The neuroprotective effects of AF4, a flavonoid-enriched extract derived from the peel of Northern Spy apples (containing quercetin-3-O-glucoside, quercetin-3-O-galactoside, quercetin-3-O-rhamnoside, quercetin-3-O-rutinoside, epicatechin, and cyanidin-3-O-galactoside) were examined by assessing neuronal loss and motor impairment resulting from hypoxic-ischemic (HI) brain injury in adult C57BL/6 mice. Relative to vehicle treatment (water, 10mL/kg/day), oral administration of AF4 (50 mg/kg/day) for 3 days reduces HI-induced neuronal loss in the striatum and hippocampus, motor impairments, and reduces the ability of LPS to stimulate the production of TNF-alpha in whole blood. Pretreatment with AF4 (1 ug/mL) decreased the death of mouse primary cortical neurons subjected to oxygen glucose deprivation (12 hours) in comparison to vehicle (DMSO) or the same concentration of quercetin or its metabolites. Taken together these findings indicate that AF4 reduces HI-induced brain injury and motor deficits by increasing the resistance of vulnerable neurons to ischemic cell death and decreasing the production of inflammatory cytokines.

The neuroprotective effects of AF4, a flavonoid-enriched extract derived from the peel of Northern Spy apples (containing quercetin-3-O-glucoside, quercetin-3-O-galactoside, quercetin-3-O-rhamnoside, quercetin-3-O-rutinoside, epicatechin, and cyanidin-3-O-galactoside) were examined by assessing neuronal loss and motor impairment resulting from hypoxic-ischemic (HI) brain injury in adult C57BL/6 mice. Relative to vehicle treatment (water, 10mL/kg/day), oral administration of AF4 (50 mg/kg/day) for 3 days reduces HI-induced neuronal loss in the striatum and hippocampus, motor impairments, and reduces the ability of LPS to stimulate the production of TNF-alpha in whole blood. Pretreatment with AF4 (1 ug/mL) decreased the death of mouse primary cortical neurons subjected to oxygen glucose deprivation (12 hours) in comparison to vehicle (DMSO) or the same concentration of quercetin or its metabolites. Taken together these findings indicate that AF4 reduces HI-induced brain injury and motor deficits by increasing the resistance of vulnerable neurons to ischemic cell death and decreasing the production of inflammatory cytokines.

The primary treatment options for head and neck cancer are radiation therapy or surgery, or both combined; chemotherapy is often used as an additional, or adjuvant, treatment. Patients treated with radiotherapy are exposed to a high cumulative dose of radiation over a period of time and there is a 17-33% chance of recurrence. High cumulative doses of radiation, a long time course of treatment, side effects and the possibility of recurrence provide the rationale for developing approaches for radiation sensitization, which could be helpful to patients in decreasing the dose, duration of radiation, side effects, or the chance of recurrence. Radiation induces autophagy, which is a catabolic process involving the degradation of the cell’s own components to generate energy under conditions of stress. Autophagy can be cytoprotective helping the cell to survive during stress such as nutrient deprivation or it can be cytotoxic, leading the cell toward death. We investigated whether blocking autophagy by the use of the antimalarial drug, chloroquine, could sensitize head and neck cancer cells to radiation. Studies were performed using the HN30 human head and neck cancer line (p53 wild type) derived from the pharynx as well as HN6 human cells (p53 mutant) derived from the base of the tongue. Cell viability was determined by cell counting and clonogenic survival assays, autophagy was monitored based on acridine orange staining accompanied by flow cytometry, while western blotting, DAPI and TUNEL staining and PI/annexin/FACS were utilized for determination and quantification of apoptosis. Senescence was monitored by beta-galactosidase staining/ FACS analysis. Radiation alone produced a transient growth arrest followed by proliferative recovery in both the HN30 and HN6 cancer cells. Radiation also promoted autophagy in both cell lines. The combination of chloroquine with radiation inhibited autophagy and promoted apoptotic cell death and suppression of proliferative recovery for the HN30 cells, but had little effect on sensitivity to radiation and proliferative recovery in the HN6 cells. The data suggest that autophagy induced by radiation serves a protective function in the HN30 cells and that a blockade to autophagy by chloroquine drives the cell toward apoptosis and death. In contrast, autophagy in HN6 cells appears to be non-protective as a pharmacological blockade did not sensitize the HN6 cells to radiation. These studies support the premise that autophagy induction by radiation need not necessarily have a cytoprotective function and further indicates that caution should be exercised in efforts to sensitize head and neck cancer to radiation through the clinical suppression of autophagy.

