Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Nutrients ; 16(8)2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38674865

RESUMO

Alcoholic Fatty Liver Disease (AFLD) is characterized by the accumulation of lipids in liver cells owing to the metabolism of ethanol. This process leads to a decrease in the NAD+/NADH ratio and the generation of reactive oxygen species. A systematic review and meta-analysis were conducted to investigate the role of oxidative stress in AFLD. A total of 201 eligible manuscripts were included, which revealed that animals with AFLD exhibited elevated expression of CYP2E1, decreased enzymatic activity of antioxidant enzymes, and reduced levels of the transcription factor Nrf2, which plays a pivotal role in the synthesis of antioxidant enzymes. Furthermore, animals with AFLD exhibited increased levels of lipid peroxidation markers and carbonylated proteins, collectively contributing to a weakened antioxidant defense and increased oxidative damage. The liver damage in AFLD was supported by significantly higher activity of alanine and aspartate aminotransferase enzymes. Moreover, animals with AFLD had increased levels of triacylglycerol in the serum and liver, likely due to reduced fatty acid metabolism caused by decreased PPAR-α expression, which is responsible for fatty acid oxidation, and increased expression of SREBP-1c, which is involved in fatty acid synthesis. With regard to inflammation, animals with AFLD exhibited elevated levels of pro-inflammatory cytokines, including TNF-a, IL-1ß, and IL-6. The heightened oxidative stress, along with inflammation, led to an upregulation of cell death markers, such as caspase-3, and an increased Bax/Bcl-2 ratio. Overall, the findings of the review and meta-analysis indicate that ethanol metabolism reduces important markers of antioxidant defense while increasing inflammatory and apoptotic markers, thereby contributing to the development of AFLD.


Assuntos
Fígado Gorduroso Alcoólico , Estresse Oxidativo , Animais , Humanos , Antioxidantes/metabolismo , Citocromo P-450 CYP2E1/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Fígado Gorduroso Alcoólico/metabolismo , Peroxidação de Lipídeos , Fígado/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Espécies Reativas de Oxigênio/metabolismo
2.
Curr Top Med Chem ; 23(23): 2197-2213, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37282633

RESUMO

Calotropis procera (Aiton) Dryand (Apocynaceae), popularly known as milkweed, has been traditionally used to treat diseases particularly associated with gastric disorders, skin disease and inflammatory processes. The present study aimed to review the current scientific evidence regarding the pharmacological effects of C. procera extracted phytochemicals and possible research opportunities as complementary and alternative medicine. Scientific publications were searched in various electronic databases (PubMed, Scopus, Web of Science, Google Scholar, Springer, Wiley, and Mendeley) using the following search terms: Calotropis procera, medicinal plants, toxicity, phytochemical characterization, and biological effects. Collected data showed that cardenolides, steroid glycoside and flavonoids are the main classes of phytochemicals identified in C. procera latex and leaves. In addition, lignans, terpenes, coumarins, and phenolic acids have been reported. These metabolites have been correlated with their biological activities, including mainly antioxidant, anti-inflammatory, antitumoral, hypoglycemic, gastric protective, anti-microbial, insecticide, anti-fungal, anti-parasitic, among others. However, some of the studies were carried out with only a single dose or with a high dose not achievable under physiological conditions. Therefore, the validity of C. procera biological activity may be questionable. Not less important to highlight are the risks associated with its use and the possibility of accumulation of heavy metals that can be toxic. Furthermore, there are no clinical trials with C. procera to date. In conclusion, the need of bioassayguided isolation of bioactive compounds, bioavailability and efficacy, as well as pharmacological and toxicity studies, are needed using in vivo models and clinical trials in order to support the traditionally claimed health benefits.


