EFFECTS OF SELECTED MEDICINAL PLANT EXTRACTS ON MITOCHONDRIAL FUNCTION

ABSTRACT Mitochondria are organelles present in the eukaryotic cell that produce about 90% of the energy required by the cell through oxidative phosphorylation. They also play vital roles in other metabolic processes in the cell. They have unique features that make them sensitive to a number of xenobiotics. Thus, they serve as primary or secondary targets for these xenobiotics. Medicinal plants contain a range of phytochemicals which also have the potential to interfere with mitochondrial function. Therefore, there is the need to study the effects of these medicinal plants, especially those in Ghana, on mitochondrial function. This study aimed to determine the effects of Taraxacum officinale, Morinda citrifolia and Millettia thonningii on mitochondrial function. The antioxidant properties, phenolic content and phytochemistry of the extracts were determined. Effects of the extracts on cell viability and mitochondrial respiratory chain activity were also determined. All the extracts significantly stimulated basal respiration and also caused an increase in complex IV respiration. The extracts showed strong antioxidant activities and all of them contained phytochemicals which have been shown to have antioxidant properties. M. thonningii partially blocked the effect of rotenone while Noni juice partially blocked the effect of antimycin A. The extracts, however, had weak cytotoxic effects on the Jurkat leukemia cells and the MCF7 breast cancer cells.