Mangifera indica L.: Avaliando a citogenotoxicidade do extrato aquoso através do micronúcleo e ensaio de eletroforese em gel de célula única

Mangifera indica L., known as mango tree, is a species belonging to family Anacardiaceae, widely used in popular medicine whose leaves are used to treat several diseases. Although several studies did not detect the cytogenotoxic activity of M. indica leaf extract, other authors have observed these feature and highlighted the importance of further research about the toxic potential of M. indica leaf extract. The aim of the current research is to assess the cytogenotoxic potential of the aqueous extract of M. indica leaves through comet DNA assay and micronucleus test. It was possible observing significant increase in the number of micronucleated polychromatic erythrocytes (MNPCE) in mice subjected to the treatment with the extract, in addition to significant increase in DNA damage index in comparison to the negative control group. The extract also presented cytotoxic effect caused by significant reduction in the polychromatic:normochromatic erythrocyte (PCE/NCE) ratio in comparison to the negative control group. The extract of M. indica leaves is cytogenotoxic under the conditions used in the current research; this outcome highlighted the importance of comparative studies applied to the several used processing methods, as well as to cultivation conditions, to certify the safety in the popular use of medicinal plants.Mangifera indica L., conhecida como mangueira, é uma espécie pertencente à família Anacardiaceae, amplamente utilizada na medicina popular, cujas folhas são utilizadas no tratamento de diversas doenças. Embora vários estudos não tenham detectado a atividade citogenotóxica do extrato da folha de M. indica, outros autores observaram essa característica e destacaram a importância de novas pesquisas sobre o potencial tóxico do extrato da folha de M. indica. Sendo assim, o trabalho objetivou analisar o potencial citogenotóxico do extrato aquoso das folhas de M. indica, através do ensaio de DNA cometa e do teste do micronúcleo. Foi possível observar um aumento significativo no número de eritrócitos policromáticos micronucleados (MNPCEs) nos camundongos submetidos ao extrato, além de um aumento significativo no índice de danos ao DNA, quando comparado ao controle negativo. O extrato também apresentou efeito citotóxico, com uma redução significativa na relação de eritrócitos policromáticos/eritrócitos normocromáticos (PCE/NCE) quando comparado ao controle negativo. Conclui-se que o extrato obtido a partir das folhas de M. indica é citogenotóxico nas condições utilizadas neste trabalho; estes resultados reforçam a importância de estudos comparativos aplicados aos diversos métodos de processamento utilizados, bem como às condições de cultivo, para atestar a segurança no uso popular de plantas medicinais

Laurus nobilis L.: assessment of the cytotoxic and genotoxic potential of aqueous extracts by micronucleus and Allium cepa assays

Laurus nobilis L. is a large shrub belonging to the Lauracea family. Its leaves are widely used for food seasoning as well as in folk medicine. Various studies have demonstrated the antiproliferative, antifungal and antibacterial effects of Laurus nobilis, but no studies have investigated the genotoxic effect of the aqueous extract of the plant. The objective of this study was to analyze the genotoxic potential of an aqueous extract of leaves, using the Allium cepa assay and mouse peripheral blood cell micronucleus test. The results showed that the extract did not have any genotoxic activity, but cytotoxic activity was observed in the two experimental models used. The extract had an antiproliferative effect, detected through the reduction of the mitotic index and the polychromatic/normochromatic erythrocyte (PCE/NCE) ratio. The tests also demonstrated a large number of cells undergoing apoptosis and with nuclear abnormalities related to cell death processes. These results can be explained by the presence of phenolic compounds, saponins, flavonoids and alkaloids, detected in the phytochemical analysis of the extract. Therefore, the extract from L. nobilis in the form generally used by the population does not pose risks related to its genotoxic potential, and also contains components with apoptotic and antigenotoxic potential

Nitric Oxide as a Central Molecule in Hypertension: Focus on the Vasorelaxant Activity of New Nitric Oxide Donors

