Connarus favosus Planch.: An inhibitor of the hemorrhagic activity of Bothrops atrox venom and a potential antioxidant and antibacterial agent

• Published in: Journal of ethnopharmacology Vol. 183; pp. 166 - 175
• Main Authors: Silva, Thaís Pereira da, Moura, Valéria Mourão de, Souza, Maria Carolina Scheffer de, Santos, Vanessa Neves Carvalho, Silva, Kissinara A.M. Moreira da, Mendes, Mara Giselle Guimarães, Nunez, Cecília Verônica, Almeida, Patrícia Danielle Oliveira de, Lima, Emerson Silva, Mourão, Rosa Helena Veras, Dos-Santos, Maria Cristina
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 13.05.2016
• Subjects: Animals; Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Anti-snakebite plants; Antioxidants - pharmacology; Antivenins - chemistry; Antivenins - pharmacology; Bothrops; Bothrops atrox; Brazil; Connaraceae - chemistry; Connarus favosus; Crotalid Venoms - administration & dosage; Female; Folk medicine; Hemorrhage - drug therapy; Hemorrhage - metabolism; Male; Medicine, Traditional - methods; Mice; Phospholipases A2 - metabolism; Phytochemicals - chemistry; Phytochemicals - pharmacology; Plant Extracts - chemistry; Plant Extracts - pharmacology; Snake Bites - drug therapy; Snakebites; Tannins - metabolism; Connarus favosus; Anti-snakebite plants; Folk medicine; Bothrops atrox; Snakebites
• ISSN: 0378-8741; 1872-7573
• DOI: 10.1016/j.jep.2016.02.043

The plant species Connarus favosus is used in folk medicine in the west of Pará state, Brazil, to treat snakebites. To investigate the potential of the aqueous extract of Connarus favosus (AECf) to inhibit hemorrhagic and phospholipase A2 activities induced by Bothrops atrox venom (BaV) and to determine the antioxidant and antimicrobial potentials of the extract. AECf was analyzed phytochemically for phenolics (condensed tannins and hydrolyzable tannins) by colorimetry. Antioxidant activity was evaluated by quantitative assays using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Fe3+/phenanthroline. Antimicrobial activity was evaluated by the minimal inhibitory concentration test, and cytotoxicity was evaluated using human fibroblast cells (MRC-5). Inhibition of BaV-induced hemorrhagic activity was assessed after oral administration of the extract using pre-treatment, post-treatment and combined (BA plus AECf) treatment protocols. Inhibition of indirect hemolysis caused by phospholipase A2 (PLA2) was investigated in vitro. Interaction between AECf and BaV was investigated by SDS-PAGE electrophoresis, Western blot (Wb) and zymography. The phytochemical profile of AECf revealed ten secondary metabolite classes, and colorimetry showed high total phenolic and total (condensed and hydrolyzable) tannin content. AECf exhibited high antioxidant and antimicrobial potentials. The IC50 for the cytotoxic effect was 51.91 (46.86–57.50)µg/mL. Inhibition of BaV-induced hemorrhagic activity was significant in all the protocols, and inhibition of PLA2 activity was significant with the two highest concentrations. The BaV/AECf mixture produced the same bands as BaV by itself in SDS-PAGE and Wb although the bands were much fainter. Zymography confirmed the proteolytic activity of BaV, but when the venom was pre-incubated with AECf this activity was blocked. AECf was effective in reducing BaV-induced hemorrhagic activity when administered by the same route as that used in folk medicine and exhibited antioxidant and antimicrobial potentials. [Display omitted]