Investigating the Modulatory Effect of Methanol Extract of Daniellia oliveri (ROLFE) Leaves on Mitochondrial Membrane Permeability Transition (MPT) Pore

Abstract

Background: Mitochondrial-mediated cell death begins with opening of mitochondrial membrane permeability transition (mPT) pore and medicinal plants contain phytochemicals that modulate the mPT pore. Hypothesis and Purpose: We investigated the modulatory effects of crude methanol extract of Daniellia oliveri leaves (CMDO) on mPT pore in vitro. Study Design and Methods: Phytochemical screening and antioxidant activities of crude methanol extract of Daniellia oliveri leaves (CMDO) were evaluated according to standard procedures. CMDO was partitioned into chloroform fraction (CFDO), ethyl acetate fraction (EFDO) and methanol fraction (MFDO) by Vacuum liquid chromatography (VLC). Effects of CMDO, CFDO, EFDO and MFDO on mPT pore were assessed by spectrophotometry. Effects of the most potent fraction on mitochondrial ATPase, Fe-induced lipid peroxidation and cytochrome c release were assessed by spectrophotometry. CMDO was subjected to GC-MS analysis to identify the bioactive compounds present. Results: CMDO contains phytochemicals and showed appreciable total flavonoid content (0.483±0.02 QE mg/100g), total phenolic content (0.886±0.12 GAE mg/100g), total antioxidant capacity (0.039±0.001 AE mg/100 g), ferric antioxidant reducing power (IC50=350 µg/ml) and 2, 2-diphenyl-1 picrylhydrazyl (DPPH) radical scavenging activity (IC50=166 µg/ml). The maximum induction of mPT pore opening in the absence and presence of calcium, respectively, were as follows: CMDO (10.11 folds, 5.18 folds), CFDO (19.9 folds, 16.3 folds), EFDO (7.5 folds, 23.2 folds), MFDO (22.2 folds, 31.3 folds). The most potent mPT pore-opening fraction (MFDO) enhanced mitochondrial ATPase activity, inhibited Fe-induced lipid peroxidation and caused cytochrome c release. GC-MS analysis of CMDO revealed the presence of bioactive compounds including methyl propanamide, Dibutyl phthalate, saturated and unsaturated fatty acids. Conclusion: Methanol fraction (MFDO) of CMDO most potently induced mPT pore opening via enhancement of mitochondrial ATPase activity, which was substantiated by the release of cytochrome c (in vitro). This includes MFDO as a candidate pharmacologic remedy for diseases associated with insufficient apoptosis.