Toxicity studies on dermal application of plant extract of Dodonaea viscosa used in Ethiopian traditional medicine.

Despite advances in the understanding of the medicinal properties of many herbs, the consumer today is confronted with the lack of or misinformation concerning the safety of these herbs that rivals the heyday of the patent medicine era. In the present study, Dodonaea viscosa (Sapindaceae), a medicinal plant commonly used for skin diseases in Ethiopia was subjected to a systematic dermatotoxicity study. To this effect, the dermatotoxicity of an 80% methanol extract of the leaf was investigated in animals following standard procedures for irritation, sensitization, acute toxicity and repeated toxicity tests. The skin irritation test in rabbits showed the extract to be a slight or negligibly slight irritant, with a primary irritation index of 0.45. A sensitization test in mice by the mouse ear swelling test method revealed the extract to be a non-sensitizer in the dose range 12-30 mg/mL. The percent responder was zero. The acute and repeated dermal toxicity tests on rats did not show any overt sign of toxicity. The findings of this study collectively indicate that dermal application of D. viscosa is not associated with any toxicologically relevant effects and the data could provide satisfactory preclinical evidence of safety to launch a clinical trial on a standardized formulation of the plant extracts. (c) 2009 John Wiley & Sons, Ltd.