Neutralising ability of Terminalia fagifolia extract (Combretaceae) against the in vitro neuromuscular effects of Bothrops jararacussu venom.

The ability of Terminalia fagifolia hydroalcoholic extract (Tf-HE) to neutralise the paralysis and myotoxicity induced by Bothrops jararacussu venom was assayed using mouse phrenic nerve-diaphragm (PND) preparation and two varieties of chick biventer cervicis (BC) preparations. Tf-HE 100 µg/mL and 500 µg/mL were tested against 40 and 200 µg of venom/mL in PND and BC preparations, respectively, using pre- and post-venom incubation treatments. The effects of Tf-HE against the myotoxicity caused by venom were evaluated via histological analysis (PND) and creatine kinase (CK) release (BC). Tf-HE was able to reverse the venom paralysis in both preparation types. The contractures to exogenous ACh in BC preparations showed that Tf-HE may act on extrinsic, preserving those intrinsic postsynaptic receptors. There was a positive correlation between CK and morphological changes. The high non-hemolytic saponin content can explain the Tf-HE efficacy against the toxic effects of B. jararacussu venom in vertebrate neuromuscular preparations.

Anti-Inflammatory and Antibothropic Properties of Jatropha Elliptica, a Plant from Brazilian Cerrado Biome.

Purpose: The aim of this study was to evaluate the antibothropic and anti-inflammatory properties of J. elliptica.Methods: Phytochemical screening and thin-layer chromatography (TLC) assays were performed on J. elliptica hydroalcoholic extract (TE) in order to observe its main constituents. The antibothropic activity of TE was evaluated by the in vitro neuromuscular blockade caused by Bothrops jararacussu venom (Bjssu), in a mouse phrenic nerve-diaphragm model (PND). A quantitative histological study was carried out to observe a possible protection of TE against the venom myotoxicity. The anti-inflammatory activity was also evaluated in two models, Bjssu-induced paw edema, and carrageenan-induced neutrophils migration in the peritoneal cavity. Results: TLC analysis revealed several compounds in TE, such as saponins, alkaloids, and phenolic constituents. TE was able to neutralize the blockade and the myotoxicity induced by venom, when it was pre-incubated for 30 min with venom. In addition, it showed anti-inflammatory activity, inducing less neutrophils migration and reducing paw edema. Conclusion:J. elliptica showed both antibothropic and anti-inflammatory properties.

Vellozia flavicans Mart. ex Schult. hydroalcoholic extract inhibits the neuromuscular blockade induced by Bothrops jararacussu venom.

BACKGROUND: Snakebite is a significant public health issue in tropical countries. In Brazil, some of the most common snake envenomations are from Bothrops. Bothrops bites trigger local and systemic effects including edema, pain, erythema, cyanosis, infections, and necrosis. Vellozia flavicans is a plant from the Brazilian "cerrado" (savanna) that is popularly used as an anti-inflammatory medicine. Since inflammation develops quickly after Bothrops bites, which can lead to infection, the aim of the present study was to observe possible anti-snake venom and antimicrobial activities of V. flavicans (Vf). METHODS: The chromatographic profile of the main constituents from the Vf leaf hydroalcoholic extract was obtained by thin-layer chromatography (TLC). The anti-snake venom activity was measured by Vf's ability to neutralize the in vitro neuromuscular blockade caused by Bothrops jararacussu venom (Bjssu) in a mouse phrenic nerve-diaphragm model (PND). After a 20 min incubation, preparations of PND were added to Tyrode's solution (control); Vf (0.2, 0.5, 1, and 2 mg/mL); 40 µg/mL Bjssu; pre-incubation for 30 min with Bjssu and 1 mg/mL Vf; and a Bjssu pretreated preparation (for 10 min) followed by 1 mg/mL Vf. Myographic recording was performed, and the contractile responses were recorded. The antimicrobial activity (minimum inhibitory concentration [MIC] and minimum bactericidal concentration [MBC]) was obtained for Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Enterococcus faecalis, using gentamicin and vancomycin as positive controls. RESULTS: TLC analysis yielded several compounds from Vf, such as flavonoids (quercetin) and phenolic acids (chlorogenic acid). Bjssu completely blocked the contractile responses of PND preparations, while Vf preserved 97% (±10%) of the contractile responses when incubated with Bjssu. In the PND pretreated with Bjssu, Vf was able to inhibit the neuromuscular blockade progress. MIC and MBC of Vf ranged from 2.5 to 5.0 mg/mL for P. aeruginosa and S. aureus strains, while no antimicrobial activity was observed for E. coli and E. faecalis. CONCLUSIONS: The hydroalcoholic extract from Vf leaves was able to neutralize and decrease the in vitro neuromuscular blockade caused by Bjssu. However, it did not show significant antimicrobial activity against the tested bacteria.

