Review on Chemical Constituents and Biological Activities of Genus Peganum with a Special Focus on <i>Peganum harmala</i>

Introduction: Genus Peganum belongs to the family Zygophyllaceae. The most researched and well-known species is P. harmala, which is known as “Espand” in Iran, “Harmel” in North Africa, and “Turkish rue” in the US. It is widely available and used as a medicinal plant to treat a variety of conditions, including colic, asthma, high blood pressure, blood sugar, and cancer. The majority of experimental investigations conducted on the composition of these plant extracts revealed that the key alkaloidal chemical constituents are quinazoline and beta-carboline. The chemistry and pharmacology of the genus Peganum, and more especially the species P. harmala, are the subject of this review of the literature. Future in vivo research on humans will allow researchers to fully explore the Peganum genus' potential to enhance human health and well-being. Methods: First, a search was performed across different databases, including Scopus, Science Direct, Google Scholar, The Cochrane Library, Web of Science, and PubMed from the year 2000 to 2025. Second, articles were chosen based on specific related criteria as mentioned below. As this is a review article, we include most types of articles relevant to our subject and published in peer-reviewed journals. Inclusion Criteria: • Original research articles, short communications, and comprehensive reviews published in peer-reviewed journals. • Studies focused explicitly on Peganum species, reporting phytochemical profiling, biological activity assessments, or both. • In vitro or in vivo pharmacological evaluations are conducted under standardized conditions. • Investigations into structure–activity relationships. Exclusion Criteria: • Non-peer-reviewed materials (e.g., conference abstracts, editorials, book chapters, theses). • Articles with inadequate methodological detail or irreproducible protocols. • Non-English articles without verified translations. • Case reports or opinion pieces without original data. Results: The search yielded 110 articles, and most of them were selected as the basis for the construction of the review. Discussion: This literature review discussed the biological constituents and pharmacology of genus Peganum. Conclusion: Based on the promising results collected in this manuscript, we recommend further research to be carried out on the extracts of plants of this genus for the extraction and identification of further molecules that can be helpful in medicine.