In Vitro Antiophidian Mechanisms of Hypericum brasiliense Choisy Standardized Extract: Quercetin-Dependent Neuroprotection

• Published in: BioMed research international 2013-01, Vol.2013 (2013), p.1-6
• Main Authors: Dal Belo, Cháriston André, Marangoni, Sérgio, Seibert França, Hildegardo, Rocha, Leandro, Vinadé, Lúcia, Lucho, Ana Paula de Bairros, Rodrigues-Simioni, Lea
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Animals; Binding sites; Brain - cytology; Brain - drug effects; Carbon dioxide; Cell Survival - drug effects; Colleges & universities; Crotalid Venoms - toxicity; Crotoxin - toxicity; Diaphragm - drug effects; Free radicals; Humans; Hypericum - chemistry; Kinases; Mice; Neuromuscular Blockade; Neuroprotective Agents - administration & dosage; Neurotoxicity; Phrenic Nerve - drug effects; Phrenic Nerve - physiopathology; Plant Extracts - administration & dosage; Plant Extracts - chemistry; Quercetin; Quercetin - administration & dosage; Rattlesnakes; St. John's wort; Venom
• ISSN: 2314-6133; 2314-6141
• DOI: 10.1155/2013/943520

The neuroprotection induced by Hypericum brasiliense Choisy extract (HBE) and its main active polyphenol compound quercetin, against Crotalus durissus terrificus (Cdt) venom and crotoxin and crotamine, was enquired at both central and peripheral mammal nervous system. Cdt venom (10 μg/mL) or crotoxin (1 μg/mL) incubated at mouse phrenic nerve-diaphragm preparation (PND) induced an irreversible and complete neuromuscular blockade, respectively. Crotamine (1 μg/mL) only induced an increase of muscle strength at PND preparations. At mouse brain slices, Cdt venom (1, 5, and 10 μg/mL) decreased cell viability. HBE (100 μg/mL) inhibited significantly the facilitatory action of crotamine (1 μg/mL) and was partially active against the neuromuscular blockade of crotoxin (1 μg/mL) (data not shown). Quercetin (10 μg/mL) mimicked the neuromuscular protection of HBE (100 μg/mL), by inhibiting almost completely the neurotoxic effect induced by crotoxin (1 μg/mL) and crotamine (1 μg/mL). HBE (100 μg/mL) and quercetin (10 μg/mL) also increased cell viability in mice brain slices. Quercetin (10 μg/mL) was more effective than HBE (100 μg/mL) in counteracting the cell lysis induced by Cdt venom (1 and 10 μg/mL, resp.). These results and a further phytochemical and toxicological investigations could open new perspectives towards therapeutic use of Hypericum brasiliense standardized extract and quercetin, especially to counteract the neurotoxic effect induced by snake neurotoxic venoms.