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Envenomations by snakes represent a neglected health problem in tropical and subtropical countries. In South America, Lachesis muta occasionally causes severe human envenomation, with treatment being conditioned to an unspecific antivenom. In this work, we examined the neutralizing ability of Coutarea hexandra stem bark hydroalcoholic extract (Ch‐E), including the commercial phytochemicals coumarin and quinine, on the neuromuscular blockade induced by L. m. muta venom in mouse phrenic nerve‐diaphragm preparation. Biological assays were performed following conventional myographic technique ex vivo. Ch‐E was phytochemically characterized to detect the presence of coumarin and quinine using analytical methods. Ch‐E and commercial phytochemicals were tested separately or combined under pre‐ and post‐venom incubation protocols. Ch‐E attenuated the venom‐induced neuromuscular blockade only under the pre‐venom incubation protocol. Quinine was not detected in Ch‐E. Commercial coumarin and quinine exhibited a concentration‐dependent counteracting effect on the venom‐induced neuromuscular blockade. The pre‐venom incubation protocol showed to be efficient in attenuating the L. m. muta venom–induced neuromuscular blockade, most likely due to the presence of coumarin derivatives and unknown alkaloids in this extract. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) are of particular interest for their antibacterial properties and are produced by the action of reducing agents on silver ions. Curcumin from Curcuma longa (Zingiberaceae) has been used as a precursor for obtaining biogenic AgNPs, to act as a potential drug. This study aimed to evaluate the toxicity of AgNPs synthesized with curcumin (Cur-AgNPs 0.081 mg/mL, ~130 nm) through the Salmonella/ microsome (Ames test), one of the first required assays for evaluating toxicity. The study design was experimental and in vitro. After defining the preliminary toxicity, the mutagenicity was assessed in a concentration range of 0.0010–0.0081 mg/plate Cur-AgNPs using histidine negative (His−) Salmonella Typhimurium strains TA97a, TA98, TA100, and TA102, with (+S9) and without metabolic activation (−S9), in triplicate. Assays were monitored by positive and negative controls. The results were statistically analyzed by Salanal software with p < 0.05 values considered significant. The data obtained in the absence of metabolic activation showed that Cur-AgNPs is not mutagenic, but when exposed to the presence of S9, Cur-AgNPs became mutagenic to TA98 and TA100 strains, showing the significance of metabolizer enzymes to activate Cur-AgNPs on these bacteria, which recovered their abilities in synthesizing histidine (His+). Cur-AgNPs is mutagenic in the presence (+S9), but not in the absence (−S9) of metabolic activation, being able to act as indirect mutagens potentially to organisms that share the same genotype vulnerabilities found in TA98 and TA100 strains to cause a frameshift and base-pair substitution mutations, respectively. [ABSTRACT FROM AUTHOR]