School of Marine Sciences, Department of Oceanography and Coastal Area Studies, Alagappa University, Thondi Campus, Thondi, 623 409, Ramanathapuram District, Tamil Nadu, India.
Parasitol Res. 2012 Jun;110(6):2255-62. doi: 10.1007/s00436-011-2757-x. Epub 2011 Dec 23.
Malaria is the most important parasitic disease, leading to annual death of about one million people, and the Plasmodium falciparum develops resistance to well-established antimalarial drugs. The newest antiplasmodial drug from a marine microorganism helps in addressing this problem. In the present study, Haliclona Grant were collected and subjected for enumeration and isolation of associated bacteria. The count of bacterial isolates was maximum in November 2007 (18 × 10(4) colony-forming units (CFU) g(-1), and the average count was maximum during the monsoon season (117 × 10(3) CFU g(-1)). Thirty-three morphologically different bacterial isolates were isolated from Haliclona Grant, and the extracellular ethyl acetate extracts were screened for antiplasmodial activity against P. falciparum. The antiplasmodial activity of bacterium RJAUTHB 14 (11.98 μg[Symbol: see text]ml(-1)) is highly comparable with the positive control chloroquine (IC(50) 19.59 μg[Symbol: see text]ml(-1)), but the other 21 bacterial extracts showed an IC(50) value of more than 100 μg[Symbol: see text]ml(-1). Statistical analysis reveals that significant in vitro antiplasmodial activity (P < 0.05) was observed between the concentrations and time of exposure. The chemical injury to erythrocytes showed no morphological changes in erythrocytes by the ethyl acetate extract of bacterial isolates after 48 h of incubation. The in vitro antiplasmodial activity might be due to the presence of reducing sugars and alkaloids in the ethyl acetate extracts of bacterium RJAUTHB 14. The 16S rRNA gene partial sequence of bacterium RJAUTHB 14 is deposited in NCBI (GenBank accession no. GU269569). It is concluded from the present study that the ethyl acetate extracts of bacterium RJAUTHB 14 possess lead compounds for the development of antiplasmodial drugs.
疟疾是最重要的寄生虫病，每年导致约 100 万人死亡，而恶性疟原虫已经对现有的抗疟药物产生了耐药性。一种来自海洋微生物的新型抗疟药物有助于解决这一问题。在本研究中，采集了 Grant 海葵并对其相关细菌进行计数和分离。2007 年 11 月细菌分离物的数量最多（18×10^4 菌落形成单位（CFU）/g），而季风季节的平均数量最多（117×10^3 CFU/g）。从 Grant 海葵中分离出 33 种形态不同的细菌分离物，并对其胞外乙酸乙酯提取物进行抗疟原虫活性筛选，以评估其对恶性疟原虫的抑制活性。细菌 RJAUTHB 14 的抗疟原虫活性（11.98μg/ml）与阳性对照氯喹（IC50 为 19.59μg/ml）非常相似，但其他 21 种细菌提取物的 IC50 值均大于 100μg/ml。统计分析表明，在浓度和暴露时间之间观察到显著的体外抗疟原虫活性（P<0.05）。在孵育 48 小时后，细菌分离物的乙酸乙酯提取物对红细胞没有造成化学损伤，也没有导致红细胞出现形态变化。体外抗疟原虫活性可能是由于细菌 RJAUTHB 14 的乙酸乙酯提取物中存在还原糖和生物碱。细菌 RJAUTHB 14 的 16S rRNA 基因部分序列已在 NCBI（GenBank 登录号：GU269569）中提交。本研究得出结论，细菌 RJAUTHB 14 的乙酸乙酯提取物可能含有开发抗疟药物的先导化合物。
