摘要

Taraxacum officinale leaves are popular among Ghanaians as vegetable and/or beverage while extracts of Taraxacum officinale, Paulliniia pinnata and Thonningia sanguinea are present in common herbal remedies widely available without prescription in Ghana. This study was therefore aimed to identify possible interactions between these medicinal plant extracts and mitochondrial respiratory chain activity. The effects of these extracts on mitochondrial oxygen consumption were therefore investigated in situ using permeabilized mouse cardiac muscle fiber preparations and a substrate-inhibitor titration. The results showed that the ethanolic fraction of T. officinale leaves significantly increased the respiration rate in presence of rotenone and the state 3/state 2 ratio (respiratory control ratio) while the ethanolic extract of P. pinnata stem significantly decreased succinate-stimulated respiration. The aqueous extract of T. sanguinea also significantly decreased respiration in presence of rotenone.