African medicinal plants: an appraisal of inhalation techniques and therapeutic potential

Traditional medicine remains a vital part of African healthcare, with a substantial proportion of the population relying on plant-based remedies for their primary health needs. Among the various preparation methods are therapies administered via the respiratory system, such as smoking, fumigation, steam inhalation, and snuffing.

This review aims to provide a comprehensive synthesis of African medicinal plants administered via the respiratory route, examining their ethnobotanical significance, preparation methods, pharmacological and clinical relevance, and socio-economic value.

This review compiled and analysed 46 peer-reviewed articles and provided a descriptive overview of the plant species, families, preparation methods and uses.

A total of 209 plant species from 72 families were identified. The prominent families were Asteraceae, Lamiaceae, Euphorbiaceae, Fabaceae, and Solanaceae, which accounted for 34.5% of the recorded plants. Southern and Eastern Africa exhibit the highest regional diversity, reflecting ecological richness and strong ethnomedical traditions. These plant families address conditions ranging from respiratory infections such as asthma and tuberculosis to neurological and spiritual disorders, including the "evil eye". Leaves (34.3%) and roots (30.4%) are the most utilised parts, primarily administered via smoking (31.4%) and steam inhalation (30.2%). Validating these plant species offers significant socio-economic potential for reducing rural poverty, supporting sustainable livelihoods, and possibly enabling further local drug development.

Despite widespread use, scientific understanding of phytochemical changes during combustion and of clinical validation remains limited. Further research into pharmacological efficacy, toxicity, and herb-drug interactions is essential to bridge traditional ethnomedicine and modern pharmacotherapeutics.