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1.
Huan Jing Ke Xue ; 44(9): 4927-4940, 2023 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-37699811

RESUMO

The current situation of antibiotic pollution in lakes is critical. At present, most of the previous studies on antibiotics in lakes have focused on the spatiotemporal distribution and risk assessment, while less attention has been paid to the source apportionment. Ultra-high performance liquid chromatography-mass spectrometry was used to determine the concentration of tetracyclines (TCs), sulfonamides (SAs), and quinolones (QNs) in the samples. The source apportionment and source-specific risk of typical antibiotics in the study area were analyzed using the combination of a PMF model and risk quotients (RQ). The results showed that ① the total concentrations of target antibiotics (Σ antibiotics) ranged from ND to 2635 ng·L-1 for surface water and from ND to 259.8 ng·g-1 for sediments. ② The spatial distribution of QNs in surface water decreased from west to east, SAs decreased from middle to north and south, and TCs increased from middle to north and south. In the sediment, QNs decreased from middle to east and west, whereas SAs and TCs increased from east to west. ③ Aquaculture was the major antibiotic source, accounting for the highest proportion (33.2%), followed by sewage treatment plants (29.2%), livestock activities (18.9%), and domestic sewage (18.7%). ④ The ecological risk assessment results showed that enrofloxacin and flumequine were at a medium-high risk level. ⑤ For the spatial distribution of source-specific risk, the results showed that the aquaculture at S1 was at a high risk level, whereas the source-specific risks for other sites were at a medium-low risk level. In terms of source types, aquaculture was at a medium-high risk level, whereas the other sources were at a medium-low risk level. Therefore, considering the major sources and source-specific risk level of antibiotics, more precise and scientific antibiotic risk control should be adopted in Baiyangdian Lake.


Assuntos
Antibacterianos , Lagos , Esgotos , Sulfanilamida , Enrofloxacina , Sulfonamidas
3.
Ying Yong Sheng Tai Xue Bao ; 34(8): 2274-2284, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37681392

RESUMO

Sulfonamides (SAs) are the first broad-spectrum synthetic antimicrobial agents used in human health and veterinary medicine. The majority of SAs entering human body is discharged into aquatic environment in the form of parent material or metabolites. The residues of SAs and their metabolites in the aquatic environment and the development of drug resistance can be serious threats to ecosystems and human health. We summarized recent advances in the research of SAs. The main metabolite types of SAs and the distribution characteristics of metabolites in different aquatic environments were introduced. The ecotoxicology of SAs metabolites, especially the distribution and hazards of sulfonamide resistance genes (sul-ARGs), were discussed with emphasis. Finally, the future research works were proposed. This paper could provide basic information for further research on SAs.


Assuntos
Ecossistema , Ecotoxicologia , Humanos , Sulfanilamida , Sulfonamidas/toxicidade
5.
Nat Commun ; 14(1): 5709, 2023 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-37726279

RESUMO

The BCL-2 inhibitor Venetoclax is a promising agent for the treatment of acute myeloid leukemia (AML). However, many patients are refractory to Venetoclax, and resistance develops quickly. ATP-binding cassette (ABC) transporters mediate chemotherapy resistance but their role in modulating the activity of targeted small-molecule inhibitors is unclear. Using CRISPR/Cas9 screening, we find that loss of ABCC1 strongly increases the sensitivity of AML cells to Venetoclax. Genetic and pharmacologic ABCC1 inactivation potentiates the anti-leukemic effects of BCL-2 inhibitors and efficiently re-sensitizes Venetoclax-resistant leukemia cells. Conversely, ABCC1 overexpression induces resistance to BCL-2 inhibitors by reducing intracellular drug levels, and high ABCC1 levels predicts poor response to Venetoclax therapy in patients. Consistent with ABCC1-specific export of glutathionylated substrates, inhibition of glutathione metabolism increases the potency of BCL-2 inhibitors. These results identify ABCC1 and glutathione metabolism as mechanisms limiting efficacy of BCL-2 inhibitors, which may pave the way to development of more effective therapies.


