/kg of losartan prevents the effects of 5-FU on intestinal mucosa in mice.

In vitro-in vivo availability of metformin hydrochloride-PLGA nanoparticles in diabetic rats in a periodontal disease experimental model.

CONTEXT: Metformin is an important oral anti-hyperglycemic used in diabetes. Polylactic-co-glycolic acid (PLGA) has been widely used due to its reliability in controlling the release of drugs. OBJECTIVE: This study evaluates the in vitro-in vivo availability of metformin hydrochloride-loaded polylactic-co-glycolic acid. MATERIAL AND METHODS: In vitro metformin release (Met-free or PLGA + Met-12.5 mg/mL per 360 min) was evaluated using static Franz vertical diffusion cells. The in vivo study was performed with two control groups (validation bioanalytical method) and two experimental groups of diabetic male Wistar rats treated with PLGA + Met 10 mg/kg or Met 100 mg/kg by oral gavage. Diabetes was induced by streptozotocin (40 mg/kg) through the penile vein. Blood samples were collected 0.5, 1, 4, 7, 10, 12, 18, 24, 36, 48 and 72 h and analysed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). RESULTS: PLGA + Met 10 mg/kg was released in the in vitro assay suggesting a parabolic diffusion kinetic model (K -0.0619-0.5h) with a 100% release profile in 10 h by controlled diffusion. The in vivo assay showed the apparent volume of distribution Vz/F (PLGA + Met 10 mg/kg, 40971.8 mL/kg vs. Met 100 mg/kg, 2174.58 mL/kg) and mean residence time MRTinf (PLGA + Met 10 mg/kg, 37.66 h vs. Met 100 mg/kg, 3.34 h). DISCUSSION AND CONCLUSIONS: The formulation modifies pharmacokinetics parameters such as apparent distribution volume and mean residence time. The PLGA + Met 10 mg/kg had a slower elimination rate compared to Met 100 mg/kg in diabetic rats in a periodontal disease experimental model.

AT1 and AT2 Receptor Knockout Changed Osteonectin and Bone Density in Mice in Periodontal Inflammation Experimental Model.

BACKGROUND: The aim of this study was to evaluate the role of AT1 and AT2 receptors in a periodontal inflammation experimental model. METHODS: Periodontal inflammation was induced by LPS/Porphyromonas gingivalis. Maxillae, femur, and vertebra were scanned using Micro-CT. Maxillae were analyzed histopathologically, immunohistochemically, and by RT-PCR. RESULTS: The vertebra showed decreased BMD in AT1 H compared with WT H (p < 0.05). The femur showed increased Tb.Sp for AT1 H and AT2 H, p < 0.01 and p < 0.05, respectively. The Tb.N was decreased in the vertebra (WT H-AT1 H: p < 0.05; WT H-AT2 H: p < 0.05) and in the femur (WT H-AT1 H: p < 0.01; WT H-AT2 H: p < 0.05). AT1 PD increased linear bone loss (p < 0.05) and decreased osteoblast cells (p < 0.05). RANKL immunostaining was intense for AT1 PD and WT PD (p < 0.001). OPG was intense in the WT H, WT PD, and AT2 PD when compared to AT1 PD (p < 0.001). AT1 PD showed weak immunostaining for osteocalcin compared with WT H, WT PD, and AT2 PD (p < 0.001). AT1 H showed significantly stronger immunostaining for osteonectin in fibroblasts compared to AT2 H (p < 0.01). CONCLUSION: AT1 receptor knockout changed bone density, the quality and number of bone trabeculae, decreased the number of osteoblast cells, and increased osteonectin in fibroblasts.

Suitability of the muscle O2 resaturation parameters most used for assessing reactive hyperemia: a near-infrared spectroscopy study.

