RESUMO
Despite increased access to contraception over the last 60 years, unplanned pregnancies continue to contribute to economic disparities and overpopulation. Additionally, the burden of family planning falls primarily on women, as a reliable pharmaceutical male contraceptive has yet to be developed. The objective of this literature-based systematic review was to identify compounds for future study from natural sources with potential nonhormonal male contraceptive activity. After the exclusion of extracts and compounds with known hormonal mechanisms, 26 unique compounds were identified from natural species. The plant source, compound class, structure, target, mechanism of action, safety/toxicity profile, and in vitro, in vivo, and human studies for each compound were evaluated and discussed. ß-Caryophyllene, embelin, oleanolic acid, triptonide, and N-butyldeoxynojirimycin (NB-DNJ) were selected as the five most promising compounds for future study using prespecified criteria such as number of studies, efficacy and safety profile, reversibility, and previous use in humans for any indication. In order to move forward with development of a male contraceptive from a natural source, additional studies are needed to determine the predicted safety and efficacy for in vivo and human clinical trials.
Assuntos
Produtos Biológicos/farmacologia , Anticoncepcionais Masculinos/farmacologia , Humanos , Estrutura Molecular , Fitoquelatinas/farmacologiaRESUMO
Longipetalol A (1) is an unprecedented highly modified triterpenoid with a unique 1,2-seco-3-(2-oxo-phenylethyl)-17α-13,30-cyclodammarane skeleton, featuring an acetal-lactone fragment. It was isolated from Dichapetalum longipetalum along with two additional derivatives, namely, longipetalols B (2) and C (3). Their structures were elucidated using spectroscopic analyses combined with single-crystal X-ray diffraction. Compounds 1, 2, and 3 exhibited inhibitory effects on nitric oxide production in lipopolysaccharide-induced RAW264.7 macrophages.
Assuntos
Anti-Inflamatórios/farmacologia , Magnoliopsida/química , Triterpenos/farmacologia , Animais , Anti-Inflamatórios/isolamento & purificação , China , Macrófagos/efeitos dos fármacos , Camundongos , Estrutura Molecular , Óxido Nítrico/biossíntese , Fitoquelatinas/isolamento & purificação , Fitoquelatinas/farmacologia , Células RAW 264.7 , Triterpenos/isolamento & purificaçãoRESUMO
S-nitrosophytochelatins (SNOPCs) are novel analogues of S-nitrosoglutathione (GSNO) with the advantage of carrying varying ratios of S-nitrosothiol (SNO) moieties per molecule. Our aim was to investigate the in vivo pharmacological potency and biodistribution of these new GSNO analogues after intravenous (i.v.) and intranasal (i.n.) administration in mice. SNOPCs with either two or six SNO groups and GSNO were synthesized and characterized for purity. Compounds were administered i.v. or i.n. at 1 µmol NO/kg body weight to CD-1 mice. Blood pressure was measured and biodistribution studies of total nitrate and nitrite species (NOx) and phytochelatins were performed after i.v. administration. At equivalent doses of NO, it was observed that SNOPC-6 generated a rapid and significantly greater reduction in blood pressure (â¼60% reduction compared to saline) whereas GSNO and SNOPC-2 only achieved a 30-35% decrease. The reduction in blood pressure was transient and recovered to baseline levels within â¼2 min for all compounds. NOx species were transiently elevated (over 5 min) in the plasma, lung, heart and liver. Interestingly, a size-dependent phytochelatin accumulation was observed in several tissues including the heart, lungs, kidney, brain and liver. Biodistribution profiles of NOx were also obtained after i.n. administration, showing significant lung retention of NOx over 15 min with minor systemic increases observed from 5 to 15 min. In summary, this study has revealed interesting in vivo pharmacological properties of SNOPCs, with regard to their dramatic hypotensive effects and differing biodistribution patterns following two different routes of administration.
