RESUMO
As the skin is the main protective organ of the body, it is exposed to wounds or injuries which carry out a healing process during a period of approximately 15 days depending on the severity of the injury. In the present research, the development of chitosan-based hydrogels loaded with silver nanoparticles and calendula extract (Ch-AgNPs-Ce) was proposed. This can be used to fulfill the hemostatic, anti-infective, antibacterial, healing and anti-inflammatory functions through controlled release of the nanoparticles and calendula extract in substitution of commonly used drugs. The physical properties of the silver nanoparticles were analyzed by UV-visible spectroscopy, scanning and transmission electron microscopy, showing a size between 50 and 100 nm. The antibacterial properties were evaluated by the agar well diffusion method. Antimicrobial testing of the hydrogels showed that the inclusion of silver nanoparticles provides concentration-dependent antibacterial behavior against E. coli and S. aureus. The healing properties of the system were tested in two diabetic patients to whom said hydrogels were placed, obtaining a positive curative result after a few weeks. Therefore, it can be concluded that Ch-AgNPs-Ce hydrogels can achieve healing in chronic or exposed wounds after a period of time which can be used in alternative treatments in patients with poor healing capacity.
Assuntos
Quitosana , Nanopartículas Metálicas , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Calendula , Quitosana/farmacologia , Preparações de Ação Retardada , Escherichia coli , Humanos , Hidrogéis/farmacologia , Extratos Vegetais , Prata/farmacologia , Staphylococcus aureus , CicatrizaçãoRESUMO
BACKGROUND: Karwinskia humboldtiana (Kh) is a poisonous plant of the rhamnacea family. To elucidate some of the subcellular effects of Kh toxicity, membrane fluidity and ATPase activities as hydrolytic and as proton-pumping activity were assessed in rat liver submitochondrial particles. Rats were randomly assigned into control non-treated group and groups that received 1, 1.5 and 2 g/Kg body weight of dry powder of Kh fruit, respectively. Rats were euthanized at day 1 and 7 after treatment. RESULTS: Rats under Kh treatment at all dose levels tested, does not developed any neurologic symptoms. However, we detected alterations in membrane fluidity and ATPase activity. Lower dose of Kh on day 1 after treatment induced higher mitochondrial membrane fluidity than control group. This change was strongly correlated with increased ATPase activity and pH gradient driven by ATP hydrolysis. On the other hand, membrane fluidity was hardly affected on day 7 after treatment with Kh. Surprisingly, the pH gradient driven by ATPase activity was significantly higher than controls despite an diminution of the hydrolytic activity of ATPase. CONCLUSIONS: The changes in ATPase activity and pH gradient driven by ATPase activity suggest an adaptive condition whereby the fluidity of the membrane is altered.
Assuntos
Adenosina Trifosfatases/metabolismo , Karwinskia/toxicidade , Fluidez de Membrana/efeitos dos fármacos , Mitocôndrias Hepáticas/efeitos dos fármacos , Animais , Frutas/toxicidade , Masculino , Mitocôndrias Hepáticas/enzimologia , Força Próton-Motriz/efeitos dos fármacos , Distribuição Aleatória , Ratos Sprague-Dawley , Frações Subcelulares/efeitos dos fármacos , Partículas Submitocôndricas/efeitos dos fármacosRESUMO
Multiple sclerosis (MS) exhibits many of the hallmarks of an inflammatory autoimmune disorder including breakdown of the blood-brain barrier (BBB), the recruitment of lymphocytes, microglia, and macrophages to lesion sites, the presence of multiple lesions, generally being more pronounced in the brain stem and spinal cord, the predominantly perivascular location of lesions, the temporal maturation of lesions from inflammation through demyelination, to gliosis and partial remyelination, and the presence of immunoglobulin in the central nervous system and cerebrospinal fluid. Lymphocytes activated in the periphery infiltrate the central nervous system to trigger a local immune response that ultimately damages myelin and axons. Pro-inflammatory cytokines amplify the inflammatory cascade by compromising the BBB, recruiting immune cells from the periphery, and activating resident microglia. inflammation-associated oxidative burst in activated microglia and macrophages plays an important role in the demyelination and free radical-mediated tissue injury in the pathogenesis of MS. The inflammatory environment in demyelinating lesions leads to the generation of oxygen- and nitrogen-free radicals as well as proinflammatory cytokines which contribute to the development and progression of the disease. Inflammation can lead to oxidative stress and vice versa. Thus, oxidative stress and inflammation are involved in a self-perpetuating cycle.
