ApoA-I and ApoB levels, and ApoB-to-ApoA-I ratio as candidate pre-treatment biomarkers of pathomorphological response to neoadjuvant therapy in gastric and esophago-gastric junction adenocarcinoma.

<b><br>Introduction:</b> Neoadjuvant chemotherapy (NAC) is a part of the current standard of care in a locally advanced gastric adenocarcinoma (GA) and esophagogastric junction adenocarcinoma (EGJA), but only patients with good pathomorphological response (pR) to NAC benefit from prolonged overall survival.</br> <b><br>Aim:</b> The study aims to evaluate ApoA-I and ApoB as candidate pre-treatment biomarkers of pR to NAC in patients with GA and EGJA.</br> <b><br>Materials and methods:</b> Serum samples were collected from 18 patients with GA and 9 with EGJA before the initiation of NAC to determine the ApoA-I and ApoB levels. After NAC tumor regression grade (TRG) was evaluated in resected specimens according to the Mandard's tumor regression grading system and correlated with pre-treatment ApoA-I and ApoB serum concentration, and ApoB-to-ApoA-I serum concentration ratio.</br> <b><br>Results:</b> We found a positive correlation of ApoA-I level and pR (95% CI: -0.863 to -0.467; P < 0.0001), a negative correlation of ApoB level and pR (95% CI: 0.445 to 0.857; P < 0.0001), a negative correlation of ApoB-to-ApoA-I ratio and pR (95% CI: 0.835 to 0.964; P < 0.0001).</br> <b><br>Conclusions:</b> ApoA-I and ApoB levels, and ApoB-to-ApoA-I ratio are candidate pre-treatment predictors of pR to NAC in GA and may help to guide personalized therapy.</br>Our work fits into the dynamically developing trend of personalized treatment. It describes a potentially important rationale for further evaluation of apolipoprotein A-I and apolipoprotein B as predictors of cancer response to neoadjuvant therapy.

Cytotoxic activity of methanolic fractions of different Marrubium spp. against melanoma cells is independent of antioxidant activity and total phenolic content.

The Marrubium genus (horehound) has proved to be an abundant source of biologically active compounds, but there is little knowledge about its potential anticancer activity. Moreover, some Marrubium species have not been the subject of study in this regard. In this study, we performed comparative analysis of phenolic acid (PhA) content and total phenolic content in fractions obtained from methanolic extracts of Marrubium vulgare L. (common horehound), Marrubium cylleneum Boiss. & Heldr. and Marrubium friwaldskyanum Boiss herbs. We examined the cytotoxicity of these fractions against a human melanoma cancer cell line (A375) and normal human skin fibroblasts (BJ) using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide test, cell cycle analysis and real-time monitoring of cell viability. We detected caffeic, p-coumaric, ferulic and gentisic acids among the PhAs. Although the extracts obtained demonstrated low total phenolic content and did not show significant antioxidative properties, the nonhydrolyzed PhA fraction exhibited cytotoxic activity against a human melanoma cancer cell line, without affecting normal fibroblasts. Both acidic and alkaline hydrolysis abolished this activity, indicating that the esterified forms of phenolic compounds caused the observed cytotoxic effects. Further investigation of these compounds may facilitate the development of novel drugs for cancer treatment.

The beneficial effects of resveratrol on steatosis and mitochondrial oxidative stress in HepG2 cells.

Nonalcoholic fatty liver disease (NAFLD) is currently one of the most common chronic liver diseases, especially in developed countries. One group of substances with a potential use in the treatment of NAFLD are plant polyphenols, represented by resveratrol. The aim of this study was to evaluate the effect of resveratrol on steatosis and oxidative stress in HepG2 cells. The steatosis of cells was carried out using free fatty acids: oleic or palmitic acid and their mixtures. Steatosis was visualized using the intracellular lipid staining by Nile Red dye with a fluorescence microscope. This study also determined the viability of cells and mitochondrial membrane potential. The current study showed that fatty acids and their mixtures induced fat overloading in HepG2 cells. In the group of cells incubated with oleic acid (OA), observed changes were moderate with prevailing micro-vesicular steatosis. In case of cells incubated with palmitic acid (PA) and the mixtures of fatty acids, micro- and macro-vacuolar steatosis occurred in most of the cells. Resveratrol decreased steatosis in HepG2 cells induced by OA, PA, as well as their mixtures, and in most of experimental groups did not reduce cells viability. Resveratrol reduced the oxidative stress in HepG2 cells treated with fatty acids mixtures.

