Vol. 12, Issue 1, Part A (2025)

Methods: After preliminary screening done by crude extract and petroleum ether solvent extract of two plants, J. ruscifolia and T. orientalis were examined separately and in combinations (1:1, 1:2 and 2:1) against filarial vector Cx. quinquefasciatus third-instar larvae with gradually increasing concentration (50 ppm to 250 ppm). To observe the synergistic effect, if any, LC₅₀ values are first estimated. Synergistic factor (SF) can be calculated by using LC₅₀ value of the individual plant extract/ LC₅₀ value of the combined plant extracts at different consecutive periods (24, 48 and 72 hours). SF value > 1 shows presence of synergism. Phytochemical analyses of extract done by IR and GC-MS analysis.

Results: 100% mortality was recorded when bioassay experiment was done with petroleum ether extract of J. ruscifolia flower and T. orientalis strobili in their combinations at 250 ppm concentration against third-instar Cx. quinquefasciatus in 72 hours of continuous exposure. For every case SF obtained > 1 showing synergism. The dose-effect curve and combination-index plot suggesting 1:2 combination showing synergism with gradual increased concentration among three. FT-IR analysis suggesting presence of functional groups like alkane, aldehyde, amine salt, aromatics, ether and ester. GC-MS analysis suggest presence of five active compounds, viz., Scopolamine; 1-methyl-7-azabicyclo [4,1,0] heptane; 6-methyl-6-[5-methyl-4-propyl-2-yl] heptane 2-one; Pyrrolidinium 2, carboxy 4-hydroxy-1,1 dimethyl hydroxide and 5-hydroxy pentanamide.