Virucidal evaluation of sodium dichloroisocyanurate formulation against nucleopolyhedroviruses of silkworm / Avaliação antiviral do formulado de sódio dicloroisocianurato contra o nucleopoliedrovírus do bicho-da-seda

This study evaluated the effectiveness of a disinfectant with low corrosive action and which is not toxic to the environment, the sodium dichloroisocyanurate formulation, on the Bombyx mori nucleopolyhedrovirus (BmNPV). For this, 5th-instar B. mori silkworm larvae were divided into four experimental groups of 4 replicates with 15 larvae each, totalling 60 larvae per group. The groups were fed with mulberry (Morus sp.) leaf discs containing: BmNPV treated with the disinfectant, untreated BmNPV, only the disinfectant, and water (control). The results showed that the disinfectant does not inactivate the BmNPV and also exerts a negative effect on the insect"s resistance.

O estudo avaliou a eficiência de um desinfetante que apresenta baixa ação corrosiva e que não é tóxico ao meio ambiente, o formulado de sódio dicloroisocianurato, sobre o nucleopoliedrovírus Bombyx mori (BmNPV). Para tanto, lagartas do bicho-da-seda, B. mori, de 5º instar foram divididas em quatro grupos experimentais, 4 repetições com 15 lagartas cada, totalizando 60 lagartas por grupo. Os grupos foram alimentados com discos foliares de amoreira (Morus sp.) contendo: o BmNPV tratado com o desinfetante (solução 1); o BmNPV não tratado (solução 2); apenas o desinfetante (solução 3); e água (solução 4, controle). Os resultados mostraram que o desinfetante não inativa o BmNPV e também exerce efeito negativo na resistência do inseto.

Neutralization of pharmacological and toxic activities of Bothrops jararacussu snake venom and isolated myotoxins by Serjania erecta methanolic extract and its fractions

Most of the snakebites recorded in Brazil are caused by the Bothrops genus. Given that the local tissue damage caused by this genus cannot be treated by antivenom therapy, numerous studies are focusing on supplementary alternatives, such as the use of medicinal plants. Serjania erecta has already demonstrated anti-inflammatory, antiseptic and healing properties. In the current study, the aerial parts of S. erecta were extracted with methanol, then submitted to chromatographic fractionation on a Sephadex LH20 column and eluted with methanol, which resulted in four main fractions. The crude extract and fractions neutralized the toxic activities of Bothrops jararacussu snake venom and isolated myotoxins (BthTX-I and II). Results showed that phospholipase A2, fibrinogenolytic, myotoxic and hemorrhagic activities were inhibited by the extract. Moreover, the myotoxic and edematous activities induced by BthTX-I, and phospholipase A2 activity induced by BthTX-II, were inhibited by the extract of S. erecta and its fraction. The clotting time on bovine plasma was significantly prolonged by the inhibitory action of fractions SF3 and SF4. This extract is a promising source of natural inhibitors, such as flavonoids and tannins, which act by forming complexes with metal ions and proteins, inhibiting the action of serineproteases, metalloproteases and phospholipases A2.

Antiophidian properties of plant extracts against Lachesis muta venom

Snakebites comprise a serious health problem in several countries due to their global incidence, which exceeds 2.5 million per year, and the elevated number of victim fatalities. To counteract envenomations, antivenoms have been used regularly for more than a century. Apart from side effects including anaphylactic reactions, antivenoms are not able to efficiently neutralize local tissue damage, which contributes to increasing the severity and morbidity observed in patients. This fact, in turn, may be responsible for economic hardship, particularly in rural populations of developing countries. In the present work, we evaluated the antiophidian properties of 12 Brazilian plant extracts against the hemolytic, coagulant, hemorrhagic and proteolytic effects of Lachesis muta venom. Taken together, our data revealed that most of these aqueous products were capable of inhibiting those activities at different levels, except for Sapindus saponaria extract. In contrast, Stryphnodendron barbatiman extract completely neutralized all the analyzed biological activities. Thus, we may conclude that Brazilian flora may also be useful against L. muta accidents.