Girardi Cynthia, Fabre Nicolas, Paloque Lucie, Ramadani Arba Pramundita, Benoit-Vical Françoise, González-Aspajo German, Haddad Mohamed, Rengifo Elsa, Jullian Valérie
Université de Toulouse, UPS, UMR 152 Pharma-DEV, Université Toulouse 3, Faculté des Sciences Pharmaceutiques, F-31062 Toulouse Cedex 09, France; Institut de Recherche pour le Développement (IRD), UMR 152 Pharma-DEV, F-31062 Toulouse Cedex 09, France.
CNRS, LCC (Laboratoire de Chimie de Coordination) UPR 8241, 31077 Toulouse Cedex 4, France; Université de Toulouse, UPS, INPT, 31077 Toulouse Cedex 4, France.
J Ethnopharmacol. 2015 Jul 21;170:167-74. doi: 10.1016/j.jep.2015.05.014. Epub 2015 May 14.
Pseudelephantopus spiralis (Less.) Cronquist is distributed in the Caribbean, Mesoamerica and Latin America. Preparations of the plant are traditionally used in Latin America for the treatment of various diseases including fever, malaria, and spleen or liver inflammations.
Aerial parts of P. spiralis were extracted with either ethanol or distilled water. Seven hirsutinolide-type sesquiterpenoids were isolated: 8-acetyl-13-ethoxypiptocarphol (1), diacetylpiptocarphol (2), piptocarphins A (3), F (4) and D (5), (1S(),4R(),8S(),10R())-1,4-epoxy-13-ethoxy-1,8,10-trihydroxygermacra-5E,7(11)-dien-6,12-olide (6), and piptocarphol (7). Extracts and isolated compounds (2, 3, 5-7) were screened for their in vitro antiplasmodial activity against the chloroquine-resistant Plasmodium falciparum strain FcM29-Cameroon and antileishmanial activity against three stages of Leishmania infantum. Their cytotoxicities were also evaluated against healthy VERO cell lines and J774A.1 macrophages, the host cells of the Leishmania parasites in humans.
Aqueous extracts showed a greater inhibitory effect than alcoholic extracts, with IC50 on P. falciparum of 3.0µg/mL versus 21.1µg/mL, and on L. infantum of 13.4µg/mL versus >50µg/mL. Both extracts were found to be cytotoxic to VERO cells (CC50<3µg/mL). Sesquiterpene lactones 2 and 3 showed the best activity against both parasites but failed in selectivity. Carbon 8 hydroxylated hirsutinolides 5-7 presented the particularity of exhibiting two conformers observed in solution during extensive NMR analyses in CD3OD and UHPLC-MS. The presence of a hydroxyl function at C-8 decreased the activity of 5-7 on the two parasites and also on VERO cells.
The antiplasmodial activity displayed by the aqueous extract explains the traditional use of P. spiralis in the treatment of malaria. This activity seems to be attributable to the presence of sesquiterpene lactones 2 and 3, the most active against P. falciparum. Aqueous extract and compounds 2, 3 and 6 were also active against L. infantum but lacked in selectivity due to their cytotoxicity towards macrophages. Exploring the safety and antiplasmodial efficacy of this traditional remedy will require further toxicological and in vivo studies in the light of the cytotoxicity towards healthy cell lines displayed by the aqueous extract and compounds 2 and 3.
假地胆草（Pseudelephantopus spiralis (Less.) Cronquist）分布于加勒比地区、中美洲和拉丁美洲。在拉丁美洲，该植物的制剂传统上用于治疗包括发烧、疟疾以及脾脏或肝脏炎症在内的各种疾病。
用乙醇或蒸馏水提取假地胆草的地上部分。分离出七种海兔内酯型倍半萜类化合物：8-乙酰基-13-乙氧基哌啶醇（1）、二乙酰基哌啶醇（2）、海兔内酯A（3）、F（4）和D（5）、(1S(),4R(),8S(),10R())-1,4-环氧-13-乙氧基-1,8,10-三羟基吉马-5E,7(11)-二烯-6,12-内酯（6）以及哌啶醇（7）。对提取物和分离出的化合物（2、3、5 - 7）进行体外抗疟活性筛选，针对耐氯喹恶性疟原虫菌株FcM29 - 喀麦隆，以及针对婴儿利什曼原虫三个阶段的抗利什曼活性筛选。还评估了它们对健康VERO细胞系和J774A.1巨噬细胞（人类利什曼原虫寄生虫的宿主细胞）的细胞毒性。
水提取物显示出比醇提取物更强的抑制作用，对恶性疟原虫的IC50为3.0μg/mL，而醇提取物为21.1μg/mL；对婴儿利什曼原虫的IC50为13.4μg/mL，醇提取物则>50μg/mL。发现两种提取物对VERO细胞均具有细胞毒性（CC50<3μg/mL）。倍半萜内酯2和3对两种寄生虫均表现出最佳活性，但选择性不佳。在CD3OD和超高效液相色谱 - 质谱联用的广泛核磁共振分析中，8 - 碳羟基化海兔内酯5 - 7呈现出在溶液中观察到两种构象的特殊性。C - 8位存在羟基降低了5 - 7对两种寄生虫以及VERO细胞的活性。
水提取物所显示的抗疟活性解释了假地胆草在治疗疟疾方面的传统用途。这种活性似乎归因于倍半萜内酯2和3的存在，它们对恶性疟原虫的活性最强。水提取物以及化合物2、3和6对婴儿利什曼原虫也有活性，但由于它们对巨噬细胞具有细胞毒性，所以缺乏选择性。鉴于水提取物以及化合物2和3对健康细胞系具有细胞毒性，探索这种传统药物的安全性和抗疟功效将需要进一步的毒理学和体内研究。
