Inhibition of Naja kaouthia venom activities by plant polyphenols

• Published in: Journal of ethnopharmacology Vol. 97; no. 3; pp. 527 - 533
• Main Authors: Pithayanukul, Pimolpan, Ruenraroengsak, Pakatip, Bavovada, Rapepol, Pakmanee, Narumol, Suttisri, Rutt, Saen-oon, Suwipa
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 21.03.2005; Elsevier
• Subjects: Animals; Anti-snake venom; Antivenins - chemistry; Antivenins - metabolism; Antivenins - pharmacology; antivenoms; Areca catechu; Binding Sites - physiology; Biological and medical sciences; Dose-Response Relationship, Drug; Elapid Venoms - antagonists & inhibitors; Elapid Venoms - metabolism; Female; Flavonoids - chemistry; Flavonoids - metabolism; Flavonoids - pharmacology; General pharmacology; Male; Malvaceae; Medical sciences; medicinal plants; Mice; Naja kaouthia; Naja kaouthia venom; Naja naja; Naja naja siamensis; Nicotinic acetylcholine receptor; Pentace burmanica; Pharmacognosy. Homeopathy. Health food; Pharmacology. Drug treatments; Phenols - chemistry; Phenols - metabolism; Phenols - pharmacology; phytochemicals; Pithecellobium dulce; Plant Bark; plant extracts; Plant Extracts - chemistry; Plant Extracts - metabolism; Plant Extracts - pharmacology; Plant polyphenols; Polyphenols; Quercus; Quercus infectoria; Rats; Rats, Sprague-Dawley; Seeds; snake bites; snakes; Tannins; venoms; α-Cobratoxin; Thailand; AC; MND; PB; Tannins; PD; Nicotinic acetylcholine receptor; QI; Naja kaouthia venom; α-Cobratoxin; NK; Plant polyphenols; Anti-snake venom; Pharmacognosy; Medicinal plant; Polyphenol; Cholinergic receptor; Tannin; Antivenom; Venom; Plant origin; Phenols; Nicotinic receptor
• ISSN: 0378-8741; 1872-7573
• DOI: 10.1016/j.jep.2004.12.013

Plant polyphenols from the aqueous extracts of Pentace burmanica, Pithecellobium dulce, Areca catechu and Quercus infectoria were tested for their inhibitory activities against Naja kaouthia (NK) venom by in vitro neutralization method. The first three extracts could completely inhibit the lethality of the venom at 4 LD50 concentration and the venom necrotizing activity at the minimum necrotizing dose while also inhibited up to 90% of the acetylcholinesterase activity of NK venom at much lower tannin concentrations than that of Quercus infectoria. The ED50 of plant tannins in inhibiting NK venom activities varied according to condensed tannins and their content in the extracts. Molecular docking of the complexes between α-cobratoxin and either hydrolysable or condensed tannins at their lowest energetic conformations were proposed. The anti-venom activities of these plant polyphenols by selectively blocking the nicotinic acetylcholine receptor and non-selectively by precipitation of the venom proteins were suggested.