Chemical composition and in vitro antileishmanial activity of essential oil of the leaves of Discopodium pennnervium Hochst
Discopodium penninervium Hochst (Solanaceae), locally known as Ameraro (Amharic), is traditionally used in Ethiopia for the treatment of various ailments including schistosomiasis, stomachache, eczema, leprosy, diarrhea, liver disease and cancer. The chemical composition and biological activities of D. penninervium essential oil has not been reported. The objectives of the present study were therefore, to determine the chemical composition and evaluate the in vitro antileshmanial activity of the essential oil of D. penninervium. Fresh leaves of D. peninnervium were subjected to hydrodistillation using Clevenger-type apparatus. Chemical composition of the essential oil obtained was determined by gas chromatography-mass spectrometry (GC-MS). In vitro antileishmanial activity of the oil was evaluated against the promastigote stage of L. aethiopica and L. donovani. Hydrodistillation of the leaves of D. penninervium afforded a colourless essential oil with yield of 0.01% (w/w). GC-MS analysis revealed the presence of 65 components comprising 98.6% of the total oil. Majorly, the oil is composed of hydrocarbons such as 1,4-diethyl benzene (11.49%), 1,2-diethyl benzene (11.86%) and m- xylene (8.45%) and terpenoids including 1,8-cineole (9.8%), geranic acid (8.28%) and dihydrocitronellol (5.0%). The oil possesses antileishmanial activity against L. aethiopica and L. donovani with IC50 values of 12.62 and 19.93 µl/ml, respectively. The results show that the essential oil of the leaves of D. penninervium is mainly composed of aromatic hydrocarbons and terpenoids, and exhibits antileshmanial activity on both L. aethopica and L. donovani .
Keywords: Discopodium penninervium, essential oil, antileshmanial activity, chemical composition, traditional medicine