Abstract
Chromium is an essential trace element required for normal protein, fat and carbohydrate metabolism. It also helps in energy production and increasing lean body mass. Niacin-bound chromium (NBC) is a unique form of bioavailable chromium that promotes healthy lipid profile. This study was focused on determining the broad spectrum safety of NBC. Acute oral, acute dermal, primary dermal irritation and primary eye irritation toxicities of NBC were evaluated. Ames bacterial reverse mutation assay, mouse lymphoma test and a dose-dependent 90-day subchronic toxicity were also conducted. In safety studies, the acute oral LD50 of NBC was found to be greater then 5000 mg/kg in both male and female Sprague-Dawley rats. No changes in body weight or adverse effects were observed following necropsy. The acute dermal LD50 of NBC was found to be >2000 mg/kg. The primary skin irritation test was conducted with NBC on New Zealand Albino rabbits. NBC was classified as slightly irritating. The primary eye irritation test was conducted with NBC on rabbits. NBC was classified as practically non-irritating to the eye. NBC did not induce mutagenic effects in the bacterial reverse mutation test in five Salmonella typhimurium strains (TA1535, TA98, TA100, TA97a and TA102), either with or without metabolic activation. Similarly, NBC did not induce mutagenic effects in the mammalian cell gene mutation test in L5178Y mouse lymphoma cells TK (+/-), either with or without metabolic activation. A dose-dependent 90-day subchronic toxicity study demonstrated no significant changes in selected organ weights individually and as percentages of body and brain weights. NBC supplementation did not cause changes in hepatic lipid peroxidation or DNA fragmentation after 30, 60 or 90 days of treatment. Hematology, clinical chemistry and histopathological evaluations did not show any adverse effects in all organs tested. Taken together, the above results indicate a broad spectrum of safety for NBC.