Performance of a UV-A LED system for degradation of aflatoxins B1 and M1 in pure water: kinetics and cytotoxicity study

The efficacy of a UV-A light emitting diode system (LED) to reduce the concentrations of aflatoxin B1, aflatoxin M1 (AFB1, AFM1) in pure water was studied. This work investigates and reveals the kinetics and main mechanism(s) responsible for the destruction of aflatoxins in pure water and assesses the cytotoxicity in liver hepatocellular cells. Irradiation experiments were conducted using an LED system operating at 365 nm (monochromatic wave-length). Known concentrations of aflatoxins were spiked in water and irradiated at UV-A doses ranging from 0 to 1,200 mJ/cm2. The concentration of AFB1 and AFM1 was determined by HPLC with fluorescence detection. LC–MS/MS product ion scans were used to identify and semi-quantify degraded products of AFB1 and AFM1. It was observed that UV-A irradiation significantly reduced aflatoxins in pure water. In comparison to control, at dose of 1,200 mJ/cm2 UV-A irradiation reduced AFB1 and AFM1 concentrations by 70 ± 0.27 and 84 ± 1.95%, respectively. We hypothesize that the formation of reactive species initiated by UV-A light may have caused photolysis of AFB1 and AFM1 molecules in water. In cell culture studies, our results demonstrated that the increase of UV-A dosage decreased the aflatoxins-induced cytotoxicity in HepG2 cells, and no significant aflatoxin-induced cytotoxicity was observed at UV-A dose of 1,200 mJ/cm2. Further results from this study will be used to compare aflatoxins detoxification kinetics and mechanisms involved in liquid foods such as milk and vegetable oils

Granular Activated Carbons from Agricultural By-products: Process Description and Estimated Cost of Production (Bulletin #881)

This bulletin is a follow-up, in part, of Bulletin #869, “Granular Activated Carbons from Agricultural By-products: Preparation, Properties and Application in Cane Sugar Refining.” An estimation of production costs for these by product-based carbons was considered prudent because of the potential interest from both bagasse and shell producers and activated carbon manufacturers based on the use of these carbons in various applications compared to commercial carbons.https://digitalcommons.lsu.edu/agcenter_bulletins/1034/thumbnail.jp

Impact of UV-C irradiation on the quality, safety, and cytotoxicity of cranberry-flavored water using a novel continuous flow UV system

The influence of short wavelength UV-C irradiation at 254 nm on microbial inactivation, anthocyanins stability, ascorbic acid, and cytotoxicity of formulated cranberry flavored water was studied. Escherichia coli ATCC 25922 and Salmonella enterica serovar Typhimurium ATCC 13311 were inactivated by more than 5 log10 at UV-C fluence of 21 mJ cm−2. At UV-C fluence of 40 mJ cm−2 the content of ascorbic acid was 82% of that in the untreated beverage. The concentrations of the anthocyanins (Cy3Ar, Cy3Ga, Pe3Ar, and Pe3Ga) were not significantly affected at the same treatment level. Cytotoxicity evaluation of the irradiated beverage on normal colon (CCD-18Co), colon cancer (HCT-116), and healthy mice liver (AML-12) cells showed that UV-C irradiation had no cytotoxic effects on all three cell lines. This research study suggests that UV-C treatment of formulated cranberry flavored water can achieve high levels of microbial inactivation without significantly decreasing the concentration of anthocyanins, ascorbic acid content or generating cytotoxic effects. These results suggest that UV-C irradiation can be an alternative to thermal pasteurization in producing high quality beverages

Agricultural by-products as important food sources of polyphenols

Polyphenols are secondary metabolites of plants. Dietary phenolics are not only classified as human nutrients, but play important roles in human health and are therefore called nutraceuticals. Both epidemiological studies and controlled human studies have shown that regular intakes of diets rich in phenolics are inversely related to some chronic diseases such as certain cancers and coronary heart diseases. Types and contents of phenolics in different food system vary greatly and foods of plant origin including fruits, vegetables, legumes and some beverages are good sources of bioactive phenolics. Beside the edible part of plant foods, some agricultural by-products usually contain higher levels of polyphenols, particularly, flavonoids than products themselves. This chapter describes the major classes of dietary phenolics, and their occurence in the commercially important agricultural by-products including peanuts skin, grape pomace, apples pomace, citrus processing by-products, and cranberry pomace. The possible applications of the polyphenolics from these agricultural by-products in food system are also discussed.Scopu

Coupling In vitro and In vivo Paradigm Reveals a Dose Dependent Inhibition of Angiogenesis Followed by Initiation of Autophagy by C6-Ceramide

