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BACKGROUND/AIMS: Recent studies demonstrated that the treatment with mesenchymal stem cells (MSCs) obtained from the human umbilical cord blood improved survival, reduced brain damage, prevented apoptosis, suppressed inflammatory responses, downregulated the DNA damage-inducing genes, upregulated the DNA repair genes, and facilitated neurological recovery in stroke-induced animals. Emerging stroke literature supports the concept that the exosomes released from MSCs are the primary biological principles underlying the post-stroke neuroprotection offered by MSCs treatment. METHODS: Because the treatment with exosomes has a great potential to overcome the limitations associated with cell-based therapies, we tested the efficacy of exosomes secreted from HUCB-MSCs under standard culture conditions on post-stroke brain damage and neurological outcome in a rat model of ischemic stroke by performing TTC staining as well as the modified neurological severity scores, modified adhesive removal, beam-walking, and accelerating Rotarod performance tests before ischemia and at regular intervals until seven days reperfusion. RESULTS: Exosomes treatment attenuated the infarct size. Treatment with exosomes did not affect the post-stroke survival rate and body weight changes, but exacerbated the somatosensory and motor dysfunction and adversely affected the natural recovery that occurs without any treatment. CONCLUSION: Treatment with exosomes secreted from HUCB-MSCs under standard culture conditions attenuates the ischemic brain damage but does not improve the post-stroke neurological outcome.
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Encéfalo/patologia , Exossomos/transplante , Células-Tronco Mesenquimais/citologia , Acidente Vascular Cerebral/terapia , Animais , Encéfalo/fisiopatologia , Linhagem Celular , Modelos Animais de Doenças , Masculino , Atividade Motora , Ratos Sprague-Dawley , Acidente Vascular Cerebral/patologia , Acidente Vascular Cerebral/fisiopatologia , Resultado do TratamentoRESUMO
BACKGROUND/AIMS: Stem cell treatment is one of the potential treatment options for ischemic stroke. We recently demonstrated a protective effect of human umbilical cord blood-derived mesenchymal stem cells (HUCB-MSCs) in a rat model of ischemic stroke. The treatment attenuated apoptosis and prevented DNA damage. A collection of published studies, including several from our laboratory, indicated the induction and detrimental role for several matrix metalloproteinases (MMPs) in post-stroke brain injury. We hypothesized that the HUCB-MSCs treatment after focal cerebral ischemia prevents the dysregulation of MMPs and induces the expression of endogenous tissue inhibitors of metalloproteinases (TIMPs) to neutralize the elevated activity of MMPs. METHODS: To test our hypothesis, we administered HUCB-MSCs (0.25 million cells/animal and 1 million cells/animal) intravenously via tail vein to male Sprague-Dawley rats that were subjected to a transient (two-hour) right middle cerebral artery occlusion (MCAO) and one-day reperfusion. Ischemic brain tissues obtained from various groups of rats seven days after reperfusion were subjected to real-time PCR, immunoblot, and immunofluorescence analysis. RESULTS: HUCB-MSCs treatment prevented the induction of MMPs, which were upregulated in ischemia-induced rats that received no treatment. HUCB-MSCs treatment also prevented the induction of TIMPs expression. The extent of prevention of MMPs and TIMPs induction by HUCB-MSCs treatment is similar at both the doses tested. CONCLUSION: Prevention of stroke-induced MMPs upregulation after HUCB-MSCs treatment is not mediated through TIMPs upregulation.
