Biondo Ronaldo, Pereira Ana Maria S, Marcussi Silvana, Pereira Paulo S, França Suzelei C, Soares Andreimar M
Unidade de Biotecnologia, Universidade de Ribeirão Preto UNAERP, Bloco A, Avenida Costábile Romano 2201, CEP 14096 380 Ribeirão Preto, SP, Brazil.
Biochimie. 2003 Oct;85(10):1017-25. doi: 10.1016/s0300-9084(03)00138-x.
Phospholipases A(2) (PLA(2)) are multifunctional proteins which exhibit varied biological activities correlated to the structural diversities of the sub-classes. The crude aqueous extract from subterranean system of Mandevilla velutina, a plant found in Brazilian savanna, was assayed for its ability to inhibit biological activities of several snake venoms and isolated PLA(2)s. The extract induced total inhibition of the phospholipase activity of Crotalus durissus terrificus venom and only partial inhibition of Bothrops venoms. When assayed against purified toxins, the highest efficacy was detected against CB and crotoxin, while almost ineffective against PLA(2)s from the genus Bothrops. Although M. velutina crude extract significantly inhibited the myotoxic activity of C. d. terrificus venom and CB, it produced only partial inhibition of either Bothrops jararacussu venom or its main myotoxins BthTX-I (basic Lys49), BthTX-II (basic Asp49) and BthA-I-PLA(2) (acidic Asp49). The extract exhibited also full inhibition of hemorrhage caused by Bothrops alternatus, Bothrops moojeni and Bothrops pirajai snake venoms, but partial inhibition (90%) of that induced by B. jararacussu venom. The extract was ineffective to inhibit the fibrinogenolytic activity of B. moojeni, B. alternatus and B. pirajai crude venoms, while their caseinolytic activity was only partially inhibited. No inhibition of the anticoagulant activity, although partial reduction of the edema-inducing activity of C. d. terrificus and B. alternatus crude venoms, CB, PrTX-I, BthTX-I and crotoxin was observed. Besides extending survival of mice injected with lethal doses of C. d. terrificus and B. jararacussu venoms, M. velutina extract decreased to 50% the lethality of mice. Extracts of 18 month old micropropagated plants were able to partially neutralize the effect of the crude venoms and toxins.
磷脂酶A(2)（PLA(2)）是多功能蛋白质，其表现出与亚类结构多样性相关的多种生物活性。对在巴西稀树草原发现的植物曼德维拉绒毛花地下系统的粗水提取物进行了检测，以评估其抑制几种蛇毒和分离的PLA(2)生物活性的能力。该提取物可完全抑制杜氏响尾蛇毒液的磷脂酶活性，而对矛头蝮属毒液仅产生部分抑制作用。在针对纯化毒素进行检测时，发现其对CB和响尾蛇毒素的效果最佳，而对矛头蝮属的PLA(2)几乎无效。尽管曼德维拉绒毛花粗提取物显著抑制了杜氏响尾蛇毒液和CB的肌毒性活性，但对巴西矛头蝮毒液或其主要肌毒素BthTX-I（碱性Lys49）、BthTX-II（碱性Asp49）和BthA-I-PLA(2)（酸性Asp49）仅产生部分抑制作用。该提取物还能完全抑制交替矛头蝮、穆氏矛头蝮和皮氏矛头蝮蛇毒引起的出血，但对巴西矛头蝮毒液诱导的出血仅产生部分抑制作用（90%）。该提取物对穆氏矛头蝮、交替矛头蝮和皮氏矛头蝮粗毒液的纤维蛋白溶解活性无抑制作用，而对其酪蛋白溶解活性仅产生部分抑制作用。未观察到对抗凝活性的抑制作用，尽管杜氏响尾蛇和交替矛头蝮粗毒液、CB、PrTX-I、BthTX-I和响尾蛇毒素的致水肿活性有所部分降低。除了延长注射致死剂量杜氏响尾蛇和巴西矛头蝮毒液的小鼠的存活时间外，曼德维拉绒毛花提取物还将小鼠的致死率降低了50%。18个月大的微繁殖植物提取物能够部分中和粗毒液和毒素的作用。
