Liver Mitochondrial Membrane Permeability Transition Research Articles

Modulation of mitochondrial permeability transition pore opening by Myricetin and prediction of its-drug-like potential using in silico approach

Myricetin has been demonstrated to have multiple biological functions with promising research and development prospects. This study investigated the effect of myricetin on liver mitochondrial membrane permeability transition pores and its inhibitory potential on proteins that are important in the apoptotic process in silico. Mitochondrial swelling was assessed as changes in absorbance under succinate-energized conditions. Cytochrome c release, mitochondrial-lipid peroxidation, caspase 3 and 9 expressions, as well as calcium ATPase, were assessed. Pharmacokinetic properties of myricetin were predicted through the SwissADME server while the binding affinity of myricetin toward the proteins was computed using the AutodockVina Screening tool. The conformational stability of protein-ligand interactions was evaluated using molecular dynamics simulations analysis through the iMODS server. Myricetin inhibited the opening of the mitochondrial permeability transition pore and also reversed the increase in mitochondrial lipid peroxidation caused by calcium and other toxicants. Myricetin also caused a reduction in the expression of caspase 3 and 9 as well as calcium ATPase activity. The molecular docking results revealed that myricetin had a considerable binding affinity to the pocket site of caspase 3 and 9 as well as calcium ATPase. Myricetin showed a good drug-likeness based on the predicted pharmacokinetic properties as revealed by low CYP 450 inhibitory promiscuity and relatively low toxicity. It could therefore be suggested that myricetin could be useful in the management of diseases where too many apoptosis occur characterized by excessive tissue wastage such as neurodegenerative conditions and could as well play a role in protecting the physicochemical properties of membrane bilayers from free radical-induced severe cellular damage.

Kigelia africana (Lam.) Benth leaf extract inhibits rat brain and liver mitochondrial membrane permeability transition pore opening

The effect of Kigelia africana on mitochondrial membrane permeability transition has not been explored. In this study, the effect of a solvent fraction of Kigelia africana leaf extract on mitochondrial membrane permeability transition of rat brain and liver was evaluated. A methanol extract of K. africana leaves was fractionated into different solvents by vacuum liquid chromatography and following preliminary screening, the dichloromethane:ethylacetate (1:1) fraction was selected for further assays. Constituent phytochemicals in the fraction were revealed by thin-layer chromatography and further purification was carried out to characterize the compounds. Brain and liver mitochondria were isolated and used for mitochondrial membrane permeability transition and adenosine triphosphatase assays. Exogenous Ca2+ and Al3+ were used to trigger the mitochondrial membrane permeability transition opening. Physicochemical properties revealed by thin-layer chromatography showed that the isolated compounds were flavonoids. The extract inhibited mitochondrial membrane permeability transition opening in the presence and absence of triggering agents in brain and liver mitochondria. It also inhibited mitochondrial lipid peroxidation and adenosine triphosphatase activity. These results suggest that the extract can limit the rate of apoptosis via inhibition of mitochondrial membrane permeability transition which is pivotal to the mitochondrial apoptotic pathway and is an important therapeutic target in some pathological conditions.

Methanol extract and fraction of Anchomanes difformis root tuber modulate liver mitochondrial membrane permeability transition pore opening in rats.

Extracts of Anchomanes difformis (AD) are used in folkloric medicine to treat several diseases and infections. However, their roles in mitochondrial permeability transition pore opening are not known. The viability of mitochondria isolated from Wistar rat liver used in this experiment, was assessed by monitoring their swelling amplitude in the absence of calcium and reversal of calcium-induced pore opening by spermine. The effects of methanol extract and fraction of A. difformis (MEAD and MFAD, respectively) on Mitochondrial Membrane Permeability Transition (MMPT) pore opening, ATPase activity, cytochrome c release and ferrous-induced lipid peroxidation were assessed spectrophotometrically. Phytochemical constituents of MEAD and MFAD were assessed using Gas Chromatography- Mass Spectrometry (GC-MS). The MEAD (10, 20, 40 and 80 μg/ ml) had no effect on MMPT pore opening in the absence of Ca2+, whereas MFAD at 80 μg/ml had a large amplitude pore opening effect. Both MEAD and MFAD reversed Ca2+‌‌-induced swelling with inhibition values of 18, 21, 24, 23% (for MEAD) and 41, 36, 35, and 26% (for MFAD) at 10, 20, 40 and 80 μg/ml, respectively. MFAD significantly enhanced F1F0 ATPase activity and caused cytochrome c release. Both MEAD and MFAD significantly inhibited ferrous-induced lipid peroxidation by 33.0, 64.0, 66, and 75% (for MEAD) and 24, 25, 30, and 45% (for MFAD), respectively. The GC-MS results revealed the presence of squalene as one of the major constituents of MEAD. These findings suggest that MFAD can be used to induce cell death via mitochondrial permeability transition in isolated rat liver. Inhibition of lipid peroxidation by MEAD and MFAD showed that the pore opening effect of the extract and fraction was not mediated via peroxidation of mitochondrial membrane lipids.

