Dietary Polyacetylenic Oxylipins Falcarinol and Falcarindiol Prevent Inflammation and Colorectal Neoplastic Transformation: A Mechanistic and Dose-Response Study in A Rat Model.

Falcarinol (FaOH) and falcarindiol (FaDOH) are cytotoxic and anti-inflammatory polyacetylenic oxylipins, which are commonly found in the carrot family (Apiaceae). FaOH and FaDOH have previously demonstrated a chemopreventive effect on precursor lesions of colorectal cancer (CRC) in azoxymethane (AOM)-induced rats. The purpose of the present study was to elucidate possible mechanisms of action for the preventive effect of FaOH and FaDOH on colorectal precancerous lesions and to determine how this effect was dependent on dose. Gene expression studies performed by RT-qPCR of selected cancer biomarkers in tissue from biopsies of neoplastic tissue revealed that FaOH and FaDOH downregulated NF-κß and its downstream inflammatory markers TNFα, IL-6, and COX-2. The dose-dependent anti-neoplastic effect of FaOH and FaDOH in AOM-induced rats was investigated in groups of 20 rats receiving a standard rat diet (SRD) supplemented with 0.16, 0.48, 1.4, 7 or 35 µg FaOH and FaDOH g-1 feed in the ratio 1:1 and 20 rats were controls receiving only SRD. Analysis of aberrant crypt foci (ACF) showed that the average number of small ACF (<7 crypts) and large ACF (>7 crypts) decreased with increasing dose of FaOH and FaDOH and that this inhibitory effect on early neoplastic formation of ACF was dose-dependent, which was also the case for the total number of macroscopic neoplasms. The CRC protective effects of apiaceous vegetables are mainly due to the inhibitory effect of FaOH and FaDOH on NF-κB and its downstream inflammatory markers, especially COX-2.

Fast cleavage of phycocyanobilin from phycocyanin for use in food colouring.

Phycocyanins from cyanobacteria are possible sources for new natural blue colourants. Their chromophore, phycocyanobilin (PCB), was cleaved from the apoprotein by solvolysis in alcohols and alcoholic aqueous solutions. In all cases two PCB isomers were obtained, while different solvent adducts were formed upon the use of different reagents. The reaction is believed to take place via two competing pathways, a concerted E2 elimination and a SN2 nucleophilic substitution. Three cleavage methods were compared in terms of yield and purity: conventional reflux, sealed vessel heated in an oil bath, and microwave assisted reaction. The sealed vessel method is a new approach for fast cleavage of PCB from phycocyanin and gave at 120°C the same yield within 30min compared to 16h by the conventional reflux method (P<0.05). In addition the sealed vessel method resulted in improved purity compared to the other methods. Microwave irradiation increased product degradation.

Effect of resveratrol on experimental non-alcoholic fatty liver disease depends on severity of pathology and timing of treatment.

BACKGROUND AND AIM: Non-alcoholic steatohepatitis (NASH) is a leading cause of chronic liver disease with few therapeutic options. Resveratrol (RSV) prevents the development of steatosis in a number of experimental fatty liver (non-alcoholic fatty liver [NAFL]) models, but the preventive or therapeutic effects on experimental NASH are not yet clarified, and clinical results on non-alcoholic fatty liver disease are ambiguous. Thus, we aimed to compare the RSV-mediated preventive and therapeutic effects on experimental NAFL and NASH. METHODS: We used a high-fat (HF) diet to generate a rat NAFL model and a high-fat, high-cholesterol (HFC) diet to generate a rat NASH model. The preventive and therapeutic potential of RSV was tested by adding RSV to the HF and HFC diet from study start or after 1 week of the diets. Animals were sacrificed after 8 weeks with appropriate controls. Blood and liver were harvested for analysis, including measurement of RSV metabolites. RESULTS: Resveratrol reduced the development of histological steatosis (P = 0.03) and partly triglyceride accumulation (fold change reduced from 3.6 to 2.4, P = 0.08) in the male NAFL model, although effects were moderate. In NASH prevention, RSV reduced the accumulation of triglyceride in hepatic tissue (P < 0.01), while there was no effect on biochemical, histopathological, or transcriptional NASH changes. Further, RSV had no therapeutic effect on established NASH. We found RSV metabolites but no parent RSV in serum or liver tissue, confirming low bioavailability. CONCLUSIONS: These experimental findings suggest that a weak hepatic benefit of RSV treatment is seen in prevention of steatosis only.