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Metaloproteinases da Matriz/metabolismo , Transplante de Células-Tronco Mesenquimais , Acidente Vascular Cerebral/terapia , Inibidores Teciduais de Metaloproteinases/metabolismo , Animais , Modelos Animais de Doenças , Sangue Fetal/citologia , Masculino , Metaloproteinases da Matriz/genética , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Microscopia de Fluorescência , Artéria Cerebral Média/lesões , Ratos , Ratos Sprague-Dawley , Inibidores Teciduais de Metaloproteinases/genética , Regulação para Cima/efeitos dos fármacosRESUMO
Previous studies have demonstrated that endogenous tissue-type plasminogen activator (tPA) is upregulated in the brain after an acute ischemic stroke (AIS). While mixed results were observed in genetic models, the pharmacological inhibition of endogenous tPA showed beneficial effects. Treatment with exogenous recombinant tPA exacerbated brain damage in rodent models of stroke. Despite the detrimental effects of tPA in ischemic stroke, recombinant tPA is administered to AIS patients to recanalize the occluded blood vessels because the benefits of its administration outweigh the risks associated with tPA upregulation and increased activity. We hypothesized that tPA knockdown following recanalization would ameliorate sensorimotor deficits and reduce brain injury. Young male and female rats (2-3 months old) were subjected to transient focal cerebral ischemia by occlusion of the right middle cerebral artery. Shortly after reperfusion, rats from appropriate cohorts were administered a nanoparticle formulation containing tPA shRNA or control shRNA plasmids (1 mg/kg) intravenously via the tail vein. Infarct volume during acute and chronic phases, expression of matrix metalloproteinases (MMPs) 1, 3, and 9, enlargement of cerebral ventricle volume, and white matter damage were all reduced by shRNA-mediated gene silencing of tPA following reperfusion. Additionally, recovery of somatosensory and motor functions was improved. In conclusion, our results provide evidence that reducing endogenous tPA following recanalization improves functional outcomes and reduces post-stroke brain damage.
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Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Ratos , Masculino , Feminino , Animais , Lactente , Ativador de Plasminogênio Tecidual , AVC Isquêmico/tratamento farmacológico , Isquemia Encefálica/metabolismo , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/patologia , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/uso terapêutico , Fibrinolíticos/uso terapêutico , Fibrinolíticos/farmacologia , Modelos Animais de DoençasRESUMO
Tissue-type plasminogen activator (t-PA) expression is known to increase following transient focal cerebral ischemia and reperfusion. Previously, we reported downregulation of t-PA upon suppression of matrix metalloproteinase-12 (MMP-12), following transient focal cerebral ischemia and reperfusion. We now present data on the temporal expression of t-PA in the brain after transient ischemia, as well as the interaction between MMP-12 and t-PA, two proteases associated with the breakdown of the blood-brain barrier (BBB) and ischemic brain damage. We hypothesized that there might be reciprocal interactions between MMP-12 and t-PA in the brain after ischemic stroke. This hypothesis was tested using shRNA-mediated gene silencing and computational modeling. Suppression of t-PA following transient ischemia and reperfusion in rats attenuated MMP-12 expression in the brain. The overall effect of t-PA shRNA administration was to attenuate the degradation of BBB tight junction protein claudin-5, diminish BBB disruption, and reduce neuroinflammation by decreasing the expression of the microglia/macrophage pro-inflammatory M1 phenotype (CD68, iNOS, IL-1ß, and TNFα). Reduced BBB disruption and subsequent lack of infiltration of macrophages (the main source of MMP-12 in the ischemic brain) could account for the decrease in MMP-12 expression after t-PA suppression. Computational modeling of in silico protein-protein interactions indicated that MMP-12 and t-PA may interact physically. Overall, our findings demonstrate that MMP-12 and t-PA interact directly or indirectly at multiple levels in the brain following an ischemic stroke. The present findings could be useful in the development of new pharmacotherapies for the treatment of stroke.