Phytochemical, Antioxidant and Mitochondrial Permeability Transition Studies on Fruit-Skin Ethanol Extract ofAnnona muricata

Uncontrolled cell proliferation hallmarks cancer and most cancer cells have developed multiple resistance to the drugs employed for their treatment. The study examined the phytochemical and antioxidant properties of the fruit-skin ethanol extract of Annona muricata Linn. (ESA) and its effect on rat liver mitochondrial membrane permeability transition (MMPT). Qualitative phytochemical study and antioxidant assays were carried out following established protocols while the opening of the MMPT pore in the presence of varying concentrations of the extract was assayed spectrophotometrically under succinate-energized conditions. Calcium chloride (CaCl2) and spermine were used to trigger and inhibit pore opening respectively. Cytochrome c release was assayed for using ELISA kit. Terpenoids, steroids, phenols among other phytochemicals were found present in ESA and the extract showed very low antioxidant properties at the tested concentrations based on the diphenyl-1-picryhydrazyl (DPPH) radical scavenging activity assay. Lipid peroxidation was induced in a concentration-dependent manner on both the cytosolic and mitochondrial hepatocyte fractions in vitro. In the absence of CaCl2 0.84 mg/mL concentration of ESA induced MMPT pore opening by 129% while the extracts showed no inhibitory activity in its presence. The induction fold corresponded with the concentrations of cytochrome c released. The fruit-skin ethanol extract of Annona muricata at certain concentrations may possibly contain bioactive compounds that induce apoptosis.

Liver mitochondrial membrane permeability modulation in insulin-resistant, uninephrectomised male rats by Clerodendrum volubile P. Beauv and Manihot esculenta Crantz

BackgroundNon-alcoholic fatty liver disease, which occurs in people who are not alcohol drinkers, describes some of the pathogenic conditions that may be in the least characterized by simple steatosis or can be as serious as non-alcoholic steatohepatitis and cirrhosis. Its mechanistic pathogenesis has been said to arise from insulin resistance and oxidative stress, which may be compounded by obesity. An experimental model showing, systemic insulin resistance, obesity and accumulated hepatic fatty acids was created in adult male rats using high-fat diet manipulation and surgical removal of the left kidney (uninephrectomy). This study sought to identify the impact of these multiple burdens on the liver mitochondrial membrane permeability transition pore opening, and the possible in vitro effects of the extracts of Clerodendrum volubile and Manihot esculenta leaves on the membrane permeabilization.ResultsThe results indicated that the methanolic extract of Clerodendrum volubile leaf inhibited mitochondrial membrane pore opening in the insulin resistance condition or when it is followed by uni-nephrectomy, while the ethanolic extract of Manihot esculenta leaf does the same in the insulin resistance condition both prior to and following uni-nephrectomy.ConclusionSince the vegetable extracts were able to abrogate mitochondrial pore opening at low concentrations, the structural integrity of the mitochondria can possibly be restored over time if treated by the vegetable extracts. Research efforts should, therefore, be made to harness the drugability of the bioactives of these vegetables for use in the treatment of non-alcoholic fatty liver disease arising from insulin resistance and renal failure.

Mild depolarization is involved in troglitazone-induced liver mitochondrial membrane permeability transition via mitochondrial iPLA2 activation.