Indiana University-Purdue University Indianapolis (IUPUI) / The Keap1-Nrf2 pathway regulates a wide range of cytoprotective genes, and has been found to serve a protective and beneficial role in many body systems. There is limited information available, however, about its role in bone homeostasis. While Nrf2 activation has been suggested as an effective method of increasing bone mass and quality, there have been conflicting reports which associate Keap1 deficiency with detrimental phenotypes. As Keap1 deletion is a common method of Nrf2 activation, further study should address the impacts of various methods of regulating Nrf2 expression. Also, little research has been conducted on the specific pathways by which Nrf2 activation improves bone quality. In this study, the effects of alterations to Nrf2 activation levels were explored in two specific and varied scenarios. In the first experiment, moderate Nrf2 activation was achieved via partial deletion of its sequestering protein, Keap1, in an aging mouse model. The hypothesis tested here is that moderate Nrf2 activation improves bone quality by affecting bone metabolism and response to mechanical loading. The results of this first experiment suggest a subtle, sex-specific effect of moderate Nrf2 activation in aging mice which improves specific indices of bone quality to varying degrees, but does not affect loading-induced bone formation. It is likely that the overwhelming phenotypic impacts associated with aging or the systemic effects of global Keap1 deficiency may increase the difficulty in parsing out significant effects that can be attributed solely to Nrf2 activation. In the second experiment, a cell-specific knockout of Nrf2 in the osteocytes was achieved using a Cre/Lox breeding system. The hypothesis tested here is that osteocyte-specific deletion of Nrf2 impairs bone quality by affecting bone metabolism and response to mechanical loading. The results of this experiment suggest an important role of Nrf2 in osteocyte function which improves certain indices of bone quality, which impacts male and female bones in different 7 ways, but did not significantly impact loading-induced bone formation. Further studies should modify the method of Nrf2 activation in an effort to refine the animal model, allowing the effects of Nrf2 to be isolated from the potential systemic effects of Keap1 deletion. Future studies should also utilize other conditional knockout models to elucidate the effects of Nrf2 in other specific cell types.

In general, ionizing radiation promotes cytoprotective autophagy in a majority of breast tumor cells. Previous studies from our laboratory indicated that radiation (5x2 Gy) induces cytoprotective autophagy in MCF-7 cells. In the current work, inhibition of autophagy by silencing of Beclin-1 in MCF-7 cells resulted in an increase in sensitivity to radiation based both on cell number and clonogenic survival; however, there was no increase in apoptosis and the basis for this sensitization is currently under investigation. Unexpectedly, enhancement of autophagy by silencing of Bcl-2 also led to an increase in sensitivity to radiation, possibly through the conversion of cytoprotective to cytostatic autophagy. In contrast to the MCF-7 cells, radiation (5x2 Gy) induces non-protective autophagy in Hs578t cells. Interference with autophagy through silencing of Beclin-1 or induction of Bcl-2 did not alter radiation sensitivity in the Hs578t cells. Since the induction of cytoprotective autophagy can represent an impediment to radiation therapy, it is important to understand the types of autophagy that occur in response to radiation in specific cellular settings and whether interference with autophagy can increase sensitivity to different forms of cancer treatment.

Submitted by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2016-02-04T16:39:34Z No. of bitstreams: 1 Ana Paula Amaral de Brito Efeito... 2015.pdf: 1294909 bytes, checksum: 78c71eb987dd6a713939584ccdf4650a (MD5) / Approved for entry into archive by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2016-02-04T16:39:50Z (GMT) No. of bitstreams: 1 Ana Paula Amaral de Brito Efeito... 2015.pdf: 1294909 bytes, checksum: 78c71eb987dd6a713939584ccdf4650a (MD5) / Made available in DSpace on 2016-02-04T16:39:50Z (GMT). No. of bitstreams: 1 Ana Paula Amaral de Brito Efeito... 