Assuntos
Esclerose Múltipla/imunologia , Esclerose Múltipla/metabolismo , Estresse Oxidativo , Animais , Antioxidantes/metabolismo , Citocinas/metabolismo , Humanos , Peroxidação de Lipídeos , NF-kappa B/metabolismoRESUMO
Parkinson's disease is a neurodegenerative disease whose hallmark pathological features include a selective loss of dopaminergic neurons in the midbrain. Ciclooxygenase-2 activity induction and oxidative stress have been implicated in the aetiology of Parkinson's disease and in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) animal model of Parkinson disease. Upon administration of fish oil, melatonin and vitamin E, neuroprotective effects on MPTP-induced neurotoxicity have been indicated. The aim of this study was to investigate the time course and compare the potency of these agents alone, on several parameters such as COX-2 and lipid peroxides (LPO) products associated with MPTP neurotoxicity in midbrain homogenates of C57BL/6 mice. Using fish oil (0.0368 g EPA and 0.0184 g DHA, per day), melatonin (10 mg/kg/day), and vitamin E (50 mg/Kg/day) we have now shown that COX-2 activity, LPO and nitrite/nitrate levels were significantly increased in MPTP treated mice (p < 0.001) while fish oil, melatonin and vitamin E treatment were capable of decreasing significantly the outcome of all above noted parameters (p < 0.05). The effect of fish oil on COX-2 activity and nitrite/nitrate levels was more profound than that of vitamin E or melatonin while the latter was more effective on reducing the LPO levels compared to fish oil and vitamin E. In conclusion, the outcome of the neuroprotective effects of these agents is long lasting and of variable potency indicating a different anti-inflammatory mode of action.
Assuntos
1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina/farmacologia , Ciclo-Oxigenase 2/metabolismo , Óleos de Peixe/farmacologia , Melatonina/farmacologia , Mesencéfalo/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Vitamina E/farmacologia , Animais , Peroxidação de Lipídeos/efeitos dos fármacos , Mesencéfalo/enzimologia , Camundongos , Camundongos Endogâmicos C57BLRESUMO
The current values for metabolizable energy of macronutrients were proposed in 1910. Since then, however, efforts to revise these values have been practically absent, creating a crucial need to carry out a critical analysis of the experimental methodology and results that form the basis of these values. Presented here is an exhaustive analysis of Atwater's work on this topic, showing evidence of considerable weaknesses that compromise the validity of his results. These weaknesses include the following: (1) the doubtful representativeness of Atwater's subjects, their activity patterns, and their diets; (2) the extremely short duration of the experiments; (3) the uncertainty about which fecal and urinary excretions contain the residues of each ingested food; (4) the uncertainty about whether or not the required nitrogen balance in individuals was reached during experiments; (5) the numerous experiments carried out without valid preliminary experiments; (6) the imprecision affecting Atwater's experimental measurements; and (7) the numerous assumptions and approximations, along with the lack of information, characterizing Atwater's studies. This review presents specific guidelines for establishing new experimental procedures to estimate more precise and/or more accurate values for the metabolizable energy of macronutrients. The importance of estimating these values in light of their possible dependence on certain nutritional parameters and/or physical activity patterns of individuals is emphasized. The use of more precise values would allow better management of the current overweight and obesity epidemic.
Assuntos
Metabolismo Energético , Avaliação Nutricional , Dieta , Carboidratos da Dieta/administração & dosagem , Gorduras na Dieta/administração & dosagem , Proteínas Alimentares/administração & dosagem , Proteínas Alimentares/urina , Guias como Assunto , Humanos , Modelos Teóricos , Projetos de PesquisaRESUMO
BACKGROUND: Karwinskia humboldtiana (Kh) is a poisonous plant of the rhamnacea family. To elucidate some of the subcellular effects of Kh toxicity, membrane fluidity and ATPase activities as hydrolytic and as proton-pumping activity were assessed in rat liver submitochondrial particles. Rats were randomly assigned into control non-treated group and groups that received 1,1.5 and 2 g/Kg body weight of dry powder of Kh fruit, respectively. Rats were euthanized at day 1 and 7 after treatment. RESULTS: Rats under Kh treatment at all dose levels tested, does not developed any neurologic symptoms. However, we detected alterations in membrane fluidity and ATPase activity. Lower dose of Kh on day 1 after treatment induced higher mitochondrial membrane fluidity than control group. This change was strongly correlated with increased ATPase activity and pH gradient driven by ATP hydrolysis. On the other hand, membrane fluidity was hardly affected on day 7 after treatment with Kh. Surprisingly, the pH gradient driven by ATPase activity was significantly higher than controls despite an diminution of the hydrolytic activity of ATPase. CONCLUSIONS: The changes in ATPase activity and pH gradient driven by ATPase activity suggest an adaptive condition whereby the fluidity of the membrane is altered.