Cardiovascular diseases include all types of disorders related to the heart or blood vessels. High blood pressure is an important risk factor for cardiac complications and pathological disorders. An increase in circulating angiotensin-II is a potent stimulus for the expression of reactive oxygen species and pro-inflammatory cytokines that activate oxidative stress, perpetuating a deleterious effect in hypertension. Studies demonstrate the capacity of NO to prevent platelet or leukocyte activation and adhesion and inhibition of proliferation, as well as to modulate inflammatory or anti-inflammatory reactions and migration of vascular smooth muscle cells. However, in conditions of low availability of NO, such as during hypertension, these processes are impaired. Currently, there is great interest in the development of compounds capable of releasing NO in a modulated and stable way. Accordingly, compounds containing metal ions coupled to NO are being investigated and are widely recognized as having great relevance in the treatment of different diseases. Therefore, the exogenous administration of NO is an attractive and pharmacological alternative in the study and treatment of hypertension. The present review summarizes the role of nitric oxide in hypertension, focusing on the role of new NO donors, particularly the metal-based drugs and their protagonist activity in vascular function

Ammonium excretion, auxin production and effects of maize inoculation with ethylenediamine-resistant mutants of Pseudomonas sp.

<div><p>ABSTRACT Plant growth-promoting bacteria (PGPB) comprise part of plant microbiome of biotechnological interest due to their potential to decrease the use of agrochemicals in agriculture. Among the commonly found PGPB species, the Pseudomonas genus is known for high competitiveness and efficiency in expressing growth-promotion traits. To increase the contribution of diazotrophic Pseudomonas sp. to the plant nitrogen nutrition, the strain AZM-01 was chemically mutagenized with methyl methanesulfonate (MMS), following the selection for resistance to ethylenediamine (EDA). From the 13 EDA-resistant mutant strains selected, four showed increased the ammonium excretion, with the highest value reaching up to 284% increase as compared to the wild strain, and six strains were found to produce significantly more auxins than the wild strain. Two independent inoculation trials with the wild and EDA-resistant Pseudomonas were performed on maize, with the objective to study the influence of bacteria on seed germination and its potential to promote maize growth under N-limiting condition. In general, Pseudomonas inoculation modified the root architecture of germinating seeds, and increased biomass of maize plants grown under N-limiting conditions. Shoot dry weight of maize was increased by inoculation with several EDA-resistant mutants as compared to the strain AZM-01, with emphasis on the EDA-5 strain which supports biomass accumulation at equivalent amount of plants grown under full N supply. Significant correlations between in vitro and in vivo parameters were found although low coefficient values predominate. The strategy of random mutagenesis was found suitable to develop PGPB strains with higher potential to supply maize plants with nitrogen.</p></div

Persea americana Mill.: Evaluation of cytogenotoxicity and phytochemical prospection of leaf extracts

Persea americana&nbsp;Mill., belonging to the family Lauraceae, is noteworthy for the large amount of ethnopharmacological information in its regard, attributing to it many and varied medicinal properties. The tea and alcoholic extracts made from its leaves are used in folk medicine to treat various ailments. This study was designed to analyze the cytogenotoxicity and underlying chemistry of aqueous and hydroalcoholic extracts of avocado leaves, using the&nbsp;Allium cepa&nbsp;and micronucleus tests. The results obtained by applying the experimental models demonstrate that the extracts did not have a genotoxic effect at any of the concentrations analyzed, and even demonstrated a certain protective effect, possibly due to the presence of flavonoids and phenols, both of which are antioxidant substances. However, the extracts did present a cytotoxic effect. There were numerous karyorrhectic cells and those with nuclear alterations related to cell death. At the highest concentrations, it was possible to observe cytoplasmic alterations and binucleated cells. The extracts also caused a significant reduction in the number of cells undergoing division. These effects can be a response to the phytochemical agents present in the extracts. The results suggest that the extracts contain bioactive components that deserve further studies related to cancer therapies