2015.pdf: 1294909 bytes, checksum: 78c71eb987dd6a713939584ccdf4650a (MD5) Previous issue date: 2015 / Fundação Oswaldo Cruz, Centro de Pesquisas Gonçalo Moniz. Salvador, BA, Brasil / Universidade Federal da Bahia, Faculdade de Medicina. Salvador, BA, Brasil / Os astrócitos são o tipo celular mais numeroso no sistema nervoso central (SNC). Eles exercem suporte estrutural, trófico, e metabólico para neurônios e modulam a atividade sináptica. Então, o prejuízo nestas funções dos astrócitos pode influenciar na sobrevivência dos neurônios. De fato, numerosas evidências têm descrito a influência dos astrócitos no desenvolvimento de uma variedade de doenças neurodegenerativas. Neurotoxinas ambientais como rotenona, um inibidor específico do complexo I mitocondrial, provêem modelos de doenças neurodegenerativas tanto in vivo quanto in vitro. Sendo assim, a busca de novas substâncias com atividade neuroprotetora é atualmente o foco de estudos, e uma tendência crescente tem sido direcionada para plantas medicinais. Neste trabalho investigou-se a influência do extrato aquoso de Valeriana officinalis (V. officinalis) e da rotenona sobre os aspectos eletrofisiológicos do funcionamento cerebral, e o efeito citoprotetor dos extratos com éter de petróleo (PE) e metanol (MeOH) de V. Officinalis contra a toxicidade induzida pela rotenona. O estudo adotou uma abordagem que associa técnicas químicas, celulares e eletrofisiológicas. Ratos machos albinos, Wistar, adultos, em condições normais de nutrição, foram divididos em: grupo valeriana, tratados, por gavagem, com extrato aquoso de valeriana (250 mg/kg/dias) durante 15 dias; grupo rotenona, tratados, por via subcutânea, com rotenona (10 mg/kg) durante 7 dias; grupo valeriana + rotenona, submetidos a ambos tratamentos. Os respectivos controles foram igualmente tratados com solução salina ou solução de 1% de Tween-80 em água. Após o período de tratamento, os animais foram anestesiados, submetidos à trepanação seguida do registro da depressão alastrante cortical (DAC), na superfície do córtex cerebral, por 4 horas. Para avaliação da citoxicidade da rotenona e da atividade citoprotetora dos extratos de V. officinalis foram realizadas análises de viabilidade celular através da redução do brometo de 3-(4,5-dimetiltiazol-2-il)-2,5-difeniltetrazolium (MTT) e visualização por microscopia de contraste de fase em células de glioma murino (C6) e humano (GL-15), além de astrócitos de rato como controle de células normais. Os animais tratados com rotenona apresentaram redução da velocidade de propagação DAC enquanto que os animais tratados com valeriana apresentaram um aumento da velocidade de propagação. No entanto, os animais tratados com rotenona e valeriana não apresentaram diferença estatística na velocidade de propagação da DAC quando comparado aos grupos controles. Os resultados demonstraram que a rotenona foi citotóxica nas linhagens testadas, reduzindo a viabilidade e alterando a morfologia celular de maneira dose-dependente. Os extratos de PE e MeOH de V. officinalis foram efetivos em aumentar a viabilidade celular, bem como reduzir as alterações morfológicas induzidas pela rotenona nas linhagens celulares testadas. A análise do RMN 1H dos extratos de V. Officinalis demonstrou a presença de substâncias terpenoides; esse resultado relaciona os efeitos de V. Officinalis a ação antioxidante. O extrato aquoso de V. Officinalis preveniu as alterações eletrofisiológicas induzidas pela rotenona. Os resultados corroboram com estudos pregressos que descrevem os extratos de V. officinalis com função citoprotetora, deixando esse composto muito mais próximo de testes que venham a confirmar sua efetividade em diversas modalidades terapêuticas. / Astrocytes are the most numerous cell type in the central nervous system (CNS). They provide structural, trophic and metabolic support to neurons, and they modulate synaptic activity. Accordingly, impairment in these astrocyte functions can critically influence neuron survival. Indeed, several evidences have presented the influence of astrocytes for the development of a variety of neurodegenerative disorders. Environmental neurotoxins such as rotenone, a specific inhibitor of mitochondrial complex I that generates reactive oxygen species (ROS), provide models of neurodegenerative disorders both in vivo and in vitro. Thus, the search for new substances with neuroprotective activity is currently the focus of studies, and a growing trend has been directed at medicinal plants. In this study, we investigated the influence of of Valeriana officinalis (V. officinalis) and rotenone in the brain function through neurophysiological aspects, and the citoprotective effect of petroleum ether (PE) and methanol (MeOH) extracts of V. officinalis against rotenone-induced toxicity. The study adopted an approach that combines chemical, cellular and eletrophisiological techniques. Wistar male rats (adults), in normal conditions of nutrition, were divided in: valerian group, treated by gavage, for 15 days, with 250 mg/kg/day of the aqueous extract of V. officinalis; rotenone group, treated with s.c. injections at the daily dose of 10 mg/kg for 7 days; rotenone + valerian group treated with both substances. The control groups were treated equally with saline solution or 1% Tween-80 solution in water. After the treatment period, the cortical spreading depression (CSD) was recorded for 4 h at 2 cortical points in the parietal region. In order to investigate the rotenone-induced citotoxicity and the antioxidant activity of V. officinalis extracts, cell viability assays were performed through the reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and