Protective Effect of Broccoli, Onion, Carrot, and Licorice Extracts against Cytotoxicity of N-Nitrosamines Evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium Bromide Assay

Improving the Nutritional Quality of Microwave-vacuum Dried Strawberries: A Preliminary Study

Microwave-vacuum drying is an up-to-date technique for the conservation of fruits and vegetables, resulting in products with improved texture and colour. In order to evaluate the effects on the content of ascorbic acid, anthocyanins and phenolic compounds, and antioxidant capacity, three strawberry varieties were subjected to microwave-vacuum (MV) drying combined with convective pre- and post-drying, convective drying, and freeze-drying. The MV drying procedure comprised immersion in a pretreatment bath, pre-drying in a belt dryer to a moisture load of approx 45 g/100 g dry matter, and microwave treatment at 4 kPa for 8 min, leading to products with 5 g/100 g moisture. During post-drying, the moisture content was further reduced to approx 2 g/100 g. Convective drying and MV drying decreased the content of ascorbic acid to approx 40% of the initial value, phenolic compounds to approx 35%, and the antioxidative capacity to approx 60%. No reduction was observed in freeze-dried strawberries. Bypassing the pre-treatment bath, extending residence time in the pre-dryer to reduce temperature peaks, and reducing MV treatment time increased the recovery of ascorbic acid to approx 65%. Phenolic compounds remained stable, and the reduction of the antioxidative capacity was limited to 10% – 25%. Except ascorbic acid, the residual concentration of nutritionally relevant compounds after improving the processing conditions was close to the values as observed for freeze-dried products.

Protective Effect of a Lactobacillus salivarius Strain of Human Origin

The protective effect of a Lactobacillus salivariusstrain from human faeces (HA8) was evaluated against the cytotoxicity of N-nitrosodimethylamine (NDMA), N-nitrosopyrrolidine (NPYR), N-nitrosodibutylamine (NDBA) and N-nitrosopiperidine (NPIP) by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. L. salivariusHA8 strain showed a moderate protective effect against NPYR and weak against NDBA and NPIP. No protective effect against cytotoxicity of NDMA was observed at the bacterial population used. To test the effect of L. salivariusHA8 on cytokine production (interleukin-1 ± (IL-1 ±), interleukin-8 (IL-8) and tumour necrosis factor alpha (TNF-≥)), the human macrophage cell line (THP-1) was cultured in the presence and absence of lipopolysaccharide (LPS). L. salivariusHA8 induced IL-1 ±, IL-8 and TNF-≥ releases when cells were stimulating with and without LPS.

Antiamnesic Effect of Broccoli (Brassica oleracea var. italica) Leaves on Amyloid Beta (Aβ)1-42-Induced Learning and Memory Impairment

To examine the antiamnesic effects of broccoli (Brassica oleracea var. italica) leaves, we performed in vitro and in vivo tests on amyloid beta (Aβ)-induced neurotoxicity. The chloroform fraction from broccoli leaves (CBL) showed a remarkable neuronal cell-protective effect and an inhibition against acetylcholinesterase (AChE). The ameliorating effect of CBL on Aβ1-42-induced learning and memory impairment was evaluated by Y-maze, passive avoidance, and Morris water maze tests. The results indicated improving cognitive function in the CBL group. After the behavioral tests, antioxidant effects were detected by superoxide dismutase (SOD), oxidized glutathione (GSH)/total GSH, and malondialdehyde (MDA) assays, and inhibition against AChE was also presented in the brain. Finally, oxo-dihydroxy-octadecenoic acid (oxo-DHODE) and trihydroxy-octadecenoic acid (THODE) as main compounds were identified by quadrupole time-of-flight ultraperformance liquid chromatography (Q-TOF UPLC-MS) analysis. Therefore, our studies suggest that CBL could be used as a natural resource for ameliorating Aβ1-42-induced learning and memory impairment.

