Effect of plant extracts and a disinfectant on biological parameters and pathogenicity of the fungus Beauveria bassiana (Bals.) Vuill. (Ascomycota: Cordycipitaceae) / Ação de extratos vegetais e desinfetantes sobre parâmetros biológicos e patogenicidade do fungo Beauveria bassiana (Bals.) Vuill. (Ascomycota: Cordycipitaceae)

Abstract The fungus Beauveria bassiana is naturally found in poultry houses and causes high rates of mortality in Alphitobius diaperinus. Laboratory and field experiments have shown the potential of this fungus as an insect control agent. However, in poultry houses, bacteria as Salmonella, can be found and have been studied alternative control methods for this pathogen. Thus, this study aimed to evaluate the effect of plant extracts and a disinfectant on the fungus Beauveria bassiana (strain Unioeste 4). Conidial viability, colony-forming unit (CFU) counts, vegetative growth, conidia production, insecticidal activity of the fungus and compatibility were used as parameters in the evaluation of the effect of these products on the fungus. Alcoholic and aqueous extracts of jabuticaba (Myrciaria cauliflora (Mart.), guava (Psidium guajava (L.)), and jambolan (Syzygium cumini (L.), at concentrations of 10% as well as the commercial disinfectant, Peroxitane® 1512 AL, were evaluated at the recommended concentrations (RC), 1:200 (RC), 0.5 RC and 2 RC. There was a negative influence of alcoholic and aqueous extracts of jabuticaba, guava and three dilutions of Peroxitane on the viability of conidia. The CFUs and vegetative growth of the fungus were affected only by the Peroxitane (all dilutions). For conidial production, the aqueous extract of guava had a positive effect, increasing production, while the Peroxitane at the R and RC concentrations resulted in a negative influence. The mortality of A. diaperinus, caused by the fungus after exposure to these products, was 60% for the peracetic acid at 0.5 RC, and above 80% for the extracts. Thus, the results showed that all the extracts and Peroxitane at RC 0.5 are compatible with the fungus B. bassiana Unioeste 4, however only the extracts had a low impact on inoculum potential.

Resumo O fungo Beauveria bassiana é encontrado naturalmente em aviários de frango de corte, tendo sua eficácia como agente controlador do Alphitobius diaperinus, em condições de laboratório e campo. No entanto, nos aviários encontram-se também bactérias, como a Salmonella, para a qual vêm sendo pesquisadas alternativas de controle. Sendo assim, o objetivo do trabalho foi avaliar o efeito de extratos vegetais e um desinfetante com potencial de uso contra Salmonella spp., sobre os parâmetros biológicos do fungo B. bassiana isolado Unioeste 4. Foram avaliados extratos alcoólicos e aquosos de folhas de jabuticabeira (Myrciaria cauliflora (Mart.)), goiabeira (Psidium guajava (L.)), jamboleiro (Syzygium cumini (L.)), na concentração de 10% e também o desinfetante comercial Peroxitane®1512 AL na concentração recomendada – 1:200 (CR), 0,5 CR e 2CR. Foram avaliados a: germinação dos conídios, unidades formadoras de colônias (UFC), crescimento vegetativo, produção de conídios e efeito sobre a atividade inseticida do fungo contra adultos de A. diaperinus, bem como a compatibilidade entre produtos e o fungo. Verificou-se influência negativa dos extratos alcoólico e aquoso de jabuticabeira, goiabeira e das três diluições de Peroxitane sobre a viabilidade dos conídios. Já, a UFC e o crescimento vegetativo foram afetados apenas com Peroxitane (em todas as diluições). Para produção de conídios, o extrato aquoso de goiabeira teve efeito positivo, elevando a produção, enquanto as diluições recomendada e o dobro de Peroxitane mostraram influência negativa. Observou-se ainda que a mortalidade de A. diaperinus causada pelo fungo após a exposição aos produtos foi de 60% para o ácido peracético na 0,5 CR, já para os extratos foi acima de 80%. Assim, os resultados demonstraram que todos os extratos e o Peroxitane na 0,5 CR são compatíveis com o fungo B. bassiana Unioeste 4, porém apenas os extratos tiveram baixo impacto sobre o potencial de inóculo do fungo.

The toxicity evaluation of Syzygium cumini leaves in rodents

This study aimed to evaluate the safety of the hydroalcoholic extract (HE) of Syzygium cumini (L.) Skeels, Myrtaceae, leaves in rodents. Acute toxicity was evaluated through the determination of a LD50 in mice and rats (up to 14 days). In mice, the oral administration (p.o.) of the HE (0.1 at 6 g/kg) did not cause any death. When administered by intraperitoneal route (i.p.) the HE (0.1 at 1 g/kg) caused death of the animals (LD50 of 0.489 g/kg). In rats, the HE (0.5, 1 and 2 g/kg, p.o.) did not cause any death, while by i.p., only the 2 g/kg dose was lethal to 67 percent of the animals. To evaluate chronic toxicity, groups of rats daily received the HE (0.05, 0.1 and 0.25 g/kg) through p.o., during 30, 90 or 180 days and the effects on behavior, body weight, feed consumed were measured. Histology, hematology and biochemical parameters were measured at the end of the treatment. After a 30-day treatment, the HE caused changes in some biochemical parameters. Histological examination of the liver, kidneys, lungs, heart, stomach, intestine and pancreas showed normal architecture suggesting no morphological disturbances. These data may mean that the HE of S. cumini does not exert acute or chronic toxic effects by oral administration.