From folk remedies to modern therapies: Ethnobotanical insights and bioactivity screening of Serra da Estrela (Portugal) medicinal plants

Medicinal plants offer promising natural therapeutic solutions for managing diabetes and oxidative stress-related diseases, which are becoming increasingly prevalent worldwide. Portugal’s Serra da Estrela Natural Park (SENP), in the country’s central highlands, harbours one of its richest mountain floras; steep altitudinal and climatic gradients there stimulate the production of a wide range of secondary metabolites, making the park a valuable reservoir of potential bioactive compounds [ 1 ]. In this study, an ethnobotanical survey was conducted with local communities across 34 localities in five municipalities (Celorico da Beira, Covilhã, Guarda, Seia, and Gouveia), documenting traditional uses of dozens of plant species, predominantly from the Lamiaceae and Asteraceae families. Concurrently, 47 samples (leaves, flowers and fruits) were collected from SENP, processed into aqueous infusions, and evaluated for their antidiabetic, antioxidant, and anti-inflammatory properties. Initial screening indicated several extracts with notable α-glucosidase inhibitory activity. Total polyphenol content ranged from 116.966±1.326 mg gallic-acid equivalents/g dry weight to 336.393±10.222 mg/g extract, and the infusions displayed strong free radical-scavenging capacities in DPPH, nitric oxide, and superoxide anion assays. Among them, extracts from Sanguisorba minor , Viburnum tinus , and Cistus salviifolius exhibited especially promising bioactivities, although Cistus salviifolius was cytotoxic at higher concentrations. Overall, these findings highlight SENP’s flora as a valuable source of natural compounds that merit further investigation for their potential in developing novel interventions for diabetes and oxidative stress. Publication History Article published online: 05 March 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany