Benefits of flavonoid and metronidazole use after excisional hemorrhoidectomy: a randomized double-blind clinical trial.

BACKGROUND: Excisional hemorrhoidectomy remains the most effective treatment for a significant group of patients with hemorrhoids, despite the potential for postoperative pain. The purpose of this study was to evaluate the effects of flavonoid and metronidazole use in the postoperative period on patients undergoing excisional hemorrhoidectomy. METHODS: A double-blind randomized clinical study was performed. Sixty-eight patients underwent excisional hemorrhoidectomy and were randomized into 4 groups of 17 patients each to receive double-placebo (G1), metronidazole plus placebo (G2), flavonoids plus placebo (G3) or metronidazole plus flavonoids (G4) in the postoperative period. A standard analgesic protocol was offered equally for all groups. Postoperative pain, bleeding, edema, pruritus and tenesmus were evaluated during the following three periods: from immediately after the operation until postoperative day (POD)7, from POD 8 to POD 14, and from POD 15 to POD 30. The patients were required to complete symptom questionnaires and to attend postoperative follow-up on PODs 7, 14 and 30. The effect of each drug was assessed for each symptom, and the groups were compared with each other and over time. RESULTS: There was less severe pain in all postoperative periods in the groups using flavonoids (G3 and G4, both p < 0.0001), with an observed synergistic effect of flavonoids combined with metronidazole during the first 14 days after surgery (p < 0.0001). Flavonoid use was also associated with decreased bleeding (G3, p = 0.031 and G4, p = 0.016) between the first and second postoperative weeks CONCLUSIONS: The use of flavonoids alone and in combination with metronidazole resulted in a reduction of most symptoms, particularly pain, after excisional hemorrhoidectomy. TRIAL REGISTRATION: The present study was registered in the SISNEP (document CAAE-0035.0.240.000-11), after approval by the research ethics committee (CEP) of the Hospital Felício Rocho (protocol nº393 / 11).

CD73 as a target to improve temozolomide chemotherapy effect in glioblastoma preclinical model.

Glioblastoma is the most devastating primary brain tumor and effective therapies are not available. Treatment is based on surgery followed by radio and chemotherapy with temozolomide (TMZ), but TMZ increases patient survival only by 2 months. CD73, an enzyme responsible for adenosine production, emerges as a target for glioblastoma treatment. Indeed, adenosine causes tumor-promoting actions and CD73 inhibition increases sensitivity to TMZ in vitro. Here, a cationic nanoemulsion to nasal delivery of siRNA CD73 (NE-siRNA CD73) aiming glioblastoma treatment was employed alone or in combination with TMZ. In vitro, two glioblastoma cell lines (C6 and U138MG) with a chemo-resistant profile were used. Treatment alone with NE-siRNA CD73 reduced C6 and U138MG glioma cell viability by 70% and 25%, respectively. On the other hand, when NE-siRNA + TMZ combined treatment was employed, a reduction of 85% and 33% of cell viability was observed. Notably, treatment with NE-siRNA CD73 of glioma-bearing Wistar rats reduced tumor size by 80%, 60% more than the standard chemotherapy with TMZ, but no synergistic or additive effect was observed in vivo. Additionally, NE-siRNA CD73, TMZ or combined therapy decreased adenosine levels in liquor confirming the importance of this nucleoside on in vivo GB growth. Finally, no hemolytic potential was observed. These results suggest that nasal administration of NE-siRNA CD73 exhibits higher antiglioma effect when compared to TMZ. However, no synergistic or additive in vivo was promoted by the therapeutic regimen employed in this study.

Nasal Administration of Cationic Nanoemulsions as CD73-siRNA Delivery System for Glioblastoma Treatment: a New Therapeutical Approach.

Glioblastoma is the most devastating primary brain tumor. Effective therapies are not available, mainly due to high tumor heterogeneity, chemoresistance, and the difficulties imposed by blood-brain barrier. CD73, an enzyme responsible for adenosine (ADO) production, is overexpressed in cancer cells and emerges as a target for glioblastoma treatment. Indeed, ADO causes a variety of tumor-promoting actions, particularly by inducing tumor immune escape, whereas CD73 inhibition impairs tumor progression. Here, a cationic nanoemulsion to deliver CD73siRNA (NE-siRNA CD73R) via nasal route aiming glioblastoma treatment was developed. NE-siRNA CD73R was uptaken by glioma cells in culture, resulting in a parallel 60-80% decrease in AMPase activity and 30-50% in cell viability. Upon nasal delivery, NE-siRNA CD73R was detected in rat brain and serum. Notably, treatment with CD73siRNA complexes of glioma-bearing Wistar rats reduced tumor growth by 60%. Additionally, NE-siRNA CD73R treatment decreased 95% ADO levels in liquor and tumor CD73 expression, confirming in vivo CD73 silencing. Finally, no toxicity was observed in either primary astrocytes or rats with this cationic nanoemulsion. These results suggest that nasal administration of cationic NE as CD73 siRNA delivery system represents a novel potential treatment for glioblastoma. Graphical Abstract Glioblastoma is the most common and devastating form of primary brain tumor. CD73, a protein involved in cell-cell adhesion and migration processes and also responsible for extracellular adenosine (ADO) production, is overexpressed by glioma cells and emerges as an important target for glioma treatment. Indeed, ADO participates in tumor immune escape, cell proliferation, and angiogenesis, and CD73 inhibition impairs those processes. Here, a cationic nanoemulsion to deliver CD73 siRNA (NE-siRNA CD73R) via nasal route aiming glioblastoma treatment was developed. NE-siRNA CD73R knockdown in vitro and in vivo CD73. Upon nasal delivery of NE-siRNA CD73R, the treatment markedly reduced tumor volume by 60% in a rat preclinical glioblastoma model. The treatment was well tolerated, and did not induce kidney, liver, lung, olfactory, bone marrow, or behavior alterations. These results indicate that the nasal administration of NE as a CD73 siRNA delivery system offered an efficient means of gene knockdown and may represent a potential alternative for glioblastoma treatment.