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Isquemia Encefálica , Ataque Isquêmico Transitório , AVC Isquêmico , Metaloproteinase 12 da Matriz , Ativador de Plasminogênio Tecidual , Animais , Ratos , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Isquemia Encefálica/metabolismo , Ataque Isquêmico Transitório/metabolismo , AVC Isquêmico/metabolismo , Metaloproteinase 12 da Matriz/metabolismo , RNA Interferente Pequeno/genética , Ativador de Plasminogênio Tecidual/metabolismoRESUMO
We recently showed that the post-ischemic induction of matrix metalloproteinase-12 (MMP-12) in the brain degrades tight junction proteins, increases MMP-9 and TNFα expression, and contributes to the blood-brain barrier (BBB) disruption, apoptosis, demyelination, and infarct volume development. The objectives of this study were to (1) determine the effect of MMP-12 suppression by shRNA-mediated gene silencing on neurological/functional recovery, (2) establish the optimal timing of MMP-12shRNA treatment that provides maximum therapeutic benefit, (3) compare the effectiveness of acute versus chronic MMP-12 suppression, and (4) evaluate potential sex-related differences in treatment outcomes. Young male and female Sprague-Dawley rats were subjected to transient middle cerebral artery occlusion and reperfusion. Cohorts of rats were administered either MMP-12shRNA or scrambled shRNA sequence (control) expressing plasmids (1 mg/kg; i.v.) formulated as nanoparticles. At designated time points after reperfusion, rats from various groups were subjected to a battery of neurological tests to assess their reflex, balance, sensory, and motor functions. Suppression of MMP-12 promoted the neurological recovery of stroke-induced male and female rats, although the effect was less apparent in females. Immediate treatment after reperfusion resulted in a better recovery of sensory and motor function than delayed treatments. Chronic MMP-12 suppression neither enhanced nor diminished the therapeutic effects of acute MMP-12 suppression, indicating that a single dose of plasmid may be sufficient. We conclude that suppressing MMP-12 after an ischemic stroke is a promising therapeutic strategy for promoting the recovery of neurological function.
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BACKGROUND AND PURPOSE: The therapeutic potential of different stem cells for ischaemic stroke treatment is intriguing and somewhat controversial. Recent results from our laboratory have demonstrated the potential benefits of human umbilical cord blood-derived mesenchymal stem cells (MSC) in a rodent stroke model. We hypothesised that MSC treatment would effectively promote the recovery of sensory and motor function in both males and females, despite any apparent sex differences in post stroke brain injury. METHODS: Transient focal cerebral ischaemia was induced in adult Sprague-Dawley rats by occlusion of the middle cerebral artery. Following the procedure, male and female rats of the untreated group were euthanised 1 day after reperfusion and their brains were used to estimate the resulting infarct volume and tissue swelling. Additional groups of stroke-induced male and female rats were treated with MSC or vehicle and were subsequently subjected to a battery of standard neurological/neurobehavioral tests (Modified Neurological Severity Score assessment, adhesive tape removal, beam walk and rotarod). The tests were administered at regular intervals (at days 1, 3, 5, 7 and 14) after reperfusion to determine the time course of neurological and functional recovery after stroke. RESULTS: The infarct volume and extent of swelling of the ischaemic brain were similar in males and females. Despite similar pathological stroke lesions, the clinical manifestations of stroke were more pronounced in males than females, as indicated by the neurological scores and other tests. MSC treatment significantly improved the recovery of sensory and motor function in both sexes, and it demonstrated efficacy in both moderate stroke (females) and severe stroke (males). CONCLUSIONS: Despite sex differences in the severity of post stroke outcomes, MSC treatment promoted the recovery of sensory and motor function in male and female rats, suggesting that it may be a promising treatment for stroke.
