Trichoderma from Brazilian garlic and onion crop soils and description of two new species: Trichoderma azevedoi and Trichoderma peberdyi.

Fifty four Trichoderma strains were isolated from soil samples collected from garlic and onion crops in eight different sites in Brazil and were identified using phylogenetic analysis based on combined ITS region, tef1-α, cal, act and rpb2 sequences. The genetic variability of the recovered Trichoderma species was analysed by AFLP and their phenotypic variability determined using MALDI-TOF. The strain clusters from both typing techniques coincided with the taxonomic determinations made from phylogenetic analysis. The phylogenetic analysis showed the occurrence of Trichoderma asperellum, Trichoderma asperelloides, Trichoderma afroharzianum, Trichoderma hamatum, Trichoderma lentiforme, Trichoderma koningiopsis, Trichoderma longibrachiatum and Trichoderma erinaceum, in the soil samples. We also identified and describe two new Trichoderma species, both in the harzianum clade of section Pachybasium, which we have named Trichoderma azevedoi sp. nov. and Trichoderma peberdyi sp. nov. The examined strains of both T. azevedoi (three strains) and T. peberdyi (12 strains) display significant genotypic and phenotypic variability, but form monophyletic clades with strong bootstrap and posterior probability support and are morphologically distinct from their respective most closely related species.

Ability of a synthetic coumestan to antagonize Bothrops snake venom activities.

We investigated a synthetic coumestan named LQB93 and similar compounds abilities to antagonize activities of Bothrops jararacussu and Bothrops jararaca crude venoms in different protocols. The antimyotoxic activity was evaluated in vitro by the rate of release of creatine kinase (CK) from isolated mouse extensor digitorum longus muscle (EDL) induced by B. jararacussu (25 g/ml). For in vivo studies, B. jararacussu venom (1.0 mg/kg) was preincubated with LQB93 (0.1-30 mg/kg), during 30 min, for later injection in mouse tight and evaluation of the antimyotoxic and anti-edematogenic effects. LQB93 antagonized in vitro, the increase of CK release from the EDL muscle (IC(50)=0.0291 M). It also showed in vivo, antimyotoxic and anti-edematogenic effects that were dose-dependent with ID50 of 0.17 mg/kg and 0.14 mg/kg, respectively. The hemorrhage induced by B. jararaca (1.0 mg/kg) venom in the mouse skin, was abolished by LQB93 (10.0 mg/kg) preincubated with venom. Like wedelolactone, LQB93 protected rat isolated heart on a Langendorff preparation, from the cardiotoxicity of B. jararacussu venom. LQB93 inhibit the effects of Bothrops venoms like wedelolactone, a natural compound isolated from the plant Eclipta prostrata.

Ability of suramin to antagonize the cardiotoxic and some enzymatic activities of Bothrops jararacussu venom.

We have investigated the cardiotoxic effect of Bothrops jararacussu crude venom and the ability of suramin to antagonize this effect in the heart of rats, as well as the proteolytic and phospholipase A(2) (PLA(2)) venom activities. Continuous perfusion in an isolated heart of a rat on a Langendorff preparation with a Ringer's solution with B. jararacussu crude venom (2.5-10.0 microg/mL) induces stoppage and a decrease in the cardiac tension, which were time- and concentration dependent. The analysis of the heart perfusate solution showed an increase in the rate of creatine kinase induced by the venom. Pre-incubation with suramin (1.0-30.0 microM) protected against the venom cardiotoxic effect in a concentration-dependent way, reaching up to 90% with 30.0 microM, and prevent the heart stoppage and decrease the tension. These protective effects were increased by the association with polyvalent antibothropic antivenom, suggesting a synergic effect. The PLA(2) and proteolytic activities of B. jararacussu crude venom were also inhibited in a concentration-dependent way by suramin, showing that this polyanion antivenom activity has therapeutic potential to be used as an antivenom.