de Moura Valéria Mourão, da Silva Wania Cristina Rodrigues, Raposo Juliana D A, Freitas-de-Sousa Luciana A, Dos-Santos Maria Cristina, de Oliveira Ricardo Bezerra, Veras Mourão Rosa Helena
Programa Multi-institucional de Pós-graduação em Biotecnologia, Laboratório de Imunoquímica, Instituto de Ciências Biológicas, Universidade Federal do Amazonas-UFAM, Av. Rodrigo Octávio Jordão Ramos, 6.200, 69077-000 Manaus, AM, Brazil.
Programa de Pós-graduação em Recursos Naturais da Amazônia, Laboratório de Bioprospecção e Biologia Experimental, Universidade Federal do Oeste do Pará-UFOPA, rua Vera Paz, s/n, Salé, Santarém, PA 68035-110, Brazil.
J Ethnopharmacol. 2016 May 13;183:136-142. doi: 10.1016/j.jep.2016.02.047. Epub 2016 Mar 3.
Ethnobotanical studies have shown that Plathymenia reticulata Benth. (Fabaceae) has been widely used in cases of snake envenomation, particularly in Northern Brazil. In light of this, the aim of this study was to evaluate the inhibitory potential of the condensed-tannin-rich fraction obtained from the bark of P. reticulata against the main biological activities induced by Bothrops atrox venom (BaV).
The chemical composition of the aqueous extract of P. reticulata (AEPr) was first investigated by thin-layer chromatography (TLC) and the extract was then fractionated by column chromatography on Sephadex LH-20. This yielded five main fractions (Pr1, Pr2, Pr3, Pr4 and Pr5), which were analyzed by colorimetry to determine their concentrations of total phenolics, total tannins and condensed tannins and to assess their potential for blocking the phospholipase activity of BaV. The Pr5 fraction was defined as the fraction rich in condensed tannins (CTPr), and its inhibitory potential against the activities of the venom was evaluated. CTPr was evaluated in different in vivo and in vitro experimental protocols. The in vivo protocols consisted of (1) pre-incubation (venom:CTPr, w/w), (2) pre-treatment (orally administered) and (3) post-treatment (orally administered) to evaluate the effect on the hemorrhagic and edematogenic activities of BaV; in the in vitro protocol the effect on phospholipase and coagulant activity using pre-incubation in both tests was evaluated.
There was statistically significant inhibition (p<0.05) of hemorrhagic activity by CTPr when the pre-incubation protocol was used [55% (1:5, w/w) and 74% (1:10, w/w)] and when pre-treatment with doses of 50 and 100mg/kg was used (19% and 13%, respectively). However, for the concentrations tested, there was no statistically significant inhibition in the group subjected to post-treatment administered orally. CTPr blocked 100% of phospholipase activity and 63.3% (1:10, w/w) of coagulant activity when it was pre-incubated with BaV. There was a statistically significant reduction (p<0.05) in edema induced by BaV in the oral protocols. Maximum inhibition was 95% (pre-treatment).
Our findings indicate that CTPr could be a good source of natural inhibitors of the components of snake venom responsible for inducing local inflammation.
民族植物学研究表明，网脉普拉蒂木（豆科）在蛇咬伤病例中被广泛使用，尤其是在巴西北部。鉴于此，本研究的目的是评估从网脉普拉蒂木树皮中获得的富含缩合单宁的部分对矛头蝮蛇毒（BaV）诱导的主要生物活性的抑制潜力。
首先通过薄层色谱法（TLC）研究网脉普拉蒂木水提取物（AEPr）的化学成分，然后通过葡聚糖凝胶LH - 20柱色谱法对提取物进行分离。这产生了五个主要部分（Pr1、Pr2、Pr3、Pr4和Pr5），通过比色法分析以确定它们的总酚、总单宁和缩合单宁浓度，并评估它们阻断BaV磷脂酶活性的潜力。将Pr5部分定义为富含缩合单宁的部分（CTPr），并评估其对蛇毒活性的抑制潜力。CTPr在不同的体内和体外实验方案中进行评估。体内方案包括（1）预孵育（毒液：CTPr，w/w）、（2）预处理（口服给药）和（3）后处理（口服给药），以评估对BaV出血和水肿形成活性的影响；在体外方案中，使用预孵育评估对磷脂酶和凝血活性的影响。
当使用预孵育方案时[55%（1:5，w/w）和74%（1:10，w/w）]以及当使用50和100mg/kg剂量进行预处理时（分别为19%和13%），CTPr对出血活性有统计学显著抑制（p<0.05）。然而，对于所测试的浓度，口服后处理组没有统计学显著抑制。当CTPr与BaV预孵育时，它阻断了100%的磷脂酶活性和63.3%（1:10，w/w）的凝血活性。在口服方案中，BaV诱导的水肿有统计学显著降低（p<0.05）。最大抑制率为95%（预处理）。
我们的研究结果表明，CTPr可能是负责诱导局部炎症的蛇毒成分的天然抑制剂的良好来源。
