Phytochemical Profiling and Biological Activities of Rhododendron Subsect. Ledum: Discovering the Medicinal Potential of Labrador Tea Species in the Northern Hemisphere

Abstract

Rhododendron subsect. Ledum is a distinct taxonomic subdivision within the genus Rhododendron, comprising a group of evergreen shrubs and small trees. This review will comprehensively analyse the phytochemical profiles and biological properties of the Rhododendron subsect. Ledum species subsect. Ledum consists of eight plant species indigenous to temperate and subarctic regions of the Northern Hemisphere, collectively known as Labrador tea. Recent investigations have concentrated on the phytochemical constituents of these plants due to limited data, emphasizing their evergreen nature and potential industrial significance. This review summarizes their major phytochemical constituents, including flavonoids, phenolic acids, and terpenoids, and discusses their potential biological activities, such as antioxidant, anti-inflammatory, antimicrobial, antitumor, hypoglycemic, hepatoprotective, neuroprotective, and cardioprotective effects. Traditional uses of these plant species align with scientific findings, emphasizing the significance of these plants in traditional medicine. However, despite promising results, gaps exist in our understanding of specific compounds’ therapeutic effects, necessitating further research for comprehensive validation. This review serves as a valuable resource for researchers, identifying current knowledge, uncertainties, and emerging trends in the study of the Rhododendron subsect. Ledum species.