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Isquemia Encefálica , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Acidente Vascular Cerebral , Animais , Modelos Animais de Doenças , Feminino , Masculino , Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais/patologia , Ratos , Ratos Sprague-Dawley , Acidente Vascular Cerebral/terapiaRESUMO
The intense inflammatory response triggered in the brain after focal cerebral ischemia is detrimental. Recently, we showed that the suppression of toll-like receptors (TLRs) 2 and 4 attenuates infarct size and reduces the expression of pro-inflammatory cytokines in the ischemic brain. In this study, we further examined the effect of unsuppressed induction of TLRs 2 and 4 on the expression of its downstream signaling molecules and pro-inflammatory cytokines 1 week after reperfusion. The primary purpose of this study was to investigate the effect of simultaneous knockdown of TLRs 2 and 4 on M1/M2 microglial polarization dynamics and post-stroke neurological deficits and the recovery. Transient focal cerebral ischemia was induced in young adult male Sprague-Dawley rats by the middle cerebral artery occlusion (MCAO) procedure using a monofilament suture. Appropriate cohorts of rats were treated with a nanoparticle formulation of TLR2shRNA and TLR4shRNA (T2sh+T4sh) expressing plasmids (1 mg/kg each of T2sh and T4sh) or scrambled sequence inserted vector (vehicle control) expressing plasmids (2 mg/kg) intravenously via tail vein immediately after reperfusion. Animals from various cohorts were euthanized during reperfusion, and the ischemic brain tissue was isolated and utilized for PCR followed by agarose gel electrophoresis, real-time PCR, immunoblot, and immunofluorescence analysis. Appropriate groups were subjected to a battery of standard neurological tests at regular intervals until 14 days after reperfusion. The increased expression of both TLRs 2 and 4 and their downstream signaling molecules including the pro-inflammatory cytokines was observed even at 1-week after reperfusion. T2sh+T4sh treatment immediately after reperfusion attenuated the post-ischemic inflammation, preserved the motor function, and promoted recovery of the sensory and motor functions. We conclude that the post-ischemic induction of TLRs 2 and 4 persists for at least 7 days after reperfusion, contributes to the severity of acute inflammation, and impedes neurological recovery. Unlike previous studies in TLRs 2 or 4 knockout models, results of this study in a pharmacologically relevant preclinical rodent stroke model have translational significance.
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Isquemia Encefálica , Traumatismo por Reperfusão , Acidente Vascular Cerebral , Animais , Infarto da Artéria Cerebral Média , Inflamação/etiologia , Masculino , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/tratamento farmacológicoRESUMO
Emerging stroke literature suggests that treatment of experimentally induced stroke with stem cells offered post-stroke neuroprotection via exosomes produced by these cells. Treatment with exosomes has great potential to overcome the limitations associated with cell-based therapies. However, in our preliminary studies, we noticed that the exosomes released from human umbilical cord blood-derived mesenchymal stem cells (MSCs) under standard culture conditions did not improve the post-stroke neurological outcome. Because of this apparent discrepancy, we hypothesized that exosome characteristics vary with the conditions of their production. Specifically, we suggest that the exosomes produced from the cocultures of regular and oxygen-glucose-deprived (OGD) MSCs in vitro would represent the exosomes produced from MSCs that are exposed to ischemic brain cells in vivo, and offer similar therapeutic benefits that the cell treatment would provide. We tested the efficacy of therapy with exosomes secreted from human umbilical cord blood (HUCB)-derived MSCs under in vitro hypoxic conditions on post-stroke brain damage and neurological outcome in a rat model of transient focal cerebral ischemia. We performed the TTC staining procedure as well as the neurological tests including the modified neurological severity scores (mNSS), the modified adhesive removal (sticky-tape), and the beam walking tests before ischemia and at regular intervals until 7 days reperfusion. Treatment with exosomes obtained from the cocultures of normal and OGD-induced MSCs reduced the infarct size and ipsilateral hemisphere swelling, preserved the neurological function, and facilitated the recovery of stroke-induced rats. Based on the results, we conclude that the treatment with exosomes secreted from MSCs at appropriate experimental conditions attenuates the post-stroke brain damage and improves the neurological outcome.
