Acute oral safety study of rosemary extracts in rats.

Increasing interest in rosemary plants is due to their antioxidant and health-enhancing properties. The aim of this study was to evaluate the potential acute toxicity of two supercritical fluid extracts of rosemary. An acute safety study of rosemary extracts was conducted in Wistar rats at a single oral gavage dosage of 2,000 mg/kg of body weight. Rosemary extracts were well tolerated; no adverse effects or mortality were observed during the 2-week observation period. No abnormal signs, behavioral changes, body weight changes, or change in food and water consumption occurred. Two weeks after a single oral rosemary extract dose of 2,000 mg/kg of body weight, there were no changes in hematological and serum chemistry values, organ weights, or gross or histological characteristics. Rosemary extracts appear to have low acute toxicity, and the oral lethal doses (LD50) for male and female rats are greater than 2,000 mg/kg of body weight.