Assuntos
Apocynaceae , Calotropis , Calotropis/química , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Extratos Vegetais/química , Látex/química , Látex/farmacologia
3.
Cancers (Basel) ; 15(8)2023 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-37190229

RESUMO

BACKGROUND: Studies have suggested the chemopreventive effects of anthocyanins on breast cancer carcinogenesis. This systematic review and meta-analysis aimed to evaluate the effect of anthocyanins on triple-negative breast cancer cells (TNBC) cultured in vitro. METHODS: We searched for all relevant studies that evaluated the mechanisms of migration, invasion, Akt/mTOR and MAPK pathways, and apoptosis, using PubMed and Scopus. Means and standard deviation were used, and a randomized effects model was applied, with a confidence interval of 95%. Statistical heterogeneity between studies was assessed using the Chi2 test and I2 statistics. All analyses were performed using RevMan software (version 5.4). RESULTS: Eleven studies were included in the systematic review and ten in the meta-analysis, where the roles of anthocyanin-enriched extract or cyanidin-3-O-glucoside (C-3-O-G) on MDA-MB-231 and MDA-MB-453 cells were investigated. DISCUSSION: There was a significant reduction in invasion (mean difference: -98.64; 95% CI: -153.98, -43.3; p ˂ 0.00001) and migration (mean difference: -90.13; 95% CI: -130.57, -49.68; p ˂ 0.00001) in TNBC cells after anthocyanins treatment. Anthocyanins also downregulated Akt (mean difference: -0.63; 95% CI: -0.70, -0.57; p ˂ 0.00001) and mTOR (mean difference: -0.93; 95% CI: -1.58, -0.29; p = 0.005), while JNK (mean difference: -0.06; 95% CI: -1.21, 1.09; p = 0.92) and p38 (mean difference: 0.05; 95% CI: -1.32, 1.41; p = 0.95) were not modulated. There was also an increase in cleaved caspase-3 (mean difference: 1.13; 95% CI: 0.11, 2.16; p = 0.03), cleaved caspase-8 (mean difference: 1.64; 95% CI: 0.05, 3.22; p = 0.04), and cleaved PARP (mean difference: 0.93; 95% CI: 0.54, 1.32). Although the difference between control and anthocyanin groups was not significant regarding apoptosis rate (mean difference: 3.63; 95% CI: -2.88, 10.14; p = 0.27), the analysis between subgroups showed that anthocyanins are more favorable in inducing overall apoptosis (p ˂ 0.00001). CONCLUSION: The results show that anthocyanins hold promise in fighting against TNBC, but their effects should not be generalized. In addition, further primary studies should be conducted so that more accurate conclusions can be drawn.

4.
Anticancer Agents Med Chem ; 22(18): 3136-3147, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35676853

RESUMO

INTRODUCTION: Calotropis procera (Aiton) Dryand (Apocynaceae) is an herb that has been commonly used in folk medicine to treat various diseases for more than 1500 years. AIMS: Our goal was to investigate the anti-metastatic effects of phenolics extracted from C. procera (CphE) against 4T1 breast cancer cells and in BALB/c mice. METHODS: 4T1 cells were treated with CphE and quercetin (positive control) at concentrations that inhibited cell viability by 50% (IC50). Levels of reactive oxygen species (ROS), wound healing, and protein expressions were determined following standard protocols. For the in vivo pilot study, the syngeneic BALB/c mouse model was used. 4T1 cells were injected into mammary fat pads. Tumors were allowed to grow for 9 days before gavage treatment with CphE (150 mg GAE/kg/day) or PBS (controls) for one week. Excised tumors, liver, and lungs were analyzed for gene and protein expression and histology. RESULTS: In vitro results showed that CphE suppressed cell viability through apoptosis induction, via caspase-3 cleavage and total PARP reduction. CphE also scavenged ROS and suppressed Akt, mTOR, ERK1/2, CREB, and Src activation contributing to cell motility inhibition. CphE reduced IR, PTEN, TSC2, p70S6, and RPS6, protein levels, which are proteins involved in the PI3K/Akt/mTOR pathway, suggesting this pathway as CphE primary target. In vivo results showed downregulation of ERK1/2 activation by phosphorylation in tumor tissues, accompanied by angiogenesis reduction in tumor and lung tissues. A reduction of Cenpf mRNA levels in liver and lung tissues strongly suggested anti-invasive cancer activity of CphE. CONCLUSION: CphE inhibited 4T1 cell signal pathways that play a key role in cell growth and invasion. The potential for in vitro results to be translated in vivo was confirmed. A complete animal study is a guarantee to confirm the CphE anticancer and antimetastatic activity in vivo.


