Peganum harmala, commonly known as Syrian rue, is a perennial plant native to temperate desert and Mediterranean regions, including the Middle East, North Africa, and Central Asia. This article explores its reported benefits, underlying mechanisms, and crucial safety considerations.
Traditional Uses and Ethnobotanical Significance
Syrian rue has a long history of use across cultures, extending beyond medicine. Its seeds have been a source of red dye for carpets. The plant has also been used as incense, with smoke believed to offer protection or healing. In Iran and Turkey, dried seed capsules are traditionally hung to ward off the “evil eye.”
As a traditional remedy, ancient Greeks and Romans used its leaves for ailments like fever, earaches, and skin inflammations. It has also been applied to address pain, parasitic infections, gastrointestinal issues, urinary disorders, epilepsy, and menstrual problems.
Key Bioactive Compounds and Their Actions
Syrian rue’s effects stem primarily from its beta-carboline alkaloids, mainly harmine, harmaline, and tetrahydroharmine. These compounds are found in varying concentrations, with seeds often containing 2% to 7% or higher of total alkaloids.
Harmala alkaloids act as reversible monoamine oxidase inhibitors (MAOIs). MAO is an enzyme that breaks down neurotransmitters like serotonin, dopamine, and norepinephrine. By inhibiting MAO-A, harmala alkaloids temporarily increase these neurotransmitter levels. This inhibition is reversible and primarily selective for MAO-A at typical doses.
Reported Health Benefits
Syrian rue’s bioactive compounds are linked to several reported health benefits. Its MAOI activity suggests potential antidepressant and anxiolytic effects by increasing neurotransmitter levels. Some studies indicate harmine might increase brain-derived neurotrophic factor (BDNF) protein levels, often reduced in depressive states.
Preclinical investigations show anti-cancer properties, including potential to inhibit tumor growth and induce cell death in cancer cells. However, these findings are primarily from lab or animal studies, with limited human clinical trials.
Syrian rue also exhibits anti-parasitic and antimicrobial effects, with compounds active against bacteria, fungi, and parasites. Traditional uses for expelling worms align with these properties. Preliminary studies also suggest neuroprotective and anti-inflammatory potential.
Crucial Safety Considerations and Potential Risks
Despite reported benefits, Syrian rue carries significant safety concerns due to its potent MAOI effects. Ingesting it can cause adverse effects, even at low doses. Common reactions include nausea, vomiting, and dizziness. Higher doses can induce severe neurological symptoms like tremors, confusion, agitation, and hallucinations.
Dangerous drug interactions are a major risk, especially with medications affecting serotonin levels. Combining Syrian rue with SSRIs or other MAOIs can lead to serotonin syndrome, a life-threatening condition with symptoms like heart problems, seizures, and vomiting. While interactions with tyramine-rich foods are less severe than with non-reversible MAOIs, caution is still advised.
Syrian rue can also cause cardiovascular issues, including changes in heart rate and blood pressure. Liver and kidney damage have been reported, particularly with higher doses or prolonged use. Contraindications include pregnancy (due to labor induction risk) and pre-existing conditions like heart, liver, or kidney disease, or stomach ulcers. The plant has a narrow therapeutic window, meaning a small difference between effective and toxic doses, increasing adverse reaction risk.
Legal Status and Responsible Use
The legal status of Syrian rue varies globally due to its psychoactive and MAOI properties. It may be legal, restricted, or controlled depending on the region. Some U.S. states classify it as a noxious weed. Countries like France, Finland, Canada, and Australia have specific regulations, often classifying harmala alkaloids or the plant as controlled substances.
Given its potent effects and significant risks, Syrian rue is not a dietary supplement and should never be used for self-medication. Its severe health risks, especially dangerous drug interactions and organ damage, highlight the need for professional medical supervision. Recreational use is strongly discouraged due to its unpredictable and potentially life-threatening effects. Always consult a healthcare professional before considering any use of Syrian rue.