Antitumour principles from Peganum harmala seeds

From ancient times, Peganum harmala was claimed to be an important medicinal plant. Its seeds were known to possess hypothermic, and essentially hallucinogenic properties. Various authors have undertaken studies on the antibacterial, antifungal and antiviral effects of Peganum harmala seeds, but studies on the antitumour activity are not to be found in the literature. In Moroccan traditional medicine, seed powder is sometimes used on skin and subcutaneous tumours. This work was designed to investigate some aspects of the antineoplastic properties of the plant Peganum. Varying concentrations (10 to 120 micrograms/ml) of total alkaloid extracts of Peganum harmala seeds (collected in Morocco) were tested in vitro on four tumoural cell-lines: Med-mek and UCP-Med carcinoma, UCP-Med sarcoma and Sp2/O-Ag14. In vivo experiments were performed with the Sp2/O cell-line grafted subcutaneously in syngenic BALB/c mice. In vitro, proliferation of tumoural cell lines was significantly reduced by all tested concentrations of the Peganum alkaloid extracts during the first 24 h of contact. A cell lysis effect occurred after 24 h and progressed to complete cell death within 48 to 72 h depending on the alkaloid concentration. Results obtained indicate that alkaloids of Peganum have a high cell toxicity in vitro. The active principle at a dose of 50 mg/kg given orally to mice for 40 days was found to have significant antitumoural activity. Peganum harmala alkaloids thus possess significant antitumour potential, which could prove useful as a novel anticancer therapy.