Assessment of the antibacterial, cytotoxic and antioxidant activities of Morus nigra L. (Moraceae) / Avaliação das atividades antibacteriana, citotóxica e antioxidante de Morus nigra L. (Moraceae)

Abstract This study was carried out to assess the antibacterial, cytotoxic and antioxidant activities of extracts of Morus nigra L. HPLC was used to determine the fingerprint chromatogram of the crude ethanolic extract (Mn-EtOH). The antibacterial effect was assessed through the method of microdilution. The cytotoxicity was tested against human tumour cell lines using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. The total phenolic and flavonoid contents were also assessed through the Folin-Ciocalteu and aluminum chloride methods, respectively. Antioxidant activities of the extracts were evaluated by using 2,2-diphenyl-1-picrylhydrazil (DPPH) radical scavenging and β-carotene-linoleic acid bleaching methods. The presence of phenolic compounds in Mn-EtOH was confirmed using HPLC. The extracts showed activity against most microorganisms tested. The extracts did not show any expressive antiproliferative effect in the assessment of cytotoxicity. The most significant total phenolic content was 153.00 ± 11.34 mg of gallic acid equivalent/g to the ethyl acetate extract (AcOEt). The total flavonoid content was 292.50 ± 70.34 mg of catechin equivalent/g to the AcOEt extract, which presented the best antioxidant activity (IC50 50.40 ± 1.16 μg/mL) for DPPH scavenging. We can conclude that this species shows strong antibacterial and antioxidant activities, as well as weak cytotoxic effects.

Resumo Este estudo foi realizado para avaliar as atividades antibacteriana, citotóxica e antioxidante de extratos de Morus nigra L. HPLC foi utilizado para determinar o perfil de compostos fenólicos do extrato etanólico bruto (Mn-EtOH). O efeito antibacteriano foi avaliado através do método de microdiluição. A citotoxicidade foi testada contra linhagens celulares de tumores humanos utilizando o ensaio do brometo de 3-(4,5-dimetil-2-tiazolil)-2,5-difenil-2H-tetrazólio (MTT). O conteúdo total de compostos fenólicos e flavonoides também foi avaliado por meio dos métodos de Folin-Ciocalteu e cloreto de alumínio, respectivamente. A atividade antioxidante dos extratos foi avaliada por meio do sequestro do radical livre 2,2-difenil-1-picrilhidrazil (DPPH) e co-oxidação do sistema β-caroteno-ácido linoleico. A presença de compostos fenólicos em Mn-EtOH foi confirmada utilizando HPLC. Os extratos mostraram atividade contra a maioria dos microrganismos testados. Os extratos não mostraram qualquer efeito antiproliferativo expressivo na avaliação da citotoxicidade. O conteúdo fenólico total mais significativo foi de 153,00 ± 11,34 mg de equivalente de ácido gálico/g para o extrato acetato de etila (AcOEt). O conteúdo de flavonoides totais foi de 292,50 ± 70,34 mg de equivalente de catequina/g para o extrato AcOEt, que apresentou a melhor atividade antioxidante (IC50 50,40 ± 1,16 mg/mL) para o sequestro do DPPH. Podemos concluir que esta espécie apresenta forte atividade antibacteriana e antioxidante, bem como fraca atividade citotóxica.

Tumor necrosis factor accounts for the neutrophil emigration activity released by cultured malignant fibrous histiocytoma cells

Cultured malignant fibrous histiocytoma (MFH) cells obtained from a spontaneous and transplantable rat tumor were studied for their ability to release tumor necrosis factor (TNF) and a factor which induces neutrophil migration in vivo. MFH cells obtained from 7-day cultures spontaneously released both activities into the supernatant (TNF: 36 ñ 9 iu tnf/ml supernatant, N = 3; neutrophil chemoattractant factor: control, Medium ip: 6 ñ 1 x 10**6; MFH supernatant: 18 ñ 1 x 106 neutrophils/cavity, H = 5). these releases were enhanced by treating MFH cells with LPS (TNF; 61 percent; neutrophil chemoattractant factor: 46 percent) and were abolished by the glucocorticoid dexamethasone (TNF: 68 percent; neutrophil chemoattractant factor: 100 percent). Anti-TNF antiserum abolished the neutrophil chemoattractant activity of the supernatants (95 percent). The release of TNF or neutrophil chemoattractant activity was reduced in cells obtained from older cultures (14 and 21 days) (TNF: 7-day culture, 36 ñ 9;14-day culture, 19ñ2;21-day culture, 19ñ 1 IU of TNF/ml; neutrophil chemoattractant activity: 7-day culture, 18 ñ 1.6; 14-day culture, 13 ñ 3;28-day culture, 8 ñ 1 x 10**6 neutrophils/cavity). The predominant cells present in 7-day cultures of MFH were histiocyte-like cells as determined by nonspecific esterase methods. The number of these cells decreased as the cultures aged (7-day culture, 71 percent; 14-day culture, 5 percent; 21-day culture, 0 percent)...