visualization by phase contrast microscopy in rat glioma C6 cells and human glioblastoma GL-15 cells, as well as in rat astrocytes for comparison. The rotenone treated-animals presented lower mean CSD velocities, whereas CSD velocities were higher in the valerian-treated animals. When compared to the control animals, the treatment with rotenone plus valerian revealed no significant difference. The results demonstrated that rotenone was cytotoxic in the cell lines tested, reducing the cell viability and changing the cell morphology in a dose-dependent manner. The PE and MeOH extracts of V. officinalis were effective in increase cell ciability and reduce the rotenone-induced morphological changes in the tested cell lines. The 1H NMR analysis of V. Officinalis extracts showed the presence of terpenoid substances; this result relates the effects of V. Officinalis antioxidant action. The results corroborate previous studies describing the V. officinalis extracts with cytoprotective function, leaving the compound much closer to tests that will confirm their effectiveness in various therapeutic modalities

Submitted by Cristhiane Guerra (cristhiane.guerra@gmail.com) on 2017-02-01T13:21:44Z No. of bitstreams: 1 arquivototal.pdf: 3972647 bytes, checksum: f6010ee1fd045c2fe490f404bbb4d37e (MD5) / Made available in DSpace on 2017-02-01T13:21:44Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 3972647 bytes, checksum: f6010ee1fd045c2fe490f404bbb4d37e (MD5) Previous issue date: 2016-02-26 / Cissampelos sympodialis Eichl. (Menispermaceae) is an endemic species in Brazil, popularly known as "Milona", "Jarrinha" or "Orelha-de-onça". This species was selected for this study considering the chemotaxonomic (alkaloids and flavonoids) and ethnopharmacological criteria, due to this species be popularly used to treat inflammatory disorders. This study aimed to evaluate the acute preclinical toxicity and anti-ulcer activity of the ethanolic extract (EtOHE-Cs) and alkaloids total fraction (TAF-Cs) obtained from aerial parts of C. sympodialis. In acute toxicity, doses of 300 and 2000 mg/kg EtOHE-Cs were administered orally (p.o.). Our experiment conditions shows that, this type of doses did not induce signs of toxicity in female mice and 50% of lethal dose (LD50) is equal to or greater 5000 mg/kg according to the OECD 423 guide. For TAF-Cs was founded that the animals treated with the dose of 2000 mg/kg showed straub tail and analgesia. In addition, the LD50 of this substance being approximately 1000 mg/kg. To evaluate the gastroprotective activity using induced acute models of gastric ulcers were used: ethanol and containment of gastric juice in rats, anti-inflammatory non-steroidal drug (NSAID - piroxicam) and stress (immobilization and cold) in mice. In ulcer model induced by ethanol the results showed that carbenoxolone (100 mg/kg), EtOHE-Cs or TAF-Cs (62.5; 125; 250 and 500 mg/kg – v.o.) reduced the ulcerative lesion area (ULA) of 97, 69, 75, 94, 98; 97, 88, 90, 94, 95% (p<0,001) respectively in comparison with the negative control. In the same model, treatment with carbenoxolone (100 mg/kg), EtOHE-Cs (500 mg/kg) or TAF-Cs (250 mg/kg) improved histological parameters analyzed. Considering ulcers induced by NSAIDs, cimetidine (100 mg/kg), the EtOHE-Cs or TAF-Cs (62.5; 125; 250 and 500 mg/kg – p.o.) reduced the ulcerative lesion index (ULI) in 43, 59, 60, 64, 76; 47, 51, 62, 75 and 78% (p<0,001), respectively. In the lesions induced by stress cimetidine, EtOHE-Cs or TAF-Cs at the same doses reduced ULI at 44, 37, 38, 42, 52; 57, 39, 54, 75 and 76% (p<0,001), respectively. Ulcers induced by restraining of the gastric juice (pylorus ligation) treated with cimetidine (100 mg/kg), EtOHE-Cs (500 mg/kg) and TAF-Cs (250 mg/kg) decreased the ULI at 35, 42 and 40 % (p.o.) (p<0,001) and 39, 34 and 33% (intraduodenally – i.d.) (p<0,01), respectively. To investigate the mechanisms of samples of C. sympodialis involved in gastroprotective activity it was evaluated the antisecretory or neutralizing mechanisms of the gastric acid secretion and cytoprotective, antioxidant and immunoregulatory properties. Treatments (p.o. and i.d.) with EtOHE-Cs (500 mg/kg) and TAF-Cs (250 mg/kg) did not alter biochemical parameters of gastric juice, suggesting that gastroprotective activity does not involve antisecretory or neutralizing mechanisms. The gastroprotective activity of EtOHE-Cs (500 mg/kg) involves participation of sulfhydryl groups, nitric oxide, KATP, mucus and prostaglandins. The gastroprotection promoted by the TAF-Cs (250 mg/kg) involves the participation of sulfhydryl groups, mucus and prostaglandins. EtOHE-Cs (500 mg/kg) (p<0,001) and TAF-Cs (250 mg/kg) (p<0,01) showing antioxidant activity by an increase in reduced glutathione (GSH) levels compared to the negative control in ethanol-induced gastric ulcers. The EtOHE-Cs (500 mg/kg) reduces the levels of pro-inflammatory cytokines, interleukin 1 beta (IL-1β) (p<0,001) and tumor necrosis factor (TNF-α) (p<0,05) and