• Biomedical Science Letters
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• v.8 no.4
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• pp.223-228
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• 2002

In vitro bioassays of aqueous extracts of 25 herbal species were performed by ovicidal activity against Strongvloides venuelensis. 500 mg of feces from Mongorian gerbil infected with S. venuelensis were placed into polyvinyl culture with extracts of herb and anthelmintic drugs in triplicates. Larval activity inside the polyvinyl bag was recorded microscopically at 12 hours, and every 24 hours thereafter for up to 72 hrs incubation. Eggs were not hatched within 72 hrs and degeneration was evident in the presence of extracts. The ovicidal activity characterized by the absence of L$_3$ in fecal cultures inside the polyvinyl bag. 1. Among 25 herbs, 12 herbs had ovicidal effects and caused degeneration of larvae in egg. S. angustifolia, I. helenium, A. korenum, P. tenuifolia, F. virridissima, A. asiatica, S. chinensis, A. tataricus, S. baicalensis, M. rimosa, S. glabra and Z. piperitum were the most ovicidal effect. However, P. thunbergiana, T. chinensis, C. flos, G. uralensis, C. obutusifolia, C. fortunei, A. koreana, P. grandiflorum, P. tenuifolia (Radix), P. mume and A. asphodelodes showed no ovicidal effects in vinyl bag culture. 2. Of 25 hrebs, 4 herbs had ovicidal and wormicidal effects, P. thunbergiana, C. flos, B. Striata and T. chinensis were characterized by degeneration of larvae.

• Parasites, Hosts and Diseases
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• v.36 no.1
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• pp.15-22
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• 1998

An in uitro culture technique was established for harvesting Strongwloides venezuelensis free-living infective larvae using a nutrient broth medium as a substitute for rat-feces in polyvinyl culture bags ($10{\;}{\times}{\;}12{\;}cm$). The egg hatch rate V) in sterile saline at different incubation temperatures (X) was expressed as the quadratic function, Y = $-0.192X^2$ + 8.673x - 19.550 (r = 0.901). The highest (100%) egghatch rate was observed at $25^{\circ}C$. A significant difference (p<0.05) in development rate W) of free-living infective larvae was observed between different concentrations of nutrient broth (X) which was highest (20.6%1 in 0.12% nutrient broth concentrations, incubated at $20^{\circ}C$ for 5 days [Y = $-864.032X^2$ + 245.995X- 0.560 (r = 0.875)]. Yields (Y) of infective larvae were observed relatively high when the culture medium was incubated at higher temperatures (X) which peaked at $25^{\circ}C$ (20.0%) than at lower temperatures. $15^{\circ}C$M (10.9%) and $20^{\circ}C$ (18.1%) [Y = $-0.189X^2$ + 8.387x- 72.795 (r = 0.981)]. The period W) required for the development of infective larvae decreased with higher incubation temperatures (X) [Y = $0.035X^2$ - 2.025X + 32.375 (r = 0.995)] The highest yield (19.2%) of infective larvae was obtained from culture bag inoculated with 15.000 eggs than with below and over 15,000 eggs in 0.12% nutrient broth and incubated at $25^{\circ}C$ for 4 days. The newly adapted culture method (from egg to third-stage larva) may be useful as a bio-bar/bioassay system for screening new chemical products, anthelmintics and pesticides, as well as for parasito immunological studies with Strongwloides species.