The cholesterol lowering properties of the complex compound simvastatin with glycyrrhizic acid (simvaglyzin) in experimental models

A molecular complex of simvastatin (SV) and glycyrrhizic acid (GA) (at their ratio of 1 : 4) has been synthesized. The complex named “simvaglyzin” (SVG) was stable in aqueous and aqueous-alcohol solutions at GA concentrations exceeding 0.2 mM. In vitro SVG acted as an uncompetitive inhibitor of 3-hydroxy-3-methyl-glutaryl-CoA (3-HMG-CoA) reductase (Ki of 94 nM). Appearance of this inhibitory activity is associated with cytochrome P450-dependent conversion of SVG, because the addition of 1 mM metyrapone to the incubation medium fully prevented the inhibition of 3-HMG-CoA reductase. SV and SVG (used at 300 nM concentration) inhibited mevalonate synthesis rate by 39.15±8,27 and 38.85±3,04%, respectively. In vivo SVG showed a dose-dependent cholesterol lowering effect. In rats the cholesterol lowering effect of SVG used at daily doses equivalent to 66 and 100 mg/kg of SV was the same as the effect of SV administered at the daily dose of 200 mg/kg. The decrease in total cholesterol of blood serum was 7% and 9% (p < 0.05) and 8%, respectively. Myotoxicity of these SVG doses estimated by blood serum creatine phosphokinase (CPK) activity was lower than that of SV. In rats treated with SV the activity of CPK increased by 79% (p < 0.01), while in SVG treated rats it decreased by 30% and 36% (p < 0.05). Any increase of the hepatotoxicity markers alanine aminotransferase or aspartate aminotransferase in blood serum was not observed. The data suggest pharmacological synergism attributed to the SV-GA complex formation and increased safety of the resultant complex compared with a parent compound.     

Long non‐coding RNAs in melanoma

Melanoma is the most lethal cutaneous cancer with a highly aggressive and metastatic phenotype. While recent genetic and epigenetic studies have shed new insights into the mechanism of melanoma development, the involvement of regulatory non‐coding RNAs remain unclear. Long non‐coding RNAs (lncRNAs) are a group of endogenous non‐protein‐coding RNAs with the capacity to regulate gene expression at multiple levels. Recent evidences have shown that lncRNAs can regulate many cellular processes, such as cell proliferation, differentiation, migration and invasion. In the melanoma, deregulation of a number of lncRNAs, such as HOTAIR, MALAT1, BANCR, ANRIL, SPRY‐IT1 and SAMMSON, have been reported. Our review summarizes the functional role of lncRNAs in melanoma and their potential clinical application for diagnosis, prognostication and treatment.     

Carotenoids as antioxidants: spin trapping EPR and optical study.

The role of several natural and synthetic carotenoids as scavengers of free radicals was studied in homogeneous solutions. A set of free radicals: *OH, *OOH, and *CH(3) were generated by using the Fenton reaction in dimethyl sulfoxide. It was shown that the spin trapping technique is more informative than optical methods for the experimental conditions under study. 5,5-Dimethyl-pyrroline-N-oxide (DMPO) and N-tert-butyl-alpha-phenylnitrone (PBN) were used as spin traps for the EPR studies. The results show that the scavenging ability of the carotenoids towards radical *OOH correlates with their redox properties.     

Protective effect of bixin on carbon tetrachloride-induced hepatotoxicity in rats

Background

The liver is an important organ for its ability to transform xenobiotics, making the liver tissue a prime target for toxic substances. The carotenoid bixin present in annatto is an antioxidant that can protect cells and tissues against the deleterious effects of free radicals. In this study, we evaluated the protective effect of bixin on liver damage induced by carbon tetrachloride (CCl₄) in rats.

Results

The animals were divided into four groups with six rats in each group. CCl₄ (0.125 mL kg^-1 body wt.) was injected intraperitoneally, and bixin (5.0 mg kg^-1 body wt.) was given by gavage 7 days before the CCl₄ injection. Bixin prevented the liver damage caused by CCl₄, as noted by the significant decrease in serum aminotransferases release. Bixin protected the liver against the oxidizing effects of CCl₄ by preventing a decrease in glutathione reductase activity and the levels of reduced glutathione and NADPH. The peroxidation of membrane lipids and histopathological damage of the liver was significantly prevented by bixin treatment.

Conclusion

Therefore, we can conclude that the protective effect of bixin against hepatotoxicity induced by CCl₄ is related to the antioxidant activity of the compound.     

