To our knowledge, this is the first reported case of OBLD observed after the combined use of BC and ginseng. The action mechanisms, pharmacokinetics, and metabolites of BC have not been totally identified. Recent data have demonstrated that BC may have an effect on dopaminergic, serotoninergic, and GABAergic systems.1 It has been suggested that unknown dopaminergic compounds may contribute to the pharmacological activity of BC.3 More than 30 different ginsenosides, the main components responsible for the actions of ginseng, have been isolated and identified from ginseng.2 In spite of some in-vivo studies indicating that some ginsenosides can be neuroprotective to striatal neurons,4 the results from a recently-published in-vitro study were mixed. This study has shown that low doses of some ginsenosides exhibited striatal neuroprotective effects, whereas overdoses have caused striatal toxic effects.2 Wu et al.2 reported that there could only be a fine line between the neuroprotective and toxic effects of ginsenosides. The use of ginseng can cause complications when used in combination with other medications. Adverse effects, including nervousness and insomnia,2 have been reported from long-term use and high doses of ginseng; BC has been linked to liver, cardiovascular, CNS, and peripheral nervous system adverse events. It was reported that mono-preparation of BC is safe in the short term for otherwise-healthy menopausal women, and Huntley3 recommended limiting its use to 6 months.
Estrogens have well-known neuroprotective activity. Postmenopausal estrogen deficiency leaves the dopaminergic system vulnerable to neurotoxicity.5
We suggest that BC together with ginseng could be responsible for the OBLD. Previous use of BC together with ginseng should be investigated carefully in patients with OBLD. Further studies on basic pharmacological mechanisms of actions and toxicity of BC and ginsenosides are needed.