First ethnobotanical inventory and phytochemical analysis of plant species used by indigenous people living in the Maromizaha forest, Madagascar

Abstract

Ethnopharmacological relevance: Characterized by one of the highest rates of endemism and biodiversity in the world, Madagascar provides a wide variety of medicinal plants, that could represent a potential source of new drugs. The main aim of this study was to investigate the potential medicinal properties of the plant species used by indigenous people in Maromizaha forest and to provide the first ethnobotanical inventory of the area.

Materials and methods: Data were collected through open semi-structured interviews with local informants, the reported plants were collected and identified to create a specimen herbarium. Informant Consensus Factor (ICF) was calculated for each ailment category mentioned in the use-reports. A selection of seven medicinal plants was submitted to phytochemical and antimicrobial analysis. The results were discussed and compared with those described in ethnobotanical and pharmacological literature.

Results: One hundred and three villagers were interviewed and a total of 509 use-reports were recorded. Information on 117 plant species belonging to 57 botanical families were provided. 12 categories of indigenous uses were recognized, among them the higher ICF values were recorded for cardiovascular complaints (0.75), general and unspecific diseases (0.74), digestive disorders (0.69), and diseases of the skin (0.55). The traditional medicinal uses of 18 species (15 endemic) were described for the first time. In total, 22 different bioactive compounds were identified; polyphenols, monoterpenes, organic acids, and vitamin C were observed in the chemical composition of all the analyzed samples. Macaranga perrieri showed the highest values of both total polyphenolic compounds and antioxidant activity. Antimicrobial activity was observed in leaf and bark extracts of Dilobeia thouarsii.

Conclusion: These results confirmed the importance of investigating the traditional use of plant species, suggesting the crucial role of ethnobotanical studies for rural development, biodiversity conservation, and the sustainable use of plant resources in the studied area.

Keywords: Antimicrobial activity; Ascorbic acid; BENZOIC ACIDS; CATECHINS; CINNAMIC ACIDS; Caffeic acid; Castalagin; Catechin; Chlorogenic acid; Citric acid; Coumaric acid; Dehydroascorbic acid; Dilobeia thouarsii; Ellagic acid; Epicatechin; Ethnobotany; FLAVONOLS; Ferulic acid; Gallic acid; Hyperoside; Isoquercitrin; Limonene; MONOTERPENES; Macaranga perrieri; Malic acid; Medicinal plants; ORGANIC ACIDS; Oxalic acid; Phellandrene; Phytochemicals; Quercetin; Quercitrin; Quinic acid; Rutin; Sabinene; Succinic acid; TANNINS; Tartaric acid; Terpinolene; VITAMINS; Vescalagin; Vitamin C; γ-Terpinene.