Mitochondria-targeted plastoquinone derivatives as tools to interrupt execution of the aging program. 4. Age-related eye disease. SkQ1 returns vision to blind animals

Mitochondria-targeted cationic plastoquinone derivative SkQ1 (10-(6′-plastoquinonyl) decyltriphenylphosphonium) has been investigated as a potential tool for treating a number of ROS-related ocular diseases. In OXYS rats suffering from a ROS-induced progeria, very small amounts of SkQ1 (50 nmol/kg per day) added to food were found to prevent development of age_induced cataract and retinopathies of the eye, lipid peroxidation and protein carbonylation in skeletal muscles, as well as a decrease in bone mineralization. Instillation of drops of 250 nM SkQ1 reversed cataract and retinopathies in 3-12-month-old (but not in 24-month-old) OXYS rats. In rabbits, experimental uveitis and glaucoma were induced by immunization with arrestin and injections of hydroxypropyl methyl cellulose to the eye anterior sector, respectively. Uveitis was found to be prevented or reversed by instillation of 250 nM SkQ1 drops (four drops per day). Development of glaucoma was retarded by drops of 5 μM SkQ1 (one drop daily). SkQ1 was tested in veterinarian practice. A totally of 271 animals (dogs, cats, and horses) suffering from retinopathies, uveitis, conjunctivitis, and cornea diseases were treated with drops of 250 nM SkQ1. In 242 cases, positive therapeutic effect was obvious. Among animals suffering from retinopathies, 89 were blind. In 67 cases, vision returned after SkQ1 treatment. In ex vivo studies of cultivated posterior retina sector, it was found that 20 nM SkQ1 strongly decreased macrophagal transformation of the retinal pigmented epithelial cells, an effect which might explain some of the above SkQ1 activities. It is concluded that low concentrations of SkQ1 are promising in treating retinopathies, cataract, uveitis, glaucoma, and some other ocular diseases. Electronic Supplementary Material  Supplementary material is available for this article at and is accessible for authorized users. Published in Russian in Biokhimiya, 2008, Vol. 73, No. 12, pp. 1641–1654.     

Mitochondria-targeted plastoquinone derivatives as tools to interrupt execution of the aging program. 1. Cationic plastoquinone derivatives: Synthesis and in vitro studies

Synthesis of cationic plastoquinone derivatives (SkQs) containing positively charged phosphonium or rhodamine moieties connected to plastoquinone by decane or pentane linkers is described. It is shown that SkQs (i) easily penetrate through planar, mitochondrial, and outer cell membranes, (ii) at low (nanomolar) concentrations, posses strong antioxidant activity in aqueous solution, BLM, lipid micelles, liposomes, isolated mitochondria, and cells, (iii) at higher (micromolar) concentrations, show pronounced prooxidant activity, the “window” between anti- and prooxidant concentrations being very much larger than for MitoQ, a cationic ubiquinone derivative showing very much lower antioxidant activity and higher prooxidant activity, (iv) are reduced by the respiratory chain to SkQH₂, the rate of oxidation of SkQH₂ being lower than the rate of SkQ reduction, and (v) prevent oxidation of mitochondrial cardiolipin by OH^·. In HeLa cells and human fibroblasts, SkQs operate as powerful inhibitors of the ROS-induced apoptosis and necrosis. For the two most active SkQs, namely SkQ1 and SkQR1, C _1/2 values for inhibition of the H₂O₂-induced apoptosis in fibroblasts appear to be as low as 1·10⁻¹¹ and 8·10⁻¹³ M, respectively. SkQR1, a fluorescent representative of the SkQ family, specifically stains a single type of organelles in the living cell, i.e. energized mitochondria. Such specificity is explained by the fact that it is the mitochondrial matrix that is the only negatively-charged compartment inside the cell. Assuming that the Δψ values on the outer cell and inner mitochondrial membranes are about 60 and 180 mV, respectively, and taking into account distribution coefficient of SkQ1 between lipid and water (about 13,000: 1), the SkQ1 concentration in the inner leaflet of the inner mitochondrial membrane should be 1.3·10⁸ times higher than in the extracellular space. This explains the very high efficiency of such compounds in experiments on cell cultures. It is concluded that SkQs are rechargeable, mitochondria-targeted antioxidants of very high efficiency and specificity. Therefore, they might be used to effectively prevent ROS-induced oxidation of lipids and proteins in the inner mitochondrial membrane in vivo. Electronic Supplementary Material  Supplementary material is available for this article at and is accessible for authorized users. Published in Russian in Biokhimiya, 2008, Vol. 73, No. 12, pp. 1589–1606. This and the following four articles were written by the request of the Editorial Board of Biochemistry (Moscow).     

