Objective: To review the pharmacological activities of Peganum harmala L. (P. harmala, Nitrariaceae) in traditional Iranian medicine (TIM) and modern phytotherapy.
Methods: Opinions of TIM and modern phytotherapy about safety and acceptable dosage of this plant are discussed. Various medical properties of P. harmala were collected from important TIM references and added to scientific reports derived from modern medical databases like PubMed, Scirus, ScienceDirect and Scopus.
Results: The main medicinal part of the plant is the seed. In TIM resources, this plant possesses various Pharmacological activities such as carminative, galactagogue, diuretic, emmenagogue, antithrombotic and analgesic. In modern phytotherapy, P. harmala demonstrated numerous medicinal effects including cardiovascular, neurologic, antimicrobial, insecticidal, antineoplasmic, antiproliferative, gastrointestinal and antidiabetic effects. Adverse events such as neuro-sensorial symptoms, visual hallucination, bradycardia, hypotension, agitation, tremors, ataxia, abortion and vomiting cause people to use this plant cautiously. P. harmala is contraindicated during pregnancy, due to its abortive and mutagenic activities. Because of increasing the expression of CYP1A2, 2C19, and 3A4 and inhibition of monoamine oxidase, the pharmacokinetic parameters of drugs which are mainly metabolized by these enzymes may be affected by P. harmala.
Conclusion: The medicinal properties declared for this plant in TIM are compared with those showed in modern phytotherapy. Some of the TIM properties were confirmed in modern phytotherapy like emetic and analgesic activities and some have not been evaluated in modern phytotherapy such as its therapeutic effects on paralysis, epilepsy and numbness. Finally, the current review provides the evidence for other researchers to use TIM properties of P. harmala as an efficacious natural drug. Further preclinical and clinical studies for adequate evaluating safety and therapeutic efficacy are recommended.