Assuntos
Calotropis , Neoplasias , Animais , Apoptose , Calotropis/genética , Calotropis/metabolismo , Caspase 3/metabolismo , Linhagem Celular Tumoral , Camundongos , Camundongos Endogâmicos BALB C , Fosfatidilinositol 3-Quinases/metabolismo , Projetos Piloto , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Quercetina/farmacologia , RNA Mensageiro , Espécies Reativas de Oxigênio , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo
5.
Tissue Cell ; 75: 101742, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35101687

RESUMO

Mesenchymal stem cell (MSC) have immunomodulatory and anti-inflammatory effects, allowing its application in the therapy of different diseases, including articular cartilage injuries, which induce the establishment of a pro-regenerative microenvironment in the injured tissue. Therefore, our objective was to isolate, characterize and differentiate cartilage cells from different joints of New Zealand rabbit (Oryctolagus cuniculus), in order to verify their potential as MSC for future clinical use. For this, cartilage fragments were isolated from the humerus-radio-ulnar joints, humeral scapula, femoro-tibio-patellar, and lame femoris from rabbits. The results showed that the cells were rounded in the center of the plate and fibroblastoids in the periphery. After thawing, the cells did not change their growth time in culture, nor their morphology. The cells showed labeling for mesenchymal stem cell, cytoskeleton, pluripotency and cell proliferation, but not for hematopoiesis markers (CD105+ and CD34-). We also observed that, when induced, they were able to differentiate into osteogenic, adipogenic, and chondrogenic cells. After application of these cells in nude mice, no tumor growth was observed in spleen, kidney, liver, lung and heart. Therefore, we conclude that cells isolated from the articular cartilage of rabbits present characteristics of MSC with potential for future clinical applications.


Assuntos
Cartilagem Articular , Células-Tronco Mesenquimais , Animais , Diferenciação Celular , Células Cultivadas , Condrócitos , Condrogênese , Imunofenotipagem , Camundongos , Camundongos Nus , Coelhos , Células-Tronco
6.
J Food Biochem ; 46(1): e14026, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34873724

RESUMO

Osteosarcoma (OS) is a primary malignant bone tumor mainly affecting children, teenagers and young adults, being associated with early metastasis and poor prognosis. The beneficial effects of polyphenols have been investigated in different areas, including their potential to fight OS. Polyphenols are believed to reduce morbidity and/or slow down the development of cancer. This review aimed to assess the effect of polyphenols in OS and investigate their molecular mechanisms. It was observed that the broad spectrum of health-promoting properties of plant polyphenols in OS occurs mainly due to modulation of reactive oxygen species, anti-inflammatory activity, anti-angiogenesis, apoptosis inducer, inhibition of invasion and metastasis. However, it is worth mentioning that although the promising effects of polyphenols in the fight against OS, most of the studies have been performed using in vitro and in vivo animal models. Therefore, studies in humans are needed to validate the effectiveness of polyphenols in OS treatment. PRACTICAL APPLICATIONS: Polyphenols are widely used for various diseases, however, until now, their real role in the treatment of osteosarcoma remains unknown. This review provides a broad spectrum of research conducted with polyphenols and their potential as adjuvant therapy in the treatment of osteosarcoma. However, prior to their clinical application for osteosarcoma treatment, there is a need to isolate and identify specific polyphenolic compounds with high antitumor activity, increase their oral bioavailability, and to investigate their interactions with chemotherapeutic drugs being used in clinical practice.


