Medicinal plants, malaria and biotechnology

The first part of the talk will be dedicated to the investigation of medicinal plants with the objective to identify new antimalarial treatments. According to the last World Malaria Report [1], there were 584 000 deaths for 198 millions malaria cases worldwide in 2013. Particularly, the disease caused an estimated 437 000 African children died before their fifth birthday, still in 2013. Malaria is caused by a parasite, Plasmodium sp. and transmitted by Anopheles mosquitoes. The problem of parasite resistance towards common available medicines such as chloroquine, mefloquine, quinine, is increasing. In this context, the vegetal kingdom remains the main source of pharmacologically active compounds against this parasitic infection as attested by the famous quinine, isolated from Cinchona sp., artemisinin extracted from Artemisia annua and also atovaquone derived from lapachol found in several Bignoniaceae. All these substances are related to plants with traditional use against fever and malaria. Beside these well-known examples, various new antiplasmodial compounds are frequently discovered from Nature, particularly following an ethnopharmacological approach, as reviewed by several authors in recent years [2-6]. Then, the pharmacological and phytochemical study of plants from traditional pharmacopoeias can be of first interest not only to discover new antimalarial “lead compounds”, but also to valorize local vegetal species whose efficacy and safety would have been demonstrated in laboratory and by clinical investigations [7,8]. Some results obtained with Dicoma tomentosa from Burkina-Faso [9] and Terminalia mollis from Rwanda [10] will be presented.
In the second part of the talk, two applications of biotechnology for the production of artemisinin and paclitaxel and then some works developed at the ‘Université de la Réunion’ will be presented. In the framework of this collaboration, Psiadia arguta, an endemic plant from Reunion Island, which is known to have cytotoxic, anti-plasmodial and anti-inflammatory properties, was subjected to micropropagation. The objective of the work was to compare the biological properties and the phytochemical composition of callus, vitroplants and acclimatized plants of Psiadia arguta [11].

1. WHO, World Malaria Report 2014, December 2014, Geneva (http://www.who.int/malaria/publications/world_malaria_report_2014/en/).
2. Batista R, Silva Ade J Jr, de Oliveira AB: Plant-derived antimalarial agents: new leads and efficient phytomedicines. Part II. Non-alkaloidal natural products. Molecules 2009, 14:3037-72.
3. Bero J, Frédérich M, Quetin-Leclercq J : Antimalarial compounds isolated from plants used in traditional medicine. Journal of Pharmacy and Pharmacology 2009, 61:1401–1433.
4. Bero J and Quetin-Leclercq J: Natural products published in 2009 from plants traditionally used to treat malaria. Planta Medica 2011, 77:631-40.
5. Kaur K, Jain M, Kaur T, Jain R: Antimalarials from nature. Bioorganic & Medicinal Chemistry 2009, 17:3229–3256.
6. Nogueira CR and Lopes LMX: Antiplasmodial Natural Products. Molecules 2011, 16:2146-2190
7. Ginsburg H and Deharo E: A call for using natural compounds in the development of new antimalarial treatments – an introduction. Malaria Journal 2011, 10 (suppl. 1):S1
8. Willcox M, Graz B, Falquet J, Diakite C, Giani S, Diallo D: A “reverse pharmacology” approach for developing an antimalarial phytomedicine. Malaria journal 2011, 10(suppl1):S8
9. Jansen, O., Tits, M., Angenot, L., Nicolas, J.-P., De Mol, P., Nikiema, J.-B., & Frédérich, M : Anti-plasmodial activity of Dicoma tomentosa (Asteraceae) and identification of urospermal A-15-O-acetate as the main active compound. Malaria Journal 2012, 11, 289.
10. Muganga, R., Angenot, L., Tits, M., & Frédérich, M : In vitro and in vivo antiplasmodial activity of three Rwandan medicinal plants and identification of their active compounds. Planta Medica 2013, 80(6), 482-489.
11. Mahy Justine, Comparative study of biological activities and analysis of volatile compounds of Psiadia arguta in various cultures: vitroplants and acclimatized plants. Mémoire de M2, 2013, Université de Liège/Université de la Réunion.