Assuntos
Anti-Hipertensivos/administração & dosagem , Anti-Hipertensivos/farmacologia , Fitoquelatinas/administração & dosagem , Fitoquelatinas/farmacologia , S-Nitrosotióis/administração & dosagem , S-Nitrosotióis/farmacologia , Administração Intranasal , Administração Intravenosa , Animais , Anti-Hipertensivos/análise , Anti-Hipertensivos/farmacocinética , Pressão Arterial/efeitos dos fármacos , Masculino , Camundongos , Nitratos/análise , Nitritos/análise , Fitoquelatinas/farmacocinética , S-Nitrosoglutationa/farmacocinética , S-Nitrosotióis/análise , S-Nitrosotióis/farmacocinética , Umbeliferonas/análiseRESUMO
Phytochelatins (PCs) are naturally occurring thiol-rich peptides containing gamma (γ) peptide bonds and are well known for their metal-binding and detoxification capabilities. Whether synthetic phytochelatins (ECs) can be used as an alternative approach for enhancing the metal-binding capacity of plants has been investigated in this study. The metal-binding potential of ECs has been demonstrated in bacteria; however, no report has investigated the expression of ECs in plants. We have expressed three synthetic genes encoding ECs of different lengths in wild type (WT) Arabidopsis (Col-0 background) and a phytochelatin-deficient Arabidopsis mutant (cad1-3). After exposure to different heavy metals, the transgenic plants were examined for phenotypic changes, and metal accumulation was evaluated. The expression of EC genes rescued the sensitive phenotype of the cad1-3 mutant under heavy metal(loid) stress. Transgenic Arabidopsis plants expressing EC genes accumulated a significantly enhanced level of heavy metal(loid)s in comparison with the WT plant. The mutant complementation and enhanced heavy metal(loid) accumulation in the transgenic Arabidopsis plants suggest that ECs work in a manner similar to that of PCs in plants and that ECs could be used as an alternative for phytoremediation of heavy metal(loid) exposure.
Assuntos
Arabidopsis/metabolismo , Metais Pesados/metabolismo , Mutação , Fitoquelatinas/farmacologia , Ativação Transcricional , Arabidopsis/genética , Clonagem Molecular , Genes de Plantas , Teste de Complementação GenéticaRESUMO
Much of our dietary uptake of heavy metals is through the consumption of plants. A long-sought strategy to reduce chronic exposure to heavy metals is to develop plant varieties with reduced accumulation in edible tissues. Here, we describe that the fission yeast (Schizosaccharomyces pombe) phytochelatin (PC)-cadmium (Cd) transporter SpHMT1 produced in Arabidopsis (Arabidopsis thaliana) was localized to tonoplast, and enhanced tolerance to and accumulation of Cd2+, copper, arsenic, and zinc. The action of SpHMT1 requires PC substrates, and failed to confer Cd2+ tolerance and accumulation when glutathione and PC synthesis was blocked by L-buthionine sulfoximine, or only PC synthesis is blocked in the cad1-3 mutant, which is deficient in PC synthase. SpHMT1 expression enhanced vacuolar Cd2+ accumulation in wild-type Columbia-0, but not in cad1-3, where only approximately 35% of the Cd2+ in protoplasts was localized in vacuoles, in contrast to the near 100% found in wild-type vacuoles and approximately 25% in those of cad2-1 that synthesizes very low amounts of glutathione and PCs. Interestingly, constitutive SpHMT1 expression delayed root-to-shoot metal transport, and root-targeted expression confirmed that roots can serve as a sink to reduce metal contents in shoots and seeds. These findings suggest that SpHMT1 function requires PCs in Arabidopsis, and it is feasible to promote food safety by engineering plants using SpHMT1 to decrease metal accumulation in edible tissues.
Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Arabidopsis/metabolismo , Cádmio/metabolismo , Fitoquelatinas/farmacologia , Schizosaccharomyces/metabolismo , Sementes/metabolismo , Vacúolos/metabolismo , Adaptação Fisiológica/efeitos dos fármacos , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Transporte Biológico/efeitos dos fármacos , Butionina Sulfoximina/farmacologia , Cádmio/toxicidade , Citosol/efeitos dos fármacos , Citosol/metabolismo , Glutationa/metabolismo , Dados de Sequência Molecular , Mutação/genética , Especificidade de Órgãos/efeitos dos fármacos , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/metabolismo , Plantas Geneticamente Modificadas , Schizosaccharomyces/efeitos dos fármacos , Sementes/efeitos dos fármacos , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/metabolismo , Vacúolos/efeitos dos fármacosRESUMO
Heavy metals can cause several genotoxic effects on cells, including oxidative stress, DNA sequence breakage and protein modification. Among the body organs, skin is certainly the most exposed to heavy metal stress and thus the most damaged by the toxic effects that these chemicals cause. Moreover, heavy metals, in particular nickel, can induce the over-expression of collagenases (enzymes responsible for collagen degradation), leading to weakening of the skin extracellular matrix. Plants have evolved sophisticated mechanisms to protect their cells from heavy metal toxicity, including the synthesis of metal chelating proteins and peptides, such as metallothioneins and phytochelatins (PC), which capture the metals and prevent the damages on the cellular structures. To protect human skin cells from heavy metal toxicity, we developed a new cosmetic active ingredient from Lycopersicon esculentum (tomato) cultured stem cells. This product, besides its high content of antioxidant compounds, contained PC, effective in the protection of skin cells towards heavy metal toxicity. We have demonstrated that this new product preserves nuclear DNA integrity from heavy metal damages, by inducing genes responsible for DNA repair and protection, and neutralizes the effect of heavy metals on collagen degradation, by inhibiting collagenase expression and inducing the synthesis of new collagen.
