Banfi Felipe Finger, Guedes Karla de Sena, Andrighetti Carla Regina, Aguiar Ana Carolina, Debiasi Bryan Wender, Noronha Janaina da Costa, Rodrigues Domingos de Jesus, Júnior Gerardo Magela Vieira, Sanchez Bruno Antonio Marinho
Universidade Federal de Mato Grosso, Instituto de Ciências da Saúde, Sinop, MT, Brazil.
Laboratório de Química Medicinal e Experimental, Universidade de São Paulo, São Carlos, SP, Brazil.
Korean J Parasitol. 2016 Aug;54(4):415-21. doi: 10.3347/kjp.2016.54.4.415. Epub 2016 Aug 31.
The drug-resistance of malaria parasites is the main problem in the disease control. The huge Brazilian biodiversity promotes the search for new compounds, where the animal kingdom is proving to be a promising source of bioactive compounds. The main objective of this study was to evaluate the antiplasmodial and cytotoxic activity of the compounds obtained from the toad venoms of Brazilian Amazon. Toad venoms were collected from the secretion of Rhinella marina and Rhaebo guttatus in Mato Grosso State, Brazil. The powder was extracted at room temperature, yielding 2 extracts (RG and RM) and a substance ('1') identified as a bufadienolide, named telocinobufagin. Growth inhibition, intraerythrocytic development, and parasite morphology were evaluated in culture by microscopic observations of Giemsa-stained thin blood films. Cytotoxicity was determined against HepG2 and BGM cells by MTT and neutral red assays. The 2 extracts and the pure substance ('1') tested were active against chloroquine-resistant Plasmodium falciparum strain, demonstrating lower IC50 values. In cytotoxic tests, the 2 extracts and substance '1' showed pronounced lethal effects on chloroquine-resistant P. faciparum strain and low cytotoxic effect, highlighting toad parotoid gland secretions as a promising source of novel lead antiplasmodial compounds.
疟原虫的耐药性是疾病控制中的主要问题。巴西丰富的生物多样性促使人们寻找新的化合物，动物界已被证明是生物活性化合物的一个有前景的来源。本研究的主要目的是评估从巴西亚马逊蟾蜍毒液中获得的化合物的抗疟和细胞毒性活性。蟾蜍毒液是从巴西马托格罗索州的海蟾蜍（Rhinella marina）和饰纹角花蟾（Rhaebo guttatus）的分泌物中收集的。在室温下对粉末进行提取，得到2种提取物（RG和RM）以及一种被鉴定为蟾二烯羟酸内酯的物质（“1”），命名为远华蟾毒精。通过对吉姆萨染色的薄血膜进行显微镜观察，在培养物中评估生长抑制、红细胞内发育和寄生虫形态。通过MTT和中性红试验测定对HepG2和BGM细胞的细胞毒性。所测试的2种提取物和纯物质（“1”）对耐氯喹恶性疟原虫菌株具有活性，显示出较低的半数抑制浓度（IC50）值。在细胞毒性试验中，2种提取物和物质“1”对耐氯喹恶性疟原虫菌株显示出显著的致死作用，而细胞毒性作用较低，这突出表明蟾蜍腮腺分泌物是新型抗疟先导化合物的一个有前景的来源。
