Exopolysaccharides from Lactobacillus acidophilus modulates the antioxidant status of 1,2-dimethyl hydrazine-induced colon cancer rat model.

The aim of the current study is to ascertain the anticancer activity of exopolysaccharides (EPS) from probiotic Lactobacillus acidophilus in the 1, 2-dimethyl hydrazine (DMH)-induced colon cancer rat model and to determine the antioxidant status. Rats were divided into five groups of six animals each. Group I served as control, group II served as cancer control (DMH alone administered), group III as standard drug control (5-FU along with DMH) and group IV and V received EPS in two doses (200 mg/kg body weight and 400 mg/kg body weight along with DMH). EPS administration was found to reduce the number of polyps formed (Group IV-8.25 ± 1.258 and Group V-8.50 ± 1.732 vs Group II-14.50 ± 2.380) and to increase the levels of antioxidant enzymes viz. Superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) and antioxidants like vitamin C (Vit. C), reduced glutathione (GSH) which was found to be reduced in colon cancer control rats. The status of lipid peroxidation (LPO) was also evaluated. All the values which were affected by the supplementation of DMH were brought to near normal levels by the treatment with EPS. The well-preserved histology of colon and the biochemical evaluation also show that EPS could be a potential agent for the prevention and treatment of colon cancer.

The effects of flavonoids on human first trimester trophoblast spheroidal stem cell self-renewal, invasion and JNK/p38 MAPK activation: Understanding the cytoprotective effects of these phytonutrients against oxidative stress.

Adequate invasion and complete remodelling of the maternal spiral arteries by the invading extravillous trophoblasts are the major determinants of a successful pregnancy. Increase in oxidative stress during pregnancy has been linked to the reduction in trophoblast invasion and incomplete conversion of the maternal spiral arteries, resulting in pregnancy complications such as pre-eclampsia, intrauterine growth restriction, and spontaneous miscarriages resulting in foetal/maternal mortality. The use of antioxidant therapy (vitamin C and E) and other preventative treatments (such as low dose aspirin) have been ineffective in preventing pre-eclampsia. Also, as the majority of antihypertensive drugs pose side effects, choosing an appropriate treatment would depend upon the efficacy and safety of mother/foetus. Since pre-eclampsia is mainly linked to placental oxidative stress, new diet-based antioxidants can be of use to prevent this condition. The antioxidant properties of flavonoids (naturally occurring phenolic compounds which are ubiquitously distributed in fruits and vegetables) have been well documented in non-trophoblast cells. Therefore, this study aimed to investigate the effects of flavonoids (quercetin, hesperidin) and their metabolites (Quercetin 3-O-ß-glucuronide and hesperetin), either alone or in combination, on first trimester trophoblast cell line HTR-8/SVneo during oxidative stress. The data obtained from this study indicate that selected flavonoids, their respective metabolites significantly reduced the levels of reduced glutathione (p < 0.0001) during HR-induced oxidative stress. These flavonoids also inhibited the activation of pro-apoptotic kinases (p38 MAPK and c-Jun N-terminal kinase) during HR-induced phosphorylation. In addition, they enhanced spheroid stem-like cell generation from HTR8/SVneo cells, aiding their invasion. Our data suggest that dietary intake of food rich in quercetin or hesperidin during early pregnancy can significantly improve trophoblast (placenta) health and function against oxidative stress.

Antioxidative effects of flavonoids and their metabolites against hypoxia/reoxygenation-induced oxidative stress in a human first trimester trophoblast cell line.

This study aimed to investigate the cytoprotective effects of flavonoids, their metabolites alone or in combination against hypoxia/reoxygenation induced oxidative stress in the transformed human first trimester trophoblast cell line (HTR-8/SVneo). Oxidative stress was achieved with hypoxia followed by reoxygenation and the following assays were performed: MTT, CellTox™ Green Cytotoxicity, CellTiter-Glo®, NADP/NADPH-Glo™, ROS-Glo™/H2O2, GSH/GSSG-Glo™ and Caspase-Glo® 3/7 assays. HTR-8/SVneo cells, pre-treated for 24 h with flavonoids or their metabolites were protected significantly from oxidative stress. Flavonoids were associated with ROS modulation, reducing the generation of superoxide/hydrogen peroxide. The activities of caspases 3/7 were also significantly reduced significantly in HTR-8/SVneo cells pre-treated with flavonoids. This study has shown for the first time that 24 h pre-treatment with flavonoids, their metabolites alone or in combination, protected against HR-induced oxidative stress in the trophoblast cell line. These data indicate that dietary flavonoids may be beneficial to placental health and invasion during early gestation.