levels of anti-inflammatory interleukin were increased, interleukin 10 (IL-10) (p<0,001) compared to the negative control. Treatment with TAF-Cs (250 mg/kg) did not alter IL-1β and TNF-α levels, however this treatment increased IL-10 levels compared to the negative control (p<0,001). In the cysteamine-induced duodenal ulcer lansoprazole (30 mg/kg), EtOHE-Cs (500 mg/kg) or TAF-Cs (250 mg/kg) reduced the ULA in 93, 49; 61 and 89% (p<0,001), respectively. Considering these results, it was possible to suggest that C. sympodialis and derivates presents antiulcerogenic activity and the gastroprotective activity of this species involves cytoprotective, antioxidants and immunoregulatory mechanisms. / Cissampelos sympodialis Eichl. (Menispermaceae) é uma espécie endêmica no Brasil, popularmente conhecida como “milona”, “jarrinha” ou “orelha-de-onça”. Esta espécie foi selecionada para este estudo a partir de critérios quimiotaxonômicos (alcaloides e flavonoides) e etnofarmacológico, já que essa espécie é utilizada popularmente no tratamento de desordens inflamatórias. Este trabalho teve como objetivo avaliar a toxicidade pré-clínica aguda e a atividade antiulcerogênica do extrato etanólico bruto (EEtOH-Cs) e da fração de alcaloides totais (FAT-Cs) obtidos das partes aéreas de C. sympodialis. No ensaio de toxicidade aguda, as doses de 300 e 2000 mg/kg do EEtOH-Cs administrado por via oral (v.o.) não induziu sinais de toxicidade em camundongos fêmeas nas condições experimentais avaliadas e a dose letal 50% (DL50) é igual ou superior a 5000 mg/kg de acordo com o guia 423 da OECD. Para a FAT-Cs foi verificado que os animais tratados com a dose de 2000 mg/kg apresentaram cauda em straub e analgesia, sendo a DL50 dessa substância de aproximadamente 1000 mg/kg. Para a avaliação da atividade gastroprotetora foram utilizados os modelos de indução aguda de úlcera gástrica: por etanol em ratos, anti-inflamatório não-esteroidal (AINE - piroxicam), estresse (por imobilização e frio) em camundongos e contensão do suco gástrico em ratos. No modelo de úlcera induzida por etanol a carbenoxolona (100 mg/kg), o EEtOH-Cs ou FAT-Cs (62,5; 125; 250 e 500 mg/kg - v.o.) reduziram a área de lesão ulcerativa (ALU) em 97, 69, 75, 94, 98; 97, 88, 90, 94, 95% (p<0,001), respectivamente, em comparação ao controle negativo. Na úlcera por etanol, os tratamentos com carbenoxolona (100 mg/kg), EEtOH-Cs (500 mg/kg) e FAT-Cs (250 mg/kg) melhoraram os parâmetros histológicos analisados. Nas úlceras induzidas por AINE, a cimetidina (100 mg/kg), o EEtOH-Cs ou FAT-Cs (62,5; 125; 250 e 500 mg/kg - v.o.) reduziram o índice de lesão ulcerativo (ILU) em 43, 59, 60, 64, 76; 47, 51, 62, 75 e 78% (p<0,001), respectivamente. Em lesões induzidas por estresse a cimetidina, o EEtOH-Cs ou FAT-Cs nas mesmas doses reduziram o ILU em 44, 37, 38, 42, 52; 57, 39, 54, 75 e 76% (p<0,001), respectivamente. Nas úlceras induzidas por contensão do suco gástrico (ligadura do piloro) a cimetidina (100 mg/kg), o EEtOH-Cs (500 mg/kg) e FAT-Cs (250 mg/kg) diminuíram o ILU em 35, 42 e 40% (p<0,001) (v.o.) e em 39, 34 e 33% (p<0,01) (intraduodenal – i.d.), respectivamente. Na perspectiva de investigar os mecanismos envolvidos na atividade gastroprotetora das amostras de C. sympodialis foram avaliados os mecanismos antissecretórios ou neutralizantes da secreção ácida gástrica, mecanismos citoprotetores, antioxidante e imunorregulatório. Os tratamentos (v.o. e i.d.) com o EEtOH-Cs (500 mg/kg) e FAT-Cs (250 mg/kg) não alteraram os parâmetros bioquímicos do suco gástrico, sugerindo que a atividade gastroprotetora não envolve mecanismos antissecretórios ou neutralizantes. A atividade gastroprotetora do EEtOH-Cs (500 mg/kg) envolve participação de grupamentos sulfidrila, óxido nítrico, KATP, muco e prostaglandinas. A gastroproteção promovida pela FAT-Cs (250 mg/kg) envolve a participação de grupamentos sulfidrila, muco e prostaglandinas. O EEtOH-Cs (500 mg/kg) (p<0,001) e FAT-Cs (250 mg/kg) (p<0,01) apresentaram atividade antioxidante por um aumento nos níveis de glutationa reduzida (GSH) quando comparados ao controle negativo, nas úlceras induzidas por etanol. O EEtOH-Cs (500 mg/kg) diminui os níveis das citocinas pró-inflamatórias, interleucina 1 beta (IL-1β) (p<0,001) e fator de necrose tumoral alfa (TNF-α) (p<0,05) e aumentou os níveis da interleucina anti-inflamatória, interleucina 10 (IL-10) (p<0,001), quando comparado ao controle negativo. O tratamento com a FAT-Cs (250 mg/kg) não alterou os níveis de IL-1β e TNF-α mas aumentou os níveis de IL-10 (p<0,001), quando comparado ao controle negativo. No modelo de úlcera duodenal induzida por cisteamina, o lansoprazol (30 mg/kg), EEtOH-Cs (500 mg/kg) ou FAT-Cs (250 mg/kg) reduziram a ALU em 93, 49; 61, e 89% (p<0,001), respectivamente. Diante desses resultados, foi possível sugerir que C. sympodialis e seus derivados apresentam atividade antiulcerogênica e que a atividade gastroprotetora dessa espécie envolve mecanismos citoprotetores, antioxidantes e imunorregulatórios.

