In vitro antileishmanial and cytotoxicity activities of essential oils from Haplophyllum tuberculatum A. Juss leaves, stems and aerial parts

Background: Plants used for traditional medicine produce diverse and complex secondary metabolites exhibiting various medicinal properties. The medicinal plant Haplophyllum tuberculatum is used by native people against malaria and parasitic infections. Methods: In this study and in order to contribute for the search of new natural drugs for leishmaniasis, the essential oils of H. tuberculatum leaves, stems and aerial parts (leaves+stems) collected in two different periods, 2013 and 2015, and their components by GC/FID and GC/MS analyses were investigated. Those collected in 2013 were also re-analyzed two years later. The extracted oils were screened in vitro for anti-leishmanial activity on Leishmania mexicana mexicana (L.m.m.) promastigotes and cytotoxicity on the Chinese Hamster Ovary (CHO) cell line. Limonene (1.5 – 8%), its isomers (R- (+)-limonene and S-(-)-limonene), linalool and octanol were also tested. Results: Results showed that the chemical composition varied according to the year of collection. Though major compounds remain almost the same, qualitative and quantitative variations in the composition of the EOs can be observed between the two years of collection, with some minor compounds identified only in one type of samples. Variation in the composition were also observed in the re-analyzed volatile oils, showing stability concerns. The essential oils and R-(+)-limonene showed moderate anti-leishmanial activity. Their IC50 range from 6.48 to 50.28 μg/ml. Cytotoxicity assays for theses volatile extracts, R- (+)-limonene and S- (-)-limonene on CHO cells showed relatively potent cytotoxicity with a selectivity index <10. Their CC50 range from 27.79 to 82.56 μg/ml. Conclusions: The findings of the present study demonstrated that H. tuberculatum might not be considered as a natural source for production of new anti-leishmanial agents without further analyzing its eventual in vivo toxicity as well as that of major pure compounds

Natural products published in 2009 from plants traditionally used to treat malaria

Malaria is a major parasitic disease and is responsible for almost one million deaths each year in Africa. There is an urgent need to discover new active compounds. Nature and particularly plants are a potential source of new antimalarial drugs since they contain a quantity of metabolites with a great variety of structures and pharmacological activities. This review covers the compounds with antiplasmodial activity isolated from plants which have been published during 2009 organized according to their phytochemical classes. Details are given for substances with IC (50) values ≤ 11 µM. Sixty-seven references are identified

Natural Products and Tropical Diseases

Tropical diseases encompass all diseases that occur solely, or principally, in the tropics. In practice, the term is often taken to refer to infectious diseases that thrive in hot, humid conditions, such as malaria, leishmaniasis, schistosomiasis, onchocerciasis, lymphatic filariasis, Chagas disease, African trypanosomiasis, and dengue. Neglected tropical diseases affect about 1 billion people, primarily poor populations living in tropical and subtropical climates, and in 2008, malaria caused nearly one million deaths, mostly among African children (WHO, 2011)[*]. There is an urgent need to discover new treatments against these ailments or to kill their vectors because of the development of resistance and/or the side effects or costs of available treatments. Furthermore, as people suffering from these diseases are often from developing countries and have low incomes, the economical interest is not high for the research and development of new molecules. Therefore, most people still rely on traditional medicine for their prevention or treatment. As plants are a recognized source of new medicines with great potential, Planta Medica has decided to publish a special issue on natural products and tropical diseases to report advances in this area. Reviews compiled in this special issue deal with different aspects of prevention and treatment of tropical diseases as well as tests and targets for the discovery of such compounds from nature. They also include overviews of effective extracts, fractions, or isolated compounds from plants or marine sources, or improved traditional phytomedicines used against well-known diseases as malaria and others as Buruli ulcer