Background and Aim: Anacyclus pyrethrum (L.) has been used in traditional North African and Indian medicine for the treatment of several diseases such as cancer, rheumatism, epilepsy, diabetes, and Alzheimer's disease. Despite its medical benefits, few studies have examined its toxicity. The present study evaluated the acute toxicity of hydroethanolic extracts of different parts (roots, seeds, leaves, and capitula) of two varieties of A. pyrethrum (L.), namely, A. pyrethrum var. pyrethrum (L) and A. pyrethrum var. depressus (Ball) Maire, in mice.

Materials and Methods: Acute toxicity was evaluated after the oral administration of different extracts at doses of 300, 500, and 2000 mg/kg. Mortality, body weight, general behavior, and adverse effects were observed daily for 14 days. At the end of the experiment, mice were sacrificed, and biochemical parameters and histopathology of the liver, kidneys, and spleen were analyzed.

Results: The extracts of different parts of both plants induced no signs of toxicity or mortality during the observation period, excluding capitulum and seed extracts, which induced slight sedation at a dose of 2000 mg/kg. The LD₅₀ of the extracts was estimated to exceed 2000 mg/kg. The administration of A. pyrethrum var. pyrethrum roots at a dose of 300 mg/kg resulted in significantly increased AST levels. However, the A. pyrethrum var. depressus root extract induced significant increases in the levels of both transaminases (alanine aminotransferase [ALT] and aspartate aminotransferase [AST]). The remaining extracts of both plants at a dose of 500 mg/kg significantly increased AST levels. Moreover, all plant extracts excluding the A. pyrethrum var. pyrethrum capitulum extract at 2000 mg/kg provoked significant increases in AST levels, and A. pyrethrum var. depressus roots provoked a significant increase of ALT levels. Meanwhile, mice treated with high doses of extracts (2000 mg/kg) displayed histopathological changes in the liver, kidneys, and spleen characterized by hepatic distress, inflammatory infiltration, focal tubular necrosis, vascular congestion, and lymphoid hyperplasia.

Conclusion: The results of the present study indicate that the hydroethanolic extracts of different parts of two varieties of A. pyrethrum (L.) were not toxic in mice at low concentrations, whereas some toxic effects were detected in mice treated at 2000 mg/kg.

Keywords: acute oral toxicity, Anacyclus pyrethrum var. depressus (Ball) Maire, Anacyclus pyrethrum var. pyrethrum (L), histopathology, serum biochemistry analysis.