Antimalarial activity of hydroalcoholic extract and fractions from Gnidia stenophylla roots: In-Vitro effects on P. falciparum and in-Vivo suppression in P. berghei-infected mice

Abstract

Ethnopharmacological relevance: The roots of Gnidia stenophylla Gilg (Thymelaeaceae) are used in Ethiopian traditional medicine to treat malaria. This plant has not been fully evaluated scientifically for antimalarial efficacy against Plasmodium species.

Aim of the study: To assess the antimalarial potential of Gnidia stenophylla root extracts and fractions through in vitro and in vivo assays.

Materials and methods: A hydroalcoholic extract was prepared from dried G. stenophylla roots and fractionated into dichloromethane, n-butanol, and aqueous fractions. In vitro antiplasmodial activity was tested against P. falciparum using a standard lactate dehydrogenase assay to determine IC₅₀ values. For in vivo evaluation, mice were infected with P. berghei and treated with various doses of the extract/fractions. Endpoints included parasitemia suppression, survival time, packed cell volume (PCV), body weight, and temperature.

Results: The crude extract showed moderate in vitro activity (IC₅₀ = 29.96 ± 1.53 μg/mL), while the aqueous fraction was highly active (IC₅₀ = 7.65 ± 1.00 μg/mL). Dichloromethane and n-butanol fractions were weakly active. In P. berghei-infected mice, the aqueous fraction at 400 mg/kg produced the highest parasitemia suppression (62.9 %) and significantly improved survival compared to controls. This fraction also minimized PCV reduction, weight loss, and temperature drop.

Conclusions: Gnidia stenophylla root contains bioactive compounds with antimalarial efficacy. The aqueous fraction, in particular, showed strong activity both in vitro and in vivo, supporting the traditional use of this plant for malaria. These findings justify further isolation of the active constituents and development of standardized extracts.

Keywords: Antiplasmodial; Gnidia stenophylla; Mice; Plasmodium berghei; Plasmodium falciparum.