Ammi visnaga (Av) is a source of khellin where a tea made from the fruit of this plant was used as herbal medicine for kidney stones in Egypt. In the present research, the acute and subacute toxicity studies with oral intake of 150, 300 and 600 mg/kg of Av seed ethanolic extract in rats were done. In acute toxicity test, 4 groups of rats (n = 6/group: 3 males and 3 females) were chosen and the first control group received tap water, while the other three groups received Av seed ethanolic extract dissolved in tap water at doses of 150, 300, and 600 mg/kg, and general behavior, adverse effects, and mortality were recorded for up to 14 days. In subacute toxicity study, 72 rats (36 males and 36 females) were divided into 4 major groups; group I received tap water (control group), while animals in groups II, III, and IV (test groups) received oral intake of Av seed ethanolic extract dissolved in tap water at doses of 150, 300 and 600 mg/kg bwt, respectively. Each of this major group was subdivided consequently into 3 subgroups (n = 6/group: 3 males and 3 females) where brain tissue, blood sample, body and organs weights were recorded at the beginning and then after two and four weeks of the experiment for the determination of hematological, biochemical and histopathological changes in tissues (liver, kidney, brain, spleen, heart, testis and ovary). With regard to acute toxicity, Av seed ethanolic extract did not induce any toxic effects or death or any organ toxicity. In subacute toxicity study; oral intake with Av seed ethanolic extract did not reveal any change in body and organs weights, hematological parameters, serum glucose and cholesterol, brain neurotransmitters, liver and kidney functions, male and female hormones. In conclusion, Av seed ethanolic extract is nontoxic to liver, kidney, brain, spleen, heart, testis and ovary.