Troglitazone, the first peroxisome proliferator-associated receptor γ agonist developed as an antidiabetic drug, was withdrawn from the market due to idiosyncratic severe liver toxicity. One proposed mechanism by which troglitazone causes liver injury is induction of mitochondrial membrane permeability transition (MPT), which occurs in a calcium-independent phospholipase A2 (iPLA2)-dependent manner at a concentration of 10 µM. MPT, induced by opening of the MPT pore, leads to the release of cytochrome c and consequent apoptosis or necrosis. In the present study, we aimed to clarify the mechanism of troglitazone-induced MPT in more detail using isolated rat liver mitochondria. We focused on extra-mitochondrial Ca2+ and membrane potential as triggers of iPLA2 activation or MPT induction. As a link between iPLA2 and MPT, we focused on cardiolipin (CL), a unique, mitochondria-specific phospholipid with four acyl chains that affects respiration, the morphology, and other mitochondrial functions. We found that (1) Ca2+ release from the mitochondrial matrix was induced prior to troglitazone-induced onset of MPT, (2) released Ca2+ was involved in troglitazone-induced MPT, (3) mild depolarization (approximately 10%) may be a trigger of troglitazone-induced MPT and (4) enhanced decomposition of CL following mitochondrial iPLA2 activation might mediate troglitazone-induced MPT.

Inhibition of liver mitochondrial membrane permeability transition pore opening by quercetin and vitamin E in streptozotocin-induced diabetic rats

Diabetes mellitus is a chronic metabolic disorder characterized by rise in blood glucose levels and generation of free radicals which could induce mitochondrial membrane permeability transition (MMPT) pore opening. This study examined the in vivo action of quercetin and vitamin E on MMPT in the liver of streptozotocin-induced diabetic rats orally pre-treated with 30 mg quercetin/kg body weight (STZQ), 10 mg vitamin E/kg body weight (STZVit.E) and 0.6 mg glibenclamide/kg body weight (STZG). Male albino wistar rats were used in the study and were injected intraperitonially with streptozotocin (STZ) (45 mg/kg body weight) in citrate buffer. The degrees of serum and tissue peroxidation, alanine and aspartate aminotransferase activity were investigated. MMPT pore was assessed as mitochondrial swelling and was monitored spectrophotometrically as changes in absorbance at 540 nm under succinate-energized condition. There was significant increase in serum glucose level, degree of tissue peroxidation, alanine and aspartate aminotransferase activity, cholesterol and triglycerides values in the diabetic control rats following streptozotocin induction. All the treatment had effect on the damage caused by streptozotocin. Quercetin exhibited the highest chemopreventive activity. Quercetin and vitamin E significantly reduced the blood glucose level, degree of tissue peroxidation and alanine and aspartate amino transferase activity. In vivo rat liver MMPT pore was opened in diabetic control rats and significantly inhibited in STZQ, STZV and STZG treated groups by 72.3%, 58.5% and 87.5% respectively. The activity of quercetin and vitamin E were substantiated by histopathological evaluation. Our study suggests that quercetin is an effective therapeutic agent for preventing hepatic tissues from oxidative stress resulting from streptozotocin-induced diabetes by inhibiting apoptotic processes in their target cells.

Butanol extract of <i>Manihot esculenta</i> leaf modulated cigarette butt leachate-mediated liver mitochondrial membrane permeabilization and its functional capacity