BACKGROUND: There is a spectrum of possibilities for analyzing muscle O2 resaturation parameters for measurement of reactive hyperemia in microvasculature. However, there is no consensus with respect to the responsiveness of these O2 resaturation parameters for assessing reactive hyperemia. OBJECTIVES: This study investigates the responsiveness of the most utilized muscle O2 resaturation parameters to assess reactive hyperemia in the microvasculature of a clinical group known to exhibit impairments of tissue O2 saturation (StO2). METHODS: Twenty-three healthy young adults, twenty-nine healthy older adults, and thirty-five older adults at risk of cardiovascular disease (CVD) were recruited. Near-infrared spectroscopy (NIRS) was used to assess StO2 after a 5-min arterial occlusion challenge and the following parameters were analyzed: StO2slope_10s, StO2slope_30s, and StO2slope_until_baseline (upslope of StO2 over 10s and 30s and until StO2 reaches the baseline value); time to StO2baseline and time to StO2max (time taken for StO2 to reach baseline and peak values, respectively); ∆StO2reperfusion (the difference between minimum and maximum StO2 values); total area under the curve (StO2AUCt); and AUC above the baseline value (StO2AUC_above_base). RESULTS: Only StO2slope_10s was significantly slower in older adults at risk for CVD compared to healthy young individuals (p < 0.001) and to healthy older adults (p < 0.001). Conversely, time to StO2max was significantly longer in healthy young individuals than in older adult at CVD risk. CONCLUSIONS: Our findings suggest that StO2slope_10s may be a measure of reactive hyperemia, which provides clinical insight into microvascular function assessment.

CONTEXTO: Existe um espectro de possibilidades na análise dos parâmetros de ressaturação de O2 muscular como uma medida de hiperemia reativa na microvasculatura. No entanto, não há consenso com relação à responsividade desses parâmetros de ressaturação de O2 para avaliação de hiperemia reativa. OBJETIVOS: Este estudo investigou a capacidade de resposta dos parâmetros de ressaturação muscular de O2 mais utilizados para avaliar a hiperemia reativa na microvasculatura de um grupo clínico conhecido por apresentar comprometimento da saturação de O2 (StO2). MÉTODOS: Foram recrutados 23 jovens saudáveis, 29 idosos saudáveis e 35 idosos com risco para doença cardiovascular. A espectroscopia no infravermelho próximo foi usada para avaliar a StO2 após um teste de oclusão arterial de 5 minutos, no qual os seguintes parâmetros foram analisados: StO2slope_10s, StO2slope_30s e StO2slope_until_baseline (inclinação da StO2 em 10 s, 30 s e até StO2 atingir valores basais); tempo para StO2baseline e tempo para StO2máx (o tempo necessário para StO2 atingir os valores da linha de base e o máximo, respectivamente); ∆StO2reperfusão (a diferença entre o valor de StO2mínimo e StO2máximo); área total sob a curva (StO2AUCt); e área sob a curva acima do valor da linha de base (StO2AUC_above_base). RESULTADOS: Apenas StO2slope_10s foi significativamente mais lento em idosos em risco de doença cardiovascular comparados com indivíduos jovens saudáveis (p < 0,001) e idosos saudáveis (p < 0,001). Por outro lado, o tempo para StO2max foi significativamente maior em indivíduos jovens saudáveis do que em idosos em risco de doença cardiovascular. CONCLUSÕES: Nossos achados sugerem que StO2slope_10s pode ser uma medida de hiperemia reativa, que fornece informações clínicas sobre a avaliação da função microvascular.

The effect of high concentration of zoledronic acid on tooth induced movement and its repercussion on root, periodontal ligament and alveolar bone tissues in rats.

Zoledronic acid (ZA) is often prescribed for osteoporosis or resorptive metabolic bone disease. This study aims to evaluate the effect of ZA on orthodontic tooth movement (OTM) and root and bone resorption and its repercussion on root, periodontal ligament and alveolar bone tissues. The experimental group consisted of 72 Wistar rats divided in four subgroups: Naive, Saline and Zoledronic Acid groups at the concentration of 0.2 mg/kg [ZA (0.2)] or 1.0 mg/kg [ZA (1.0)]. The animals were subjected to i.v (dorsal penile vein) administrations of ZA or saline solution, on days 0, 7, 14 and 42. Under anesthesia, NiTi springs were installed in the first left maxillary molar with 50gf allowing the OTM, except for the negative control group (N) for mesial movement of the left first maxillary teeth. The animals were sacrificed and maxillae were removed for macroscopic and histopathological analyzes, scanning electron microscopy, computerized microtomography and confocal microscopy. Treatment with ZA decreased the OTM and the number of osteoclasts and loss of alveolar bone when compared to the naive and saline groups. Reduction of radicular resorption, increased necrotic areas and reduced vascularization in the periodontal ligament were observed in the ZA groups. ZA interferes with OTM and presents anti-resorptive effects on bone and dental tissues associated with a decreased vascularization, without osteonecrosis.