Browsing by Author "Humberto, Jorge Luiz"

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    Antidiabetic effect of Equisetum giganteum L. extract on alloxan-diabetic rabbit.
    (2020) Vieira, Geisla Teles; Oliveira, Tânia Toledo de; Carneiro, Marco Antonio Alves; Cangussú, Silvia Dantas; Humberto, Gabriel Almeida Paes; Taylor, Jason Guy; Humberto, Jorge Luiz
    Ethnopharmacological relevance: Equisetum giganteum has been traditionally used as an anti-diabetic herbal remedy to treat diabetes in the southern state of Rio Grande do Sul in Brazil. Aim of the study: Considering the ethonopharmacology and historical importance of E. giganteum, its potential antidiabetic effect was evaluated in alloxan induced diabetic rabbits. Material and methods: Samples of Equisetum giganteum were collected in the city of Ouro Preto, Minas Gerais, Brazil. Butanolic and aqueous extracts were prepared and subsequently evaluated for anti-diabetic properties in vivo using albino male rabbits. At the end of the treatment period, the animals were euthanized, and histopathological analysis were carried out. The following biochemical parameters were studied: glucose, triacylglycerol, cholesterol, albumin, creatinine, glycosylated hemoglobin and lipase. The phytochemical profile of the extracts was studied by liquid chromatography techniques coupled to a UV/VIS detector and highresolution mass spectrometry. Results: Both aqueous and butanolic extracts were capable of reducing significantly the levels of glucose, cholesterol and triacylglycerol and thus demonstrating their hypolipidemic and hypoglycemiant effects. Furthermore, the extracts prevented the occurrence of hepatic complications during treatment. The phytochemical profile of the extracts was investigated, and the natural products detected were in agreement with those that had been previously described in the literature. Conclusion: Based on the significant reductions in biochemical parameters and the histologic evidence for the absence of complications in the liver, pancreas of the treated animals, Equisetum giganteum can be a therapeutically relevant resource in the treatment of diabetes and hyperlipidemia.
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    Antioxidant properties of Baccharis trimera in the neutrophils of Fisher rats.
    (2010) Pádua, Bruno da Cruz; Silva, Lucas Dornela; Rossoni Júnior, Joamyr Victor; Humberto, Jorge Luiz; Chaves, Míriam Martins; Silva, Marcelo Eustáquio; Pedrosa, Maria Lúcia; Costa, Daniela Caldeira
    Ethnopharmacological relevance: Baccharis trimera (Less.) (Asteraceae) is a native plant of Brazil. Also known as “carqueja”, it has been popularly used to treat liver diseases, diabetes, as well as digestive disorders. Other studies have described the hepatoprotective, antioxidant and anti-inflammatory activities of the species. Aim of the study: The aim of the present study was to investigate the antioxidant properties of Baccharis trimera in the neutrophils of Fisher rats in both in vitro and in vivo experimental models. Material and methods: In the in vitro assay, the neutrophils of male rats were isolated and incubated with Baccharis trimera extract at concentrations of 0.5, 5.0 and 50.0_g/mL. In the in vivo assay, male rats were first treated with crude extract 600 mg/kg body weight of Baccharis trimera or with 50 mg/kg body weight of quercetin (reference substance) and then treated with 835 mg/kg of acetaminophen (APAP) after 24 h. Results: The hydroethanolic extract of Baccharis trimera reduced the release of reactive oxygen species in the neutrophils in both the in vitro and in vivo experimental models. Therefore confirming its antioxidant effect. Conclusion: The results of this study confirm the antioxidant effect of Baccharis trimera.
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    Síntese e avaliação anti T. cruzi e antimicrobiana de derivados do Xilitan.