The Positive Synergism of CPT and MK-801 in Behavioral Tests and in Reduction of Environmental Stress and Redox Signaling Changes in Mice Cerebral Cortex.

BACKGROUND: Depressive disorders are associated with oxidative stress. Therefore, it is interesting if antidepressants can affect redox equilibrium and signaling. The first step of our study was to determine the influence of the adenosine system on the antidepressant-like activity of noncompetitive antagonist of the NMDA (N-methyl-d-aspartate) receptor complex - dizocilpine (MK- 801). To this aim, two behavioral tests commonly used to assess the antidepressant capability of drugs - the forced swim test (FST) and tail suspension test (TST), were performed. Locomotor activity was estimated to verify and exclude false positive/negative results in the FST and TST. To examine whether antidepressants affect redox equilibrium, we have investigated lipid peroxidation products (LPO), GSH (glutathione), GSSG (glutathione disulfide), NADP+ (nicotinamide adenine dinucleotide phosphate) and NADPH (reduced nicotinamide adenine dinucleotide phosphate) in the cerebral cortex of mice following administration of CPT (8-cyclopentyl-1,3-dimethylxanthine) and MK-801 (dizocilpine) under environmental stress conditions. METHOD: The experiments were carried out using male Albino Swiss mice (25-30 g). The drugs were administered ip., alone and simultaneously, 60 min before tests. RESULTS: The behavioural tests results showed that CPT (3 mg/kg) potentiated the antidepressant-like activity of MK-801 (0.05 mg/kg) and the observed effects were not due to the increase in mice locomotor activity. Positive synergism of CPT and MK-801 in reduction of environmental stress conditions was revealed. In this group an increase in GSH and GSSG without changes in GSH/GSSG ratio and reduction of LPO was found. The level of lipid peroxidation products was also decreased in group receiving CPT and MK-801 separately. CONCLUSION: Examined antidepressant agents may increase antioxidant defences however further studies are needed with different range of time.

The differential effects of green tea on dose-dependent doxorubicin toxicity.

BACKGROUND: Doxorubicin (DOX) is an anticancer drug displaying cardiac and hepatic adverse effects mostly dependent on oxidative stress. Green tea (GT) has been reported to play a protective role in diseases resulting from oxidative stress. OBJECTIVE: The objective of this study was to evaluate if GT protects against DOX-induced oxidative stress, heart and liver morphological changes, and metabolic disorders. METHODS: Male Wistar rats received intraperitoneal injection of DOX (1.0 or 2.0 mg/kg b.w.) for 7 weeks or concomitantly GT extract soluble in drinking water. RESULTS: There were multidirectional effects of GT on blood metabolic parameters changed by DOX. Among all tested biochemical parameters, statistically significant protection of GT against DOX-induced changes was revealed in case of blood fatty acid-binding protein, brain natriuretic peptide, and superoxide dismutase. CONCLUSION: DOX caused oxidative stress in both organs. It was inhibited by GT in the heart but remained unchanged in the liver. DOX-induced general toxicity and histopathological changes in the heart and in the liver were mitigated by GT at a higher dose of DOX and augmented in rats treated with a lower dose of the drug.

Protective effect of Mutellina purpurea polyphenolic compounds in doxorubicin-induced toxicity in H9c2 cardiomyocytes.

The delayed cardiomyopathy caused by doxorubicin - an chemotherapeutic drug with broad spectrum of anticancer activity - is mainly triggered by oxidative stress. The aim of this study was to assess an effect of Mutellina purpurea methanolic extract fraction and other antioxidants of plant origin: rutin, quercetin and chlorogenic acid (all 1 mg% w/v) on oxidative stress and morphological changes induced by doxorubicin in cardiomyocytes H9c2. Mitochondrial oxidative stress in cardiomyocytes induced by 1 µM doxorubicin was evidenced by MitoTracker and RedoxSensor Red CC-1 dyes. Moreover, cardiomyocytes morphological changes and cell viability were evaluated. The tested fraction slightly reduced mitochondrial ROS fluorescence, similar to quercetin. Chlorogenic acid revealed concentration dependent prooxidative and antioxidative properties in the applied H9c2 model. The evaluation of the protective effect of tested compounds on doxorubicin-induced cytotoxicity was based on the examination of induced oxidative stress and morphology changes. The protective effect was described in the following order: rutin > chlorogenic acid (0.5 µM) > LH8 and quercetin. According to the MTT test, rutin seems to be the most promising compound that should be tested in a future studies.

