RESUMO
BACKGROUND: Bioactive agents from medicinal and dietary plants have been reported to modulate the mitochondrial membrane permeability transition pores. OBJECTIVE: This study investigated the in vitro effects of C. sinensis (CSE) and M. oleifera (MOE) methanol leaf extracts and their epiphytes (CEP and MEP) on mitochondria permeability transition pores. METHODS: In vitro antioxidant activities of the extracts were determined using standard procedures and quantification of polyphenolic compounds in the extract was done using HPLC-DAD. Opening of the mitochondrial permeability transition pores was assessed as mitochondrial swelling and observed spectrophotometrically as changes in absorbance under succinate-energized conditions. Cytochrome c release was also assessed spectrophotometrically. RESULTS: From the results, CSE, MOE, CEP, and MEP inhibited lipid peroxidation and scavenged nitric oxide and DPPH radicals in a concentration-dependent manner. All extracts exhibited greater ferric reducing antioxidant potential. More so, the results showed that CSE, MOE, CEP, and MEP possess the substantive amount of total flavonoids and total phenolics. CSE and MOE had higher total flavonoids and total phenolic content when compared with the epiphytes. HPLC-DAD results revealed Tangeretin as the most abundant in CSE; Eriocitrin in citrus epiphytes; Moringine in MOE and Flavones in moringa epiphytes. All extracts inhibited calcium-induced opening of the pores in a concentration- dependent manner, with C. sinensis leaf extract (CSE) and moringa epiphyte (MEP) being the most potent in this regard with no significant release of cytochrome c at all concentrations. CONCLUSION: The results suggest that CSE and MEP have bioactive agents, which could be useful in the management of diseases where too much apoptosis occurs characterized by excessive tissue wastage, such as neurodegenerative conditions.