Species of the genus Psychotria are used for multiple purposes in Brazilian folk medicine,either as water infusions,baths or poultices.This study was aimed to evaluate the genotoxic and antiproliferative effects of in...Species of the genus Psychotria are used for multiple purposes in Brazilian folk medicine,either as water infusions,baths or poultices.This study was aimed to evaluate the genotoxic and antiproliferative effects of infusions of Psychotria brachypoda and P.birotula on the Allium cepa test.Exposure to distilled water was used as a negative control,while exposure to glyphosate was used as a positive control.The interaction of extracts(as a post-treatment)with the effects of glyphosate was also studied.Results showed that glyphosate and the extracts of both P.brachypoda and P.birotula reduced the mitotic index as compared with the negative control(distilled water).Surprisingly,however,both extracts from P.brachypoda and P.birotula caused a partial reversal of the antiproliferative effect of glyphosate when used as a post-treatment.Glyphosate also induced the highest number of cells with chromosomal alterations,which was followed by that of P.birotula extracts.However,the extracts from P.brachypoda did not show any signifi cant genotoxic effect.Post-treatment of glyphosate-treated samples with distilled water allowed a partial recovery of the genotoxic effect of glyphosate,and some of the Psychotria extracts also did so.Notably,post-treatment of glyphosatetreated samples with P.brachypoda extracts induced a statistically signifi cant apoptotic effect.It is concluded that P.brachypoda extracts show antiproliferative effects and are not genotoxic,while extracts of P.birotula show a less potent antiproliferative effect and may induce chromosomal abnormalities.The fi nding of a partial reversion of the effects of glyphosate by a post-treatment with extracts from both plants should be followed up.展开更多
The aims of this study were to determine the meiotic behavior and to estimate pollen grains via-bility in bean(Phaseolus vulgaris L.)cultivars.Flower buds were collected during different developmental stages of the Me...The aims of this study were to determine the meiotic behavior and to estimate pollen grains via-bility in bean(Phaseolus vulgaris L.)cultivars.Flower buds were collected during different developmental stages of the Mesoamerican bean cultivars IAPAR 44,Guapo Brilhante,BRS Expedito,BRS Valente,Guateian 6662 and Pérola,and the Andean bean cultivar Iraí,grown in a greenhouse.The meiotic index was determined by anther squashing of material fixed in absolute ethanol-glacial acetic acid(3:1)and stained with acetic orcein.No meiotic abnormalities were observed and the meiotic indices were high for all cultivars,indicating that the mismatch generated during crosses is not related to any meiotic changes.Estimation of pollen viability was made by comparing acetic orcein staining vs.Alexander’s reactive:pollen viability was high in all cultivars with either stain,but was significantly higher when using the acetic orcein stain(>99%).Though some cultivar showed a significantly smaller pollen size,the range of variation among cultivars was low(means’range 51-66μm).展开更多
Polygala paniculata L.is a medicinal plant that grows in the Brazilian Atlantic coast,known as‘barba-de-São-João’,‘barba-de-bode’,‘vassourinha branca’,and‘mimosa’.In this study,pollen viability was e...Polygala paniculata L.is a medicinal plant that grows in the Brazilian Atlantic coast,known as‘barba-de-São-João’,‘barba-de-bode’,‘vassourinha branca’,and‘mimosa’.In this study,pollen viability was estimated by three different staining methods:2%acetic orcein,2%acetic carmine,and Alexander’s stain.The young inflorescences of twenty accessions were collected and fixed in a solution of ethanol:acetic acid(3:1)for 24 hours,then stored in ethanol 70%under refrigeration.Six slides per plant,two for each stain,were prepared by squashing,and 300 pollen grains per slide were analyzed.Pollen viability was high(>70%)for most accessions of P.paniculata using the Alexander’s stain,which proved the most adequate method to estimate pollen viability.展开更多
基金the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior(CAPES)for fi nancial support.
文摘Species of the genus Psychotria are used for multiple purposes in Brazilian folk medicine,either as water infusions,baths or poultices.This study was aimed to evaluate the genotoxic and antiproliferative effects of infusions of Psychotria brachypoda and P.birotula on the Allium cepa test.Exposure to distilled water was used as a negative control,while exposure to glyphosate was used as a positive control.The interaction of extracts(as a post-treatment)with the effects of glyphosate was also studied.Results showed that glyphosate and the extracts of both P.brachypoda and P.birotula reduced the mitotic index as compared with the negative control(distilled water).Surprisingly,however,both extracts from P.brachypoda and P.birotula caused a partial reversal of the antiproliferative effect of glyphosate when used as a post-treatment.Glyphosate also induced the highest number of cells with chromosomal alterations,which was followed by that of P.birotula extracts.However,the extracts from P.brachypoda did not show any signifi cant genotoxic effect.Post-treatment of glyphosate-treated samples with distilled water allowed a partial recovery of the genotoxic effect of glyphosate,and some of the Psychotria extracts also did so.Notably,post-treatment of glyphosatetreated samples with P.brachypoda extracts induced a statistically signifi cant apoptotic effect.It is concluded that P.brachypoda extracts show antiproliferative effects and are not genotoxic,while extracts of P.birotula show a less potent antiproliferative effect and may induce chromosomal abnormalities.The fi nding of a partial reversion of the effects of glyphosate by a post-treatment with extracts from both plants should be followed up.
基金the study and for a graduate fellowship and to CNPq for an undergraduate fellowship.
文摘The aims of this study were to determine the meiotic behavior and to estimate pollen grains via-bility in bean(Phaseolus vulgaris L.)cultivars.Flower buds were collected during different developmental stages of the Mesoamerican bean cultivars IAPAR 44,Guapo Brilhante,BRS Expedito,BRS Valente,Guateian 6662 and Pérola,and the Andean bean cultivar Iraí,grown in a greenhouse.The meiotic index was determined by anther squashing of material fixed in absolute ethanol-glacial acetic acid(3:1)and stained with acetic orcein.No meiotic abnormalities were observed and the meiotic indices were high for all cultivars,indicating that the mismatch generated during crosses is not related to any meiotic changes.Estimation of pollen viability was made by comparing acetic orcein staining vs.Alexander’s reactive:pollen viability was high in all cultivars with either stain,but was significantly higher when using the acetic orcein stain(>99%).Though some cultivar showed a significantly smaller pollen size,the range of variation among cultivars was low(means’range 51-66μm).
文摘Polygala paniculata L.is a medicinal plant that grows in the Brazilian Atlantic coast,known as‘barba-de-São-João’,‘barba-de-bode’,‘vassourinha branca’,and‘mimosa’.In this study,pollen viability was estimated by three different staining methods:2%acetic orcein,2%acetic carmine,and Alexander’s stain.The young inflorescences of twenty accessions were collected and fixed in a solution of ethanol:acetic acid(3:1)for 24 hours,then stored in ethanol 70%under refrigeration.Six slides per plant,two for each stain,were prepared by squashing,and 300 pollen grains per slide were analyzed.Pollen viability was high(>70%)for most accessions of P.paniculata using the Alexander’s stain,which proved the most adequate method to estimate pollen viability.
