RESUMO
Nephrotoxicity is an important adverse effect of oxidative stress induced by hexavalent chromium [Cr(VI)]. The effect of ellagic acid, a dietary polyphenolic compound with potent antioxidant activity, was investigated in Cr(VI)-induced kidney injury. Six groups of male Wistar rats were treated intragastrically with vehicle or ellagic acid (15 and 30 mg/kg) for 10 days. On day 10, rats received saline or Cr(VI) (K2Cr2O7 15 mg/kg) subcutaneously. Cr(VI) significantly increased kidney weight, affected kidney function assessed by biomarkers in blood and urine (protein, creatinine and urea nitrogen), caused histological changes (tubular injury and glomerular capillary tuft damage), increased markers of oxidative stress and reduced the activity of antioxidant enzymes. In addition, Cr(VI) altered mitochondrial ultrastructure, impaired mitochondrial respiration, increased lipid peroxidation, and inhibited the function of mitochondrial enzymes. Pretreatment with ellagic acid (30 mg/kg) attenuated all the aforementioned alterations. Furthermore, we explored whether ellagic acid might regulate the tumor necrosis factor-alpha (TNF-α)/receptor-interacting protein kinase 3 (RIPK3) pathway, reducing Cr(VI)-induced tubular necrosis. Cr(VI) upregulated both TNF-α and RIPK3, but ellagic acid only decreased TNF-α levels, having no effect on RIPK3 content. Therefore, understanding the mechanisms through which Cr(VI) promotes necroptosis is crucial for future studies, in order to design strategies to mitigate kidney damage. In conclusion, ellagic acid attenuated Cr(VI)-induced renal alterations by preventing oxidative stress, supporting enzymatic activities, suppressing TNF-α, and preserving mitochondrial ultrastructure and function, most likely due to its antioxidant properties.
Assuntos
Antioxidantes , Fator de Necrose Tumoral alfa , Animais , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Biomarcadores/metabolismo , Cromo/metabolismo , Cromo/toxicidade , Creatinina , Ácido Elágico/metabolismo , Ácido Elágico/farmacologia , Rim , Masculino , Mitocôndrias/metabolismo , Nitrogênio/metabolismo , Estresse Oxidativo , Proteínas Quinases/metabolismo , Ratos , Ratos Wistar , Fator de Necrose Tumoral alfa/metabolismo , Ureia/metabolismoRESUMO
The comparison of chemical and histopathological data obtained from the analysis of excised tumor fragments oral squamous cell carcinoma (OSCC) with the demographic and clinical evolution data is an effective strategy scarcely explored in OSCC studies. The aim was to analyze OSCC tissues for protein expression of enzymes related to oxidative stress and DNA repair and trace elements as candidates as markers of tumor aggressiveness and prognosis. Tumor fragments from 78 OSCC patients that had undergone ablative surgery were qualitatively analyzed by synchrotron micro-X-ray fluorescence for trace elements. Protein expression of SOD-1, Trx, Ref-1 and OGG1/2 was performed by immunohistochemistry. Sociodemographic, clinical, and histopathological data were obtained from 4-year follow-up records. Disease relapse was highest in patients with the presence of chlorine and chromium and lowest in those with tumors with high OGG1/2 expression. High expression of SOD-1, Trx, and Ref-1 was determinant of the larger tumor. Presence of trace elements can be markers of disease prognosis. High expression of enzymes related to oxidative stress or to DNA repair can be either harmful by stimulating tumor growth or beneficial by diminishing relapse rates. Interference on these players may bring novel strategies for the therapeutic management of OSCC patients.
Assuntos
Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas , Cloro/metabolismo , Cromo/metabolismo , Reparo do DNA , DNA de Neoplasias/metabolismo , Neoplasias Bucais , Proteínas de Neoplasias/metabolismo , Estresse Oxidativo , Idoso , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/diagnóstico , Neoplasias Bucais/metabolismo , Neoplasias Bucais/patologia , Prognóstico , Estudos RetrospectivosRESUMO
Despite the knowledge about heavy metals toxicity on humans, its use is widely spread mainly for industrial processes. Chromium is an element that belongs to this group and although it is present in our daily diet, it can also be harmful for humans, causing skin allergies and increasing the risk of lung cancer, among other health effects reported. In this review, we highlight its nutritional role, its toxicokinetic and toxicodynamic in humans, its regulation in the industry and the biomonitoring proposal of this element in blood and urine samples with the aim to control the level of exposure of the workers in military industry and also of the general population.