Assuntos
Neoplasias Ósseas , Osteossarcoma , Animais , Apoptose , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/patologia , Proliferação de Células , Osteossarcoma/tratamento farmacológico , Osteossarcoma/patologia , Polifenóis/farmacologia , Polifenóis/uso terapêutico
7.
J Med Food ; 24(9): 968-977, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33523759

RESUMO

Jaboticaba (Myrciaria cauliflora), a Brazilian fruit, is a good source of dietary fiber and phenolic compounds, which are concentrated mainly in the peel. These compounds have been considered promising in prevention and treatment of hypercholesterolemia and hepatic steatosis. In this study, we investigated the effects of 4% jaboticaba peel powder (JPP) supplementation on cholesterol metabolism and hepatic steatosis in livers of rats fed a high-fat (HF) diet. The rats were fed a standard AIN-93M (control) diet or an HF diet containing 32% lard and 1% cholesterol, both with and without 4% JPP. The M. cauliflora peel composition revealed a low-lipid high-fiber content and phenolic compounds. The phenolic compounds in JPP, tentatively identified by high-performance liquid chromatography and mass spectrometry (HPLC-MS/MS) analysis, were confirmed to contain phenolic acids, flavonoids, and anthocyanins. Moreover, JPP presented significant antioxidant activity in vitro and was not cytotoxic to HepG2 cells, as determined by the lactate dehydrogenase (LDH) assay. After 6 weeks of treatment, our results showed that JPP supplementation increased lipid excretion in feces, reduced serum levels of total cholesterol and nonhigh-density lipoprotein cholesterol, decreased serum aspartate aminotransferase (AST) activity, and attenuated hepatic steatosis severity in rats fed the HF diet. Furthermore, JPP treatment downregulated expression of ACAT-1, LXR-α, CYP7A1, and ABCG5 genes. Therefore, jaboticaba peel may represent a viable dietary strategy to prevent nonalcoholic fatty liver disease as the JPP treatment alleviated hepatic steatosis through improvement of serum lipid profiles and modulation of mRNA expression of genes involved in cholesterol metabolism.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Animais , Antocianinas , Colesterol , Dieta Hiperlipídica/efeitos adversos , Suplementos Nutricionais , Fígado , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/prevenção & controle , Ratos , Espectrometria de Massas em Tandem
8.
Adv Exp Med Biol ; 1245: 1-38, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32266651

RESUMO

The extracellular matrix (ECM) regulates the development and maintains tissue homeostasis. The ECM is composed of a complex network of molecules presenting distinct biochemical properties to regulate cell growth, survival, motility, and differentiation. Among their components, proteoglycans (PGs) are considered one of the main components of ECM. Its composition, biomechanics, and anisotropy are exquisitely tuned to reflect the physiological state of the tissue. The loss of ECM's homeostasis is seen as one of the hallmarks of cancer and, typically, defines transitional events in tumor progression and metastasis. In this chapter, we discuss the types of proteoglycans and their roles in cancer. It has been observed that the amount of some ECM components is increased, while others are decreased, depending on the type of tumor. However, both conditions corroborate with tumor progression and malignancy. Therefore, ECM components have an increasingly important role in carcinogenesis and this leads us to believe that their understanding may be a key in the discovery of new anti-tumor therapies. In this book, the main ECM components will be discussed in more detail in each chapter.


Assuntos
Matriz Extracelular , Neoplasias , Microambiente Tumoral , Carcinogênese , Movimento Celular , Humanos , Neoplasias/patologia , Proteoglicanas
9.
Oxid Med Cell Longev ; 2018: 5048031, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30524657

RESUMO

Sepsis is a complex disease and is the cause of many deaths worldwide. Sepsis pathogenesis involves a dysregulated inflammatory response with consequent production of inflammatory mediators and reactive species. The production and excessive release of these substances into the systemic circulation trigger various cellular and metabolic alterations that are observed during the disease evolution. Thus, more studies have been carried out to investigate the therapeutic potential of plants such as Morus nigra L., popularly known as black mulberry. Studies have shown that plants belonging to the Morus genus are rich in secondary metabolites such as flavonoids which are associated with important biological activities as antioxidant and anti-inflammatory actions. Based on this context, the objective of our study was to evaluate the anti-inflammatory and antioxidant properties of Morus nigra L. in a sepsis model induced by LPS. Male C57BL/6 mice were distributed in four groups: control, sepsis, sepsis treated with leaf extract of mulberry, and sepsis treated with mulberry pulp. The animals were treated with 100 µL of their respective treatments for twenty-one days. Sepsis was induced at the 21st day with lipopolysaccharide (LPS) by intraperitoneal injection. The animals were euthanized 24 hours after receiving the LPS injection. The data obtained were analyzed in GraphPad Prism 6.0 software. Our results showed that treatment with either extract significantly decreased the number of leukocytes in the bronchoalveolar lavage fluid and serum levels of TNF in septic animals. Regarding the redox status, the treatments significantly decreased the antioxidant activity of the enzyme glutathione peroxidase. Regarding metalloproteinase type 2, it was observed that the treatment with black mulberry pulp was able to significantly reduce the activity of this enzyme concerning the sepsis group. Finally, these results together promoted an increase in the animal's survival that received the black mulberry leaf or pulp extract.


