Kaushik Naveen Kumar, Murali Thokur Sreepathy, Sahal Dinkar, Suryanarayanan T S
Malaria Research Laboratory, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
Acta Parasitol. 2014 Oct;59(4):745-57. doi: 10.2478/s11686-014-0307-2. Epub 2014 Sep 20.
Eighty four different fungal endophytes isolated from sea grasses (5), marine algae (36) and leaves or barks of forest trees (43) were grown in vitro and the secondary metabolites secreted by them were harvested by immobilizing them on XAD beads. These metabolites were eluted with methanol and screened using SYBR Green I assay for their antiplasmodial activity against blood stage Plasmodium falciparum in human red blood cell culture. Our results revealed that fungal endophytes belonging to diverse genera elaborate antiplasmodial metabolites. A Fusarium sp. (580, IC50: 1.94 μg ml(-1)) endophytic in a marine alga and a Nigrospora sp. (151, IC50: 2.88 μg ml(-1)) endophytic in a tree species were subjected to antiplasmodial activity-guided reversed phase high performance liquid chromatography separation. Purification led to potentiation as reflected in IC50 values of 0.12 μg ml(-1) and 0.15 μg ml(-1) for two of the fractions obtained from 580. Our study adds further credence to the notion that fungal endophytes are a potential storehouse for a variety of novel secondary metabolites vested with different bioactivities including some that can stall the growth of the malaria parasite.
从海草（5种）、海藻（36种）以及林木的叶子或树皮（43种）中分离出84种不同的真菌内生菌，在体外进行培养，并通过将它们固定在XAD珠上收集其所分泌的次生代谢产物。这些代谢产物用甲醇洗脱，并使用SYBR Green I分析法在人红细胞培养物中针对恶性疟原虫的血液阶段进行抗疟活性筛选。我们的结果表明，属于不同属的真菌内生菌能产生抗疟代谢产物。对一种存在于海藻中的镰刀菌属菌株（580，IC50：1.94 μg ml(-1)）和一种存在于树种中的链格孢属菌株（151，IC50：2.88 μg ml(-1)）进行了抗疟活性导向的反相高效液相色谱分离。纯化后活性增强，从580号菌株得到的两个馏分的IC50值分别为0.12 μg ml(-1)和0.15 μg ml(-1)。我们的研究进一步证实了这样一种观点，即真菌内生菌是各种具有不同生物活性的新型次生代谢产物的潜在储存库，其中一些次生代谢产物能够抑制疟原虫的生长。
