Effect of the phospholipase A inhibitor Varespladib, and its synergism with crotalic antivenom, on the neuromuscular blockade induced by Crotalus durissus terrificus venom (with and without crotamine) in mouse neuromuscular preparations.

The venom of the South American rattlesnake Crotalus durissus terrificus causes an irreversible neuromuscular blockade in isolated preparations due to action of the presynaptically-acting heterodimeric phospholipase A (PLA) crotoxin. Some populations of this subspecies contain, in addition to crotoxin, the toxin crotamine, which acts directly on muscle fibers. In this study we used C.

Evaluation of Protection by Caffeic Acid, Chlorogenic Acid, Quercetin and Tannic Acid against the In Vitro Neurotoxicity and In Vivo Lethality of (South American Rattlesnake) Venom.

Systemic envenomation by (South American rattlesnake) can cause coagulopathy, rabdomyolysis, acute kidney injury, and peripheral neuromuscular blockade, the latter resulting in flaccid paralysis. Previous studies have shown that plant products such as tannic acid and theaflavin can protect against the neuromuscular blockade caused by venom in vitro. In this work, we used mouse-isolated phrenic nerve-diaphragm preparations to examine the ability of caffeic acid, chlorogenic acid, and quercetin to protect against venom-induced neuromuscular blockade in vitro.

In Situ Effects of Doxycycline on Neuromuscular Junction in Mice.

Background: The antibacterial mechanism of doxycycline is known, but its effects on the nerve-muscle system are still not unclear.

Objective: The aim of the study was to combine molecular targets of the neuromuscular machinery using the in situ neuronal blocker effect of doxycycline, a semisynthetic second-generation tetracycline derivative, on mice neuromuscular preparations.

Methods: The effects of doxycycline were assessed on presynaptic, synaptic cleft, and postsynaptic neurotransmission, along with the muscle fiber, using the traditional myographic technique.

The Influence of Silver Nanoparticles Against Toxic Effects of Venom.

Purpose: A silver nanoparticle obtained by reducing salts with solid dispersion of curcumin (130 nm, 0.081 mg mL) was used to counteract against the toxic - edematogenic, myotoxic, and neurotoxic - effects of venom.

Methods: The edematogenic effect was evaluated by plasma extravasation in rat dorsal skin after injection of 50 µg per site of venom alone or preincubated with 1, 10, and 100 µL of AgNPs; the myotoxicity was evaluated by measuring the creatine kinase released into the organ-bath before the treatment and at the end of each experiment; and neurotoxicity was evaluated in chick biventer cervicis using the conventional myographic technique, face to the exogenous acetylcholine (ACh) and potassium chloride (KCl) added into the bath before the treatment and after each experiment.

Are Silver Nanoparticles Useful for Treating Second-Degree Burns? An Experimental Study in Rats.

In this work, the potential usefulness of silver nanoparticles (AgNPs) for treating burn wounds was examined. Second-degree burns were induced in male Wistar rats by touching the skin with a heated (70°C) metallic device for 10 s, after which the animals were randomly allocated to one of two groups: control (n=8, treated with sterile saline) and experimental (n=8, treated with AgNPs, 0.081 mg/mL; 50 µL applied to the burn surface).

Varespladib (LY315920) inhibits neuromuscular blockade induced by Oxyuranus scutellatus venom in a nerve-muscle preparation.

The phospholipase A (PLA) inhibitors varespladib (LY315920) and its orally available derivative methyl-varespladib (LY333013) have been proposed as potential therapies for the treatment of snakebite envenomings in which toxicity depends on the action of PLAs. In this study, the ability of LY315920 to abrogate the effect of the potent neurotoxic venom of Oxyuranus scutellatus (taipan) was assessed using the mouse phrenic nerve-diaphragm preparation. LY315920 inhibited the venom when (a) incubated with venom before addition to the medium; (b) added to the medium before addition of venom, and; (c) added to the medium within 30 min after addition of venom, and even after the onset of decline in twitch response.

Experimental model for removal of snake venom via hemoperfusion in rats.

Objective: To examine the efficiency of hemoperfusion in removing South American rattlesnake (Crotalus durissus terrificus) venom from rats compared with neutralization by antivenom.

Design: An exploratory experimental investigation in rats involving the injection of snake venom with or without subsequent hemoperfusion or antivenom administration.

Setting: Basic animal research laboratory in a private university.

Acute kidney injury caused by the intraperitoneal injection of venom in rats.

We examined the ability of venom (12.5 mg/kg) injected intraperitoneally (i.p.

Activity of silver nanoparticles on prokaryotic cells and Bothrops jararacussu snake venom.

Nanoparticle-conjugated venom-toxins of venomous animals and its therapeutic efficacy against emerging or neglecting diseases is a promising strategy. In this study, silver nanoparticles (AgNPs ∼50 nm, 0.081 mg mL) were studied against the neuromuscular blockade, myotoxic effects induced by Bothrops jararacussu venom (60 µg mL) and also against prokaryotic cells.

Prospective study of a venom batch (Bj2015) - phospholipase A activity, immunogenicity, neurotoxicity, and myotoxicity parameters.

venom's (Bj2015) batch was biomonitored quarterly for one year to assess phospholipase A (PLA) activity, immunogenicity, neurotoxicity, and myotoxicity. models were applied to evaluate losses using decay model and recoveries by predictive trend analysis. Mice were immunized with Bj2015.

