Cytotoxicity of selected medicinal and nonmedicinal plant extracts to microbial and cervical cancer cells.

This study investigated the cytotoxicity of 55 species of plants. Each plant was rated as medicinal, or nonmedicinal based on the existing literature. About 79% of the medicinal plants showed some cytotoxicity, while 75% of the nonmedicinal plants showed bioactivity. It appears that Asteraceae, Labiatae, Pinaceae, and Chenopodiaceae were particularly active against human cervical cancer cells. Based on the literature, only three of the 55 plants have been significantly investigated for cytotoxicity. It is clear that there is much toxicological work yet to be done with both medicinal and nonmedicinal plants.

Competitive exclusion of Cyanobacterial species in the Great Salt Lake.

The Great Salt Lake is separated into different salinity regimes by rail and vehicular causeways. Cyanobacterial distributions map salinity, with Aphanothece halophytica proliferating in the highly saline northern arm (27% saline), while Nodularia spumigena occurs in the less saline south (6-10%). We sought to test if cyanobacterial species abundant in the north are competitively excluded from the south, and if southern species are excluded by the high salinity of the north. Autoclaved samples from the north and south sides of each causeway were inoculated with water from each area. Aphanothece, Oscillatoria, Phormidium, and Nodularia were identified in the culture flasks using comparative differential interference contrast, fluorescence, and scanning electron microscopy. Aphanothece halophytica occurred in all inocula, but is suppressed in the presence of Nodularia spumigena. N. spumigena was found only in inocula from the less saline waters in the south, and apparently cannot survive the extremely hypersaline waters of the northern arm. These data suggest that both biotic and abiotic factors influence cyanobacterial distributions in the Great Salt Lake.

A retrospective analysis of prevalence of gastrointestinal parasites among school children in the Palajunoj Valley of Guatemala.

This study retrospectively analyzed demographic factors that may affect the prevalence of intestinal parasites among Guatemalan school children. The findings of the study showed that young age, wet season, female gender, and severe malnutrition all correlated positively with increased rates of infection. Clinical visits were performed on 10,586 school children aged 5-15 years over a four-year period (2004-2007) in the Palajunoj Valley of Guatemala, during which 5,705 viable stool samples were screened for infection with the following parasites: Ascaris lumbricoides, Giardia lamblia, Entamoeba histolytica, Hymenolepis nana, and Blastocystis hominis. The average overall prevalences of infection for specific parasites were A. lumbricoides 17.7%, E. histolytica 16.1%, G. lamblia 10.9%, H. nana 5.4%, and B. hominis 2.8%. Statistical analysis showed significantly higher rates of infection among younger children with G. lamblia (odds ratio [OR]=0.905, 95% confidence interval [CI] 0.871-0.941, p<0.0001) and E. histolytica (p=0.0006), greater prevalence of H. nana among females (OR=1.275, CI 1.010-1.609, p=0.0412), higher infection rates during the wet season for E. histolytica (p=0.0003) and H. nana (OR=0.734, CI 0.557-0.966, p=0.0275), and greater rates of infection with G. lamblia among malnourished children (for moderately malnourished children OR=1.498, CI 1.143-1.963, p<0.0001) and E. histolytica (for mildly malnourished children OR=1.243, CI 1.062-1.455, p=0.0313). The results suggest that the prevalence of gastrointestinal parasites among young Guatemalan children is highly dependent on the specific species of the parasite.

Cytotoxicity of Atriplex confertifolia.

The search for cancer treatment continues to be a global effort. As part of this global effort, many natural products have been tested against cancer cell lines, mostly from tropically located plants. This study reports that extracts of Atriplex confertifolia (Torr. and Frem.) S. Watson (Chenopodiaceae), a native North American plant (also known as shadscale or saltbush), has significant bioactivity against human breast cancer cell lines MCF-7, MDA-MB 435, MDA-MB 231, and HeLa cells (cervical cancer cells). The bioactivity of A. confertifolia extracts on these cells lines was compared to an FDA-approved cancer drug (Onxol((R))) and an industry-standard leukocyte control cell line. Active portions of the extracts were found primarily in the polar fractions of the plant. A dose-response curve of the extracts displayed significant cell death similar to Onxol((R)). The plant extracts did not significantly inhibit the viability of the leukocyte cell line. In a timed study, over 90% of cell lines MDA-MB 435 and HeLa died after 24 hours. Cell death appears to result from apoptosis.

Hazard evaluation for northern bobwhite quail (Colinus virginianus) exposed to chlorpyrifos-treated turf and seed.

This study evaluated the toxicity effects of chlorpyrifos on bobwhite quail (Colinus virginianus) kept in 27 field-exposed large pens arranged over turf in a randomized block design with nine blocks of three pens (16 adult birds per pen). Nine pens were treated with one application of 3.4 kg active ingredient (ai) per hectare followed by a second 3.4 -kg ai/ha application 2 weeks later, nine pens with one 6.7 -kg ai/ha application, and nine pens with formulation blank. In addition, the seed fed to the birds in the two chemically treated pens was also treated with chlorpyrifos. Mean residue in the grass samples from the first 3.4-kg treatment pens ranged from 306+/-95 ppm on day 0 to 18+/-8 ppm on day 14 after treatment. The second 3.4 -kg ai/ha treatment grass residues ranged from 361+/-167 ppm on day 0 to 38+/-24 ppm on day 14 after treatment. Grass residues from the 6.7-kg treatment pens ranged from 903+/-310 ppm on day 0 to 9+/-8 ppm on day 30 after treatment. Half-lives were approximately 2 days and 10 days for grass and seeds, respectively. Whereas the incidence of behavioral deficits was significantly (P = 0.0156) higher in the 6.7-kg pens (five females, one male), two of the females could have been the same bird because they were both seen in the same pen on days 23 and 24 after treatment. There was no significant difference in mortality, brain acetylcholinesterase activity, or any other measured parameter among any of the treatments. We conclude that application of chlorpyrifos to turf at 3.4 and 6.7 kg ai/ha is not expected to have chronic deleterious effects on populations of bobwhite quail grazing on treated grass or seeds, provided there is an abundant supply of seeds for the quail to eat.