The activity of N-hexanoyl-D-erythro-sphingosine, a C6-ceramide against angiogenesis was tested in vitro and in vivo. The effect of ceramide in inhibiting MCF-7 cancer cells was also determined. The aim of this study was to potentiate the effect of ceramide as anti-angiogenic compound that can regulate tumor induced angiogenesis.C6-ceramide inhibited vascular endothelial growth factor (VEGF)-induced human umbilical vein endothelial cells (HUVEC) tube formation in a dose-dependent manner within 24 hours. Ceramide at concentrations between 12.5 and 25 &#956;M inhibited the viability of MCF-7 cells and reduced VEGF-induced cell migration in 24 hours. At 50 &#956;M, ceramide induced MCF-7 cell death via autophagy as demonstrated by accumulation of MDC in ceramide-treated MCF-7 vacuoles. The expression of VEGF was reduced and the levels of cathepsin D in MCF-7 increased. In vivo, 50 &#956;M ceramide caused a 40% reduction of new vessel formation in the CAM assay within 24 hours. Zebrafish exposed to 100 - 400 &#956;M ceramide had a distinct disruption of blood vessel development at 48 hours post-fertilization. Ceramide-exposed embryos also had primary motoneurons exhibiting abnormal axonal trajectories and ectopic branching. Ceramide induced cell-death was not detected in the zebrafish assay. Collectively, these data indicate that ceramide is a potent anti-angiogenic compound and that the mechanism underlying its anti-angiogenic capabilities does not rely upon the induction of apoptosis.</p

Targeting MicroRNA in Cancer Using Plant-Based Proanthocyanidins

Proanthocyanidins are oligomeric flavonoids found in plant sources, most notably in apples, cinnamon, grape skin and cocoa beans. They have been also found in substantial amounts in cranberry, black currant, green tea, black tea and peanut skins. These compounds have been recently investigated for their health benefits. Proanthocyanidins have been demonstrated to have positive effects on various metabolic disorders such as inflammation, obesity, diabetes and insulin resistance. Another upcoming area of research that has gained widespread interest is microRNA (miRNA)-based anticancer therapies. MicroRNAs are short non-coding RNA segments, which plays a crucial role in RNA silencing and post-transcriptional regulation of gene expression. Currently, miRNA based anticancer therapies are being investigated either alone or in combination with current treatment methods. In this review, we summarize the current knowledge and investigate the potential of naturally occurring proanthocyanidins in modulating miRNA expression. We will also assess the strategies and challenges of using this approach as potential cancer therapeutics

Bioavailability and hypolipidemic effects of peanut skin polyphenols

Peanut skin is a rich source of polyphenols, such as proanthocyanidins. Peanut skin proanthocyanidins mainly consist of a subgroup called procyanidins. Peanut-based procyanidins contain oligomers of both type A and type B procyanidins. Recent studies have shown that peanut skin extracts exert protection against hepatic steatosis induced on rats fed with a high-fat diet. Studies have shown that proanthocyanidins protect against cardiovascular diseases (CVDs). The mechanism of CVD protection and hypolipidemic effect of peanut skin procyanidins has been gradually revealed in recent years. Due to the high molecular weight of procyanidins, they are not readily absorbed through the gut barrier. It is hypothesized that procyanidins exert their effect by inhibiting the absorption of dietary lipid and chylomicron secretion by enterocytes. In this review, we aim to highlight the hypolipidemic effects of peanut skin polyphenols and discuss the various molecular mechanisms, with which the polyphenols may exert the lipid-lowering function observed by weighing the absorption characteristics as well as gene expression mechanism responsible for lipid homeostasis

Disruption of the Murine Protein Kinase Cβ Gene Promotes Gallstone Formation and Alters Biliary Lipid and Hepatic Cholesterol Metabolism*

The protein kinase C (PKC) family of Ca2+ and/or lipid-activated serine-threonine protein kinases is implicated in the pathogenesis of obesity and insulin resistance. We recently reported that protein kinase Cβ (PKCβ), a calcium-, diacylglycerol-, and phospholipid-dependent kinase, is critical for maintaining whole body triglyceride homeostasis. We now report that PKCβ deficiency has profound effects on murine hepatic cholesterol metabolism, including hypersensitivity to diet-induced gallstone formation. The incidence of gallstones increased from 9% in control mice to 95% in PKCβ−/− mice. Gallstone formation in the mutant mice was accompanied by hyposecretion of bile acids with no alteration in fecal bile acid excretion, increased biliary cholesterol saturation and hydrophobicity indices, as well as hepatic p42/44MAPK activation, all of which enhance susceptibility to gallstone formation. Lithogenic diet-fed PKCβ−/− mice also displayed decreased expression of hepatic cholesterol-7α-hydroxylase (CYP7A1) and sterol 12α-hydroxylase (CYP8b1). Finally, feeding a modified lithogenic diet supplemented with milk fat, instead of cocoa butter, both increased the severity of and shortened the interval for gallstone formation in PKCβ−/− mice and was associated with dramatic increases in cholesterol saturation and hydrophobicity indices. Taken together, the findings reveal a hitherto unrecognized role of PKCβ in fine tuning diet-induced cholesterol and bile acid homeostasis, thus identifying PKCβ as a major physiological regulator of both triglyceride and cholesterol homeostasis