We have studied the state of the mitochondrial permeability transition pore (MPTP), respiration, and oxidative phosphorylation in mitochondria of the liver and pancreas of the rats with streptozotocin-induced diabetes. In addition, we considered the approaches to the correction of membraneous lesions with the help of glycorazmulin, a hypoglycemic preparation based on mumiyo (Jew's tar) and an extract from rhodiola roots and tubers (Rhodiola Semenovii A.). The mitochondria swelling rate in the liver and pancreas of the rats with experimental diabetes mellitus is known to be lower than in the unaffected animals; in other words, hepatic and pancreatic megapores in case of pathology remain open. Glycorazmulin normalizes their state and thereby eliminates the effect of spreptozotocin on mitochondria. The mitochondrial respiration rate in the liver and pancreas of the rats with experimental diabetes inceases at states V3 and V4 which results in a significant decrease of respiratory and ADP/O coefficients compared with the control values. The results of the study suggest decoupling of respiration from oxidative phosphorylation in the rats with experimental diabetes. Glycorazmulin administered per os at a dose of 50 mg/kg b.w. during 8 days eliminated functional disorders of mitochondria in the liver and pancreas of the rats, presumably by virtue of its antioxidative properties.

Flavonoids are proved to be prominent plant-derived compounds generally found in fruit- and vegetable- rich diets with free radicals quenching ability. Quercetin, a member of flavonoids subclass – flavonols, has gained major attention due to its overwhelming potential. Quercetin was demonstrated to preserve diverse degenerative diseases by inhibiting lipid peroxidation. In the present paper, we deal with two polyphenolic compounds’ – quercetin and dihydroquercetin – influence on functional parameters of mitochondria. Thus, the fore mentioned flavonols showed the mitochondrial permeability transition pore (mPTP) inhibition and ATP-sensitive potassium channel activation capacities as well as strong antioxidаnt/antiradiсal activity. Improving functional parameters of mitochondria by both quercetin and dihydroquercetin formed a basic idea of the hypothesis that the studied flavonols may provide antihypoxic defense.

Fruit proteins, seed proteins and capsaicinoids fractions were isolated from red pepper of Capsicum annum L. plants family and their effects on mitochondrial permeability transition pore (MPTP) and lipid peroxidation of rat liver were studied in vitro. Seed proteins did not influence to MPTP; however fruit proteins caused MPTP to open and led to mitochondrial membrane permeabilization. Opening of the MPTP causes massive swelling of mitochondria; capsaicinoids fractions inhibited the swelling process of mitochondria and caused the closed state of the MPTP. Fruits and seeds protein fractions from red pepper did not reduce the effect of Fe2+/ascorbate-induced mitochondrial swelling and had no effect on the accumulation of malondialdehyde (MDA) in the membranes of mitochondria. Capsaicinoid fraction had a concentration-dependent inhibitory effect on the Fe2+/ascorbate-dependent swelling of mitochondria and of lipid peroxidation. Half-maximal inhibitory concentration (IC50) on the swelling of mitochondria fraction was 2 µg/ml. Сapsaicinoids fraction prevented the effect of Fe2+/ascorbate on mitochondria and reduced the accumulation of MDA in membrane. Complete inhibition of lipid peroxidation was shown at a 50 µg/ml capsaicinoids concentration. Capsaicinoids, reducing the membrane destructive effects of Fe2+/ascorbate, had antioxidant properties and a protective effect on mitochondria. The obtained results showed the presence of different compounds in red pepper differently affecting MPTP and lipid peroxidation.

No abstract

No abstract