METHODS: A group of mice (n = 5) treated orally with a single dose (5000 mg/kg) of MEDL was first subjected to the acute toxicity study using the OECD 420 model. In the hepatoprotective study, six groups of rats (n = 6) were used and each received as follows: Group 1 (normal control; pretreated with 10% DMSO (extract's vehicle) followed by treatment with 10% DMSO (hepatotoxin's vehicle) (10% DMSO +10% DMSO)), Group 2 (hepatotoxic control; 10% DMSO +3 g/kg APAP (hepatotoxin)), Group 3 (positive control; 200 mg/kg silymarin +3 g/kg APAP), Group 4 (50 mg/kg MEDL +3 g/kg APAP), Group 5 (250 mg/kg MEDL +3 g/kg APAP) or Group 6 (500 mg/kg MEDL +3 g/kg APAP). The test solutions pre-treatment were made orally once daily for 7 consecutive days, and 1 h after the last test solutions administration (on Day 7th), the rats were treated with vehicle or APAP. Blood were collected from those treated rats for biochemical analyses, which were then euthanized to collect their liver for endogenous antioxidant enzymes determination and histopathological examination. The extract was also subjected to in vitro anti-inflammatory investigation and, HPLC and GCMS analyses.
RESULTS: Pre-treatment of rats (Group 2) with 10% DMSO failed to attenuate the toxic effect of APAP on the liver as seen under the microscopic examination. This observation was supported by the significant (p
AIM OF THE STUDY: The aim of the current study is to evaluate the traditionally used medicinal plants for in vitro anti-malarial activity against human malaria parasite Plasmodium falciparum and profiling secondary metabolite using spectroscopic and chromatographic methods. Chemical profiling of active secondary metabolites in the extracts was undertaken using LC-MS.
MATERIALS AND METHODS: Based on the ethno-botanical data V. negundo L. was selected for in vitro anti-malarial activity against P. falciparum chloroquine-sensitive (3D7) and multidrug resistant (K1) strains using SYBR Green-I based fluorescence assay. Cytotoxicity of extracts was evaluated in VERO cell line using the MTT assay. Haemolysis assay was performed using human red blood cells. Secondary metabolites profiling was undertaken using chromatographic and spectroscopic analysis. Liquid chromatography analysis was performed using a C18, 150 X 2.1, 2.6 μm column with gradient mobile phase Solvent A: 95% (H2O: ACN), Solvent B: Acetonitrile, Solvent C: Methanol, Solvent D: 5 mM NH4 in 95:5 (H2O: ACN) at a constant flow rate of 0.250 ml/min. The LC-MS spectra were acquired in both positive and negative ion modes with electrospray ionization (ESI) source.
RESULTS: The anti-malarial active extract of V. negundo L. leaf exhibited potent anti-malarial activity with IC50 values of 7.21 μg/ml and 7.43 μg/ml against 3D7 and K1 strains, respectively with no evidence of significant cytotoxicity against mammalian cell line (VERO) and no toxicity as observed in haemolysis assay. The HPLC-LC-MS analysis of the extract led to identification of 73 compounds. We report for the first time the presence of Sabinene hydrate acetate, 5-Hydroxyoxindole, 2(3,4-dimethoxyphenyl)-6, 7-dimethoxychromen-4-one, Cyclotetracosa-1, 13-diene and 5, 7-Dimethoxyflavanone in the anti-malarial active extract of V. negundo L. leaf. Agnuside, Behenic acid and Globulol are some of the novel compounds with no reports of anti-malarial activity so far and require further evaluation in pure form for the development of potent anti-malarial compounds.
CONCLUSIONS: The result report and scientifically validate the traditional use of V. negundo L. for the treatment of malaria providing new avenues for anti-malarial drug development. Several novel and unknown compounds were identified that need to be further characterized for anti-malarial potential.