Assuntos
Antineoplásicos , Leucemia Mieloide Aguda , Humanos , Sulfonamidas/farmacologia , Sulfonamidas/uso terapêutico , Transportadores de Cassetes de Ligação de ATP , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Glutationa , Proteínas Proto-Oncogênicas c-bcl-2/genética
6.
Eur J Med Chem ; 260: 115725, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37657269

RESUMO

This paper describes the rational design, synthesis, structure-activity relationship (SAR), and biological profile of presenilin-1 (PSEN-1) complex selective γ-secretase inhibitors, assessed for selectivity using a unique set of four γ-secretase subtype complexes. A set of known PSEN-1 selective γ-Secretase inhibitors (GSIs) was analyzed to understand the pharmacophoric features required for selective inhibition. Conformational modeling suggests that a characteristic 'U' shape orientation between aromatic sulfone/sulfonamide and aryl ring is crucial for PSEN-1 selectivity and potency. Using these insights, a series of brain-penetrant 2-azabicyclo[2,2,2]octane sulfonamides was devised and synthesized as a new class of PSEN-1 selective inhibitors. Compounds 13c and 13k displayed high potency towards PSEN1-APH1B complex but moderate selectivity towards PSEN2 complexes. However, compound (+)-13b displayed low nanomolar potency towards the PSEN1-APH1B complex, little (∼4-fold) selectivity towards PSEN1-APH1A, and high selectivity (>350-fold) versus PSEN2 complexes. Excellent brain penetration, no significant CYP inhibition, or cardiotoxicity, good solubility, and permeability make (+)-13b an excellent candidate for further lead optimization.


Assuntos
Secretases da Proteína Precursora do Amiloide , Sulfonamidas , Sulfonamidas/farmacologia , Presenilina-1 , Octanos , Sulfanilamida , Encéfalo
7.
Pol J Vet Sci ; 26(3): 431-440, 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37727128

RESUMO

The main purpose of the study was to determine the safety of oclacitinib (OCL), a Janus kinase inhibitor, with respect of its effect on CD4 + and CD8 + T cells as well as B cells in the lymphoid tissue. The mice were treated orally with OCL at a dose of 2.7 mg/kg for 14 days and peripheral blood, head and neck lymph nodes (HNLNs), mediastinal lymph nodes (MLNs) and spleen were collected. The study found that OCL induced depletion of CD4 + T cells in the HNLNs and MLNs, while it did not affect the absolute count of CD8 + T cells in these tissues. Also OCL caused a loss of B cells in the HNLNs, although not in the MLNs. Moreover, OCL depleted B cells in the peripheral blood, but did not affect the absolute count of CD4 + and CD8 + T cells. Thus, it can be concluded that OCL may induce a depletive effect on CD4 + and CD8 + T cells as well as B cells in the lymphoid tissue. This effect should be seen as an unfavorable one, especially in patients with infections. Therefore, a clinical implication is that in such patients, the benefit/risk ratio should be thoroughly considered by clinicians. Moreover, OCL reduced the absolute count of eosinophils, basophils, neutrophils and monocytes. However, it is uncertain whether this effect should be considered to be of clinical importance because the levels of these cells were within the physiological range. It is possible that the depletive effect of OCL toward T and B cells, as well as eosinophils and basophils may contribute to the beneficial effects of the drug in the treatment of skin allergic diseases.


Assuntos
Inibidores de Janus Quinases , Animais , Camundongos , Inibidores de Janus Quinases/farmacologia , Tecido Linfoide , Linfócitos B , Sulfonamidas/farmacologia
8.
Blood Cancer J ; 13(1): 142, 2023 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-37696819

RESUMO

FLT3 is the most frequently mutated gene in acute myeloid leukemia (AML), with FLT3 internal tandem duplication (ITD) mutations being associated with a more aggressive clinical course. While two large, randomized clinical trials have shown a survival benefit with the frontline use of an oral FLT3 inhibitor (midostaurin or quizartinib) in patients with FLT3-mutated AML, the role of FLT3 inhibitors in older adults with newly diagnosed FLT3-mutated AML remains unclear. A definitive improvement in survival has not been observed in intensively treated patients over 60 years of age receiving frontline FLT3 inhibitors. Furthermore, many patients with FLT3-mutated AML are unsuitable for intensive chemotherapy due to age and/or comorbidities, and this population represents a particular unmet need. For these older patients who are unfit for intensive approaches, azacitidine + venetoclax is a new standard of care and is used by many clinicians irrespective of FLT3 mutation status. However, FLT3-ITD mutations confer resistance to venetoclax and are a well-established mechanism of relapse to lower-intensity venetoclax-based regimens, leading to short durations of remission and poor survival. Preclinical and clinical data suggest synergy between FLT3 inhibitors and venetoclax, providing rationale for their combination. Novel strategies to safely incorporate FLT3 inhibitors into the standard hypomethylating agent + venetoclax backbone are now being explored in this older, less fit population with newly diagnosed FLT3-mutated AML, with encouraging early results. Herein, we discuss the frontline use of FLT3 inhibitors in older adults with FLT3-mutated AML, including the potential role of FLT3 inhibitors in combination with intensive chemotherapy and as part of novel, lower-intensity doublet and triplet regimens in this older population.