In vitro evaluation of anticancer properties of exopolysaccharides from Lactobacillus acidophilus in colon cancer cell lines.

The present work aims at studying the effect of exopolysaccharides (EPS) from Lactobacillus acidophilus on the colon cancer cell lines in vitro. Initial analysis showed that EPS has antioxidative properties. EPS was also found to induce cytotoxicity in two colon cancer cell lines, viz. HCT15 and CaCo2 under normoxia and hypoxia. The membrane integrity was also found to be affected in EPS-treated cells. Once the toxic concentration was determined (5 mg/ml), the effect of EPS on the messenger RNA (mRNA) expression of various genes was studied by quantitative real-time (RT)-PCR under both normoxic and hypoxic conditions. The results suggest that EPS downregulated the expression of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1α (HIF-1α) and upregulated the expression of tissue inhibitor of metalloproteinases-3 (TIMP-3), hypoxia-inducible factor-2α (HIF-2α), and hemeoxygenase-1 (HO-1). An increase in plasminogen activator inhibitor-1 (PAI-1) was also observed. These results show that EPS may inhibit the expressions of genes involved in tumor angiogenesis and survival. Increase in the expression of HO-1 also shows that EPS have antioxidative properties.

Optimization of anticancer exopolysaccharide production from probiotic Lactobacillus acidophilus by response surface methodology.

Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths in the Western world. Recently, much attention has been focused on decreasing the risk of CRC by consuming probiotics. In the present study, exopolysaccharide (EPS) extracted from Lactobacillus acidophilus was found to inhibit the growth of CaCo2 colon cancer cell line in a dose-dependent manner. The experiment was performed in both normoxic and hypoxic conditions, and EPS was found to reduce the survival of CaCo2 cell line in both the conditions. Quantitative polymerase chain reaction (qPCR) studies demonstrated that EPS treatment upregulated the expression of peroxisome proliferator activator receptor-γ (PPAR-γ) in both normoxia and hypoxia conditions, whereas it upregulated the expression of erythropoietin (EPO) in the normoxic condition, but there was no significant expression under hypoxic conditions. Hence, the EPS production was optimized by Plackett-Burman design followed by central composite rotatory design. The optimized production of EPS at 24 hr was found to be 400 mg/L. During batch cultivation the production peaked at 21 hr, resulting in an EPS concentration of 597 mg/L.

Post-moderate exercise testing and clinical predictive value of ankle arm index measurements.

Since peripheral vascular disease (PVD) is the forerunner of coronary heart disease (CHD), it is vital to detect PVD at an early stage. In the past, the non-invasive ankle arm index (AAI) has been successfully used to predict the susceptibility of PVD/CHD. However, different authors have used different permutations (i.e. highest, average and lowest) of ankle (ASBP) and arm (HSBP) systolic blood pressures to calculate AAI. This study aims to investigate the validity and applicability of different permutations of AAI formulae to predict sub-clinical PVD/CHD in young individuals. The study also investigated whether the use of AAI post-moderate exercise would enhance the predictability of PVD or CHD at an early stage. Individuals from different ethnic background within the UK took part in this study. Following 5min moderate cycle exercise using 50% of heart reserve, the AAI was significantly reduced (P<0.05). It was found that not all the permutations of AAI were acceptable and some over/under estimated AAI compared to currently accepted methodologies. According to the statistical analysis (ANOVA and 95% limits of agreement) calculation of AAI using values of (1) highest ASBP divided by highest HSBP, (2) highest ASBP divided by average HSBP, (3) average ASBP divided by highest HSBP and (4) lowest ASBP divided by average HSBP were within acceptable agreement with the standard method of calculating AAI. Inclusion of these permutations together with the standard method, would give a better predictions of PVD/CHD at an early age.