Protection by Mikania laevigata (guaco) extract against the toxicity of Philodryas olfersii snake venom

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• 作者：Rita de C¨¢ssia O. Colla?o ; Jos¨¦ Carlos Cogo ; L¨¦a Rodrigues-Simioni ; Thalita Rocha ; Yoko Oshima-Franco ; Priscila R ; azzo-Moura
• 关键词：Antiophidic ; Anti-inflammatory ; Guaco ; Neuromuscular junction ; Plant extract
• 刊名：Toxicon
• 出版年：2012
• 出版时间：15 September, 2012
• 年：2012
• 卷：60
• 期：4
• 页码：614-622
• 全文大小：1658 K

文摘

Philodryas olfersii is responsible for most colubrid snakebites in Brazil. In this work, we examined the ability of an ethanolic extract from Mikania laevigata (guaco) leaves to protect against the in?vitro neuromuscular activity of P. olfersii venom in mouse phrenic nerve-diaphragm (PND) and chick biventer cervicis (BC) preparations. M. laevigata extract caused moderate twitch-tension facilitation at low concentrations (107.4?¡À?6.2 % with 20?¦Ìl/ml and 118.9?¡À?9.3 % with 40?¦Ìl/ml in PND, and 120.7?¡À?7.7 % with 40?¦Ìl/ml and 114.5?¡À?4.4 % with 50?¦Ìl/ml in BC after 120?min; n?=?4-6, mean?¡À?SEM). In PND, the ethanol alone (40?¦Ìl/ml, n?=?4) did not change the twitch-tension when compared with control. However, in BC, the ethanol produced a higher facilitation when compared to control. At higher concentrations (>50?¦Ìl/ml) the extract caused total and reversible blockade in both preparations. Venom (50?¦Ìg/ml) caused partial blockade in PND (58.5?¡À?12 % , n?=?4) and almost total blockade in BC (93.5?¡À?2.2 % , n?=?4). Pretreatment of the preparations with extract (40?¦Ìl/ml) for 30?min before incubation with venom (50?¦Ìg/ml) completely protected PND from neuromuscular blockade and delayed the blockade in BC. The extract alone caused only mild morphological alterations (12.5?¡À?0.5 % and 10.9?¡À?2.3 % fiber damage in PND and BC, respectively, compared to 2.3?¡À?0.3 % and 3?¡À?0 in controls; n?=?3), with no increase in expression of the inflammatory cytokines TNF¦Á and IFN¦Ã. The ethanol alone also caused slight muscle damage: 4.3?¡À?2.4 % in PND and 6.7?¡À?3.3 % in BC (both n?=?3) and little or no TNF¦Á and IFN¦Ã expression in both preparations as observed in control. Venom (50?¦Ìg/ml) caused 53.5?¡À?8.5 % and 55.8?¡À?4.3 % fiber damage in PND and BC, respectively; (n?=?3, p?<?0.05 vs. controls) and enhanced expression of TNF¦Á and IFN¦Ã. Pretreatment of the preparations with extract protected against venom-induced muscle damage by 80.3 and 60.4 in PND and BC, respectively, and prevented TNF¦Á and IFN¦Ã expression. These results indicate that the M. laevigata extract protected nerve-muscle preparations against the myotoxic, neurotoxic and inflammatory effects of P. olfersii venom.