title: Chronic toxicological evaluation of dietary NovaSil clay in Sprague-Dawley rats.
abstract: NovaSil (NS) clay, a common anti-caking agent in animal feeds, has been shown to sorb aflatoxins in the GI tract and diminish their bioavailability and adverse effects in short-term animal studies. Based on this evidence, it is hypothesized that clay-based enterosorption of aflatoxins may be a useful strategy for the prevention of aflatoxicosis in human populations. However, the potential toxicity of long-term dietary exposure to NS has not been determined. In this research, 5-6-week-old male and female Sprague-Dawley rats were fed rations containing 0, 0.25, 0.5, 1.0, or 2.0% (w/w) levels of NS for 28 weeks. Analysis of the NS showed negligible levels of dioxin and furan contaminants. Total feed consumption, cumulative feed consumption, body weight, total body weight gain, feed conversion efficiency, cumulative feed conversion efficiency, and relative organ weights were unaffected in either sex at the doses tested. No NS-dependent differences in relative organ weights or gross or histopathological changes were observed. Analysis of hematological parameters, clinical chemistry, and selected vitamin and mineral levels revealed isolated significant differences between some treatments and control groups (mean corpuscular hemoglobin, serum Ca, serum vitamin A, and serum Fe). However, the differences observed in each case were not dose-dependent. These results suggest that dietary inclusion of NS at levels as high as 2.0% (w/w) does not result in overt toxicity. These findings (as well as others) support the use of NS clay for dietary intervention studies in human populations at high risk for aflatoxicosis.
authors: Intercollegiate Faculty of Toxicology, Department of Veterinary Integrative Biosciences, College of Veterinary Medicine, Texas A&M University 4458 TAMU, College Station, TX 77843-4458, USA.
authors: Evans
authors: E
authors: Afriyie-Gyawu
authors: John
authors: J
authors: Mackie
authors: Bhagirathi
authors: B
authors: Dash
authors: Melinda
authors: M
authors: Wiles
authors: John
authors: J
authors: Taylor
authors: Henry
authors: H
authors: Huebner
authors: Lili
authors: L
authors: Tang
authors: Hongxia
authors: H
authors: Guan
authors: Jia-Sheng
authors: JS
authors: Wang
authors: Timothy
authors: T
authors: Phillips
mesh_terms: D000042:Absorption; D000348:Aflatoxins / Q000378:metabolism; D000821:Animal Feed / Q000009:adverse effects*; D000818:Animals; D001546:Bentonite / Q000008:administration & dosage / Q000009:adverse effects*; D001773:Blood Cells / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D005260:Female; D005503:Food Additives / Q000008:administration & dosage / Q000009:adverse effects*; D008099:Liver / Q000737:chemistry / Q000473:pathology; D008297:Male; D009929:Organ Size / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014801:Vitamin A / Q000032:analysis; D014810:Vitamin E / Q000032:analysis
chemical_list: D000348:Aflatoxins; D005503:Food Additives; D014801:Vitamin A; D001546:Bentonite; D014810:Vitamin E