Fate and transport of ethoprophos in the Jamaican environment

The hydrolytic half lives of ethoprophos in distilled, river, brackish and open sea water were 25, 133, 65 and 81 days, respectively. Under laboratory conditions, volatilisation of the residues after 12 h was 1.4 - 3.6, 2.3 - 4.5 and 6.5 - 20.2 percent from a sandy loam soil with 1, 10 and 20 percent moisture levels, respectively. Photolysis in soil was significantly faster (P< 0.05) in direct sunlight (T 1/2 of 12.3 days). The microbial degradation of ethoprophos from unweeded plantation soil at 23 degrees slope was significantly (P=0.015) less than at 38 degrees slope; the amounts lost after 9 weeks and 27.5 mm of rainfall were 89.4 and 91.2 percent respectively, of the applied amount from the two respective slopes. In the weeded plots, 93.6 and 92.4 percent of the applied insecticide were lost from 23 degrees and 38 degrees slopes, respectively. Under laboratory conditions, between 67.0 and 85.1 percent of ethoprophos leached through the soil columns. Under field conditions, after 9 weeks and 25 mm of rainfall, only 2.8 and 2.0 percent residues were recovered at a depth of 10-15 cm from unweeded and weeded slopes, respectively at 23 degrees slope, and 2.2 and 1.9 percent from the two respective plots at 38 degrees slope. (AU)

Inactivation of strongyloides stercoralis filariform larvae in vitro by six Jamaican plant extracts and three commercial antihelminthics

In vitro bioassay of (a) aqueous methanol extracts (AME) of the green leaves of mimosa (Mimosa pudica), love weed (Cuscuta americana), vervine (Stachytarpheta jamaicensis), chicken weed (Salvia serotina) and breadfruit (Artocarpus altilis); (b) methanol-water fraction (MWF) of breadfruit leaves, and (c) commercially available drugs albendazole, thiabendazole and levamisole were assayed for nematode inactivating potential, using filariform larvae of Strongyloides stercoralis. Test larvae were obtained from a 10-day-old charcoal coproculture. Bioassays were conducted in Locke's solution, using 100 larvae in each of three replicates. Inactivation was recorded microscopically at 1, 2, 6 and 12 hours, then every 24 hours up to 5 days' incubation. It(50) (time for inactivation of 50 percent of larvae) values read: levamisole and mimosa extract < 1 hour; love weed extract, approximately 2 hours; breadfruit (MWF), 9.5 hours; chicken weed, 20 hours; albendazole, 35 hours; breadfruit (AME), 49 hours; thiabendazole, 74 hours and vervine extract, 81.5 hours. It(95) values followed a similar trend, and were approximately double the It(50) measures. A potential role for locally available natural products in the treatment of strongyloidiasis is highlighted (AU)