Dietary-induced cancer prevention: An expanding research arena of emerging diet related to healthcare system

Diet plays a vital role in the management of cancer because they are the source of important physiologically functional components. Scientific observations support the idea that dietary supplement can prevent breast cancer recurrences. Strong correlations are established between the high intake of saturated fat and the incidence of different types of cancer. It is found that chronic alcohol consumption is associated with increased risk of cancers of oral cavity, pharynx, esophagus, and larynx. Again, some evidences are also found regarding phosphorous, glutamate level in the body, and incidence of cancer. Different physiologically functional components are found in the dietary materials. Fibers, the major dietary components, have long been recognized for the unique properties in the treatment of cancer, which are related to its antineoplastic functions. Antioxidant rich diet has been added to the list of cancer-preventing dietary components. Also, recently published research has shown that natural carotenoids in the diet leads to a normalization of body epithelial cells and protects against the risk of stomach and esophagus cancer, and improves the immune system's response. Again, fruit juices, processed vegetable juices, orange peel, green tea, vitamins, flavonoids, and trace materials have cancer inhibitory properties. Clearly, there has been increasing recognition of chemoprotective functions. Now, it can be recognized for another kind of functionality for the improvement of the health of mankind.

Antimutagenic effect of broccoli flower head by the ames salmonella reverse mutation assay

A study was performed to investigate the antimutagenic effect of broccoli flower head by the Ames Salmonella reverse mutation assay. Broccoli flower head being the most highly edible part in the plant was analysed for its antimutagenic effect. Without isolating the phytomolecules, the crude ethanol extract of broccoli flower head was tested for suppressing the mutagenic effect induced by certain chemical mutagens. Three strains - TA 98, TA102 and TA 1535 were used in the study. The tester strains were challenged with their respective mutagens. These were challenged with the ethanol extract of broccoli flower head at concentrations of 23 and 46 mg/plate. The plates were incubated for 72 h and the revertant colonies were counted. The crude extract did not prove to be promutagenic. The ethanol extract of the broccoli flower head at 46 mg/plate suppressed the mutagenic effect induced by the corresponding positive mutagens on all the three tester strains used in this study. The crude extract of broccoli flower head alone was not cytotoxic even at the maximum concentration tested (46 mg/plate). In conclusion, the ethanol extract of broccoli at 46 mg/plate suggests their diverse antimutagenic potential against the mutagenic chemicals employed in this study.

Selenazoles (selenium compounds) facilitate survival of cultured rat pheochromocytoma PC12 cells after serum-deprivation and stimulate their neuronal differentiation via activation of Akt and mitogen-activated protein kinase, respectively

The activation of extracellular receptor kinase (ERK) is one of the checkpoints to assess the activation of the classical Ras/mitogen-activated protein kinase (MAPK) cascade. Therefore, we tested more than 100 selenium-containing compounds for their ability to activate the MAPK signal pathway. Among them, we found that three selenazoles, 5-chloroacetyl-2-piperidino-1,3-selenazole (CS1), 5-chloroacetyl-2-morpholino-1,3-selenazole (CS2), and 5-chloroacetyl-2-dimethylamino-1,3-selenazole (CS3), induced the phosphorylation of ERK. These compounds also enhanced the phosphorylation of Akt, a signal transducing protein kinase for cell survival; and this phosphorylation was followed by suppression of cell death, thus suggesting that they had anti-apoptotic effects. Moreover, CSs 1-3 induced neurite outgrowth and facilitated the expression of neurofilament-M of PC12 cells, demonstrating that they induced neuronal differentiation of these cells. On the other hand, the CS-induced phosphorylation of MAPK was enhanced by buthionine sulfoximine (BSO), an activator of protein tyrosine phosphatases (PTPs), but inhibited by N-acetyl-l-cysteine (NAC), an inhibitor of receptor tyrosine kinase. These results imply that activation of some receptor tyrosine kinase(s) is involved in the mechanism of action of CSs 1-3. The activation of MAPK by CSs 1-3 was suppressed by U0126, a MEK inhibitor, but not by K252a, an inhibitor of TrkA; AG1478, an antagonist of epidermal growth factor receptor (EGFR); or by pertussis toxin. These results demonstrate that the CS-induced phosphorylation of Akt and MAP kinase (receptor tyrosine kinase(s)-MEK1/2-ERK1/2) cascades was responsible for suppression of apoptosis and facilitation of neuronal differentiation of PC12 cells, respectively. Our results suggest that CSs 1-3 are promising candidates as neuroprotective and/or neurotrophic agents for the treatment of various neurodegenerative neurological disorders.

