Olfactory Loss Management in View of Avicenna: Focus on Neuroprotective Plants

Background: Loss of olfaction can cause noticeable reduction in general quality of life. Only a small portion of patients with olfactory loss respond to current medications. Thus, development of novel therapeutic strategies seems to be necessary. Looking into traditional medical knowledge can be of great value in addressing useful remedies. Traditional Persian Medicine (TPM) has been practiced in Persia for more than 2000 years. Avicenna is the most eminent Persian physician. Objective: To survey Avicennas views on etiology and management of olfactory loss and to search for relevant modern pharmacological data. Methods: Avicennas views on etiology and management (including suggested medicinal plants) of olfactory loss were obtained from “Canon of Medicine”. In addition, a detailed search in ScienceDirect, PubMed, Scopus and Google Scholar databases was performed to elucidate relevant pharmacological actions and mechanisms of the plants and their major compounds with special focus on neuroprotective activity. Results: Acorus calamus L., Allium cepa L., Allium sativum L., Aloe spp., Cinnamomum cassia (L.) J.Presl, Lavandula stoechas L., Mentha longifolia (L.) L., Nigella sativa L., Peganum harmala L., Piper nigrum L. and Zingiberci offinale Roscoe were found to be the most emphatic plants for the treatment of olfactory loss. Pharmacological studies revealed biological activities including neuroprotective, anti-inflammatory, free radical scavenging activities and promoting endogenous antioxidant capacity for these plants and their major components. Conclusion: regarding the lack of effective treatments for recruiting normal smell in many cases, treatments suggested by Avicenna worth entering pharmacologic experiments and clinical trials.