Acorus tatarinowii, commonly known as Shi Chang Pu, is a perennial plant with a long history of use in traditional medicine. For centuries, it has been a component of Traditional Chinese Medicine (TCM), where its properties have been applied for various health purposes. Its historical use has prompted modern scientific inquiry into its chemical makeup and biological effects, bridging its role as an ancient remedy with contemporary research.
Botanical Profile and Traditional Significance
Acorus tatarinowii is a perennial herb that thrives in aquatic environments like marshes and wetlands in East Asia. It features long, sword-shaped, grass-like leaves and spreads through a thick, branched underground stem known as a rhizome. This highly aromatic rhizome is the primary medicinal part of the plant and is harvested in the autumn for use.
In Traditional Chinese Medicine, the rhizome of Acorus tatarinowii was first documented over 2,000 years ago in Shennong’s Classic of Materia Medica. Traditional applications describe its function as “opening the orifices” to restore consciousness and calming the spirit, or “Shen.” These uses positioned it as a treatment for conditions like dizziness, deafness, and mental disorders.
Key Bioactive Compounds
The plant’s chemistry, particularly the compounds within its rhizome, bridges its traditional use with modern understanding. Scientific analysis has identified over 160 compounds, but the primary constituents are the volatile oils. These oils are responsible for the rhizome’s distinct aroma and many of its biological effects.
Within this oil, two phenylpropanoids, alpha-asarone and beta-asarone, are the primary active components. These compounds are isomers, meaning they have the same chemical formula but a different arrangement of atoms. They are responsible for many of the plant’s effects, as studies show they can cross the blood-brain barrier to act on the central nervous system.
Researched Therapeutic Uses
Modern research explores the scientific basis for the traditional uses of Acorus tatarinowii, focusing on its effects on the nervous system. A primary area of investigation is its neuroprotective properties. Studies suggest the plant’s extracts and its main components, alpha- and beta-asarone, may protect nerve cells from damage, leading to research on its applications for cognitive function and memory.
Research indicates the plant’s volatile oil may improve cognitive dysfunction by reducing the buildup of proteins that are hallmarks of Alzheimer’s disease. Animal studies have shown that beta-asarone can improve cognitive impairment and alleviate damage to the hippocampus, a brain region involved in memory. The mechanisms appear linked to reducing inflammation and cellular damage.
Further studies have explored its anticonvulsant, anxiolytic (anti-anxiety), and antidepressant effects, aligning with its traditional use for calming the spirit. The plant’s decoctions and its isolated volatile oils have demonstrated an ability to decrease epileptic rates in animal models. Research has also shown that alpha-asarone and beta-asarone can produce antidepressant-like effects in animal studies.
Preparation and Safety Profile
Traditionally, the rhizome of Acorus tatarinowii is prepared by drying it, after which it can be used in powdered form or boiled in water to create a decoction. These preparations are often combined with other herbs in complex TCM formulas to treat specific conditions.
Despite its long history of use, there are safety concerns centered on its bioactive compounds. The compound beta-asarone has been identified as a potential carcinogen and is associated with toxicity in preclinical studies. Due to these risks, some regulatory bodies have set strict limits on the permissible levels of beta-asarone in food and beverages.
The concentration of alpha- and beta-asarone can vary depending on the plant’s origin and preparation method, making standardized dosing difficult. Long-term or high-dose consumption poses risks, and potential toxicity has been noted in some clinical observations. Therefore, self-medication with Acorus tatarinowii is strongly discouraged, and anyone considering its use should consult a qualified healthcare professional or licensed TCM practitioner.