Protective effects of isothiocyanates towards N-nitrosamine-induced DNA damage in the single-cell gel electrophoresis (SCGE)/HepG2 assay

The aim of this study was to investigate the protective effect of isothiocyanates towards N-nitrosamine-induced DNA damage in the single-cell gel electrophoresis (SCGE)/HepG2 assay. None of the isothiocyanates (ITCs) concentrations tested in the presence or absence of formamidopyrimidine-DNA glycosylase (Fpg) caused DNA damage per se. Combined treatments of HepG2 cells with phenethyl isothiocyanate (PEITC), allyl isothiocyanate (AITC) or indol-3-carbinol (I3C) and N-nitrosopyrrolidine (NPYR) or N-nitrosodimethylamine (NDMA) reduced the genotoxic effects of the N-nitrosamines in a dose-dependent manner. The protective effect of the three ITCs tested was higher towards NPYR-induced oxidative DNA damage than against NDMA. The greatest protective effect towards NPYR-induced oxidative DNA damage was shown by I3C (1 microM, 79%) and by PEITC (1 microM, 67%) and I3C (1 microM, 61%) towards NDMA (in presence of Fpg enzyme). However, in absence of Fpg enzyme, AITC (1 microM, 72%) exerted the most drastic reduction towards NPYR-induced oxidative DNA damage, and PEITC (1 microM, 55%) towards NDMA. Our results indicate that ITCs protect human-derived cells against the DNA damaging effect of NPYR and NDMA, two carcinogenic compounds that occur in the environment.

Retracted: Protective effects of isothiocyanates towardsN-nitrosamine-induced DNA damage in the single-cell gel electrophoresis (SCGE)/HepG2 assay

The aim of this study was to investigate the protective effect of isothiocyanates towards N-nitrosamine-induced DNA damage in the single-cell gel electrophoresis (SCGE)/HepG2 assay. None of the isothiocyanates (ITCs) concentrations tested in the presence or absence of formamidopyrimidine-DNA glycosylase (Fpg), caused DNA damage per se. Combined treatments of HepG2 cells with phenethyl isothiocyanate (PEITC), allyl isothiocyanate (AITC) or indol-3-carbinol (I3C) and N-nitrosopyrrolidine (NPYR) or N-nitrosodimethylamine (NDMA) reduced the genotoxic effects of the N-nitrosamines in a dose-dependent manner. The protective effect of the three ITCs tested was higher towards NPYR-induced oxidative DNA damage than against NDMA. The greatest protective effect towards NPYR-induced oxidative DNA damage was shown by I3C (1 microm, 79%) and by PEITC (1 microm, 67%) and I3C (1 microm, 61%) towards NDMA (in the presence of Fpg enzyme). However, in the absence of Fpg enzyme, AITC (1 microm, 72%) exerted the most drastic reduction towards NPYR-induced oxidative DNA damage, and PEITC (1 microm, 55%) towards NDMA. The results indicate that ITCs protect human-derived cells against the DNA damaging effect of NPYR and NDMA, two carcinogenic compounds which occur in the environment.

Antimutagenic effect of fruit and vegetable ethanolic extracts against N-nitrosamines evaluated by the Ames test

The inhibitory effect of nine fruit and vegetable ethanolic extracts against the mutagenicity of N-nitrosodimethylamine (NDMA), N-nitrosopyrrolidine (NPYR), N-nitrosodibutylamine (NDBA), and N-nitrosopiperidine (NPIP) was evaluated by means of the Ames test. Licorice ethanolic extract was the only one that showed an inhibitory effect (ranging from moderate to strong) against mutagenicity of all N-nitrosamines tested. This ethanolic extract showed the greatest inhibition effect against NPIP (72%), NDMA (45%), and NPYR (39%). The greatest inhibition effect (51%) of the mutagenicity of NDBA was shown by kiwi ethanolic extract. Vegetable and fruit ethanolic extracts that exhibited an antimutagenic effect (at the range 50-2000 microg/plate), in decreasing order, against NDMA and NPYR were as follows: licorice > kiwi > carrot and licorice > broccoli > pineapple > kiwi, respectively. Decreasing orders against NDBA and NPIP were, respectively, kiwi > onion > licorice = garlic > green pepper > carrot and licorice > garlic > pineapple > carrot.