CD73 Downregulation Decreases In Vitro and In Vivo Glioblastoma Growth.

Glioblastoma is the worst and most common primary brain tumor. Here, we demonstrated the role of CD73, an enzyme responsible for adenosine (ADO) production, in glioblastoma progression. ADO increased glioma cell viability via A1 receptor sensitization. CD73 downregulation decreased glioma cell migration and invasion by reducing metalloproteinase-2 and vimentin expression and reduced cell proliferation by 40%, which was related to necrosis and sub-G1 phase blockage of cell cycle. Those effects also involved the stimulation of Akt/NF-kB pathways. Additionally, CD73 knockdown or enzyme inhibition potentiated temozolomide cytotoxic effect on glioma cells by decreasing the IC50 value and sensitizing cells to a non-cytotoxic drug concentration. CD73 inhibition also decreased in vivo rat glioblastoma progression. Delivery of siRNA-CD73 or APCP reduced tumor size by 45 and 40%, respectively, when compared with control. This effect was followed by a parallel 95% reduction of ADO levels in cerebrospinal fluid, indicating the role of extracellular ADO in in vivo glioma growth. Treatment did not induce systemic damage or mortality. Altogether, we conclude that CD73 is an interesting target for glioblastoma treatment and its inhibition may provide new opportunities to improve the treatment of brain tumors. Graphical Abstract ᅟ.

Disruption of redox homeostasis and histopathological alterations caused by in vivo intrastriatal administration of D-2-hydroxyglutaric acid to young rats.

High accumulation of D-2-hydroxyglutaric acid (D-2-HG) is the biochemical hallmark of patients affected by the inherited neurometabolic disorder D-2-hydroxyglutaric aciduria (D-2-HGA). Clinically, patients present neurological symptoms and basal ganglia injury whose pathophysiology is poorly understood. We investigated the ex vivo effects of intrastriatal administration of D-2-HG on important parameters of redox status in the striatum of weaning rats. D-2-HG in vivo administration increased malondialdehyde (MDA) and carbonyl formation (lipid and protein oxidative damage, respectively), as well as the production of reactive nitrogen species (RNS). D-2-HG also compromised the antioxidant defenses by decreasing reduced glutathione (GSH) concentrations, as well as the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx). Increased amounts of oxidized glutathione (GSSG) with no significant alteration of total glutathione (tGS) were also found. Furthermore, D-2-HG-induced lipid oxidation and reduction of GSH concentrations and GPx activity were prevented by the N-methyl-d-aspartate (NMDA) receptor antagonist dizocilpine maleate (MK-801) and the nitric oxide synthase (NOS) inhibitor N(ω)-nitro-l-arginine methyl ester (l-NAME), suggesting the participation of NMDA receptors and nitric oxide derivatives in these effects. Creatine also impeded D-2-HG-elicited MDA increase, but did not change the D-2-HG-induced diminution of GSH and of the activities of SOD and GPx. We also found that DCFH oxidation and H2O2 production were not altered by D-2-HG, making unlikely an important role for reactive oxygen species (ROS) and reinforcing the participation of RNS in the oxidative damage and the reduction of antioxidant defenses provoked by this organic acid. Vacuolization, lymphocytic infiltrates and macrophages indicating brain damage were also observed in the striatum of rats injected with D-2-HG. The present data provide in vivo solid evidence that D-2-HG disrupts redox homeostasis and causes histological alterations in the rat striatum probably mediated by NMDA overstimulation and RNS production. It is therefore presumed that disturbance of redox status may contribute at least in part to the basal ganglia alterations characteristic of patients affected by D-2-HGA.

Disruption of redox homeostasis and brain damage caused in vivo by methylmalonic acid and ammonia in cerebral cortex and striatum of developing rats.

Hyperammonemia is a common finding in children with methylmalonic acidemia and propionic acidemia, but its contribution to the development of the neurological symptoms in the affected patients is poorly known. Considering that methylmalonic acid (MMA) and propionic acid (PA) predominantly accumulate in these disorders, we investigated the effects of hyperammonemia induced by urease treatment in 30-day-old rats receiving an intracerebroventricular (ICV) injection of MMA or PA on important parameters of redox homeostasis in cerebral cortex and striatum. We evaluated glutathione (GSH) concentrations, sulfhydryl content, nitrate and nitrite concentrations, 2',7'-dichlorofluorescein (DCFH) oxidation, and the activity of antioxidant enzymes. MMA decreased GSH concentrations and sulfhydryl content and increased nitrate and nitrite concentrations in cerebral cortex and striatum from hyperammonemic rats, whereas MMA or ammonia per se did not alter these parameters. MMA plus hyperammonemia also decreased glutathione reductase activity in rat cerebral cortex, but did not affect catalase, superoxide dismutase and glutathione peroxidase activities, neither DCFH oxidation. Furthermore, ICV PA administration alone or combined with hyperammonemia did not alter any of the evaluated parameters. We also found that pre-treatment with antioxidants prevented GSH reduction and sulfhydryl oxidation, whereas N(ω)-nitro-L-arginine methyl ester (L-NAME) prevented the increased nitrate and nitrite concentrations provoked by MMA plus ammonia treatments. Histological alterations, including vacuolization, ischemic neurons, and pericellular edema, were observed in brain of hyperammonemic rats injected with MMA. The data indicate a synergistic effect of MMA and ammonia disturbing redox homeostasis and causing morphological brain abnormalities in rat brain.