New pharmacological insights of .

leaves are popularly used against snakebites in Brazil. The hydroethanolic extract from aerial parts of (HEGg) was assayed against the neurotoxicity and myotoxicity induced by venom. A traditional myographic technique was applied for neurotoxicity and the resulting muscles were treated routinely by light microscopy analysis for myotoxicity.

Pharmacological Properties of (Vochysiaceae) Extract to Neutralize the Neuromuscular Blockade Induced by Bothropstoxin-I (Lys49 Phospholipase A) Myotoxin.

Bothrops snakes are responsible for more than 70 % of snakebites every year in Brazil and their venoms cause severe local and systemic damages. The pharmacological properties of medicinal plants have been widely investigated in order to discover new alternative treatments for different classes of diseases including neglected tropical diseases as envenomation by snakebites. In this work, we have investigated the ability of Vochysia haenkeana stem barks extract (VhE) to neutralize the neuromuscular effects caused by Bothropstoxin-I (BthTX-I), the major phospholipase A (PLA) myotoxin from B.

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).

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

The aim of this study was to evaluate the antibothropic and anti-inflammatory properties of Phytochemical screening and thin-layer chromatography (TLC) assays were performed on hydroalcoholic extract (TE) in order to observe its main constituents. The antibothropic activity of TE was evaluated by the neuromuscular blockade caused by 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.

A Highly Polar Phytocomplex Involving Rutin is Responsible for the Neuromuscular Facilitation Caused by Casearia sylvestris (guaçatonga).

Background: Of the various biological activities ascribed to extracts from Casearia sylvestris (guaçatonga), its facilitatory activity, i.e., ability to increase skeletal muscle contractile amplitude, has promising therapeutic applications.

Evaluation of Betulin Mutagenicity by Salmonella/Microsome Test.

Betulin is a pentacyclic triterpene found in the outer barks of innumerous plants. This secondary metabolite is easily isolated from plants with the major interest in converting it to betulinic acid, which pharmacological properties were much more exploited than betulin. But, investments in the own betulin have been grown since no chemical step is necessary.

The Triterpenoid Betulin Protects against the Neuromuscular Effects of Bothrops jararacussu Snake Venom In Vivo.

We confirmed the ability of the triterpenoid betulin to protect against neurotoxicity caused by Bothrops jararacussu snake venom in vitro in mouse isolated phrenic nerve-diaphragm (PND) preparations and examined its capability of in vivo protection using the rat external popliteal/sciatic nerve-tibialis anterior (EPSTA) preparation. Venom caused complete, irreversible blockade in PND (40 μg/mL), but only partial blockade (~30%) in EPSTA (3.6 mg/kg, i.

Healing activity of Casearia sylvestris Sw. in second-degree scald burns in rodents.

Background: Every year thousands of people are victims of burns, mainly scald burns. Many of these victims have small size wounds and superficial partial thickness and do not seek specialized medical care. As in Brazil Casearia sylvestris Sw.

The facilitatory effect of Casearia sylvestris Sw. (guaçatonga) fractions on the contractile activity of mammalian and avian neuromuscular apparatus.

Many natural products influence neurotransmission and are used clinically. In particular, facilitatory agents can enhance neurotransmission and are potentially useful for treating neuromuscular diseases in which muscular weakness is the major symptom. In this work, we investigated the facilitatory effect of apolar to polar fractions of Casearia sylvestris Sw.

The Facilitatory Effect of Casearia sylvestris Sw. (guaçatonga) Fractions on the Contractile Activity of Mammalian and Avian Neuromuscular Apparatus.

Many natural products influence neurotransmission and are used clinically. In particular, facilitatory agents can enhance neurotransmission and are potentially useful for treating neuromuscular diseases in which muscular weakness is the major symptom. In this work, we investigated the facilitatory effect of apolar to polar fractions of Casearia sylvestris Sw.

Safety assessment of the royal sun mushroom, Agaricus brasiliensis (higher Basidiomycetes) intake during rat pregnancy.

In this study, we investigated the reproductive capacity of pregnant rats exposed to daily orally administered powder-dehydrated reconstituted of Agaricus brasiliensis (=Agaricus blazei sensu Murrill), the fetal organogenesis, and the development of the pups. Pregnant rats were exposed for the entire gestational period to water (control) and A. brasiliensis at 300 or 600 mg/kg/day.

An isoflavone from Dipteryx alata Vogel is active against the in vitro neuromuscular paralysis of Bothrops jararacussu snake venom and bothropstoxin I, and prevents venom-induced myonecrosis.

Snakebite is a neglected disease and serious health problem in Brazil, with most bites being caused by snakes of the genus Bothrops. Although serum therapy is the primary treatment for systemic envenomation, it is generally ineffective in neutralizing the local effects of these venoms. In this work, we examined the ability of 7,8,3'-trihydroxy-4'-methoxyisoflavone (TM), an isoflavone from Dipteryx alata, to neutralize the neurotoxicity (in mouse phrenic nerve-diaphragm preparations) and myotoxicity (assessed by light microscopy) of Bothrops jararacussu snake venom in vitro.