Assuntos
Antioxidantes/farmacologia , Cosméticos/farmacologia , Metais Pesados/toxicidade , Extratos Vegetais/farmacologia , Pele/efeitos dos fármacos , Solanum lycopersicum/química , Animais , Antioxidantes/isolamento & purificação , Sobrevivência Celular/efeitos dos fármacos , Colágeno/metabolismo , Cosméticos/isolamento & purificação , Queratinócitos/efeitos dos fármacos , Solanum lycopersicum/citologia , Camundongos , Células NIH 3T3 , Fitoquelatinas/farmacologia , Extratos Vegetais/isolamento & purificação , RNA/química , RNA/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Pele/metabolismo , Pele/patologia , Espectrometria de Massas em TandemRESUMO
This study investigates the in vitro bioactivity of S-nitrosophytochelatins (SNOPCs), oligopeptide analogues of S-nitrosoglutathione (GSNO), and their mechanisms of nitric oxide (NO) delivery. SNOPCs were more potent than GSNO in inhibiting platelet aggregation and stimulating vasorelaxation. Their potency was related to the number of S-nitrosated moieties per mole compound. Transnitrosation reactions with cell membrane surface components were shown to be the primary mode of NO delivery to intracellular targets for SNOPCs, while delivery via γ-glutamyl transpeptidase was unique to GSNO. Due to rapid NO release, larger SNOPCs elicited a more transitory effect compared to smaller compounds. The duration of effect was influenced by compound molecular weight, NO release kinetics, ability to undergo transnitrosation, and incubation time with tissues. In summary, a new oligopeptide NO delivery system based on SNOPCs was shown to be biologically active and can be used to investigate the mechanisms of NO delivery to intracellular targets.
Assuntos
Aorta/efeitos dos fármacos , Materiais Biomiméticos/farmacologia , Proteínas de Transporte/farmacologia , Sistemas de Liberação de Medicamentos/métodos , Óxido Nítrico/metabolismo , Fitoquelatinas/farmacologia , S-Nitrosoglutationa/farmacologia , Vasodilatação/efeitos dos fármacos , Animais , Aorta/fisiologia , Transporte Biológico/efeitos dos fármacos , Materiais Biomiméticos/química , Materiais Biomiméticos/metabolismo , Plaquetas/efeitos dos fármacos , Proteínas de Transporte/química , Proteínas de Transporte/metabolismo , Humanos , Fitoquelatinas/química , Fitoquelatinas/metabolismo , Inibidores da Agregação Plaquetária/farmacologia , Ratos , S-Nitrosoglutationa/análogos & derivados , Técnicas de Cultura de Tecidos , Vasodilatação/fisiologia , gama-Glutamiltransferase/metabolismoRESUMO
Exposure to cadmium (Cd(2+)) can result in cell death, but the molecular mechanisms of Cd(2+) cytotoxicity in plants are not fully understood. Here, we show that Arabidopsis (Arabidopsis thaliana) cell suspension cultures underwent a process of programmed cell death when exposed to 100 and 150 microm CdCl(2) and that this process resembled an accelerated senescence, as suggested by the expression of the marker senescence-associated gene12 (SAG12). CdCl(2) treatment was accompanied by a rapid increase in nitric oxide (NO) and phytochelatin synthesis, which continued to be high as long as cells remained viable. Hydrogen peroxide production was a later event and preceded the rise of cell death by about 24 h. Inhibition of NO synthesis by N(G)-monomethyl-arginine monoacetate resulted in partial prevention of hydrogen peroxide increase, SAG12 expression, and mortality, indicating that NO is actually required for Cd(2+)-induced cell death. NO also modulated the extent of phytochelatin content, and possibly their function, by S-nitrosylation. These results shed light on the signaling events controlling Cd(2+) cytotoxicity in plants.
Assuntos
Apoptose/efeitos dos fármacos , Arabidopsis/efeitos dos fármacos , Cádmio/toxicidade , Óxido Nítrico/fisiologia , Apoptose/fisiologia , Arabidopsis/citologia , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Ascorbato Peroxidases , Catalase/metabolismo , Técnicas de Cultura de Células , Senescência Celular/efeitos dos fármacos , Cisteína Endopeptidases/metabolismo , Peróxido de Hidrogênio/metabolismo , Óxido Nítrico/metabolismo , Peroxidases/metabolismo , Fitoquelatinas/farmacologia , Transdução de SinaisRESUMO
Phytochelatins (PCs) are heavy-metal-binding peptides found in some eukaryotes. This study investigates the use of plant-derived PCs for the inhibition of metal-induced protein aggregation. The results of this study show that PCs inhibit zinc-induced alpha-crystallin aggregation, and suggest that PCs might be useful as anti-cataract agents.