Phytochemicals, antioxidant ability and in vitro anthelmintic activity of crude extracts from Vitexnegundo leaves against Haemonchus contortus.

Abstract

The aim of this study was to evaluate the in vitro anthelmintic effect of crude aqueous, methanol, ethanol, hydro alcohol and acetone extracts of Vitex negundo leaves against Haemonchus contortus eggs and larvae. Phytochemical analysis to identify the number of compounds in extracts was done by chemical tests and gas chromatography coupled to a mass spectrophotometer detector (GC-MS). First off all the effectiveness of dried plant materials was evaluated on larval development by mixing powdered material (no nano particles) to faecal cultures from donor sheep. Adding powder to the faecal culture resulted into 100% inhibition in larval development at 200 and 300mg/g of faeces. The anthelmintic activity was assessed using the egg hatch assay (EHA) and the larval mortality assay (LMA). Comparison of mean inhibition percentage of egg embryonation, mean inhibition percentage of egg hatching and mean percentage of larval mortality at different concentrations with control was performed by one-way ANOVA. The means were compared for statistical significance using DMRT at P < 0.05. For both the assays, 50% inhibitory concentration (IC50) and lethal concentration (LC50) were calculated by probit analysis. Chemical test revealed presence of high concentration of saponin and flavoinoids and moderate concentration of total phenols in leaves. The antioxidant activity (radical scavenging activity, RSA %) measured was 35.47%. On GC-MS, the methanolic leaves extract revealed 30 phyto-compounds. On EHA, there was marked effect on inhibition of egg hatching by aqueous, hydro alcohol and acetone extracts. On LMA all the five extracts showed excellent larvicidal activity. V. negundo leaves methanol extract mediated silver nanoparticles were found very effective at much lower concentrations as compared to crude methanol extract. The results indicated that the V. negundo leaves crude extracts possessed excellent in vitro ovicidal and larvicidal properties against H. contortus which needs more investigation, especially in vivo trials for the control of parasite.