In vitro and in vivo antileishmanial activity of parthenin a sesquiterpene lactone obtained from Parthenium hysterophorous

Abstract

Background: Leishmaniasis, a vector borne disease caused by haemoflagellate leishmania parasites. It is caused by several species of flagellated protozoans belonging to the genus Leishmania of the family Trypanosomatidae, affecting 12 million people worldwide is transmitted to humans by the bite of infected female phlebotomine sand flies.In the present study we undertook an examination of the potential antileishmanial activity of T. parthenium. Methods & Materials: Parthenium hysterophorus were collected and shade dried for about 15-20 days. Dried and finely powdered leaves and influorescence were extracted with hexane in Soxhlet apparatus to remove fatty substances followed by chloroform.The structure of the isolated compound was identified by nuclear magnetic resonance (NMR; Gemini 2000 BB; Varian), 1H NMR (300 MHz), and 13C NMR (75.5 MHz) analyses in CDCl3; The compound was characterized by HPLC-UV mass spectra data peaks were detected at 210 nm and nuclear magnetic resonance (NMR) spectra data. To determine the 50% inhibitory concentration i.e. IC50 of parthenin, the MTT assay, micro method was followed. Briefly, log-phase Leishmania promastigote cells (2 × 105/well) were seeded in 96-well (Corning Inc., COSTAR).During In-vivo study, Female hamsters were infected, with 2 × 107 amastigotes of Ag83 L. donovani, via the tail vein. After 30 days post infection the potency of infection has been checked against the drug and test compound doses that were given. Results: A structure identified corresponding to a sesquiterpene lactone, 4,5 epoxy-germacra-1- (10),11(13)-dien-12,6-olide (parthenin) by nuclear magnetic resonance (NMR) and HPLC-UV mass spectra data peaks.Parthenin exhibit significant inhibitory activity on L. donovani promastigotes incubated with varying concentration (0 - 5 mg/ml) for 48 h of Parthenin and half of the inhibitory concentration (IC50) as determined from dose–response curve was 0.65 ± 0.03 mg/ml. In-vivo results suggest that the load of the parasites was found to be significantly lower for group A (93.2 ± 6.7%) compared with group B (74.6 ± 14.8). Conclusion: The antileishmanial effect was found during in-vitro and in-vivo study. It will be worthwhile to instigate a large-scale study to look at the toxicity level in animal model before clinical studies are contemplated