M Johanna Bapela1, J J Marion Meyer2, Marcel Kaiser3. 1. Department of Plant Science, Plant Sciences Complex, University of Pretoria, Hatfield 0083, South Africa. Electronic address: johanna.bapela@up.ac.za. 2. Department of Plant Science, Plant Sciences Complex, University of Pretoria, Hatfield 0083, South Africa. 3. Swiss Tropical and Public Health Institute, Socinstrasse 57, CH-4002 Basel, Switzerland.
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE: Plant species used by Venda people of South Africa in the treatment of malaria and associated symptoms were evaluated for their antiplasmodial efficacy as well as cytotoxic properties and some showed significant activity. MATERIALS AND METHODS: In vitro antiplasmodial activity and cytotoxic properties were evaluated on 20 indigenous plant species. Ground plant material was extracted in dichloromethane: 50% methanol (1:1). Antiplasmodial activity was evaluated against the chloroquine-sensitive strain of Plasmodium falciparum (NF54). The cytotoxicity of the plant extracts were assessed against mammalian L-6 rat skeletal myoblast cells and the selectivity index (SI) calculated. RESULTS: Of the 43 plant extracts evaluated, 10 exhibited pronounced antiplasmodial activity (IC₅₀ ≤ 5 μg/ml) with good therapeutic indices (SI ≥ 10). Lipophilic plant extracts were relatively more potent than polar extracts. Tabernaemontana elegans Stapf. (Apocynaceae) and Vangueria infausta Burch. subsp. infausta (Rubiaceae) extracts displayed significant antiplasmodial activity (IC₅₀ < 2 μg/ml). CONCLUSION: Findings of this study partly support the ethnomedical use of the investigated plant species by Venda people as antimalarial remedies. The study also highlights some of the knowledge gaps that require further phytochemical studies on the specified plant species.
ETHNOPHARMACOLOGICAL RELEVANCE: Plant species used by Venda people of South Africa in the treatment of malaria and associated symptoms were evaluated for their antiplasmodial efficacy as well as cytotoxic properties and some showed significant activity. MATERIALS AND METHODS: In vitro antiplasmodial activity and cytotoxic properties were evaluated on 20 indigenous plant species. Ground plant material was extracted in dichloromethane: 50% methanol (1:1). Antiplasmodial activity was evaluated against the chloroquine-sensitive strain of Plasmodium falciparum (NF54). The cytotoxicity of the plant extracts were assessed against mammalianL-6rat skeletal myoblast cells and the selectivity index (SI) calculated. RESULTS: Of the 43 plant extracts evaluated, 10 exhibited pronounced antiplasmodial activity (IC₅₀ ≤ 5 μg/ml) with good therapeutic indices (SI ≥ 10). Lipophilic plant extracts were relatively more potent than polar extracts. Tabernaemontana elegans Stapf. (Apocynaceae) and Vangueria infausta Burch. subsp. infausta (Rubiaceae) extracts displayed significant antiplasmodial activity (IC₅₀ < 2 μg/ml). CONCLUSION: Findings of this study partly support the ethnomedical use of the investigated plant species by Venda people as antimalarial remedies. The study also highlights some of the knowledge gaps that require further phytochemical studies on the specified plant species.