Mitochondria-targeted plastoquinone derivatives as tools to interrupt execution of the aging program. 2. Treatment of some ROS- and Age-related diseases (heart arrhythmia, heart infarctions, kidney ischemia, and stroke)

Effects of 10-(6′-plastoquinonyl) decyltriphenylphosphonium (SkQ1) and 10-(6′-plastoquinonyl) decylrhod-amine 19 (SkQR1) on rat models of H₂O₂- and ischemia-induced heart arrhythmia, heart infarction, kidney ischemia, and stroke have been studied ex vivo and in vivo. In all the models listed, SkQ1 and/or SkQR1 showed pronounced protective effect. Supplementation of food with extremely low SkQ1 amount (down to 0.02 nmol SkQ1/kg per day for 3 weeks) was found to abolish the steady heart arrhythmia caused by perfusion of isolated rat heart with H₂O₂ or by ischemia/reperfusion. Higher SkQ1 (125–250 nmol/kg per day for 2–3 weeks) was found to decrease the heart infarction region induced by an in vivo ischemia/reperfusion and lowered the blood levels of lactate dehydrogenase and creatine kinase increasing as a result of ischemia/reperfusion. In single-kidney rats, ischemia/reperfusion of the kidney was shown to kill the majority of the animals in 2–4 days, whereas one injection of SkQ1 or SkQR1 (1 μmol/kg a day before ischemia) saved lives of almost all treated rats. Effect of SkQR1 was accompanied by decrease in ROS (reactive oxygen species) level in kidney cells as well as by partial or complete normalization of blood creatinine and of some other kidney-controlled parameters. On the other hand, this amount of SkQ1 (a SkQ derivative of lower membrane-penetrating ability than SkQR1) saved the life but failed to normalize ROS and creatinine levels. Such an effect indicates that death under conditions of partial kidney dysfunction is mediated by an organ of vital importance other than kidney, the organ in question being an SkQ1 target. In a model of compression brain ischemia/reperfusion, a single intraperitoneal injection of SkQR1 to a rat (1 μmol/kg a day before operation) effectively decreased the damaged brain area. SkQ1 was ineffective, most probably due to lower permeability of the blood-brain barrier to this compound. Electronic Supplementary Material  Supplementary material is available for this article at and is accessible for authorized users. Published in Russian in Biokhimiya, 2008, Vol. 73, No. 12, pp. 1607–1621.     

The effect of tumor promoters and antagonists on in vitro directional migration of 10T1/2 mouse embryo cells

In vitro directional migration of 10 T1/2 fibroblasts is partially inhibited by TPA but not by its non promoting analogues. Other tumor promoters, e.g., phenobarbital, saccharin, and benzoylperoxide had no measurable effect when added in concentrations known to affect in vitro two-step transformation or intercellular communication. Inhibitors of in vitro transformation do not affect migration, except for dexamethasone, which inhibited it. Hence, there is no evidence for a general correlation between tumor promoting potential and inhibition of in vitro directional migration.Abbreviations DDT 1,1,1-trichloro-2,2-bis(p-cholorophenyl) ethane - DEXA dexamethasone - DMSO dimethylsulfoxide - RA retinylacetate - SD standard deviation - SOD superoxide dismutase - TPA 12-0-tetradecanoylphorbol-13-acetate; 4-0-Me-TPA, 4-0-methyl-TPA     

G1对EA.hy926内皮细胞内质网应激的抑制作用

目的观察GPR30受体激动剂G1对高糖诱导的EA.hy926内皮细胞内质网应激(endoplasmic reticulum stress,ERS)的影响。方法选用EA.hy926内皮细胞为研究对象,分为3组:正常对照组(Con,17.51mmol/L葡萄糖)、高糖组(HG,33.3mmol/L葡萄糖)、高糖+G1组(HG+G1,HG+1umol/L G1),利用流式细胞术检测3组细胞凋亡率,Western blot法检测ERS相关分子Bip、IRE1、PERK及凋亡分子Bax、Bcl-2的表达变化,RT-PCR法检测Bip和CHOP的mRNA表达变化。结果 HG组与Con组比较,细胞凋亡率明显升高(P0.01),Bip、IRE1、PERK及凋亡分子Bax表达上调(P0.01,P0.05或P0.001),Bcl-2的表达下调(P0.01),Bip mRNA、CHOP mRNA表达上调(P0.001及P0.01);HG+G1组与HG组比较,细胞凋亡率明显降低(P0.05),Bip、IRE1、PERK及凋亡分子Bax表达下调(P0.05或P0.01),Bcl-2的表达上调(P0.05),Bip mRNA、CHOP mRNA表达下调(P0.001及P0.01)。结论 GPR30受体激动剂G1可抑制EA.hy926内皮细胞内质网应激。     

