Macrofilaricidal Activity of Leaf Extracts of Rauvolfia tetraphylla L. Against Bovine Filarial Parasite Setaria cervi.

Abstract

Leaf extracts of Rauvolfia tetraphylla were evaluated for antifilarial potential using Setaria cervi as target parasite. Four extracts were tested these were hexane, chloroform, acetone and methanol. The activity was assessed by means of worm motility assay, MTT reduction and GST enzyme inhibition assay using female worms of Setaria cervi. DEC was used as a standard drug. Methanol extract exhibited significant activity among all the extracts with percentage of reduction 89.28% at 10mg/ml concentration. DEC was comparitively less active than methanolic extract with 79.22% activity at the same dose. The IC50 value for methanolic extract was found to be 0.03mg/ml, which was better than the standard DEC i.e. 2.84mg/ml. The methanol extract significantly inhibited the GST enzyme activity of Setaria worms as compared to untreated worms with percentage of inhibition value of 56.41% at 10mg/ml. The most active methanol extract was finally explored for cell viability study by using trypan blue dye exclusion test. The methanolic extract significantly killed the oocytes of Setaria worms as all the oocytes stained blue in treated worms and unstained in control oocytes. The findings indicate that the methanolic extract has potent macrofilaricidal ativity.