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Dano Encefálico Crônico/prevenção & controle , Isquemia Encefálica/terapia , Exossomos , Células-Tronco Mesenquimais/metabolismo , Traumatismo por Reperfusão/prevenção & controle , Animais , Peso Corporal , Dano Encefálico Crônico/etiologia , Dano Encefálico Crônico/patologia , Isquemia Encefálica/complicações , Hipóxia Celular , Técnicas de Cocultura , Sangue Fetal/citologia , Glucose/farmacologia , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/biossíntese , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/fisiologia , Masculino , Oxigênio/farmacologia , Equilíbrio Postural , Desempenho Psicomotor , Ratos , Traumatismo por Reperfusão/etiologia , Regulação para CimaRESUMO
The role of matrix metalloproteinase-12 (MMP-12) in the pathogenesis of several inflammatory diseases such as chronic obstructive pulmonary disease, emphysema, and asthma is well established. Several new studies and recent reports from our laboratory and others highlighted the detrimental role of MMP-12 in the pathogenesis of several neurological diseases. In this review, we discuss in detail the pathological role of MMP-12 and the possible underlying molecular mechanisms that contribute to disease pathogenesis in the context of central nervous system diseases such as stroke, spinal cord injury, and multiple sclerosis. The available information on the specific MMP-12 inhibitors used in several preclinical and clinical studies is also reviewed. Based on the reported studies to date, MMP-12 suppression could emerge as a promising therapeutic target for several CNS diseases that were discussed in this review.
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Metaloproteinase 12 da Matriz/metabolismo , Esclerose Múltipla/metabolismo , Traumatismos da Medula Espinal/metabolismo , Acidente Vascular Cerebral/metabolismo , HumanosRESUMO
Background and purpose: Recent reports from our laboratory demonstrated the post-ischaemic expression profile of various matrix metalloproteinases (MMPs) in rats and the detrimental role of MMP-12 in post-stroke brain damage. We hypothesise that the post-stroke dysregulation of MMPs is similar across species and that genetic deletion of MMP-12 would not affect the post-stroke expression of other MMPs. We tested our hypothesis by determining the pre-ischaemic and post-ischaemic expression profile of MMPs in wild-type and MMP-12 knockout mice. Methods: Focal cerebral ischaemia was induced in wild-type and MMP-12 knockout mice by middle cerebral artery occlusion procedure by insertion of a monofilament suture. One hour after ischaemia, reperfusion was initiated by removing the monofilament. One day after reperfusion, ischaemic brain tissues from various groups of mice were collected, and total RNA was isolated and subjected to cDNA synthesis followed by PCR analysis. Results: Although the post-stroke expression profile of MMPs in the ischaemic brain of mice is different from rats, there is a clear species similarity in the expression of MMP-12, which was found to be predominantly upregulated in both species. Further, the post-stroke induction or inhibition of various MMPs in MMP-12 knockout mice is different from their respective expression profile in wild-type mice. Moreover, the brain mRNA expression profile of various MMPs in MMP-12 knockout mice under normal conditions is also different to their expression in wild-type mice. Conclusions: In the ischaemic brain, MMP-12 upregulates several fold higher than any other MMP. Mice derived with the genetic deletion of MMP-12 are constitutive and have altered MMP expression profile both under normal and ischaemic conditions.
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Deleção de Genes , Infarto da Artéria Cerebral Média/enzimologia , Metaloproteinase 12 da Matriz/deficiência , RNA Mensageiro/metabolismo , Transcriptoma , Animais , Modelos Animais de Doenças , Regulação Enzimológica da Expressão Gênica , Infarto da Artéria Cerebral Média/genética , Masculino , Metaloproteinase 12 da Matriz/genética , Camundongos Endogâmicos C57BL , Camundongos Knockout , RNA Mensageiro/genética , Ratos , Especificidade da Espécie , Fatores de TempoRESUMO
Toll-like receptor 2 (TLR2) and TLR4 belong to a family of highly conserved pattern recognition receptors and are well-known upstream sensors of signaling pathways of innate immunity. TLR2 and TLR4 upregulation is thought to be associated with poor outcome in stroke patients. We currently show that transient focal ischemia in adult rats induces TLR2 and TLR4 expression within hours and shRNA-mediated knockdown of TLR2 and TLR4 alone and in combination decreases the infarct size and swelling. We further show that TLR2 and TLR4 knockdown also prevented the induction of their downstream signaling molecules MyD88, IRAK1, and NFκB p65 as well as the pro-inflammatory cytokines IL-1ß, IL-6, and TNFα. This study thus shows that attenuation of the severity of TLR2- and TLR4-mediated post-stroke inflammation ameliorates ischemic brain damage.
