Bantie Laychiluh, Assefa Solomon, Teklehaimanot Tilahun, Engidawork Ephrem
Department of Pharmacology and Clinical Pharmacy, School of Pharmacy, Addis Ababa University, P,O, Box 1176, Addis Ababa, Ethiopia.
BMC Complement Altern Med. 2014 Mar 1;14:79. doi: 10.1186/1472-6882-14-79.
The issue of resistance in malarial infection makes development of novel drugs a necessity. An alternative source for discovering such drugs is natural products. Croton macrostachyus H. (Euphorbiaceae) is used in Ethiopian folklore medicine for the treatment of malaria and found to possess antimalarial activity in vitro. However, no further scientific investigations have been carried out to substantiate the claim. This study therefore aimed at investigating the in vivo antiplasmodial activity of 80% methanol extract and solvent fractions of the leaves of Croton macrostachyus H. in rodent model of malaria.
A rodent malaria parasite, Plasmodium berghei, was used to inoculate healthy male Swiss Albino mice of age 6-8 weeks and weight 23-27 g. A hydro-alcoholic crude extract and the solvent fractions (chloroform, methanol and aqueous) were administered at different doses 200, 400 and 600 mg/kg. Parameters, including parasitemia, survival time, body weight, temperature, and packed cell volume were then determined using standard tests such as Peter's and Rane's test.
Chemoprotective effect exerted by the crude extract and fractions ranged between 44-91% and 12-76%, respectvely. The chemotherapeutic effect of the crude extract and chloroform fraction was in the range of 39-83% and 66-82%, respectively. Maximum effect in both tests was observed with the larger dose of the crude extract and chloroform fraction. The crude extract prevented loss of weight and reduction in temperature but did not affect packed cell volume. However, the chloroform fraction did also reverse reduction in packed cell volume due to the absence of saponins in the fraction.
The results collectively indicate that the plant has a promising antiplasmodial activity against Plasmodium berghei, which upholds the earlier in vitro findings as well as its folkloric use. Thus, it could be considred as a potential source to develop new antimalarial agents.
疟疾感染中的抗药性问题使得开发新型药物成为必要。发现此类药物的一个替代来源是天然产物。大戟科的大戟叶巴豆在埃塞俄比亚民间医学中用于治疗疟疾，并且在体外被发现具有抗疟活性。然而，尚未进行进一步的科学研究来证实这一说法。因此，本研究旨在研究大戟叶巴豆叶的80%甲醇提取物及其溶剂萃取物在啮齿动物疟疾模型中的体内抗疟原虫活性。
使用啮齿动物疟原虫伯氏疟原虫接种6-8周龄、体重23-27克的健康雄性瑞士白化小鼠。以200、400和600毫克/千克的不同剂量给予水醇粗提物及其溶剂萃取物（氯仿、甲醇和水相）。然后使用彼得氏试验和拉内氏试验等标准测试来测定包括疟原虫血症、存活时间、体重、体温和红细胞压积等参数。
粗提物及其萃取物发挥的化学保护作用分别在44%-91%和12%-76%之间。粗提物和氯仿萃取物的化学治疗作用分别在39%-83%和66%-82%之间。在两种试验中，使用较大剂量的粗提物和氯仿萃取物时观察到最大效果。粗提物可防止体重减轻和体温降低，但不影响红细胞压积。然而，由于该萃取物中不含皂苷，氯仿萃取物也能逆转红细胞压积的降低。
这些结果共同表明，该植物对伯氏疟原虫具有有前景的抗疟原虫活性，这证实了早期的体外研究结果及其民间药用价值。因此，它可被视为开发新型抗疟药物的潜在来源。
