Oral acute and subacute toxicity studies as well as safety pharmacology in beagle dogs of total lignans from <i>Arctii Fructus</i>

<i>Arctii Fructus</i> is a frequently used Chinese materia medica and the dried ripe fruit of <i>Arctium lappa</i> L. (family Asteraceae). Previous studies discovered that the total lignans from <i>Arctii Fructus</i> (TLAF) could inhibit streptozotocin-induced diabetic retinopathy in addition to having hypoglycemic action on a variety of diabetic animal models. The oral toxicity of TLAF in rats has been reported, but there are no reports on its oral toxicity in beagle dogs. This study evaluated the acute and subacute toxicity of TLAF, as well as its effects on the respiratory and cardiovascular systems in beagle dogs at the first time. The approximate lethal dose of TLAF administered orally to beagle dogs was greater than 5000 mg/kg in the acute oral toxicity testing, and the respiratory and cardiovascular systems of conscious beagle dogs were not significantly affected by the oral administration of TLAF. However, repeated oral administration of TLAF (540 mg/kg) to beagle dogs for 28 days can cause 50% of administered animals to die. The toxic reactions are mainly seen in the digestive system, heart, liver, and kidneys. These results reduce the feasibility of developing TLAF as a clinical drug to treat diabetes and its complications.