Inhibitory effect of β-diketones and their metal complexes on TNF-α induced expression of ICAM-1 on human endothelial cells

Recent reports show that the natural β-diketone curcumin displays important biological properties regarding the intercellular adhesion molecule-1 (ICAM-1), which plays a critical role in the immune responses and inflammation. In this study the ICAM-1 inhibitory activity of β-diketone compounds, which are curcumin models lacking aromatic peripheral hydroxyl and methoxy groups, along with some metal derivatives is investigated. β-Diketones are systematically more active than metal complexes and the best obtained inhibition is 75% for both groups. The best inhibitors are 4-benzoyl-3-methyl-1-phenyl-pyrazol-5-one (HQ^Ph) among the ligands, and sodium benzoylacetonato among metal derivatives. These results appear in line with the reported antitumor activity of related species. Since 4-acyl-5-pyrazolones posses four tautomeric forms, those corresponding to HQ^Ph were investigated using density functional theory. Docking of all HQ^Ph tautomers on ICAM-1 protein was performed suggesting one keto-enol form favored to act in biological environment.     

Inhibitory effect of 13 taxane diterpenoids from Chinese yew (Taxus chinensis var. mairei) on the proliferation of HeLa cervical cancer cells

The inhibitory effect of 13 taxanes isolated from the Chinese yew (Taxus chinensis var. mairei) on the proliferation of human cervical cancer HeLa cells were examined using an MTT assay. Four compounds having a hydrophobic cinnamate side chain showed antiproliferative activity, which may be due to increased cell permeability.     

Effects of triptolide from Tripterygium wilfordii on ERα and p53 expression in two human breast cancer cell lines

The aim of the study was to discover possible differential cytotoxicity of triptolide towards estrogen-sensitive MCF-7 versus estrogen-insensitive MDA-MB-231 human breast cancer cells. Considering that MCF-7 cells express functional Estrogen receptor α (ERα) and wild-type p53, whereas MDA-MB-231 cells which are ERα-negative express mutant p53, the anti-proliferation effect of triptolide on MCF-7 and MDA-MB-231 cells were examined, the apoptotic effect and cell cycle arrest caused by triptolide were investigated, ERα and p53 expression were also observed in this paper. The results showed that the anti-proliferation effects were induced by triptolide in both cell lines. But the value of IC₅₀ in MCF-7 cells for its anti-proliferation effect was about one tenth of that in MDA-MB-231 cells, which indicated that the effect is more potent in MCF-7 cells. Condensed chromatin or fragmented nuclei could be found in MCF-7 cells treated with only 40 nM triptolide but in MDA-MB-231 cells they couldn’t be observed until the concentration reached to 400 nM. Triptolide induced significant S cell cycle arrest along with the presence of sub-G0/G1 peak in MDA-MB-231 cells, whereas there was only slightly S cell cycle arrest on cell cycle distribution in MCF-7 cells. The role of p53 in two breast cancer cells was examined, the results showed that the mutant p53 in MDA-MB-231 cells was suppressed and the wild-type p53 in MCF-7 was increased. Moreover, triptolide could down regulate the expression of ERα in MCF-7 cells. The results showed that triptolide is much more sensitive to ERα-positive MCF-7 cells than to ERα-negative MDA-MB-231 cells, and the sensitivity is significantly associated with the ERα and p53 status.     

Inhibitory effect of extracts from Brazilian medicinal plants on the adhesion of <Emphasis Type="Italic">Candida albicans</Emphasis> to buccal epithelial cells

Plants are known to produce a plethora of secondary metabolites which are recognized as a useful source of new drugs or drug leads. Extracts and fractions of Schinus terebinthifolius Raddi (Anacardiaceae), Piper regnellii C.D.C. (Piperaceae), Rumex acetosa L. (Polygonaceae), and Punica granatum L. (Punicaceae) were assessed for their antifungal activity against eight clinical isolates of C. albicans. They were also evaluated for their effect on the adhesion of these C. albicans isolates to buccal epithelial cells (BECs). The ethyl acetate fraction from the leaves of S. terebinthifolius showed promising activity, inhibiting the growth of three C. albicans isolates at 7.8 μg ml⁻¹ and significantly inhibiting their adhesion to BEC at 15 μg ml⁻¹ . In addition, this fraction did not show cytotoxic activity against murine macrophages. The results show the potential of the plant extracts studied as a source of new antifungal compounds. Further studies are necessary for isolation and characterization of the active compounds of these plants.