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Isquemia Encefálica/metabolismo , Isquemia Encefálica/terapia , Inflamação/metabolismo , Inflamação/prevenção & controle , Receptor 2 Toll-Like/genética , Receptor 4 Toll-Like/genética , Animais , Edema Encefálico/etiologia , Edema Encefálico/metabolismo , Edema Encefálico/prevenção & controle , Isquemia Encefálica/complicações , Modelos Animais de Doenças , Escherichia coli , Técnicas de Silenciamento de Genes , Inflamação/etiologia , Quinases Associadas a Receptores de Interleucina-1/metabolismo , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Masculino , Fator 88 de Diferenciação Mieloide/metabolismo , Proteínas de Neoplasias/metabolismo , Neuroproteção/fisiologia , Proteínas de Transporte Nucleocitoplasmático/metabolismo , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/administração & dosagem , Distribuição Aleatória , Ratos Sprague-Dawley , Fator de Necrose Tumoral alfa/metabolismoRESUMO
BACKGROUND: To date, anti-obesity agents based on natural products are tested for their potential using lipase inhibition assay through the interference of hydrolysis of fat by lipase resulting in reduced fat absorption without altering the central mechanisms. Previous screening study had indicated strong anti-obesity potential in Eleusine indica (E. indica), but to date, no pharmacologic studies have been reported so far. OBJECTIVE: This study was performed to investigate the lipid-lowering effects of E. indica using both in vitro and in vivo models. METHODS: The crude methanolic extract of E. indica was fractionated using hexane (H-Ei), dichloromethane (DCM-Ei), ethyl acetate (EA-Ei), butanol (B-Ei), and water (W-Ei). All the extracts were tested for antilipase activity using porcine pancreatic lipase. Because H-Ei showed the highest inhibition, it was further subjected to chemical profiling using high-performance liquid chromatography. Subsequently, oral toxicity analysis of H-Ei was performed [Organization for Economic Cooperation and Development guidelines using fixed dose procedure (No. 420)]; efficacy analysis was performed using high-fat diet (HFD)-induced hyperlipidemic female Sprague-Dawley rats. RESULTS: According to the toxicity and efficacy analyses, H-Ei did not demonstrate any noticeable biochemical toxicity or physiologic abnormalities and did not cause any tissue damage as per histologic analysis. Furthermore, H-Ei significantly reduced body weight and improved serum profile and did not show hepatotoxicity and nephrotoxicity based on the serum profile. Moreover, H-Ei alleviated HFD-induced hepatosteatosis and ameliorated induced adiposity in both visceral and subcutaneous adipose tissue. CONCLUSION: Our results demonstrate that H-Ei effectively improved hyperlipidemia. Further studies to explore its possibility as an alternative pharmacologic agent to treat obesity are warranted. SUMMARY: Hexane extract of Eleusine indica (H-Ei) showed strong potential in the inhibition of porcine pancreatic lipase (27.01 ± 5.68%).The acute oral toxicity of E. indica hexane extract on animal model falls into Globally Harmonized System Category 5 (low hazard), since mortality, clinical toxicity symptoms, gross pathologic, or histopathologic damage was not observed.The hexane extract of E. indica had significantly reduced the body weight and improved serum lipid profile, with reduction in serum triglycerides, total cholesterol, low-density lipoprotein, and elevation in high-density lipoprotein when comparing against the high-fat diet control group.Microscopic evaluation on histologic slides of liver and adipose tissues suggested that E. indica hexane extract had greatly improved liver steatosis and adipose tissue hypertrophy in high-fat diet control group. Abbreviation used: ALT: Alanine transaminase; AST: Aspartate transaminase; B-Ei: Butanol extract of E. indica; DCM-Ei: Dichloromethane extract of E. indica; EA-Ei: Ethyl acetate extract of E. indica; GHS: Globally Harmonized System; HDL: High-density lipoprotein; H-Ei: Hexane extract of E. indica; HFD: High-fat diet; HPLC: High-performance liquid chromatography; LDL: Low-density lipoprotein; NFD: Normal fed diet; PPL: Porcine pancreatic lipase; SEM: Standard error of mean; SD: Standard deviation; TC: Total cholesterol; TG: Triglycerides; W-Ei: Water extract of E. indica.