Submitted by Maike Costa (maiksebas@gmail.com) on 2017-09-11T12:49:46Z No. of bitstreams: 1 arquivototal.pdf: 2180300 bytes, checksum: e42cbf6e6ed01099835b19ef61a6b55b (MD5) / Made available in DSpace on 2017-09-11T12:49:46Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2180300 bytes, checksum: e42cbf6e6ed01099835b19ef61a6b55b (MD5) Previous issue date: 2016-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Rosmarinic acid (RA) is a secondary metabolite present in several plant species, chemically characterized as a phenolic compound, derived from the esterification of caffeic acid and 3,4-dihydroxyphenyl lactic acid. Its name is derived from Rosmarinus officinalis, a species from which it was first isolated. Several biological effects have been described for RA as the antioxidant, antiallergic, anticancer, antimicrobial, neuroprotective, hepatoprotective, among others. The objective of the present study was to evaluate the acute toxicity, the gastroprotective activity of rosmarinic acid, and related mechanisms of action in animal models. In the acute toxicity model in female mice, rosmarinic acid at doses of 300 and 2000 mg / kg, v, did not show any behavioral changes in the parameters evaluated, nor did the changes in water and feed intake, body weight and macroscopic organ structure . Due to the presence of death at the dose of 2000 mg / kg, the LD50 of rosmarinic acid was set at 2500 mg / kg, according to OECD Guideline 423, which suggested low toxicity. The gastroprotective activity of RA was evaluated at different doses of 25, 50, 100 and 200 mg / kg (v0) in different models of acute ulcer induction: acidified ethanol, ethanol, immobilization and cold stress, non-steroidal anti-inflammatory NSAIDs) and contention of gastric juice. In the pharmacological screening with acidified ethanol in mice, RA and carbenoxolone decreased the ulcerative lesion index (ILU) in 42, 42, 40, 66 and 42%, respectively, when compared to the negative control group (saline solution 0.9 %). In the ethanol model, AR (50, 100 and 200 mg / kg) and carbenoxolone (100 mg / kg) reduced the ALU by 52, 68, 96 and 93%, respectively, when compared to the negative control group. In the stress model, RA (25, 50, 100 and 200 mg / kg) and cimetdine (100 mg / kg) decreased the ILU by 39, 41, 69, 71 and 40% when compared to the saline group 0 , 9%. In the NSAID-induced ulcer model RA (25, 50, 100 and 200 mg / kg) and cimetdine (100 mg / kg) decreased the ILU by 36, 39, 49, 67 and 29% when compared to the control group negative. In the gastric juice-induced ulcer model, RA (200 mg / kg) and cimetidine (100 mg / kg) when administered orally or intraduodenal reduced ILU by 38 and 51%; 43 and 31%, respectively, when compared to their negative controls. The presence of anti-secretory or neutralizing mechanisms (biochemical parameters), cytoprotection (sulfhydryl groups, nitric oxide, muco, prostaglandin), antioxidant (GSH) and immunoregulatory (TNF-, IL-1 and IL-10) were evaluated. It was observed that the gastroprotective effect of rosmarinic acid is not related to the alteration of the biochemical parameters of the gastric juice (pH, volume and [H +]), it does not involve nitric oxide, muco and prostaglandins, but it is related to the participation of the sulfhydryl groups , increased GSH levels, reduction of proinflammatory cytokines (IL-1 and TNF-) and maintenance of anti-inflammatory cytokines (IL-10) levels. In this way, it is possible to infer that rosmarinic acid has gastroprotective activity, related to cytoprotective, antioxidant and anti-inflammatory mechanisms. / O ácido rosmarínico (AR) é um metabólito secundário presente em diversas espécies de plantas, quimicamente caracterizado como um composto fenólico, oriundo da esterificação do ácido cafeico e do ácido lático 3,4 dihidroxifenil. Seu nome é derivado da Rosmarinus officinalis, espécie da qual foi isolada pela primeira vez. Diversos efeitos biológicos têm sido descritos para o AR como o antioxidante, antialérgico, anticâncer, antimicrobiano, neuroprotetor, hepatoprotetor, entre outros. O presente trabalho teve por objetivo avaliar a toxicidade aguda, a atividade gastroprotetora do ácido rosmarínico, e os mecanismos de ação relacionados, em modelos animais. No modelo de toxicidade aguda em camundongos fêmeas, o ácido rosmarínico nas doses de 300 e 2000 mg/kg, v.o, não demonstrou nenhuma alteração comportamental nos parâmetros avaliados, nem alterações no consumo de água e ração, peso corpóreo e na estrutura macroscópica dos órgãos. Devido a presença de morte na dose de 2000 mg/kg, a DL50 do ácido rosmarínico foi estipulada em 2500 mg/kg, de acordo com o guia 423 da OECD, o que sugeri baixa toxicidade. A atividade gastroprotetora do AR foi avaliada nas doses de 25, 50, 100 e 200 mg/kg (v.o) em diferentes modelos de indução aguda de úlcera: etanol acidificado, etanol, estresse por imobilização e frio, anti-inflamatório não-esteroidal (AINE) e contensão do suco gástrico. Na triagem farmacológica com o etanol acidificado em camundongos, o AR e a carbenoxolona diminuiu o índice de lesão ulcerativa (ILU) em 42, 42, 40, 66 e 42%, respectivamente, quando comparado ao grupo controle negativo (solução