Chemical profiling and quantification of potential active constituents responsible for the antiplasmodial activity of Cissampelos pareira

Abstract

Ethnopharmacological relevanceCissampelos pareira is used traditionally in India as a remedy for the treatment of various diseases including malaria but the active ingredients responsible for antiplasmodial activity have not yet been investigated.Aim of the study: The identification and quantification of compounds responsible for antiplasmodial activity in different parts (leaf, stem and root) of C. pareira is the target of current study. Material and methodsThe hydro ethanolic parent extracts of different parts of C. pareira and fractions prepared from these extracts were evaluated against Pf3D7 (chloroquine sensitive) and PfINDO (chloroquine resistance) strains in culture to quantify the IC50 for extracts and fractions. Promising fractions of root part of plant were subjected to silica gel column chromatography to obtain pure compounds and their structures were elucidated by detailed spectroscopic analysis. Pure compounds were also tested against Pf3D7 and PfINDO strains. A rapid and simple UPLC-DAD method was developed for the identification and quantification of pharmaceutically important metabolites of C. pareira. ResultsAmong different extracts, the hydro ethanolic extract of root part of C. pareira was found most active with IC50 values (μg/ml) of 1.42 and 1.15 against Pf 3D7 and Pf INDO, respectively. Tested against Pf 3D7 the most potent fractions were root ethyl acetate fraction (IC50 4.0 μg/ml), stem water fraction (IC50 4.4 μg/ml), and root water fraction (IC50 8.5 μg/ml). Further, phytochemical investigation of active fractions of root part led to the isolation and characterization of a new isoquinoline alkaloid, namely pareirarine (8), along with five known compounds magnoflorine (5), magnocurarine (10), salutaridine (11), cissamine (13) and hayatinine (15). Hayatinine (15), a bisbenzylisoquinoline alkaloid, isolated from root ethyl acetate fraction was most promising compound with IC50 of 0.41 μM (Pf INDO) and 0.509 μM (Pf 3D7). Magnocurarine (10) and cissamine (13) were also found active with IC50 values of 12.51 and 47.34 μM against Pf INDO and 12.54 and 8.76 μM against Pf 3D7, respectively. A total of thirty compounds were detected in studied extracts and fractions, structures were assigned to 15 of these and five of these biologically important compounds were quantified. Isolation of saluteridine (11) from C. pareira and the evaluation of antiplasmodial activity of pure compound from C. pariera is disclosed for the first time. ConclusionThis study concludes that the antimalarial potential of C. pareira may be attributed to isoquinoline type alkaloids present in this plant and also provides the scientific evidence for the traditional use of this plant in treatment of malaria.