In vitro and in vivo safety evaluation of Dipteryx alata Vogel extract.

BACKGROUND: Dipteryx alata Vogel popularly known as "baru" is an important commercial leguminous tree species from the Brazilian Cerrado, which possess medicinal properties, besides its fruits consumption by animals and humans. The use of the "naturally occurring plants" as herbal remedies and foods mainly from leaves, seeds, flowers and roots of plants or extracts require precautions before ensuring these are safe and efficacious. The objective of this study was to evaluate the safety of D. alata barks extract. METHODS: Vegetal drugs of D. alata barks were submitted to quality control assays and further to the safety assays under 1) in vitro parameter by Salmonella (Ames) mutagenicity, and 2) in vivo parameter on the pregnancy of rats. RESULTS: The extract was non-mutagenic to any of the assessed strains TA97a, TA98, TA100 and TA102 even after metabolic activation (+S9). All in vivo parameters (reproductive ability evaluation, physical development of rat offsprings, and neurobehavioral development assays) showed no changes related to control group. CONCLUSION: D. alata barks extract is neither mutagenic by the Ames test nor toxic in the pregnancy of rats, with no physical-neurobehavioral consequences on the rat offsprings development.

In vitro antiophidian properties of Dipteryx alata Vogel bark extracts.

Extracts from Dipteryx alata bark obtained with different solvents (hexane, dichloromethane, ethyl acetate and methanol) were mixed in vitro with Bothrops jararacussu (Bjssu, 40 µg/mL) and Crotalus durissus terrificus (Cdt, 15 µg/mL) snake venoms, and applied to a mouse phrenic nerve-diaphragm preparation to evaluate the possible neutralization of venom effects. Cdt venom neurotoxic effect was not inhibited by any of the extracts, while the neurotoxic and myotoxic actions of Bjssu venom were decreased by the methanolic extract. This inhibition appears to be augmented by tannins. Dichloromethane bark extract inhibited ~40% of Bjssu venom effects and delayed blockade induced by Cdt. The methodology used to determine which extract was active allows inferring that: (i) phenolic acids and flavonoids contained in the methanolic extract plus tannins were responsible mostly for neutralization of Bjssu effects; (ii) terpenoids from the dichloromethane extract may participate in the anti-Cdt and anti-Bjssu venom effects; (iii) a given extract could not inhibit venoms from different species even if those belong to the same family, so it is improper to generalize a certain plant as antiophidian; (iv) different polarity extracts do not present the same inhibitory capability, thus demonstrating the need for characterizing both venom pharmacology and the phytochemistry of medicinal plant compounds.

The inhibitory effect of Camellia sinensis extracts against the neuromuscular blockade of Crotalus durissus terrificus venom.

In geographically isolated populations where intensive medical care or serum therapy is not easily accessible snake envenomation is a major cause for concern. The aim of the present study was to test Camellia sinensis extracts, theaflavin and epigallocatechin (two of the main C. sinensis components) against the irreversible neuromuscular blockade induced by Crotalus durissus terrificus venom in mouse phrenic-nerve diaphragm preparations. A quantitative histological study was also performed. The venom (20µg/ml) completely decreased twitch tension after 70min and 5µg/ml venom abolished 50% of twitch amplitude after 60min. C. sinensis extract induced intense facilitatory effect in the preparation activity at 0.2mg/ml and slightly facilitatory effect at 0.05mg/ml. Both 0.05mg/ml C. sinensis extract and 0.05mg/ml commercial theaflavin maintained partial muscular activity in presence of 5µg/ml venom. The histological data confirms that Cs is able to protect the muscle from the myotoxic activity of the venom. Commercial epigallocatechin gallate did not show pre-synaptic nor post-synaptic activities. C. sinensis extract was able to protect the mouse phrenic-nerve diaphragm against the irreversible neuromuscular blockade induced by C. durissus terrificus venom.