Assuntos
Leucemia Mieloide Aguda , Sulfonamidas , Humanos , Pessoa de Meia-Idade , Idoso , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Mutação , Tirosina Quinase 3 Semelhante a fms/genética
9.
J Int Med Res ; 51(8): 3000605231194890, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37641866

RESUMO

Cough is a frequent symptom accompanied by lung cancer. More potent antitussive treatment for this complex and distressing symptom is required, but anti-cancer chemotherapy cannot fully manage the cough. Inhibition of vagal nerves might control coughing in patients with troublesome lung cancer-related cough and P2X3 inhibitory therapy may be useful for targeting neuronal function. We report the case of a woman in her late 70s who never smoked and had advanced lung cancer. She visited our hospital complaining of serious deterioration of a non-productive cough. She was diagnosed with relapse of lung cancer, but she requested 2-week anti-tussive therapy before second-line chemotherapy. Gefapixant (P2X3 antagonist) add-on at a dose of 90 mg/day (45 mg twice daily as the usual dosage in Japan) improved her cough as indicated by an improvement in the visual analog scale for cough from 70 to 20 mm and in the Japanese version of the Leicester Cough Questionnaire from 8.2 to 16.3, despite a deterioration in lung cancer after 2 weeks. There are no current guidelines for cough accompanied by lung cancer; however, our findings suggest that P2X3 inhibition is a potent therapeutic option for lung cancer-related cough.


Assuntos
Antitussígenos , Neoplasias Pulmonares , Humanos , Feminino , Tosse/tratamento farmacológico , Tosse/etiologia , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/tratamento farmacológico , Sulfonamidas , Antitussígenos/uso terapêutico
10.
Zhonghua Yi Xue Za Zhi ; 103(32): 2509-2515, 2023 Aug 29.
Artigo em Chinês | MEDLINE | ID: mdl-37650197

RESUMO

Objective: To systematically evaluate the efficacy and safety of new systemic therapies (biological agents and JAK inhibitors) in moderate-to-severe elderly atopic dermatitis. Methods: The database of Embase, PubMed, Web of Science,Cochrane, the Global Resource of Eczema Trials database, ClinicalTrials. Gov, CNKI, Wanfang, VIP were used to search for literatures of randomized controlled trials (RCTs) and real-world studies of the treatment of moderate-to-severe AD with the new systemic therapies from January 2014 to February 2023. Two reviewers independently screened the literature, extracted the data and evaluated the risk of bias included in the study. Data were analyzed by Review Manager 5.3 software for meta-analysis and odds ratio (OR) and 95% confidence interval were used as the effect statistics. The heterogeneity and publication bias were assessed. Results: A total of five studies (523 elderly patients and 802 young patients) using dupilumab were included for meta-analysis. Dupilumab showed good efficacy in elderly AD, with 74.6%(390/523) of patients whose EASI reached 75, which there was no significant difference with young patients (OR=0.79, 95%CI:0.58-1.07, P=0.122); the proportion of elderly patients with NRS improvement≥4 was 68.7%(244/355), and there was no significant difference with young patients (OR=0.79, 95%CI:0.55-1.14, P=0.213). The most common adverse reactions were conjunctivitis, facial and neck erythema and injection site reactions, and there are no serious adverse events in both groups. The incidence of adverse events in elderly patients was 24.3%(65/267), which was not significantly different from that in young patients (OR=1.07, 95%CI:0.65-1.77, P=0.789). There are few studies on other biological agents and JAK inhibitors in elderly AD patients. We only found 4 studies of elderly AD patients using JAK inhibitors (2 studies on abrocitinib and 2 studies on upadacitinib). The clinical efficacy of abrocitinib in the elderly was not significantly different from that in the young. The incidence of serious adverse events of abrocitinib and upadacitinib increased in the elderly and was dose-related. Conclusion: The efficacy and safety of dupilumab in elderly AD patients were similar to those in the young patients, and the JAK inhibitor needs to be further studied and verified.