Assuntos
Cromo/metabolismo , Dermatite/metabolismo , Neoplasias Pulmonares/metabolismo , Cromo/efeitos adversos , Cromo/análise , Dermatite/sangue , Dermatite/urina , Monitoramento Ambiental , Humanos , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/urinaRESUMO
AIM: Chemically disparate toxic organic and/or inorganic molecules produced by anthropogenic activities often hinder the bioremediation process. This research was conducted to understand the capacity of Streptomyces sp. MC1 to remove chemically disparate toxics such as Cr(VI) or phenanthrene. METHODS AND RESULTS: Genomic, metabolic modeling and proteomic approaches were used in this study. Our results demonstrated that Streptomyces sp. MC1 has the genetic determinants to remove Cr(VI) or degrade phenanthrene. Proteomics showed that these genetic determinants were expressed. Metabolic versatility of the strain was confirmed by two metabolic models in complex and minimal media. Interestingly, our results also suggested a connection between the degradation of phenanthrene and synthesis of specialized metabolites. CONCLUSIONS: Streptomyces sp. MC1 has the genetic and physiological potential to remove Cr(VI) or degrade phenanthrene SIGNIFICANCE AND IMPACT OF STUDY: The probability of a microorganism to survive in the presence of different contaminants depends on its genetic potential and the ability to express it. The genetic and proteomic profiles obtained for Streptomyces sp. MC1 can be recommended as model and predict if other Streptomyces strains can be used in bioremediation processes. Our work also hypothesized that intermediates of the phenanthrene degradation serve as precursors for the specialized metabolism.
Assuntos
Cromo/metabolismo , Fenantrenos/metabolismo , Streptomyces/genética , Streptomyces/metabolismo , Biodegradação Ambiental , Genômica , ProteômicaRESUMO
Soil management using fertilizers can modify soil chemical, biochemical and biological properties, including the concentration of trace-elements as cadmium (Cd), chromium (Cd) and nickel (Ni). Bacterial isolates from Cd, Cr, and Ni-contaminated soil were evaluated for some characteristics for their use in bioremediation. Isolates (592) were obtained from soil samples (19) of three areas used in three maize cultivation systems: no-tillage and conventional tillage with the application of mineral fertilizers; minimum tillage with the application of sewage sludge. Four isolates were resistant to Cr3+ (3.06 mmol dm-3) and Cd2+ (2.92 mmol dm-3). One isolate was resistant to the three metals at 0.95 mmol dm-3. All isolates developed in a medium of Cd2+, Cr3+ and Ni2+ at 0.5 mmol dm-3, and removed Cd2+ (17-33%) and Cr6+ (60-70%). They were identified by sequencing of the gene 16S rRNA, as bacteria of the genera Paenibacillus, Burkholderia, Ensifer, and two Cupriavidus. One of the Cupriavidus isolate was able to remove 60% of Cr6+ from the culture medium and showed high indole acetic acid production capacity. We evaluated it in a microbe-plant system that could potentially be deployed in bioremediation by removing toxic metals from contaminated soil.
Assuntos
Bactérias/metabolismo , Cádmio/metabolismo , Cromo/metabolismo , Níquel/metabolismo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Agricultura , Bactérias/isolamento & purificação , Biodegradação Ambiental , Brasil , Clima TropicalRESUMO
Cellular response against different heavy metal stress differs with the metal. Arsenic and chromium are heavy metals and toxic to living systems. The concentration of these metals in seawater is very low. However, due to their solubility in nature, they actively enter cells via various transport mechanisms and cause damage to the cells. Brevibacterium casei #NIOSBA88, a marine-derived, gram-positive isolate was multi-metal tolerant. Proteomic analysis of this isolate in response to arsenic and chromium resulted in the identification of total 2549 proteins, out of which 880 proteins were found to be commonly expressed at 750 mgL-1 arsenic and 100 mgL-1 chromium and in absence of both the metals. In contrast, 533, 212, and 270 proteins were found to be unique in the absence of any metal, 750 mgL-1 of arsenic and 100 mgL-1 of chromium respectively. Proteins such as antibiotic biosynthesis monooxygenase, ArsR family transcriptional regulator, cytochrome C oxidase subunit II, and thioredoxin reductase were exclusively expressed only in response to arsenic and chromium. Other proteins like superoxide dismutase, lipid hydroperoxide reductase, and thioredoxin-disulfide reductase were found to be upregulated in response to both the metals. Most of the proteins involved in the normal cell functioning were found to be downregulated. Major metabolic functions affected include amino acid metabolism, carbohydrate metabolism, translation, and energy metabolism. Peptide mass fingerprinting of Brevibacterium casei #NIOSBA88 exposed to arsenic and chromium respectively revealed the deleterious effect of these metals on the bacterium and its strategy to overcome the stress.
Assuntos
Arsênio/metabolismo , Brevibacterium/metabolismo , Cromo/metabolismo , Proteômica , Proteínas de Bactérias/isolamento & purificação , Brevibacterium/efeitos dos fármacosRESUMO
Bacillus sp. SFC 500-1E, a bacterial strain isolated from tannery sediments, is able to remove Cr(VI) and simultaneously tolerate high concentrations of phenol. In this study, we used high-resolution microscopies, fluorescence polarization techniques, and several biochemical approaches to improve our understanding about the adaptive mechanisms of this strain to survive in the presence of Cr(VI) and phenol, both individually and simultaneously. Among adaptive strategies developed by Bacillus sp. SFC 500-1E, an increase in bacterial size, such as length, width, and height, and ultrastructural alterations, such as electron-dense precipitates, the presence of exopolymers, and cell lysis, are noteworthy. The exopolymers observed were consistent with the extensive biofilm formation and exopolysaccharides and extracellular protein quantification. At the cell membrane level, a rapid rigidity was induced in Cr(VI) + phenol treatment. This effect was counteracted after 16 h by changes at the level of phospholipids, mainly in the composition of fatty acids (FAs); in particular, an increase in the unsaturated fatty acid/saturated fatty acid ratio was detected. This study shows evidence of some adaptive responses displayed by Bacillus sp. SFC 500-1E, which allows it to survive in stressful conditions.
