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.