Vernonanthura polyanthes leaves aqueous extract enhances doxorubicin genotoxicity in somatic cells of Drosophila melanogaster and presents no antifungal activity against Candida spp / O extrato aquoso das folhas de Vernonanthura polyanthes potencializa a genotoxicidade da doxorrubicina em células somáticas de Drosophila melanogaster e não apresenta atividade antifúngica contra Candida spp

Abstract Vernonanthura polyanthes (Spreng.) A.J. Vega & Dematt. (Asteraceae), known as “assa-peixe”, has been used in ethnomedicine for the treatment of various diseases such as bronchitis, pneumonia, hemoptysis, persistent cough, internal abscesses, gastric and kidney stone pain. Moreover, some studies demonstrated that species of Genus Vernonia present antifungal activity. Due to the biological relevance of this species, the aim of this study was to investigate the toxic, genotoxic, antigenotoxic and antifungal potential of V. polyanthes leaves aqueous extract in somatic cells of Drosophila melanogaster or against Candida spp. The aqueous extract of the plant showed no toxic, genotoxic and antigenotoxic activity in the experimental conditions tested using the wing somatic mutation and recombination test (SMART/wing). However, when the extract was associated with doxorubicin, used in this work as a positive control, the mutagenic potential of doxorubicin was enhanced, increasing the number of mutations in D. melanogaster somatic cells. In the other hand, no inhibitory activity against Candida spp. was observed for V. polyanthes leaves aqueous extract using agar-well diffusion assay. More studies are necessary to reveal the components present in the V. polyanthes leaves aqueous extract that could contribute to potentiate the doxorubicin genotoxicity.

Resumo Vernonanthura polyanthes (Spreng.) A.J. Vega & Dematt. (Asteraceae), conhecida como “assa-peixe”, tem sido utilizada na medicina popular para o tratamento de várias doenças, como bronquite, pneumonia, hemoptise, tosse persistente, abcessos internos, afecções gástricas e cálculo renal. Além disso, alguns estudos já demonstraram que espécies do Gênero Vernonia apresentam atividade antifúngica. Devido à relevância biológica dessa espécie, o objetivo deste estudo foi investigar os efeitos citotóxico, genotóxico, antigenotóxico e antifúngico do extrato aquoso das folhas de V. polyanthes em células somáticas de Drosophila melanogaster ou contra Candida spp. O extrato aquoso da planta não apresentou atividade citotóxica, genotóxica e antigenotóxica nas condições experimentais testadas usando o teste de recombinação e mutação somática em asa (SMART-asa). No entanto, quando o extrato foi associado com a doxorrubicina, utilizada neste trabalho como controle positivo, o potencial mutagênico da doxorrubicina foi potencializado, aumentando o número de mutações em células somáticas de D. melanogaster. Por outro lado, nenhuma atividade inibitória contra Candida spp. foi observada utilizando o extrato aquoso das folhas de V. polyanthes por meio do método de difusão em ágar. Mais estudos são necessários para desvendar os componentes presentes no extrato aquoso das folhas de V. polyanthes que possam contribuir para potencializar a genotoxicidade da doxorrubicina.

Vernonanthura polyanthes leaves aqueous extract enhances doxorubicin genotoxicity in somatic cells of Drosophila melanogaster and presents no antifungal activity against Candida spp.

Vernonanthura polyanthes (Spreng.) A.J. Vega & Dematt. (Asteraceae), known as "assa-peixe", has been used in ethnomedicine for the treatment of various diseases such as bronchitis, pneumonia, hemoptysis, persistent cough, internal abscesses, gastric and kidney stone pain. Moreover, some studies demonstrated that species of Genus Vernonia present antifungal activity. Due to the biological relevance of this species, the aim of this study was to investigate the toxic, genotoxic, antigenotoxic and antifungal potential of V. polyanthes leaves aqueous extract in somatic cells of Drosophila melanogaster or against Candida spp. The aqueous extract of the plant showed no toxic, genotoxic and antigenotoxic activity in the experimental conditions tested using the wing somatic mutation and recombination test (SMART/wing). However, when the extract was associated with doxorubicin, used in this work as a positive control, the mutagenic potential of doxorubicin was enhanced, increasing the number of mutations in D. melanogaster somatic cells. In the other hand, no inhibitory activity against Candida spp. was observed for V. polyanthes leaves aqueous extract using agar-well diffusion assay. More studies are necessary to reveal the components present in the V. polyanthes leaves aqueous extract that could contribute to potentiate the doxorubicin genotoxicity.

