New research published in Communications Biology has unveiled the earliest direct chemical evidence of the medicinal and psychoactive plant Peganum harmala—commonly known as Syrian rue or harmal—being used in fumigation and inhaled as smoke in Iron Age Arabia nearly 2,700 years ago. This groundbreaking finding offers unprecedented insight into the complexity of early Arabian therapeutic and sensorial practices, revealing a sophisticated knowledge of native plants and their bioactive and psychoactive properties much earlier than previously documented.
The multidisciplinary study was led by Dr. Barbara Huber of the Max Planck Institute of Geoanthropology alongside Professor Marta Luciani from the University of Vienna, in collaboration with Saudi Arabia’s Heritage Commission. They applied cutting-edge metabolic profiling techniques to the analysis of organic residues recovered from ancient fumigation devices excavated at Qurayyah, an oasis settlement rich in Iron Age archaeological material in northwestern Saudi Arabia. Qurayyah is famous for its distinctive painted ceramics, known as Qurayyah Painted Ware, illuminating a vibrant cultural landscape where these fumigation devices were in use.
This research stands out because it provides the first metabolic profiling-based proof for the intentional burning of Peganum harmala. Using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), the investigators were able to detect harmala alkaloids, the bioactive molecules responsible for the plant’s distinctive psychoactive and antibacterial effects, despite the samples’ age and chemical degradation. This technology enabled the team to confirm that the plant residues were genuinely part of ritualistic or therapeutic inhalation practices in Iron Age Arabia, rather than contamination or incidental presence.
Prof. Marta Luciani emphasized the importance of integrating biomolecular analytics with archaeobotanical and cultural archaeological evidence. “By combining chemical signatures with the archaeological context, we move beyond identifying plant species to comprehend how ancient communities employed these plants—where, how, and why,” she said. This approach transforms our understanding of prehistoric human-plant relationships, shedding light on early pharmacopeia and sensory experiences that have barely survived in the material record.
The researchers postulate that the inhalation of Peganum harmala smoke served multiple functions within Iron Age Arabian society. Known not only for its psychoactive alkaloids but also for potent antibacterial properties, harmal smoke could have been used to cleanse and purify living spaces, protect against pathogens, and facilitate altered states of consciousness or ritual performances. The presence of such a plant in fumigation devices indicates a sophisticated cultural tradition of combining medicinal and possibly spiritual objectives in everyday communal or sacred environments.
These findings foreground the deep antiquity of traditional herbal medicine and fumigation practices that continue to thrive in parts of Arabia today, underscoring a remarkable cultural continuity. The fact that the plant was deliberately chosen and burned speaks to an ancient pharmacopeial knowledge system, reflecting broader ethnobotanical traditions across the Near East. Furthermore, the study highlights the importance of preserving intangible cultural heritage alongside tangible archaeological remains, as emphasized by Ahmed M. Abualhassan, co-director of the Qurayyah heritage project.
Adding to the global narrative of early human plant use, this discovery pushes back the timeline for the fumigatory use of Peganum harmala by millennia and represents the earliest known proof of this plant’s application anywhere in the world. Prior evidence of its use was mostly based on ethnographic analogies or textual references dating much later. The chemical confirmation from the Iron Age context provides a new benchmark for comparing ancient pharmacological knowledge and practices globally.
On the technical front, the study’s reliance on HPLC-MS/MS showcased the remarkable sensitivity of modern analytical chemistry to detect minute and ancient organic compounds in archaeological contexts. This technique separates and identifies molecular fragments based on their mass-to-charge ratio, enabling researchers to characterize complex alkaloid profiles even from degraded residues. The successful detection of harmala alkaloids in ceramic fumigation apparatuses highlights the transformative potential of biomolecular archaeology in reconstructing ancient sensory worlds and health-related behaviors.
Interestingly, the fumigation devices themselves—ceramic vessels specifically shaped and decorated—were specially designed to facilitate the burning and inhalation of medicinal plants. Their findspot in Qurayyah, a historically significant oasis settlement on trade and cultural exchange routes, suggests that the knowledge and use of Peganum harmala might have played a role not only locally but potentially within wider cultural networks, embedding this plant deeply in social and health-related practices.
The broader implications of the study extend into fields such as ethnobotany, medical anthropology, pharmacognosy, and cultural heritage studies. By establishing an ancient timeline for medicinal plant fumigation in Arabia, the research invites reevaluations of how prehistoric communities interacted with their environments and natural resources. It refines our understanding of early medicinal traditions and offers vantage points for considering the evolution of human-plant pharmacology and psychoactive drug use.
Moreover, this discovery amplifies the significance of Arabian archaeological sites like Qurayyah, which provide rare opportunities to investigate archaic plant-based therapeutic knowledge. Such sites expand the empirical basis for studying not only ancient health care and ritual but also the sensory and psychoactive dimensions of prehistoric life that conventional artifact-focused archaeology often overlooks.
In conclusion, the integration of metabolomic profiling with detailed archaeological investigation has revealed an extraordinary chapter of early Arabian health culture and ritual. It documents humankind’s longstanding engagement with the powerful properties of Peganum harmala, marking a milestone in the history of medicinal plant use worldwide. This revelation underscores the importance of interdisciplinary research in uncovering complex narratives about humanity’s past interaction with nature—narratives that resonate with present-day pharmacological and cultural practices.
Subject of Research: Early use of Peganum harmala in fumigation and inhalation practices in Iron Age Arabia.
Article Title: Metabolic profiling reveals first evidence of fumigating drug plant Peganum harmala in Iron Age Arabia.
News Publication Date: 23-May-2025.
Web References: http://dx.doi.org/10.1038/s42003-025-08096-7
Image Credits: Hans Sell.
Keywords: Peganum harmala, Syrian rue, fumigation, Iron Age Arabia, metabolic profiling, HPLC-MS/MS, psychoactive plants, archaeological chemistry, pharmacopeia, ethnobotany, heritage, bioactive compounds.