salina 0,9%). No modelo de etanol, AR (50, 100 e 200 mg/kg) e carbenoxolona (100 mg/kg) reduziu a ALU em 52, 68, 96 e 93%, respectivamente, quando comparado ao grupo controle negativo. No modelo de estresse, o AR (25, 50, 100 e 200 mg/kg) e a cimetdina (100 mg/kg) diminuiu o ILU em 39, 41, 69, 71 e 40%, quando comparado ao grupo solução salina 0,9%. No modelo de úlcera induzido por AINE o AR (25, 50, 100 e 200 mg/kg) e a cimetdina (100 mg/kg) diminuiu o ILU em 36, 39, 49, 67 e 29%, quando comparado ao grupo controle negativo. No modelo úlceras induzidas por contensão do suco gástrico, o AR (200 mg/kg) e cimetidina (100 mg/kg) quando administrado por via oral ou intraduodenal, reduziu o ILU em 38 e 51% ; 43 e 31%, respectivamente, quando comparados aos seus controles negativos. Foi avaliada a participação dos mecanismos antissecretórios ou neutralizante (parâmetros bioquímicos), citoproteção (grupamentos sulfidrila, óxido nítrico, muco, prostaglandina), antioxidante (GSH) e imunorregulatório (TNF-, IL-1 e IL-10). Foi observado que o efeito gastroprotetor do ácido rosmarínico não está relacionado à alteração dos parâmetros bioquímicos do suco gástrico (pH, volume e [H+]), não envolve a participação do óxido nítrico, muco e prostaglandinas, mas está relacionado a participação dos grupamentos sulfidrílicos, aumento dos níveis de GSH, redução de citocinas pró-inflamatórias (IL-1 e TNF-) e manutenção dos níveis de citocinas anti-inflamatórias (IL-10). Desta forma, é possível inferir que o ácido rosmarínico apresenta atividade gastroprotetora, relacionada a mecanismos citoprotetores, antioxidante e anti-inflamatórios.

Made available in DSpace on 2015-05-14T12:59:55Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1962788 bytes, checksum: d160b6c86730c61bab1734d66aa49f80 (MD5) Previous issue date: 2013-02-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Maytenus distichophylla Mart. ex Reissek, popularly known as "casca amarela" or "pau-colher", belongs to the family Celastraceae. This species was selected for this work from chemotaxonomic criteria, with a view that has been proven to gastroprotective activity in several species of this genus, which was attributed to secondary metabolites such as flavonoids, terpenoids, alkaloids and tannins. Aiming to assess the acute toxicity, gastroprotective activity, as well as mechanisms related to this activity were obtained, from the leaves of M. distichophylla, crude methanolic extract (Md-MeOHE) and ethyl acetate phase (Md-EtOAcP). The single administration (p.o.) of 2000 mg/kg in mice Md-MeOHE, did not cause behavioral changes in the evaluated parameters (such as hyperactivity, piloerection, analgesia, ambulation, among others), also caused no changes in weight or the gross structure of organs. However, was able to reduce the consumption of water and feed in male animals. Unable to determine the LD50, whereas no deaths at the end of 14 days of observation. Regarding the gastroprotective activity, Md-MeOHE and Md-EtOAcP at doses of 62.5, 125, 250 and 500 mg/kg (p.o.) were tested against different models of acute induction of ulcer (ethanol acidified, ethanol, stress immobilization and cold, nonsteroidal anti-inflammatory drug (NSAID) and containment of gastric juice). In the model of acidified ethanol, the Md-MeOHE reduced the ulcerative lesion index (ULI) for 68, 84, 81 and 80%, respectively. Front lesions by ethanol, Md-MeOHE and Md-EtOAcP in the same doses protected the gastric mucosa 40, 56, 65, 86, 12, 34, 46 and 71%, respectively. When assessing the model stress- Md-MeOHE and Md-EtOAcP decreased ULI at 58, 72, 79, 84, 29, 38, 50 and 52%, respectively. Likewise, in the model of NSAID-induced gastric ulcers, lesions was no inhibition at 46, 65, 81 and 82% for Md-MeOHE and 26, 40, 58 and 69% for Md-EtOAcP. In the ulcers induced by restraint of gastric juice (pylorus ligature) the Md-MeOHE and Md-EtOAcP in its most effective doses (500 mg/kg) caused gastric mucosa protection when administered intraduodenally 75 and 77%, respectively, compared to negative control. Also on ligation model (i.d.), Md-MeOHE and Md-EtOAcP reduced the volume of gastric contents. In order to investigate the mechanisms of action related to gastroprotection promoted by Md-MeOHE (500 mg/kg) and Md-EtOAcP (500 mg/kg), was evaluated the involvement of sulfhydryl groups, nitric oxide, prostaglandins and mucus. Thus, it was verified that the gastroprotective effect of plant samples of M. distichophylla not involve increased mucus adhered to the mucosa or participation of nitric oxide. However, this effect is related to the participation of sulfhydryl groups and increased levels of prostaglandin. Thus, these data suggest that M. distichophylla presents gastroprotective activity, possibly related to mechanisms antisecretory and cytoprotective. / Maytenus distichophylla Mart. ex Reissek, popularmente conhecida como casca amarela ou pau-colher , pertence a família Celastraceae. Esta espécie foi selecionada para este trabalho a partir de critérios quimiotaxonômicos, tendo em vista que já foi comprovada a atividade gastroprotetora em várias espécies deste gênero, a qual foi atribuída a metabólitos secundários tais como