Assuntos
Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Frutas/química , Lipopolissacarídeos/toxicidade , Morus/química , Extratos Vegetais/farmacologia , Sepse/tratamento farmacológico , Animais , Modelos Animais de Doenças , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Sepse/induzido quimicamente , Sepse/metabolismo , Sepse/patologia
10.
J Ethnopharmacol ; 215: 1-13, 2018 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-29289796

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Baccharis trimera has been traditionally used in Brazil to treat liver diseases. AIM OF THE STUDY: To evaluate the protective effect of Baccharis trimera in an ethanol induced hepatotoxicity model. MATERIALS AND METHODS: The antioxidant capacity was evaluated in vitro by the ability to scavenged the DPPH radical, by the quantification of ROS, NO and the transcription factor Nrf2. Hepatotoxicity was induced in animals by administration of absolute ethanol for 2 days (acute) or with ethanol diluted for 28 days (chronic). The biochemical parameters of hepatic function (ALT and AST), renal function (urea and creatinine) and lipid profile (total cholesterol, triglycerides and HDL) were evaluated. In addition to antioxidant defense (SOD, catalase, glutathione), oxidative damage markers (TBARS and carbonylated protein), MMP-2 activity and liver histology. RESULTS: Baccharis trimera promoted a decrease in ROS and NO, and at low concentrations promoted increased transcription of Nrf2. In the acute experiment it promoted increase of HDL, in the activity of SOD and GPx, besides diminishing TBARS and microesteatosis. Already in the chronic experiment B. trimera improved the hepatic and renal profile, decreased triglycerides and MMP-2 activity, in addition to diminishing microesteatosis. CONCLUSION: We believe that B. trimera action is possibly more associated with direct neutralizing effects or inhibition of reactive species production pathways rather than the modulation of the antioxidant enzymes activity. Thus it is possible to infer that the biological effects triggered by adaptive responses are complex and multifactorial depending on the dose, the time and the compounds used.


Assuntos
Baccharis/química , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Extratos Vegetais/farmacologia , Animais , Biomarcadores , Sobrevivência Celular/efeitos dos fármacos , Glutationa Redutase/metabolismo , Células Hep G2 , Humanos , Fígado/enzimologia , Fígado/patologia , Óxido Nítrico , Estresse Oxidativo , Fitoterapia , Extratos Vegetais/química , Ratos , Espécies Reativas de Oxigênio
11.
Artigo em Inglês | MEDLINE | ID: mdl-30622608

RESUMO

Diabetes mellitus is a metabolic disorder that causes severe complications due to the increased oxidative stress induced by disease. Many plants are popularly used in the treatment of diabetes, e.g., Baccharis trimera (carqueja). The aim of this study was to explore the potential application of the B. trimera hydroethanolic extract in preventing redox stress induced by diabetes and its hypoglycemic properties. Experiments were conducted with 48 female rats, divided into 6 groups, named C (control), C600 (control + extract 600 mg/kg), C1200 (control + extract 1200 mg/kg), D (diabetic), D600 (diabetic + 600 mg/kg), and D1200 (diabetic + 1200 mg/kg). Type 1 diabetes was induced with alloxan, and the animals presented hyperglycemia and reduction in insulin and body weight. After seven days of experimentation, the nontreated diabetic group showed changes in biochemical parameters (urea, triacylglycerol, alanine aminotransferase, and aspartate aminotransferase) and increased carbonyl protein levels. Regarding the antioxidant enzymes, an increase in superoxide dismutase activity was observed but in comparison a decrease in catalase and glutathione peroxidase activity was noted which suggests that diabetic rats suffered redox stress. In addition, the mRNA of superoxide dismutase, catalase, and glutathione peroxidase enzymes were altered. Treatment of diabetic rats with B. trimera extract resulted in an improved glycemic profile and liver function, decreased oxidative damage, and altered the expression of mRNA of the antioxidants enzymes. These results together suggest that B. trimera hydroethanolic extract has a protective effect against diabetes.