Cytotoxicity, antioxidant activity and an effect on CYP3A4 and CYP2D6 of Mutellina purpurea L. extracts.

Mutellina purpurea is an aromatic Apiaceae plant known as Alpine lovage. Its polar extracts consist of phenolic acids, tannins and flavonoids. The cytotoxic effect of methanolic and aqueous extracts from M. purpurea was studied on the most frequently used cell lines: HeLa and BHK-21. Taking into account that the natural products are often used with other medicines there is a risk of reciprocal interaction on the metabolic level. Thus, the influence of M. purpurea extracts was investigated on the activity of CYP2D6 and CYP3A4, which are the most important P450 isoenzymes from the pharmacological and toxicological points of view. Additionally, because M. purpurea contains phenolic compounds, the antioxidative properties of this plant extracts were also studied and compared.

Different effects of resveratrol on dose-related Doxorubicin-induced heart and liver toxicity.

The aim of the study was to evaluate the effect of resveratrol in doxorubicin-induced cardiac and hepatic toxicity. Doxorubicin was administered once a week throughout the period of 7 weeks with 1.0 or 2.0 mg/kg body weight or concomitantly with resveratrol (20 mg/kg of feed). Heart and liver toxicity was histologically and biochemically evaluated. Resveratrol protected from the heart lipid peroxidation caused by 1 mg doxorubicin and it sharply diminished superoxide dismutase activity. An insignificant effect of resveratrol on the lipid peroxidation level and the superoxide dismutase activity was observed in the hearts of rats administered a higher dose of doxorubicin. However, resveratrol attenuate necrosis and other cardiac histopathological changes were induced by a high dose of doxorubicin. Interestingly, it slightly intensified adverse cardiac histological changes in rats receiving a lower dose of doxorubicin. Resveratrol did not have any protective effect on the hepatic oxidative stress, while exerting a mild beneficial effect on the morphological changes caused by doxorubicin. All in all, this study has shown different effects of resveratrol on dose-related doxorubicin-induced heart and liver toxicity. Resveratrol may modulate the hepatic and cardiac effect of doxorubicin, depending on the drug dose.

Effect of selected alcohol dehydrogenase inhibitors on human hepatic lactate dehydrogenase activity - an in vitro study.

Metabolic acidosis severely complicates methanol and ethylene glycol intoxications. Acidosis is caused by acid metabolites and can be intensified by lactate elevation. Lactate concentration depends on the NADH(2)/NAD ratio. Lactate dehydrogenase (LDH, E.C.1.1.1.27.) supplies more lactate when the level of NADH(2) is elevated. The aim of the study was to evaluate the effect of alcohol dehydrogenase (ADH) inhibitors and substrates: cimetidine, EDTA, 4-methylpyrazole (4-MP), Ukrain and ethanol on LDH activity. The activity of LDH was determined spectrophotometrically in human liver homogenates incubated with cimetidine, EDTA, 4-MP and Ukrain at concentrations of 2 x 10(-6), 10(-5) and 5 x 10(-5) m as well as ethanol at concentrations of 12.50, 25.00, 50.00 mm. The LDH activity was significantly increased by 10(-5) and 5 x 10(-5) m concentrations of cimetidine and 4-MP, and by all concentrations of ethanol. The most effective change of LDH activity of about 26% (P<0.01) was observed at the highest concentration of ethanol. Ukrain inhibited LDH activity at both concentrations, i.e. 10(-5) and 5 x 10(-5) m (P<0.05). However, EDTA did not significantly influence LDH activity. The data showed that ethanol and 4-MP, the main antidotes in methanol or ethylene glycol poisoning, may increase liver LDH activity - an undesirable effect during the therapy of patients intoxicated with these alcohols. On the other hand, the decrease of LDH activity in the presence of Ukrain is a promising finding but definitely requires further investigation.