Background: 1,4-naphthoquinones, especially juglone, are known for their anticancer activity. However, plumbagin, lawsone, and menadione have been less investigated for these properties. Therefore, we aimed to determine the effects of plumbagin, lawsone, and menadione on C6 glioblastoma cell viability, ROS production, and mitochondrial function. Methods: Cell viability was assessed spectrophotometrically using metabolic activity method, and by fluorescent Hoechst/propidium iodide nuclear staining. ROS generation was measured fluorometrically using DCFH-DA. Oxygen uptake rates were recorded by the high-resolution respirometer Oxygraph-2k. Results: Plumbagin and menadione displayed highly cytotoxic activity on C6 cells (IC50 is 7.7 ± 0.28 μM and 9.6 ± 0.75 μM, respectively) and caused cell death by necrosis. Additionally, they increased the amount of intracellular ROS in a concentration-dependent manner. Moreover, even at very small concentrations (1–3 µM), these compounds significantly uncoupled mitochondrial oxidation from phosphorylation impairing energy production in cells. Lawsone had significantly lower viability decreasing and mitochondria-uncoupling effect, and exerted strong antioxidant activity. Conclusions: Plumbagin and menadione exhibit strong prooxidant, mitochondrial oxidative phosphorylation uncoupling and cytotoxic activity. In contrast, lawsone demonstrates a moderate effect on C6 cell viability and mitochondrial functions, and possesses strong antioxidant properties.
The aim of this study was to evaluate the influence of additives of Jerusalem artichoke (JA), fermented with P. acidilactici KTU05-7, P. pentosaceus KTU05-9, L. sakei KTU05-6, on the quality and safety parameters of ready -to cook -minced pork (RCMP). Fermented JA additives reduced pH of the meat products and decreased water holding capacity (WHC) from 2.01 till 2.93 %. Concentrations of biogenic amines in RCMP with additives of the lactic acid bacteria (LAB) -fermented JA were significantly lower comparing with control sample. The number of pathogenic bacteria in artificially contaminated meat samples was significantly reduced in case of LAB-fermented JA additives. The highest antimicrobial activity was obtained using P. acidilactici fermented JA additives. The amounts of microbial pathogens E. coli and Ent. faecalis, S. aureus and Streptococcus spp. were determined 3.41, 3.38, 3,96 and 4.74 log CFU/g correspondingly, whereas without LAB-fermented JA additives were 8. 94, 7.75, 8.82 and 8.58 log CFU/g, correspondingly. A possibility to improve sensory properties (flavor) of RCMP using LAB fermented JA additives was investigated. The composition of volatile compounds of RCMP without additive and with LAB-fermented JA additives was analyzed using gas chromatography-mass spectrometry (GC-MS). The results of sensory evaluation of meat products supplemented with fermented JA additives revealed specific odor, which is pleasant and acceptable for consumers might be explainable that LAB-fermented JA additives have shown considerable differences mainly due to the accumulation of volatiles such as toluene, ethylbenzene, decane, undecane, 2 methyl undecane. N-morpholinomethyl-isopropyl-sulfide, 6-undecilamine and N,N-dimethyl-1-pentadecanamine were not determined in RCMP with LAB-fermented JA additives. The results obtained show, that P. acidilactici fermented JA 5 % additive is most suitable for the RCMP processing in order to prevent microbiological spoilage, increase volatile compounds and acceptability of the products.
Cold smoked salmon products (belly flaps, pieces, fillet, and loin) obtained from the retail market in Lithuania were tested for the presence of L. monocytogenes. It was found that contamination of the cold smoked fish products with Listeria spp. depends on the type of the product. Contamination with listeria in salmon belly flaps was 7.5 times higher than in the loin (P<0.05), 1.8 times higher than in the pieces (P<0.05) and 30 times higher than in the fillet (P<0.05). Microbiological analysis showed that 32.5% (P<0.05) of the fish product samples were infected with L. monocytogenes, while multiplex PCR confirmed 31.25% positive samples (P<0.01). According to the study results, L. monocytogenes strains were divided into two serotypes: 4b (94.6%) and 1/2a (5.4%). High contamination of the products with Listeria spp. showed that cold smoked salmon products, sold in local market, can be a reason of human listeriosis in Lithuania.
The effect of taxifolin (TXF) with starter cultures (SC), such as Leuconostoc carnosum, or a mixture of strains Pediococcus pentosaceus and Staphylococcus xylosus, on the TXF stability was evaluated. UPLC analysis demonstrated that after 181 days of storage total TXF content was the highest in samples with TXF and L. carnosum (60%), compared to the 1st day of storage. The sausages with TXF and the mixture of P. pentosaceus and S. xylosus (56%) followed next. The samples treated only with TXF retained 40% of TXF, compared to the 1st day of storage. TXF had no significant effect on the growth of lactic acid bacteria. The accumulation of biogenic amines (BA), including histamine and putrescine, was more effectively reduced in sausages inoculated with the TXF plus P. pentosaceus and S. xylosus mixture. Using this mixture, the rate of lipolysis and processes of lipid oxidation were effectively slowed down. Fatty acid (FA) composition was stable in all cases.
The results show that seven types of N-nitrosamines: N-nitrosodiethylamine (NDEA), N-Nitrosopiperidine (NPIP), N-nitrosodimethylamine (NDMA), N-nitrosopyrrolidine (NPYR), N-nitrosodipropylamine (NDPA), N-nitrosodibutylamine (NDBA) and N-nitrosodiphenylamine (NDphA) were reduced after heat treatment of pork steaks marinated with L. plantarum MI-LP1, S. carnosus LM-SC1, S. vitulinus LM-SV1. Selected LAB suppressed the formation of putrescine and spermine, lowered acid and peroxide values, which were significantly lower than in the control samples, then P≤0.05 in all cases. The nitrites and nitrates amounts were significantly decreased in pork steaks samples marinated with L. plantarum MI-LP1 and S. carnosus MI-SV1 strains. These results presented that selected lactic acid bacteria could be used for marinating pork steaks to improve quality characteristics and reduce N-nitrosamine formation during grilling.
Monitoring data of group B pharmacologically active substances in the Republic of Lithuania during the period 1999-2008 are presented. Peer review is based on data taken from residue-monitoring plans of the years 1999-2008 and the National Food and Veterinary Risk Assessment Institute reports on analyses performed in various foods. The data were analysed with the SPSS statistical package. Analysis of group B pharmacologically active substances residues monitoring results from the years 1999-2008 revealed that 25,030 samples were tested to detect 421 (1.68%) non-compliant samples in three groups of substances: antibacterials, anthelmintics and non-steroidal anti-inflammatory drugs. Most residues (88.3%) were found in milk, and were far less in beef, pork, sheep and goat meat.
The cut out and dissection data from 137 carcasses of the Lithuanian slaughter pig population were used to study the impact of carcass weight on the quality of primal carcass cuts, their composition, and meat. The ratio of gilts to barrows, used in the experiment, was 1:1, and the carcass hot weight was recorded within 45 min post mortem in four groups, covering carcass weight range: under 65 kg, 65.1-76.9 kg, 77.0-85.9 kg, 86.0 kg and over. The study indicated that when the carcass weight increased there were increases in the proportion of hams, bellies and tenderloins (p<0.05) and decreases in the proportions of carcass parts of lower value (p<0.001). The increase in the carcass weight decreased the proportion of bones in ham, loin, shoulder (p<0.001) and belly (p=0.062). The highest proportions of lean tissues in the hams, loins, shoulders and bellies were obtained in the group of 77.0-85.9 kg carcass weight. Meat composition was not affected by the carcass weight. CIE
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