Objective : The experiment was designed to investigate the modulatory effects of the butanol extract of Manihot esculenta leaf, in vivo , and against the effects of cigarette butt leachate, in vitro on liver mitochondrial membrane permeability transition (MMPT), and its possible hepatoprotection in female Wistar rats. Methods : The powdery form of fresh, air-dried and pulverized M. esculenta leaves were extracted in 95% butanol using Soxhlet apparatus and concentrated to a sticky mass using rotary evaporator. Ethical approval for animal use was obtained from Ladoke Akintola University of Technology, Osogbo, Nigeria (LTH/EC/2014/10/237). Twelve Wistar rats were randomly assigned into 2 groups of 6 rats each, and a separate group of 4 rats were used for the in vitro study. The first set of rats was orally treated daily with the extract for 21 days. Following an overnight fast, the rats were sacrificed by cervical dislocation and the liver mitochondria isolated by standard methods. Mitochondrial swelling and liver function assays were done spectrophotometrically. Results : In vivo , the extract significantly induced low amplitude pore opening in the absence of exogenous Ca 2+ ; whereas when it was present, the extract slightly inhibited same. Two concentrations of cigarette butt leachate caused appreciable low amplitude swelling in control and treated animals in the presence of Ca 2+ ; in the absence of which highly significant inhibitory effects were observed at the same concentrations, in vitro . Significant increases were also recorded for AST, ALT, bilirubin, total protein and ALP, in vivo . Conclusion : The extract showed promise for hepato-protection against cigarette butt leachate toxicity in the liver of normal rats in the presence of exogenous Ca 2+ , in vitro. Keywords : Manihot esculenta leaf extract, cigarette butt leachate, mitochondrial membrane permeability transition pore, liver function

Inhibition of rat liver mitochondrial membrane permeability transition and lipid peroxidation by seeds extracts of Myristica fragrans Houtt.

Inhibition of rat liver mitochondrial membrane permeability transition and lipid peroxidation by seeds extracts of <i>Myristica fragrans</i> Houtt.

Study on Biological Effects of La(3+) on Rat Liver Mitochondria by Microcalorimetric and Spectroscopic Methods.

The effects of lanthanum on heat production of mitochondria isolated from Wistar rat liver were investigated with microcalorimetry; simultaneously, the effects on mitochondrial swelling and membrane potential (Δψ) were determined by spectroscopic methods. La(3+) showed only inhibitory action on mitochondrial energy turnover with IC50 being 55.8μmolL(-1). In the spectroscopic experiments, La(3+), like Ca(2+), induced rat liver mitochondrial swelling and decreased membrane potential (Δψ), which was inhibited by the specific permeability transition inhibitor, cyclosporine A (CsA). The induction ability of La(3+) was stronger than that of Ca(2+). These results demonstrated that La(3+) had some biotoxicity effect on mitochondria; the effects of La(3+) and Ca(2+) on rat liver mitochondrial membrane permeability transition (MPT) are different, and La represents toxic action rather than Ca analogy.

Effect of oral coadministration of artesunate with ferrous sulfate on rat liver mitochondrial membrane permeability transition

The recent resurgence of interest in the study of mitochondria has been fuelled in large part by the recognition that genetic and/or metabolic alterations in this organelle are causative or contributing factors in a variety of human diseases including cancer. This study hypothesizes that co-administration of artesunate and ferrous sulfate could induce apoptosis which can be targeted on cancerous cells in such a manner, thus providing a novel, viable and perhaps inexpensive way of dealing with the cancer scourge. Artesunate and Ferrous sulfate were co-administered to rats at various doses for seven days. At the end of the treatment, the rats were fasted overnight and sacrificed by cervical dislocation. Low ionic strength mitochondria were isolated from hepatic cells of the rats and assayed for protein content; changes in the absorbance of the liver mitochondria; and mitochondrial swelling. Co-administration of artesunate and ferrous sulfate resulted in a significant increase (P<0.05) in pore opening. The difference in pore opening was found to be statistically significant (P<0.05) when the artesunate and ferrous iron-treated groups were compared with the artesunate only treated group. Results from this study show that co-administration of artesunate and ferrous sulfate can cause an opening in the mitochondrial membrane transition pore. A combined dose of ferrous sulfate and artesunate may prove to be a more potent therapy for targeting cancerous cells.

Arachidonic acid induces specific membrane permeability increase in heart mitochondria

Micromolar concentrations of arachidonic acid cause in Ca2+ loaded heart mitochondria matrix swelling and Ca2+ release. These effects appear to be unrelated to the classical membrane permeability transition (MPT), as they are CsA insensitive, membrane potential independent and can also be activated by Sr2+. Atractyloside potentiated and ATP inhibited the arachidonic acid induced swelling. These observations suggest that the ATP/ADP translocator (ANT) may be involved in the AA induced, CsA insensitive membrane permeability increase. Under the same experimental conditions used for heart mitochondria, arachidonic acid induced the classical CsA sensitive, ADP inhibitable MPT in liver mitochondria.