Assuntos
Dermatite Atópica , Inibidores de Janus Quinases , Humanos , Dermatite Atópica/tratamento farmacológico , Sulfonamidas
11.
Int J Mol Sci ; 24(16)2023 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-37628799

RESUMO

Human carbonic anhydrases (hCAs) have enzymatic activities for reversible hydration of CO2 and are acknowledged as promising targets for the treatment of various diseases. Using molecular docking and molecular dynamics simulation approaches, we hit three compounds of methyl 4-chloranyl-2-(phenylsulfonyl)-5-sulfamoyl-benzoate (84Z for short), cyclothiazide, and 2,3,5,6-tetrafluoro-4-piperidin-1-ylbenzenesulfonamide (3UG for short) from the existing hCA I inhibitors and word-approved drugs. As a Zn2+-dependent metallo-enzyme, the influence of Zn2+ ion models on the stability of metal-binding sites during MD simulations was addressed as well. MM-PBSA analysis predicted a strong binding affinity of -18, -16, and -14 kcal/mol, respectively, for these compounds, and identified key protein residues for binding. The sulfonamide moiety bound to the Zn2+ ion appeared as an essential component of hCA I inhibitors. Vina software predicted a relatively large (unreasonable) Zn2+-sulfonamide distance, although the relative binding strength was reproduced with good accuracy. The selected compounds displayed potent inhibition against other hCA isoforms of II, XIII, and XIV. This work is valuable for molecular modeling of hCAs and further design of potent inhibitors.


Assuntos
Anidrase Carbônica I , Anidrases Carbônicas , Humanos , Reposicionamento de Medicamentos , Simulação de Acoplamento Molecular , Sulfanilamida , Sulfonamidas/farmacologia
14.
Rev Alerg Mex ; 70(1): 38-42, 2023 May 24.
Artigo em Espanhol | MEDLINE | ID: mdl-37566754

RESUMO

BACKGROUND: Stevens-Johnson syndrome is a severe drug reaction. Sulfonamides have been associated with drug reactions, complications, sequelae, even death. CASE REPORT: A 40-year-old female patient with a medical history of endometriosis and recently diagnosed chronic inflammatory ulcerative colitis. She was treated at the Allergology service of the San Juan de Dios Hospital of the Costa Rican Social Security Fund, and after 20 days of treatment with sulfasalazine she had a severe drug reaction on the skin, compatible with Stevens-Johnson syndrome. The lymphocyte transformation test was positive, confirming sulfasalazine as the causative agent. CONCLUSION: The lymphocyte transformation test is a useful method that can confirm the causative agent and prevent important complications in the future.


ANTECEDENTES: El síndrome de Stevens-Johnson es una reacción medicamentosa severa. Las sulfamidas se han asociado con reacciones medicamentosas, complicaciones, secuelas, incluso la muerte. REPORTE DE CASO: Paciente femenina de 40 años, con antecedentes médicos de endometriosis y colitis ulcerativa crónica inflamatoria de reciente diagnóstico. Fue atendida en el servicio de Alergología del Hospital San Juan de Dios de la Caja Costarricense del Seguro Social, y luego de 20 días de tratamiento con sulfasalazina tuvo una reacción medicamentosa severa en la piel, compatible con síndrome de Stevens-Johnson. La prueba de transformación linfocitaria resultó positiva, con lo que se confirmó la sulfasalazina como el agente causal. CONCLUSIÓN: La prueba de transformación linfocitaria es un método útil que puede confirmar el agente causal y prevenir complicaciones importantes a futuro.