    (2016) Elias, Paula Regina; Taylor, Jason Guy; Hilário, Flaviane Francisco; Viana, Gustavo Henrique Ribeiro; Humberto, Jorge Luiz
    A Doença de chagas, ou Tripanossomíase Americana, é uma infecção causada pelo protozoário Tripanossoma cruzi (T. cruzi). Na América Latina, essa doença acomete cerca de 18 milhões de pessoas e no Brasil, aproximadamente 3 milhões de indivíduos encontram-se infectados com o T. cruzi. O tratamento da doença de chagas é feito através do emprego dos fármacos Benzonidazol ou Nifurtimox e objetiva erradicar a infecção ainda na sua fase aguda, onde a eficácia de cura pelos medicamentos é cerca de 70%. Na fase crônica, o potencial de cura por esses medicamentos cai para cerca de 20%, o que reforça a necessidade de se encontrar fármacos que possam atuar sobretudo na fase crônica da doença. O tratamento de doenças infecciosas causadas por bactérias e fungos também continua a ser um desafio para a saúde pública. Apesar de existirem inúmeros antibióticos disponíveis para uso clínico, a resistência dos micro-organismos a esses agentes quimioterapêuticos, nas últimas décadas, reforça a necessidade substancial de novas classes de agentes antimicrobianos com novos mecanismos de ação ou que sejam mais seguros e mais eficazes do que os já existentes. Neste trabalho, foi realizada a síntese de uma série de derivados de (±) 3,5-O-isopropidileno-1,4-xilitan, um anidropentitol obtido a partir da ciclização catalisada por ácido do xilitol, um conhecido álcool de açúcar, utilizado como adoçante na indústria de alimentos. Os derivados de xilitan foram obtidos por meio de reações de substituição nucleofílica bimolecular (SN2) para obtenção de derivado mesilado, reações de esterificação e O-alquilação e reações de cicloadição CuAAC, (reação “click”) para a síntese de 1,2,3-triazóis derivados de xilitan. A maioria dos compostos sintetizados foram submetidos a ensaios in vitro para a avaliação das suas atividades biológicas (anti T. cruzi e antimicrobiana). O derivado de xilitan mais potente contra T. cruzi foi um éster de aril sulfonato contendo um grupo nitro no anel aromático cujo valor de CI50 foi 2.69 μM e ligeiramente mais ativo do que Benzonidazol. No caso da atividade antimicrobiana, muitos dos derivados xilitan foram mediamente ativos contra diferentes estirpes bacterianas e fúngica. Em particular, o éster de boronato e alguns triazóis derivados de xilitan exibiram seletividade interessante para determinadas estirpes e outros não. Os resultados foram muito promissores e novos estudos devem ser realizados para estabelecer relações de atividade estruturais e determinar o mecanismo de ação, a fim de otimizar os melhores candidatos.
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    Synthesis and trypanocidal activity of ent-kaurane glycosides.
    (2007) Batista, Ronan; Humberto, Jorge Luiz; Chiari, Egler; Oliveira, Alaíde Braga de
    Novel ent-kaurane glucosides were synthezised by a Koenigs–Knorr reaction between C17 and C19 alcohols derived from kaurenoic acid and 2,3,4,6-tetra-O-acetyl-glucopyranosyl bromide, followed by the hydrolysis of the acetates. Main products were assayed in vitro and in vivo against blood trypomastigote forms of Trypanosoma cruzi, the aetiological agent of Chagas’ disease (American trypanosomiasis). The results allowed to establish structure–activity relationships among these derivatives, as well as pointed out the C19-methylester-C17-O-glucoside as a potential trypanocidal agent, whose trypanocidal profile was shown to be comparable to those of gentian violet and benznidazole.
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    Synthesis, cytotoxic activity, and mode of action of new Santacruzamate A analogs.
    (2018) Andrade, Silmara Nunes; Evangelista, Fernanda Cristina Gontijo; Seckler, Diego Eduardo Lima; Marques, Deisielly Ribeiro; Freitas, Tulio Resende; Nunes, Renata Rachide; Oliveira, Júlia Teixeira de; Ribeiro, Rosy Iara Maciel de Azambuja; Santos, Helio Batista dos; Thomé, Ralph Gruppi; Taranto, Alex Gutterres; Santos, Fabio Vieira dos; Viana, Gustavo Henrique Ribeiro; Freitas, Rossimiriam Pereira de; Humberto, Jorge Luiz; Sabino, Adriano de Paula
    Breast and ovarian cancer are the most common cancers in women. Available cancer treatments, in general, have limited efficacy and frequent, undesirable side effects. Recently, scientists have focused on searching for new epigenetic modulators such as inhibitors of DNA methyltransferases and histone deacetylases (HDACs), with novel properties and selectivity. We report the synthesis of seven new analogs of Santacruzamate A. Molecular modeling showed that compounds 3–9 presented the best binding energies (kcal/mol) against HDAC4 compared to that of crystallographic ligand. The compounds were evaluated against MCF-7 and MDA-MB-231 (breast cancer), TOV-21G (ovarian adenocarcinoma), and WI-26VA4 (non-tumor lung fibroblasts) cells. Compound 5, the most potent and selective of the series, exhibited remarkably enhanced anticancer potency, with IC50 values for the tumor cells of 24.3–44.93 μM, compared with that of etoposide (12–18.57 μM) and doxorubicin (2.1–4.37 μM). Further investigation showed that compound 5 could promote DNA damage, increase the activity of caspases-3 and -9, and upregulate mRNA levels of p21, TP53, and BAK, suggesting apoptotic cell death of the tumor cells via the intrinsic pathway. This study demonstrated that synthetic analogs of santacruzamate A with zinc-linked groups are effective for improving both HDAC inhibition and antitumor activity.