flavonoides, triterpenos, alcaloides e taninos. Com o objetivo de avaliar a toxicidade aguda, atividade gastroprotetora, bem como mecanismos relacionados a esta atividade, foram obtidos, a partir das folhas de M. distichophylla, o extrato metanólico bruto (EMeOH-Md) e a fase acetato de etila (FaAcOEt-Md). A administração única (v.o.) de 2000 mg/kg do EMeOH-Md em camundongos, não causou alterações comportamentais nos parâmetros avaliados (tais como hiperatividade, piloereção, analgesia, ambulação, dentre outros) e também não provocou variações no peso nem na estrutura macroscópica dos órgãos. No entanto, foi capaz de reduzir o consumo de água e ração nos animais machos. Não foi possível determinar a DL50, visto que não houve mortes, ao final dos 14 dias de observação. Com relação à atividade gastroprotetora, EMeOH-Md e FaAcOEt-Md nas doses de 62,5, 125, 250 e 500 mg/kg (v.o.) foram testados frente a diferentes modelos de indução aguda de úlcera (etanol acidificado, etanol, estresse por imobilização e frio, anti-inflamatório não-esteroidal (AINE) e contensão do suco gástrico). No modelo de etanol acidificado, o EMeOH-Md reduziu o índice de lesão ulcerativo (ILU) em 68, 84, 81 e 80%, respectivamente. Frente as lesões por etanol, o EMeOH-Md e a FaAcOEt-Md nas mesmas doses protegeram a mucosa gástrica em 40, 56, 65, 86 e 12, 34, 46 e 71%, respectivamente. Quando se avaliou o modelo do estresse, EMeOH-Md e FaAcOEt-Md diminuíram o ILU em 58, 72, 79, 84 e 29, 38, 50 e 52%, respectivamente. Da mesma forma, no modelo de úlceras gástricas induzidas por AINE, houve inibição das lesões em 46, 65, 81 e 82% para o EMeOH-Md e 26, 40, 58 e 69% para a FaAcOEt-Md. Nas úlceras induzidas por contensão do suco gástrico (ligadura de piloro) o EMeOH-Md e a FaAcOEt-Md nas suas doses mais efetivas (500 mg/kg) promoveram proteção da mucosa gástrica quando administrados por via intraduodenal 75 e 77%, respectivamente, em comparação ao controle negativo. Também no modelo de ligadura (i.d.), EMeOH-Md e FaAcOEt-Md reduziram o volume do conteúdo gástrico. No intuito de investigar os mecanismos de ação relacionados a gastroproteção promovida pelo EMeOH-Md (500 mg/kg) e FaAcOEt-Md (500 mg/kg), foi avaliado o envolvimento dos grupamentos sulfidrílicos, óxido nítrico, muco e prostaglandinas. Dessa forma, foi verificado que o efeito gastroprotetor das amostras vegetais de M. distichophylla não envolve aumento do muco aderido à mucosa, nem a participação do óxido nítrico. No entanto, este efeito está relacionado à participação dos grupamentos sulfidrílicos e aumento dos níveis de prostaglandina. Logo, esses dados sugerem que M. distichophylla apresenta atividade gastroprotetora, possivelmente relacionada a mecanismos antissecretórios e citoprotetores.

The Keap1-Nrf2 pathway regulates a wide range of cytoprotective genes, and has been found to serve a protective and beneficial role in many body systems. There is limited information available, however, about its role in bone homeostasis. While Nrf2 activation has been suggested as an effective method of increasing bone mass and quality, there have been conflicting reports which associate Keap1 deficiency with detrimental phenotypes. As Keap1 deletion is a common method of Nrf2 activation, further study should address the impacts of various methods of regulating Nrf2 expression. Also, little research has been conducted on the specific pathways by which Nrf2 activation improves bone quality. In this study, the effects of alterations to Nrf2 activation levels were explored in two specific and varied scenarios. In the first experiment, moderate Nrf2 activation was achieved via partial deletion of its sequestering protein, Keap1, in an aging mouse model. The hypothesis tested here is that moderate Nrf2 activation improves bone quality by affecting bone metabolism and response to mechanical loading. The results of this first experiment suggest a subtle, sex-specific effect of moderate Nrf2 activation in aging mice which improves specific indices of bone quality to varying degrees, but does not affect loading-induced bone formation. It is likely that the overwhelming phenotypic impacts associated with aging or the systemic effects of global Keap1 deficiency may increase the difficulty in parsing out significant effects that can be attributed solely to Nrf2 activation. In the second experiment, a cell-specific knockout of Nrf2 in the osteocytes was achieved using a Cre/Lox breeding system. The hypothesis tested here is that osteocyte-specific deletion of Nrf2 impairs bone quality by affecting bone metabolism and response to mechanical loading. The results of this experiment suggest an important role of Nrf2 in osteocyte function which improves certain indices of bone quality, which impacts male and female bones in different 7 ways, but did not significantly impact loading-induced bone formation. Further studies should modify the method of Nrf2 activation in an effort to refine the animal model, allowing the effects of Nrf2 to be isolated from the potential systemic effects of Keap1 deletion. Future studies should also utilize other conditional knockout models to elucidate the effects of Nrf2 in other specific cell types.