Assuntos
Colite Ulcerativa , Ativação Linfocitária , Síndrome de Stevens-Johnson , Sulfassalazina , Adulto , Feminino , Humanos , Ativação Linfocitária/efeitos dos fármacos , Síndrome de Stevens-Johnson/diagnóstico , Síndrome de Stevens-Johnson/etiologia , Sulfanilamida/efeitos adversos , Sulfassalazina/efeitos adversos , Sulfonamidas , Colite Ulcerativa/tratamento farmacológico
15.
Chem Biodivers ; 20(9): e202300257, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37578300

RESUMO

In the presented work, a new series of three different 4-((3,5-dichloro-2-[(2/4-halobenzyl)oxy]phenyl)sulfonyl)morpholines was synthesized and the structure of these compounds were corroborated by 1 H-NMR & 13 C-NMR studies. The in vitro results established all the three compounds as potent tyrosinase inhibitors relative to the standard. The Kinetics mechanism plots established that compound 8 inhibited the enzyme non-competitively. The inhibition constants Ki calculated from Dixon plots for this compound was 0.0025 µM. Additionally, computational techniques were used to explore electronic structures of synthesized compounds. Fully optimized geometries were further docked with tyrosinase enzyme for inhibition studies. Reasonably good binding/interaction energies and intermolecular interactions were obtained. Finally, drug likeness was also predicted using the rule of five (RO5) and Chemical absorption, distribution, metabolism, excretion, and toxicity (ADMET) characteristics. It is anticipated that current experimental and computational investigations will evoke the scientific interest of the research community for the above-entitled compounds.


Assuntos
Monofenol Mono-Oxigenase , Sulfonamidas , Estrutura Molecular , Relação Estrutura-Atividade , Sulfonamidas/farmacologia , Simulação de Acoplamento Molecular , Morfolinas , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Cinética
16.
Brain Res Bull ; 202: 110743, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37591025

RESUMO

Neuroinflammation and white matter microstructure damage are important causes of cognitive impairment after subarachnoid hemorrhage (SAH). Nod-like receptor protein 3 (NLRP3) plays an important role in neuroinflammation after SAH and may be a potential therapeutic target for treatment of white matter microstructure injury. In this study, we observed whether MCC950, a specific inhibitor of the NLRP3 inflammasome, exerted a therapeutic effect after SAH. The SAH model was induced by endovascular perforation in SpragueDawley rats. MCC950 was injected intraperitoneally 1 h after SAH at a dose of 10 mg/kg. The results showed that MCC950 significantly attenuated white matter microstructure damage in some brain regions, and behavioral experiments confirmed that MCC950 ameliorated cognitive function in rats after SAH, which may provide a new method for the treatment of cognitive dysfunction in SAH patients.


Assuntos
Lesões Encefálicas , Hemorragia Subaracnóidea , Substância Branca , Animais , Ratos , Lesões Encefálicas/metabolismo , Cognição , Doenças Neuroinflamatórias , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Hemorragia Subaracnóidea/complicações , Hemorragia Subaracnóidea/tratamento farmacológico , Hemorragia Subaracnóidea/metabolismo , Sulfonamidas/farmacologia , Substância Branca/metabolismo
17.
Eur J Med Chem ; 259: 115707, 2023 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-37556946

RESUMO

In the current medical era, the utilization of a single small molecule to simultaneously target two distinct molecular targets is emerging as a highly effective strategy in the battle against cancer. Carbonic Anhydrase (CA) and Vascular-Endothelial Growth Factor (VEGF) are genes that are activated in response to low oxygen levels (hypoxia) and play a role in the development and progression of tumors in hypoxic conditions. Herein we report the design, synthesis, and biological assessment of a series of novel indolinone-based benzenesulfonamides (8a-k, 11a-d, 15a-d, and 16) as potential dual inhibitors for cancer-associated hCA IX/XII and VEGFR-2. All the synthesized sulfonamides were assessed for their inhibitory effect against four CA isoforms I, II, IX, and XII where they displayed varying degrees of hCA inhibition. The most effective and selective hCA IX and XII inhibitors 8g, 8j and 15b were chosen to be tested for their in vitro inhibitory impact against VEGFR-2 as well as their antiproliferative impact against VEGFR-2 overexpressing MDA-MB-231 and MCF-7 breast cancer cells. Furthermore, molecular docking studies were conducted within the hCA IX, XII, and VEGFR-2 active sites to explain the observed inhibitory results.


