In vitro anthelmintic activity of Psidium guajava hydroalcoholic extract against gastro-intestinal sheep nematodes.

Tanniferous plants have been used for ruminants verminosis control and represent a possibility to minimize the pharmacological resistance against conventional antiparasitics. This study aimed to evaluate the antihelminthic activity of the hydroalcoholic extract of stem bark of guava tree (PgHA). It was performed the hatchability and larval migration inhibition assays to evaluate PgHA at the following concentrations 0.62, 1.25, 2.5 and 5.0 mg mL-1 and the control treatments. The total polyphenol, flavonoid and tannin contents were determined by phytochemical analysis, high performance liquid chromatography coupled to mass spectrometry. The antioxidant activity was evaluated by 1,1-diphenyl-2-picrylhydrazyl, ferric reducing antioxidant power and thiobarbituric acid reactive substances tests. It was also determinated total protein, intracellular H2O2 and antioxidant activity of enzimes: glutathione S-transferase and superoxide dismutase. PgHA was able to inhibit both hatchability and larval migration, but only hatchability inhibition presented dose-dependent pattern. The antioxidant activity was demonstrated by linear regression with IC50 corresponding to 534.02 µg mL-1. The antiparasitic mechanism occurred through pro-oxidative activity by the increase of total proteins, intracellular H2O2 and the lipid peroxidation products, as well as the increase of the enzymes above related. Thus, the PgHA showed antiparasitic activity in vitro.

Mutagenicity, antioxidant activity and nutritional content of long-life tomato / Mutagenicidade, atividade antioxidante e conteúdo nutricional de tomate longa vida

The increasing tomato demand for the food market motivates improvements and the use of new biotechnologies in this fruit's production. The hybrid crop stands out for fruit production resistant to rot and postharvest wilt (long-life crops). Within this context, consumption of genetically modified food deserves attention regarding the safety and nutritional aspects due to the fact that inclusion and/or overexpression of genetic traits can cause harm to human health in the short or long term. In this scenario, this study aimed to evaluate genotoxicity and mutagenicity from different varieties of long-life tomatoes obtained by genetic breeding and also determines main bioactive compounds and antioxidant activity. The genotoxicity and mutagenicity were analyzed via the micronucleus test and the evaluation of chromosome aberrations in mice bone marrow respectively. We have also analyzed carotene, beta-carotene, lycopene, total phenol and flavonoid contents via spectrophotometry and antioxidant activity via DPPH radical scavenging assay. Considering the results obtained, it is possible to conclude that despite the absence of significant genotoxic activity among the evaluated samples, the antioxidant activity and the differences found in composition seems to be ruled by genetic factors, possibly due to the genetic breeding.

O aumento da demanda na produção de tomate para o mercado alimentício vem incentivando transformações e implementações de novas biotecnologias na produção desse fruto, destacando-se a utilização cultivares híbridas que produzem frutos com maior resistência ao fenecimento e apodrecimento após colheita (cultivares do tipo longa vida). Dentro deste contexto, sabe-se que o consumo de alimentos oriundos de melhoramento genético necessita de atenção no aspecto de segurança alimentar e poder nutricional, pois a inclusão e/ou super expressão de características genéticas de interesse pode acarretar a curto ou em longo prazo danos à saúde humana. Neste cenário, o presente estudo teve como objetivo avaliar a genotoxicidade e mutagenicidade de diferentes variedades de tomates do tipo "longa vida" obtidos por melhoramento genético, assim como determinar seus principais compostos bioativos e atividade antioxidante. A genotoxicidade e mutagenicidade foram analisados por meio do teste do micronúcleo e pela avaliação de aberrações cromossômicas em medula óssea de camundongos. Foram determinados caroteno, betacaroteno, licopeno e o conteúdo de polifenóis e flavonoides totais por meio espectrofotométrico e atividade antioxidante pelo método do sequestro do radical DPPH. Diante dos resultados obtidos foi possível concluir que apesar da ausência de atividade genotóxica significativa entre as amostras avaliadas, as diferenças na composição e bioatividade antioxidante observadas no presente estudo, parecem ser governados por fatores genéticos, possivelmente provenientes do melhoramento genético realizado.