EPR spin trapping detection of carbon-centered carotenoid and beta-ionone radicals

Free radical intermediates were detected by the electron paramagnetic resonance spin trapping technique upon protonation/deprotonation reactions of carotenoid and beta-ionone radical ions. The hyperfine coupling constants of their spin adducts obtained by spectral simulation indicate that carbon-centered radicals were trapped. The formation of these species was shown to be a result of chemical oxidation of neutral compounds by Fe(3+) or I(2) followed by deprotonation of the corresponding radical cations or addition of nucleophilic agents to them. Bulk electrolysis reduction of beta-ionone and carotenoids also leads to the formation of free radicals via protonation of the radical anions. Two different spin adducts were detected in the reaction of carotenoid polyenes with piperidine in the presence of 2-methyl-2-nitroso-propane (MNP). One is attributable to piperidine radicals (C(5)H(10)N*) trapped by MNP and the other was identified as trapped neutral carotenoid (beta-ionone) radical produced via protonation of the radical anion. Formation of these radical anions was confirmed by ultraviolet-visible spectroscopy. It was found that the ability of carotenoid radical anions/cations to produce neutral radicals via protonation/deprotonation is more pronounced for unsymmetrical carotenoids with terminal electron-withdrawing groups. This effect was confirmed by the radical cation deprotonation energy (H(D)) estimated by semiempirical calculations. The results indicate that the ability of carotenoid radical cations to deprotonate decreases in the sequence: beta-ionone > unsymmetrical carotenoids > symmetrical carotenoids. The minimum H(D) values were obtained for proton abstraction from the C(4) atom and the C(5)-methyl group of the cyclohexene ring. It was assumed that deprotonation reaction occurs preferentially at these positions.     

Antioxidant and redox properties of supramolecular complexes of carotenoids with beta-glycyrrhizic acid

Supramolecular complexes between carotenoids and a triterpene glycoside, beta-glycyrrhizic acid (GA), were found to exhibit unusual antioxidant activity. Complexation with GA increases a scavenging rate of canthaxanthin and 7',7'-dicyano-7'-apo-beta-carotene toward OOH radicals more than 10 times, but has no effect on the scavenging rate of zeaxanthin. Scavenging rate constants were measured in DMSO solution of carotenoids using the EPR spin-trapping technique. EPR parameters of spin adducts were determined as a(H) = 2.3 G, a(N) = 13.9 G for PBN (N-tert-butyl-alpha-phenylnitrone)-OOH, and a(H) = 3.4 G, a(N) = 14.9 G for the PBN-CH3 adduct. Taking into account the previously measured dependence of the scavenging rate constants toward OOH radicals on the oxidation potential of carotenoids, this result can be explained by the hypothesis that the complexation with GA affects the value of oxidation potentials. This hypothesis was confirmed by CV measurements.     

Vaginal microbiocenosis in trichomoniasis

Taxonomic complex of vaginal microflora and its persistence characteristics in trichomoniasis and microecological disturbances were studied. Diminution of biotope colonization resistance was characterized by decreased autochthonous microorganisms' number and increased opportunistic microflora with expressed persistence. That could be of a great pathogenetic importance in the occurrence of reproductive tract inflammatory diseases of the bacterial etiology in addition of trichomoniasis in females.     

Carotenoids as scavengers of free radicals in a Fenton reaction: antioxidants or pro-oxidants?

The spin trapping EPR technique was used to study the influence of carotenoids (beta-carotene, 8'-apo-beta-caroten-8'-al, canthaxanthin, and ethyl 8'-apo-beta-caroten-8'-oate) on the yield of free radicals in the Fenton reaction (Fe(2+) + H(2)O(2) --> Fe(3+) + .OH + -OH) in the organic solvents, DMSO, and methanol. DMPO and PBN were used as spin trapping agents. It was demonstrated that carotenoids could increase or decrease the total yield of free radicals depending on the oxidation potential of the carotenoids and the nature of the radicals. A reaction mechanism is suggested which includes the reduction of Fe(3+) to Fe(2+) by carotenoids. The effectiveness of this carotenoid-driven Fenton reaction increases with a decrease of the scavenging rates for free radicals and with decreasing oxidation potentials of carotenoids.     

Phosphorylation and biosynthesis of high molecular weight proteins of tumor nuclear matrix

INTRODUCTIONAsearlyasin1948wehavefr8CtionatedisolatednucleifromnormalandtumorcellsbyextractionwithiMNaCIanddilutealkali[1].Thenuclearresiduewasthenstudiedmorethoroughly[2,3].Lateron,sillillarproteinousnuclearresidueswereisolatedbyotherworkers[46]andasstud…     

Algorithms and software for support of gene identification experiments

MOTIVATION: Gene annotation is the final goal of gene prediction algorithms. However, these algorithms frequently make mistakes and therefore the use of gene predictions for sequence annotation is hardly possible. As a result, biologists are forced to conduct time-consuming gene identification experiments by designing appropriate PCR primers to test cDNA libraries or applying RT-PCR, exon trapping/amplification, or other techniques. This process frequently amounts to 'guessing' PCR primers on top of unreliable gene predictions and frequently leads to wasting of experimental efforts. RESULTS: The present paper proposes a simple and reliable algorithm for experimental gene identification which bypasses the unreliable gene prediction step. Studies of the performance of the algorithm on a sample of human genes indicate that an experimental protocol based on the algorithm's predictions achieves an accurate gene identification with relatively few PCR primers. Predictions of PCR primers may be used for exon amplification in preliminary mutation analysis during an attempt to identify a gene responsible for a disease. We propose a simple approach to find a short region from a genomic sequence that with high probability overlaps with some exon of the gene. The algorithm is enhanced to find one or more segments that are probably contained in the translated region of the gene and can be used as PCR primers to select appropriate clones in cDNA libraries by selective amplification. The algorithm is further extended to locate a set of PCR primers that uniformly cover all translated regions and can be used for RT-PCR and further sequencing of (unknown) mRNA.