Hemodynamic mechanisms of the attenuated blood pressure response to mental stress after a single bout of maximal dynamic exercise in healthy subjects

To determine the hemodynamic mechanisms responsible for the attenuated blood pressure response to mental stress after exercise, 26 healthy sedentary individuals (age 29 ± 8 years) underwent the Stroop color-word test before and 60 min after a bout of maximal dynamic exercise on a treadmill. A subgroup (N = 11) underwent a time-control experiment without exercise. Blood pressure was continuously and noninvasively recorded by infrared finger photoplethysmography. Stroke volume was derived from pressure signals, and cardiac output and peripheral vascular resistance were calculated. Perceived mental stress scores were comparable between mental stress tests both in the exercise (P = 0.96) and control (P = 0.24) experiments. After exercise, the blood pressure response to mental stress was attenuated (pre: 10 ± 13 vs post: 6 ± 7 mmHg; P < 0.01) along with lower values of systolic blood pressure (pre: 129 ± 3 vs post: 125 ± 3 mmHg; P < 0.05), stroke volume (pre: 89.4 ± 3.5 vs post: 76.8 ± 3.8 mL; P < 0.05), and cardiac output (pre: 7.00 ± 0.30 vs post: 6.51 ± 0.36 L/min; P < 0.05). Except for heart rate, the hemodynamic responses and the mean values during the two mental stress tests in the control experiment were similar (P > 0.05). In conclusion, a single bout of maximal dynamic exercise attenuates the blood pressure response to mental stress in healthy subjects, along with lower stroke volume and cardiac output, denoting an acute modulatory action of exercise on the central hemodynamic response to mental stress.

Hemodynamic mechanisms of the attenuated blood pressure response to mental stress after a single bout of maximal dynamic exercise in healthy subjects.

To determine the hemodynamic mechanisms responsible for the attenuated blood pressure response to mental stress after exercise, 26 healthy sedentary individuals (age 29 ± 8 years) underwent the Stroop color-word test before and 60 min after a bout of maximal dynamic exercise on a treadmill. A subgroup (N = 11) underwent a time-control experiment without exercise. Blood pressure was continuously and noninvasively recorded by infrared finger photoplethysmography. Stroke volume was derived from pressure signals, and cardiac output and peripheral vascular resistance were calculated. Perceived mental stress scores were comparable between mental stress tests both in the exercise (P = 0.96) and control (P = 0.24) experiments. After exercise, the blood pressure response to mental stress was attenuated (pre: 10 ± 13 vs post: 6 ± 7 mmHg; P < 0.01) along with lower values of systolic blood pressure (pre: 129 ± 3 vs post: 125 ± 3 mmHg; P < 0.05), stroke volume (pre: 89.4 ± 3.5 vs post: 76.8 ± 3.8 mL; P < 0.05), and cardiac output (pre: 7.00 ± 0.30 vs post: 6.51 ± 0.36 L/min; P < 0.05). Except for heart rate, the hemodynamic responses and the mean values during the two mental stress tests in the control experiment were similar (P > 0.05). In conclusion, a single bout of maximal dynamic exercise attenuates the blood pressure response to mental stress in healthy subjects, along with lower stroke volume and cardiac output, denoting an acute modulatory action of exercise on the central hemodynamic response to mental stress.

Modulation of in vitro murine B-lymphocyte response by curcumin.

Curcumin is a phenolic natural product isolated from the rhizome of Curcuma longa (tumeric). It was previously described that curcumin had a potent anti-inflammatory effect and inhibited the proliferation of a variety of tumor cells. In the present study, we investigated the inhibitory effects of curcumin on the response of normal murine splenic B cells. Curcumin inhibited the proliferative response of purified splenic B cells from BALB/c mice stimulated with the Toll-like receptor ligands LPS and CpG oligodeoxynucleotides. LPS-induced IgM secretion was also inhibited by curcumin. The proliferative response induced by either the T-independent type 2 stimuli anti-delta-dextran or anti-IgM antibodies was relatively resistant to the effect of curcumin. We investigated the intracellular signaling events involved in the inhibitory effects of curcumin on murine B cells. Curcumin did not inhibit the increase in calcium levels induced by anti-IgM antibody. Western blotting analysis showed that curcumin inhibited TLR ligands and anti-IgM-induced phosphorylation of ERK, IkappaB and p38. Curcumin also decreased the nuclear levels of NFkappaB. Our results suggested that curcumin is an important inhibitor of signaling pathways activated upon B cell stimulation by TLR ligands. These data indicate that curcumin could be a potent pharmacological inhibitor of B cell activation.