In this study, we selected two medicinal plants Citrus maxima (Burm.) Merr. and Artemisia nilagirica (C.B. Clarke) Pamp. on the basis of their traditional use in the treatment of fever associated with malaria in Assam (India) and evaluated their antimalarial potential against Plasmodium falciparum strains. The properly processed plant parts of C. maxima (Burm.) Merr. and A. nilagirica (C.B. Clarke) Pamp. were extracted with different solvents from nonpolar to polar by cold maceration technique. After that antimalarial activities of the extracts were evaluated against both chloroquine sensitive (3D7) and resistant (RKL-9) strains of P. falciparum using Giemsa staining light microscopy technique. The most active extract(s) was further screened for cytotoxicity potential against murine macrophage RAW264.7 cell line using MTT assay. Then preliminary phytochemical screening and qualitative fingerprint analysis of the active extract(s) were done to check the presence of different secondary metabolites. From the in vitro study, the hydro-alcoholic extract of C. maxima (Burm.) Merr. and methanol extract of A. nilagirica (C.B. Clarke) Pamp. were found to be the most active against both 3D7 and RKL-9 strains. In the cytotoxicity study, the CC50 values of the active extracts were found to be > 100 μg/ml, which suggested the safety of the extracts. Then phytochemical and fingerprint analysis revealed the presence of various important plant secondary metabolites in both the extracts. The findings of this study confirmed the presence of antimalarial potential of hydro-alcoholic extract of C. maxima (Burm.) Merr. and methanol extract of A. nilagirica (C.B. Clarke) Pamp without having any toxic effect. Both the extracts showed IC50 values below 5 μg/ml against 3D7 and RKL-9 strains.

中文翻译：

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两种民族药用植物对氯喹敏感和抗药性恶性疟原虫菌株的体外抗疟活性评估

在这项研究中，我们选择了两种药用植物柑桔（Burn。）Merr。和Artemisia nilagirica（CB Clarke）Pamp。基于其在阿萨姆邦（印度）治疗与疟疾相关的发热的传统方法，并评估了它们对恶性疟原虫菌株的抗疟潜力。正确处理的美人蕉（Burm。Merr。）植物部分。和A. nilagirica（CB Clarke）Pamp。通过冷浸技术用不同极性的溶剂从非极性萃取到极性萃取。之后，使用吉姆萨（Giemsa）染色光学显微镜技术评估了提取物对恶性疟原虫的氯喹敏感菌株（3D7）和耐药菌株（RKL-9）的抗疟活性。使用MTT测定法进一步筛选最具活性的提取物针对鼠巨噬细胞RAW264.7细胞系的细胞毒性潜力。然后对活性提取物进行了初步的植物化学筛选和定性指纹分析，以检查不同次生代谢产物的存在。从体外研究中，可以得出最大的C. maxima（Burm。）Merr。的水醇提取物。和A. nilagirica（CB Clarke）Pamp的甲醇提取物。被发现对3D7和RKL-9毒株最活跃。在细胞毒性研究中，发现活性提取物的CC50值> 100μg/ ml，这表明了提取物的安全性。然后植物化学和指纹分析揭示了两种提取物中都存在多种重要的植物次生代谢产物。这项研究的结果证实了最大的C. maxima（Burm。）Merr的水醇提取物具有抗疟疾的潜力。曲霉（CB）的甲醇和甲醇提取物 Clarke）帮浦，没有任何毒性作用。两种提取物对3D7和RKL-9菌株的IC50值均低于5μg/ ml。