RESUMO
Human T-lymphotropic virus type 1 (HTLV-1) induces a strong activation of the immune system, especially in individuals with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Physalin F is a secosteroid with potent anti-inflammatory and immunomodulatory activities. The present study aimed to investigate the effects of physalin F on peripheral blood mononuclear cells (PBMC) of HAM/TSP subjects. A concentration-dependent inhibition of spontaneous proliferation of PBMC from HAM/TSP subjects was observed in the presence of physalin F, as evaluated by (3)H-thymidine uptake. The IC50 for physalin F was 0.97 ± 0.11 µM. Flow cytometry analysis using Cytometric Bead Array (CBA) showed that physalin F (10 µM) significantly reduced the levels of IL-2, IL-6, IL-10, TNF-α and IFN-γ, but not IL-17A, in supernatants of PBMC cultures. Next, apoptosis induction was addressed by using flow cytometry to evaluate annexin V expression. Treatment with physalin F (10 µM) increased the apoptotic population of PBMC in HAM/TSP subjects. Transmission electron microscopy analysis of PBMC showed that physalin F induced ultrastructural changes, such as pyknotic nuclei, damaged mitochondria, enhanced autophagic vacuole formation, and the presence of myelin-like figures. In conclusion, physalin F induces apoptosis of PBMC, decreasing the spontaneous proliferation and cytokine production caused by HTLV-1 infection.
Assuntos
Imunossupressores/uso terapêutico , Leucócitos Mononucleares/patologia , Paraparesia Espástica Tropical/sangue , Paraparesia Espástica Tropical/tratamento farmacológico , Physalis/química , Secoesteroides/uso terapêutico , Proliferação de Células/efeitos dos fármacos , Citocinas/metabolismo , Humanos , Imunossupressores/farmacologia , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/ultraestrutura , Paraparesia Espástica Tropical/patologia , Fosfatidilserinas/metabolismo , Secoesteroides/química , Secoesteroides/farmacologiaRESUMO
Pain is the most common reason a patient sees a physician. Nevertheless, the use of typical painkillers is not completely effective in controlling all pain syndromes; therefore further attempts have been made to develop improved analgesic drugs. The present study was undertaken to evaluate the antinociceptive properties of physalins B (1), D (2), F (3), and G (4) isolated from Physalis angulata in inflammatory and centrally mediated pain tests in mice. Systemic pretreatment with 1-4 produced dose-related antinociceptive effects on the writhing and formalin tests, traditional screening tools for the assessment of analgesic drugs. On the other hand, only 3 inhibited inflammatory parameters such as hyperalgesia, edema, and local production of TNF-α following induction with complete Freund's adjuvant. Treatment with 1, 3, and 4 produced an antinociceptive effect on the tail flick test, suggesting a centrally mediated antinociception. Reinforcing this idea, 2-4 enhanced the mice latency reaction time during the hot plate test. Mice treated with physalins did not demonstrate motor performance alterations. These results suggest that 1-4 present antinociceptive properties associated with central, but not anti-inflammatory, events and indicate a new pharmacological property of physalins.
Assuntos
Analgésicos/farmacologia , Dor/tratamento farmacológico , Physalis/química , Secoesteroides/isolamento & purificação , Secoesteroides/farmacologia , Animais , Anti-Inflamatórios/uso terapêutico , Modelos Animais de Doenças , Edema/tratamento farmacológico , Adjuvante de Freund , Hiperalgesia/tratamento farmacológico , Masculino , Camundongos , Estrutura Molecular , Medição da Dor , Secoesteroides/química , Fator de Necrose Tumoral alfa/uso terapêuticoRESUMO
We previously observed that physalins have immunomodulatory properties, as well as antileishmanial and antiplasmodial activities. Here, we investigated the anti-Trypanosoma cruzi activity of physalins B, D, F and G. We found that physalins B and F were the most potent compounds against trypomastigote and epimastigote forms of T. cruzi. Electron microscopy of trypomastigotes incubated with physalin B showed disruption of kinetoplast, alterations in Golgi apparatus and endoplasmic reticulum, followed by the formation of myelin-like figures, which were stained with MDC to confirm their autophagic vacuole identity. Physalin B-mediated alteration in Golgi apparatus was likely due to T. cruzi protease perturbation; however physalins did not inhibit activity of the trypanosomal protease cruzain. Flow cytometry examination showed that cell death is mainly caused by necrosis. Treatment with physalins reduced the invasion process, as well as intracellular parasite development in macrophage cell culture, with a potency similar to benznidazole. We observed that a combination of physalins and benznidazole has a greater anti-T. cruzi activity than when compounds were used alone. These results indicate that physalins, specifically B and F, are potent and selective trypanocidal agents. They cause structural alterations and induce autophagy, which ultimately lead to parasite cell death by a necrotic process.
Assuntos
Physalis/química , Secoesteroides/farmacologia , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Estrutura Molecular , Secoesteroides/química , Tripanossomicidas/química , Trypanosoma cruzi/fisiologia , Trypanosoma cruzi/ultraestruturaRESUMO
The antimalarial activities of physalins B, D, F, and G (1-4), isolated from Physalis angulata, were investigated. In silico analysis using the similarity ensemble approach (SEA) database predicted the antimalarial activity of each of these compounds, which were shown using an in vitro assay against Plasmodium falciparum. However, treatment of P. berghei-infected mice with 3 increased parasitemia levels and mortality, whereas treatment with 2 was protective, causing a parasitemia reduction and a delay in mortality in P. berghei-infected mice. The exacerbation of in vivo infection by treatment with 3 is probably due to its potent immunosuppressive activity, which is not evident for 2.
