RESUMO
A lack of control over blood loss can have catastrophic implications, including death. Although several hemostatic medications have been employed to reduce bleeding, a vast majority of them are ineffective, expensive, or pose health risks to the patient. To overcome these constraints, chitosan-polyethylene glycol (CS-PEG) hemostatic gels loaded with ethanolic extract of Jatropha mollissima sap (EES) were prepared and their hemostatic, physicochemical, and cytotoxic properties were evaluated. The gels were produced by mixing CS with PEG (an external plasticizer) and EES. The phytochemical analysis revealed a significant concentration of total polyphenols and tannins content in the extract and catechin was identified as one of the key compounds of EES. Infrared spectroscopy analysis revealed the presence of EES in the gels, as well as the chemical interaction between CS and PEG. The gels were thermally stable between 25 and 37 °C (ambient and human body temperature range), had pseudoplastic deformation behavior (rheological properties preserved after shearing), were simple to inject (compression force 30 N), and were biocompatible. In vivo experiments showed that both CS-PEG-EES gels exhibited greater hemostatic action in preventing tail hemorrhage in Wistar rats, with decreased bleeding time and blood weight compared with unloaded CS-PEG gels (control groups) and Hemostank, a commercial product. However, the gel prepared with acetic acid was more efficient in controlling bleeding. These findings reveal that CS-PEG-EES gels can reduce hemorrhages and are a potent, simple, and safe hemostatic agent.
RESUMO
This study used metalloproteomic techniques to characterize mercury (Hg)-bound proteins in the muscle and liver tissue of Tucunaré (Cichla spp.) collected at the Jirau Hydroelectric Power Plant in Madeira River Basin, Brazil. The proteome of the muscle and liver tissue was obtained after two steps of fractional precipitation and separating the proteins by 2-D polyacrylamide gel electrophoresis. Hg was identified and quantified in the protein spots by graphite furnace atomic absorption spectrometry after acid mineralization in an ultrasound bath. Hg with a molecular weight <20 kDa and a concentration between 13.30 and 33.40 mg g(-1) was found in the protein spots. These protein spots were characterized by electrospray ionization tandem mass spectrometry after trypsin digestion. From a total of 12 analyzed spots, seven proteins showing Hg biomarker characteristics were identified: parvalbumin and its isoforms, ubiquitin-40S ribosomal protein S27a, zinc (Zn) finger and BTB domain-containing protein 24, and dual-specificity protein phosphatase 22-B.