12.
Exp Biol Med (Maywood) ; 242(3): 333-343, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28103717

RESUMO

Baccharis trimera, popularly known as "carqueja", is a native South-American plant possessing a high concentration of polyphenolic compounds and therefore high antioxidant potential. Despite the antioxidant potential described for B. trimera, there are no reports concerning the signaling pathways involved in this process. So, the aim of the present study was to assess the influence of B. trimera on the modulation of PKC signaling pathway and to characterize the effect of the nicotinamide adenine dinucleotide phosphate oxidase enzyme (NOX) on the generation of reactive oxygen species in SK Hep-1 cells. SK-Hep 1 cells were treated with B. trimera, quercetin, or rutin and then stimulated or not with PMA/ionomycin and labeled with carboxy H2DCFDA for detection of reactive oxygen species by flow cytometer. The PKC expression by Western blot and enzyme activity was performed to evaluate the influence of B. trimera and quercetin on PKC signaling pathway. p47 phox and p47 phox phosphorylated expression was performed by Western blot to evaluate the influence of B. trimera on p47 phox phosphorylation. The results showed that cells stimulated with PMA/ionomycin (activators of PKC) showed significantly increased reactive oxygen species production, and this production returned to baseline levels after treatment with DPI (NOX inhibitor). Both B. trimera and quercetin modulated reactive oxygen species production through the inhibition of PKC protein expression and enzymatic activity, also with inhibition of p47 phox phosphorylation. Taken together, these results suggest that B. trimera has a potential mechanism for inhibiting reactive oxygen species production through the PKC signaling pathway and inhibition subunit p47 phox phosphorylation of nicotinamide adenine dinucleotide phosphate oxidase.


Assuntos
Antioxidantes/farmacologia , Baccharis/química , NADPH Oxidases/metabolismo , Proteína Quinase C/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Linhagem Celular , Hepatócitos/metabolismo , Humanos , Ionomicina/farmacologia , NADPH Oxidases/antagonistas & inibidores , Estresse Oxidativo/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Preparações de Plantas/farmacologia , Quercetina/farmacologia , Rutina/farmacologia , Transdução de Sinais/efeitos dos fármacos
13.
J Environ Manage ; 183(Pt 3): 771-776, 2016 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-27652581

RESUMO

Because of its precision and accuracy, Pb-Fire assay is the most employed method for gold analysis in geological materials. At the second stage of the method, namely cupellation, lead is oxidized to PbO which is absorbed by the cupel, leading to metallic gold as a tiny bend at the bottom of the recipient. After cupellation, cupel becomes highly contaminated with lead, making its disposal a serious risk of environmental contamination. In the present work, a leaching process for removing lead from cupel waste is proposed, which allowed for removing 96% of PbO by weight. After a precipitation step, 92.0% of lead was recovered from leachates in the form of PbSO4. Lead in the solid wastes left by the extraction was above the limit established by Brazilian legislation and these were classified as non-hazardous. Finally, secondary effluents generated after the precipitation step presented lead content more than twenty times lower than that of leachates from cupel waste. Tons of cupel waste are annually generated from gold analysis by Pb-Fire assay. Thus, the proposed method can contribute to prevent the discharge of high amounts of lead into the environment. Also, recovery of lead can help to partially meet the industrial demand for lead compounds.


Assuntos
Ouro/análise , Resíduos Perigosos , Chumbo/isolamento & purificação , Eliminação de Resíduos/métodos , Resíduos Sólidos , Brasil , Resíduos Perigosos/análise , Resíduos Perigosos/legislação & jurisprudência , Chumbo/análise , Resíduos Sólidos/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA