LAUSR

Background: The expanded utility of herbal medicines worldwide has created a demand to determine the possible adverse effects of these plants to protect people from exposure to them. Objectives: The present study evaluated the acute and sub-chronic toxic effects of Achillea wilhelmsii extract on Wistar male and female rats to provide an accurate median lethal dose (LD50) and suggest a value for the no observed adverse effect level (NOAEL). Methods: In both phases, Wistar rats were assigned to control and intervention groups. At the end of the study, blood was collected from the heart for hematological analysis and from the retro-orbital sinus for serum biochemical assessment. Then, the heart, kidney, liver, lung, and spleen tissues were collected for histopathological studies. Results: In the acute phase of the study, no mortality was reported. Additionally, there were no significant changes in the body and organ weights in rats from all groups after 14 days at the dose of 5000 mg/kg. In the sub-chronic phase, after 60 days of oral consumption of 250, 500, and 1000 mg/kg of the extract, there were no significant body and organ weight changes between the control and treatment groups (P > 0.05). Hematological and biochemical analyses revealed no changes in the organs’ functional activity. Conclusions: Acute and repeated oral consumption of herbal medicines containing A. wilhelmsii extracts appears to be non-toxic up to the tested doses (LD50 > 5000 mg/kg, NOAEL > 1000 mg/kg).