Assuntos
Antimaláricos/farmacologia , Imunossupressores/farmacologia , Physalis/química , Plasmodium berghei/efeitos dos fármacos , Plasmodium falciparum/efeitos dos fármacos , Secoesteroides/farmacologia , Animais , Antimaláricos/química , Antimaláricos/isolamento & purificação , Imunossupressores/química , Imunossupressores/isolamento & purificação , Malária/tratamento farmacológico , Camundongos , Camundongos Endogâmicos BALB C , Parasitemia/tratamento farmacológico , Secoesteroides/química , Secoesteroides/isolamento & purificaçãoRESUMO
The effects of physalin F (1), a steroid derivative purified from Physalis angulata, were investigated in models of collagen-induced arthritis in DBA/1 mice and allergic airway inflammation in BALB/c mice. Oral treatment with 1 or dexamethasone caused a marked decrease in paw edema and joint inflammation when compared to vehicle-treated arthritic mice. In contrast, treatment with 1 had no effect in mice with allergic airway inflammation caused by ovalbumin immunization, whereas dexamethasone significantly reduced the number of inflammatory cells and eosinophils in the broncoalveolar lavage fluid and in lung sections of challenged mice. To further demonstrate that 1 acts through a mechanism different from that of glucocorticoids, a nuclear translocation assay was performed of the glucocorticoid receptor (GR) using COS-7 cells transfected with a plasmid encoding for a yellow fluorescent protein (YFP)-GR fusion protein. Untreated or treated cells with 1 had YFP staining mainly in the cytoplasm, whereas in dexamethasone-treated cells the YFP staining was concentrated in the nuclei. It is concluded that the mechanism of the immunosuppressive activity of physalin F is distinct from that of the glucocorticoids.
Assuntos
Anti-Inflamatórios/farmacologia , Artrite Experimental , Modelos Animais de Doenças , Secoesteroides/farmacologia , Administração Oral , Animais , Anti-Inflamatórios/química , Células COS , Chlorocebus aethiops , Dexametasona/farmacologia , Eosinófilos/efeitos dos fármacos , Glucocorticoides/efeitos adversos , Glucocorticoides/imunologia , Inflamação/induzido quimicamente , Camundongos , Camundongos Endogâmicos BALB C , Estrutura Molecular , Ovalbumina/administração & dosagem , Physalis/química , Secoesteroides/química , Secoesteroides/imunologiaRESUMO
Seven new C-secosteroids were isolated from the gorgonian Tripalea clavaria collected from the South Atlantic. These compounds have a Delta(5), 9,11-secosteroid nucleus together with a 22S hydroxyl group. The absolute configuration of the 22-hydroxyl group was determined with the help of COSY spectra of the Mosher esters of the compounds.
Assuntos
Antozoários/química , Secoesteroides/química , Secoesteroides/isolamento & purificação , Animais , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Antifúngicos/química , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Bacillus subtilis/efeitos dos fármacos , Botrytis/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Secoesteroides/farmacologia , Staphylococcus aureus/efeitos dos fármacosRESUMO
Phytochemical analysis of the leaves of Acnistus arborescens (Solanaceae) resulted in the isolation of two new epimeric withaphysalins (17S,20R,22R)-5beta,6beta: 18,20-diepoxy-4beta,18-dihydroxy-1-oxowitha-24-enolide (2, 18R and 18S), together with the known withaphysalin F (1, 18R and 18S). Their structures were established by spectroscopic methods, including 2D NMR data and comparison with literature data. Compounds 1 and 2 dis-played potent cytotoxic activities against several cancer cell lines with IC50 values in the range of 0.20 to 1.46 microg/mL for 1 and 0.89 to 8.08 microg/mL for 2. The strong cytotoxicity presented by 1 suggests that in this series of compounds, the 2,3-unsaturated ketone moiety is an important pharmacophoric unit. The cytotoxic activity seemed to be related to DNA synthesis inhibition, as revealed by the reduction of 5-bromo-2'-deoxyuridine incorporation after 24 hours of incubation on leukemic cells.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Ergosterol/farmacologia , Fitoterapia , Extratos Vegetais/farmacologia , Secoesteroides/farmacologia , Solanaceae , Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/uso terapêutico , Linhagem Celular Tumoral/efeitos dos fármacos , Ergosterol/análogos & derivados , Ergosterol/química , Células HL-60/efeitos dos fármacos , Humanos , Extratos Vegetais/administração & dosagem , Extratos Vegetais/química , Extratos Vegetais/uso terapêutico , Folhas de Planta , Racemases e Epimerases , Secoesteroides/químicaRESUMO
Three withaphysalins, rel-(17S,20R,22R)-5 beta,6 beta:18,20-diepoxy-4 beta-hydroxy-1,18-dioxowitha-2,24-dienolide(withaphysalin M) (1), rel-(17S,20R,22R)-5 beta,6 beta:18,20-diepoxy-4 beta-hydroxy-18-ethoxy-1-oxowitha-2,24-dienolide (withaphysalin F ethyl ether, withaphysalin O) (2), and rel-(17S,20R,22R)-5 beta,6 beta:18,20-diepoxy-4 beta-hydroxy-1,18-dioxowitha-24-enolide (withaphysalin N) (3), were isolated from the leaves of Acnistus arborescens. The structures were deduced from 1D ((1)H NMR, (13)C NMR, DEPT-(13)C NMR) and 2D (COSY, HMQC, HMBC) NMR analysis and the relative stereochemical assignments based on 1D NOESY correlations and analysis of coupling constants. Compounds 1 and 2 displayed potent cytotoxic activity against a panel of human cancer cell lines.