Neurotoxicity of Herbal Medicine

Kyoung Gyu Choi

doi:10.5124/jkma.2005.48.4.308

J Korean Med Assoc > Volume 48(4); 2005 > Article

Choi: Neurotoxicity of Herbal Medicine

Special Issue

Side Effects of Medicinal Herbs

Journal of the Korean Medical Association

Journal of the Korean Medical Association 2005; 48(4): 308-317.

Published online: April 30, 2005

DOI: https://doi.org/10.5124/jkma.2005.48.4.308

Neurotoxicity of Herbal Medicine

Kyoung Gyu Choi, M.D.

Department of Neurology, Ewha Womans University College of Medicine, Mokdong Hospital, Korea. kgchoi@ewha.ac.kr

Abstract

Herbal medicines have been used for thousands of years, and herb preparations are commercially available for the folk remedies or for the promotion of health. In contrast to chemical drugs, herbs are regarded to be non-toxic and safe, because of their natural origin. But accumulating clinical data claim the toxicity of herbal medicine. They can cause adverse effects through ① toxicity of the herb itself or bioactivation of its metabolites, ② interaction with prescribed drugs, and ③ heavy metals contaminated in the herbal products. Recent studies have disclosed various neurologic side effects of herbal medicine, including cerebrovascular accident, convulsion, encephalopathy, hallunication, and psychosis. In addition to, some herbs interact with the neurologic therapeutic drugs, such as anticoagulants and antiepileptic drugs, leading to failure to control the patients' diseases. Also, there is growing evidence that herbal medicine products contain potentially harmful levels of lead, mercury and arsenic, all of which have neurotoxicity. Systematic validation of the potency and toxicity of herbal medicines as well as screening of toxic heavy metal content should be warranted.

Keywords: Herbal medicine; Neurotoxicity; Drug interaction; Heavy metals

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