Assuntos
Antineoplásicos , Anidrases Carbônicas , Humanos , Anidrases Carbônicas/metabolismo , Estrutura Molecular , Relação Estrutura-Atividade , Oxindóis , Simulação de Acoplamento Molecular , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Antineoplásicos/química , Sulfonamidas/química , Inibidores da Anidrase Carbônica/química , Anidrase Carbônica IX/metabolismo
18.
Eur J Med Chem ; 259: 115706, 2023 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-37572538

RESUMO

The uneven regulation of inflammation is related to various diseases, making anti-inflammation a potential option for the development of novel therapies. In this study, we designed and synthesized a total of fifty-eight novel amide/sulfonamide derivatives based on our previously reported anti-inflammatory compounds. The anti-inflammatory activities of these compounds were evaluated upon LPS-stimulated J774A.1 cells. Compounds 11a, 11b, 11c, and 11d potently reduced the release of IL-6 and TNF-α, and decreased the mRNA level of cytokines in J774A.1 cells. The most active compound 11d with IC50 value of 0.61 µM for IL-6 inhibition, and 4.34 µM for TNF-α inhibition restored IκB α and inhibited the translocation of phosphorylated p65 into the nucleus. In vivo evaluation indicated that 11d improved LPS-induced ALI and alleviated DSS-induced ulcerative colitis in mice. In conclusion, these results suggested compound 11d can be a new lead structure for the development of anti-inflammatory drugs against ALI and ulcerative colitis.


Assuntos
Lesão Pulmonar Aguda , Colite Ulcerativa , Camundongos , Animais , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/tratamento farmacológico , Fator de Necrose Tumoral alfa , Amidas/farmacologia , Amidas/uso terapêutico , Lipopolissacarídeos/farmacologia , Interleucina-6 , Anti-Inflamatórios/efeitos adversos , Citocinas , Lesão Pulmonar Aguda/tratamento farmacológico , Sulfonamidas/uso terapêutico , NF-kappa B
20.
Braz J Microbiol ; 54(3): 2319-2331, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37578738

RESUMO

Sulfentrazone (STZ) is an efficient tool for the pre- and post-emergence control of monocotyledonous and dicotyledonous weeds in fields of crops such as pineapple, coffee, sugarcane, citrus, eucalyptus, tobacco, and soybean. However, this herbicide persists in the soil, causing phytotoxicity in the subsequent crop. Therefore, it is important to use efficient strategies for the remediation of STZ-contaminated areas. The aim of this study was to evaluate the effects of Crotalaria juncea L. on the remediation of STZ-contaminated soil and on the microbial activity and bacterial community structure therein. The study was conducted in three stages: (i) cultivation of C. juncea in soil contaminated with 200, 400, and 800 g ha-1 STZ; (ii) determination of the soil microbial activity (basal respiration, microbial biomass carbon, and bacterial community structure); and (iii) cultivation of a bioindicator species and determination of the residual fraction of STZ. The soil microbial activity was impacted by the soil type and STZ dose. Soil previously cultivated with C. juncea (rhizospheric soil) displayed higher CO2 and lower qCO2 values than non-rhizospheric soil (no previous C. juncea cultivation). Increasing doses of STZ reduced the activity and lowered the diversity indices of the soil microorganisms. The bacterial community structure was segregated between the rhizospheric and non-rhizospheric soils. Regardless of soil type, the bioindicator of remediation (Pennisetum glaucum R.Br.) grew only at the STZ dose of 200 g ha-1, and the plant intoxication level was also lower in rhizospheric soil treated with this herbicide dose. All P. glaucum plants died in the soils treated with 400 and 800 g ha-1 STZ. Previous cultivation of C. juncea in soils contaminated with 200, 400, and 800 g ha-1 STZ reduced the residual fraction of the herbicide by 4.8%, 12.5%, and 17.4%, respectively, compared with that in the non-rhizospheric soils. In conclusion, previous cultivation with C. juncea promoted increases in the soil bacterial activity and diversity indices, mitigated the deleterious effects of STZ on the bioindicator crop, and reduced the residual fraction of the herbicide in the soil.


Assuntos
Crotalaria , Microbiologia do Solo , Sulfonamidas , Triazóis , Crotalaria/metabolismo , Biodegradação Ambiental , Sulfonamidas/metabolismo , Triazóis/metabolismo
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