Assuntos
Bacillus/citologia , Bacillus/efeitos dos fármacos , Cromo/farmacologia , Fenol/farmacologia , Bacillus/metabolismo , Biodegradação Ambiental , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Membrana Celular/efeitos dos fármacos , Membrana Celular/fisiologia , Membrana Celular/ultraestrutura , Cromo/metabolismo , Matriz Extracelular de Substâncias Poliméricas/metabolismo , Ácidos Graxos/química , Fosfolipídeos/química , Estresse FisiológicoRESUMO
The potential of indigenously isolated bacteria from the Estância Velha stream to reduce Cr(VI) was evaluated and also the chromium contamination over the past ten years was verified in one of the most important industrial centers of Brazil, the "Brazilian Capital of Tanneries," Estância Velha municipality in the Rio Grande do Sul State, South Brazil. Samples were collected from the Estância Velha stream at the source (P1), as well as at upstream (P2) and downstream (P3) of the most demographically area. The bacterial strains reduced between 52.5 and 61.6% of 250 mg L-1 Cr(VI) in 48 h. The genus Acinetobacter was the most abundant and could efficiently reduce 500 mg L-1 of Cr(VI); for example, P2.8 and P2.9 strains of Acinetobacter ursingii reduced 21.3 and 24.5% of 500 mg L-1 of Cr(VI), respectively, after 48 h. Moreover, an analysis of Cr levels in the stream sediment reported up to 3594 mg. L-1 of total Cr and up to 138 mg. L-1 of Cr(VI) in 2009. Acinetobacter strains were identified as the most abundant and efficient in reducing Cr(VI), makes them an ideal candidate for cleaning environments contaminated with tannery effluents, an approach that is more cost-effective than the traditional methods.
Assuntos
Bactérias , Cromo/isolamento & purificação , Poluentes Ambientais/isolamento & purificação , Resíduos Industriais/análise , Rios , Bactérias/química , Bactérias/metabolismo , Biodegradação Ambiental , Brasil , Cromo/metabolismo , Poluentes Ambientais/metabolismo , Sedimentos Geológicos/química , Sedimentos Geológicos/microbiologia , Oxirredução , Rios/química , Rios/microbiologia , CurtumeRESUMO
With regards to health, chromium (Cr) is an ambiguous chemical element. Although it is considered to be an important micronutrient, it also is connected with several pathologies, including carcinogenicity. The mechanism of action of Cr and its compounds in humans is not yet fully understood. Currently, three possible mechanisms have been proposed for carcinogenesis: Cr(VI)-induced multistage carcinogenesis, genomic instability, and epigenetic modification. Therefore, in addition to the toxicity of this metal and its ions, human susceptibility to Cr-induced pathologies depends on external factors and individual characteristics, such as enzymatic polymorphisms, carriers, endogenous reducing system, adduct formation and stability, and efficiency of DNA repair mechanisms, among other factors. In fact, the variability of individual molecular constitutive factors, such as individual polymorphisms, creates an individualized environment for Cr toxicity. This mini-review contemplates the essential variables in this process.
Assuntos
Carcinogênese/efeitos dos fármacos , Carcinógenos/toxicidade , Cromo/metabolismo , Cromo/toxicidade , Epigênese Genética/efeitos dos fármacos , Instabilidade Genômica/efeitos dos fármacos , Redes e Vias Metabólicas/efeitos dos fármacos , Exposição Ambiental/efeitos adversos , Humanos , IndividualidadeRESUMO
The tannery is an important trade in various Peruvian regions; however, tannery effluents are a serious local environmental threat due to its highly toxics components and lack of efficient treatment. The untreated effluents produced by tannery factories in Arequipa Rio Seco Industrial Park (PIRS) have formed a lake in the region nearby. In this work, we study the capability of filamentous fungi species found in this effluents lake with potential for chromium (VI) bioremediation. Fourteen species of filamentous fungi were isolated; only two species were identified Penicillium citrinum and Trichoderma viride, and third strain identified as Penicillium sp. The filamentous fungi showed that are fully tolerant to chromium (VI) concentrations up to 100 mg/L. These fungal strains showed significant growth in chromium (VI) concentrations up to 250 mg/L. Tolerant index (TI) analysis revealed that P. citrinum and T. viride began adaptation to chromium (IV) concentrations of 250 and 500 mg/L, after 6 and 12 days, respectively. When exposed to higher Cr (VI) concentrations (1000 mg/L), only T. viride was able to show growth (enhance phase). Interestingly, one of the significant responses from these fungal strains to increasing chromium (VI) concentrations was an increment in secreted laccase enzymes. Our results show tolerance and adaptation to elevated concentrations of chromium (VI) of these fungal strains suggesting their potential as effective agents for bioremediation of tannery effluents.