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BACKGROUND: Terminalia chebula (Combretaceae) has been widely used in Ayurveda for the treatment of diabetes. In the present investigation, the chloroform extract of T. chebula seed powder was investigated for its antidiabetic activity in streptozotocin-induced diabetic rats using short term and long term study protocols. The efficacy of the extract was also evaluated for protection of renal functions in diabetic rats. METHODS: The blood glucose lowering activity of the chloroform extract was determined in streptozotocin-induced (75 mg/kg, i.p.; dissolved in 0.1 M acetate buffer; pH 4.5) diabetic rats, after oral administration at the doses of 100, 200 and 300 mg/kg in short term study. Blood samples were collected from the eye retro-orbital plexus of rats before and also at 0.5, 1, 2, 4, 6, 8 and 12 h after drug administration and the samples were analyzed for blood glucose by using glucose-oxidase/peroxidase method using a visible spectrophotometer. In long term study, the extract (300 mg/kg) was administered to streptozotocin-induced diabetic rats, daily for 8 weeks. Blood glucose was measured at weekly intervals for 4 weeks. Urine samples were collected before the induction of diabetes and at the end of 8 weeks of treatments and analyzed for urinary protein, albumin and creatinine levels. The data was compared statistically using one-way ANOVA with post-hoc Dunnet's t-test. RESULTS: The chloroform extract of T. chebula seeds produced dose-dependent reduction in blood glucose of diabetic rats and comparable with that of standard drug, glibenclamide in short term study. It also produced significant reduction in blood glucose in long term study. Significant renoprotective activity is observed in T. chebula treated rats. The results indicate a prolonged action in reduction of blood glucose by T. chebula and is probably mediated through enhanced secretion of insulin from the beta-cells of Langerhans or through extra pancreatic mechanism. The probable mechanism of potent renoprotective actions of T. chebula has to be evaluated. CONCLUSION: The present studies clearly indicated a significant antidiabetic and renoprotective effects with the chloroform extract of T. chebula and lend support for its traditional usage. Further investigations on identification of the active principles and their mode of action are needed to unravel the molecular mechanisms involved in the observed effects.
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Diabetes Mellitus Experimental/tratamento farmacológico , Fitoterapia/métodos , Sementes , Terminalia , Animais , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Clorofórmio , Diabetes Mellitus Experimental/sangue , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Glibureto/uso terapêutico , Hipoglicemiantes/uso terapêutico , Rim/efeitos dos fármacos , Masculino , Extratos Vegetais/uso terapêutico , Ratos , Ratos Sprague-Dawley , Estreptozocina , Resultado do TratamentoRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Blechnum orientale Linn. (B. orientale) is a fern traditionally used by the natives as a poultice to treat wounds, boils, ulcers, blisters, abscesses, and sores on the skin. AIM OF THE STUDY: To investigate the wound healing ability of a concentrated extract of B. orientale in a hydrogel formulation in healing diabetic ulcer wounds. MATERIALS AND METHODS: The water extract from the leaves of B. orientale was separated from the crude methanolic extract and subjected to flash column chromatography techniques to produce concentrated fractions. These fractions were tested for phytochemical composition, tannin content, antioxidative and antibacterial activity. The bioactive fraction was formulated into a sodium carboxymethylcellulose hydrogel. The extract-loaded hydrogels were then characterized and tested on excision ulcer wounds of streptozotocin-induced diabetic rats. Wound size was measured for 14 days. Histopathological studies were conducted on the healed wound tissues to observe for epithelisation, fibroblast proliferation and angiogenesis. All possible mean values were subjected to statistical analysis using One-way ANOVA and post-hoc with Tukey's T-test (P<0.05). RESULTS: One fraction exhibited strong antioxidative and antibacterial activity. The fraction was also highly saturated with tannins, particularly condensed tannins. Fraction W5-1 exhibited stronger antioxidant activity compared to three standards (α-Tocopherol, BHT and Trolox-C). Antibacterial activity was also present, and notably bactericidal towards Methicillin-resistant Staphylococcus aureus (MRSA) at 0.25mg/ml. The extract-loaded hydrogels exhibited shear-thinning properties, with high moisture retention ability. The bioactive fraction at 4% w/w was shown to be able to close diabetic wounds by Day 12 on average. Other groups, including controls, only exhibited wound closure by Day 14 (or not at all). Histopathological studies had also shown that extract-treated wounds exhibited re-epithelisation, higher fibroblast proliferation, collagen synthesis, and angiogenesis. CONCLUSION: The ethnopharmacological effects of using B. orientale as a topical treatment for external wounds was validated and was also significantly effective in treating diabetic ulcer wounds. Thus, B. orientale extract hydrogel may be presented as a potential treatment for diabetic ulcer wounds.
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Antibacterianos/farmacologia , Antioxidantes/farmacologia , Angiopatias Diabéticas/tratamento farmacológico , Gleiquênias/química , Extratos Vegetais/farmacologia , Pele/efeitos dos fármacos , Taninos/farmacologia , Úlcera/tratamento farmacológico , Cicatrização/efeitos dos fármacos , Animais , Antibacterianos/isolamento & purificação , Antioxidantes/isolamento & purificação , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Compostos de Bifenilo/química , Proliferação de Células/efeitos dos fármacos , Colágeno/metabolismo , Diabetes Mellitus Experimental/induzido quimicamente , Angiopatias Diabéticas/etiologia , Angiopatias Diabéticas/metabolismo , Angiopatias Diabéticas/patologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fibroblastos/patologia , Hidrogéis , Hidroxiprolina/metabolismo , Masculino , Testes de Sensibilidade Microbiana , Neovascularização Fisiológica/efeitos dos fármacos , Fitoterapia , Picratos/química , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química , Plantas Medicinais , Ratos Sprague-Dawley , Reepitelização/efeitos dos fármacos , Pele/metabolismo , Pele/patologia , Estreptozocina , Taninos/isolamento & purificação , Fatores de Tempo , Úlcera/etiologia , Úlcera/metabolismo , Úlcera/patologiaRESUMO
The aim of this study is to determine the anti-inflammatory activity of a new sphingosine derivative (1) and cembrenoid diterpene (lobohedleolide) (2) isolated from the soft corals of Sinularia crassa and Lobophytum species respectively, collected on the coasts of Andaman and Nicobar Islands. The anti-inflammatory activity was evaluated using carrageenin-induced rat hind paw edema model for acute inflammation and cotton pellet granuloma model for chronic inflammation. Indomethacin was used as a standard drug in this study. Both the sphingosine derivative (1) and the cembrenoid diterpene (2) produced the maximum effect at a dose of 10 mg/kg and this is comparable to that of indomethacin (2 mg/kg, p<0.001). The observed anti-inflammatory activity is almost identical in both the types of experimental inflammation.