Pharmacological Research - Modern Chinese Medicine (Jun 2024)
Calming effect of traditional Chinese medicine cinnabar based on neurotransmitter content and metal elements concentration in PCPA-induced insomnia rats
Abstract
Introduction: Cinnabar is a commonly utilized mineral traditional Chinese medicine (TCM) in China. It has the functions of clearing the heart and calming the mind. However, there remains a dearth of pharmacological experiments on the metal elements of cinnabar on animal models. Therefore, this study aims to investigate the effects of cinnabar on neurotransmitter levels in p-chlorophenylalanine (PCPA) induced insomnia rats and the content of metal elements in plasma, heart, liver, spleen, lung and kidney of rats. Methods: Tissue hematoxylin and eosin (H&E) staining were used to assess the histological changes. The 5-HT and GABA in plasma and hypothalamus of rats were determined by enzyme-linked immunosorbent to evaluate the therapeutic effect. The content of metal elements in plasma, heart, liver, spleen, lung and kidney of rats was determined by ICP-MS. Results: After cured with cinnabar and its processed for fourteen days, the level of 5-HT in the plasma and hypothalamus increased (P<0.05), and the level of GABA decreased (P<0.05). Furthermore, both low dose (1 mg/kg) and high dose (10 mg/kg) of cinnabar resulted in an increase in plasma 5-HT levels;, however, the high dose of cinnabar increased the level of 5-HT more than low dose of cinnabar. The content of metal elements in plasma, hemocyte and heart, liver, spleen, lung and kidney of rats ranged from less than 1 µg.g−1 to hundreds of µg.g−1, among which the highest content was Fe in rat's spleen of cinnabar sedative pill group, and the content is 919 µg.g−1. The content of most metal elements in plasma and hemocyte of rats was significantly lower than that in heart, liver, spleen, lung and kidney. There is no obvious difference of Hg in plasma and tissue of rats between the control group fed normally and rats fed with drugs. Discussion: Cinnabar and its products can improve insomnia symptoms in rats by regulating the neurotransmitters 5-HT and GABA. Cinnabar is basically non-toxic in short-term (less than 14 days) use accordance with the dosage prescribed by pharmacopoeia.
