Protein and Peptide Letters - Volume 24, Issue 5, 2017

The harmful effects of mycotoxins on intestinal health have received worldwide attention. Mycotoxins are toxic secondary metabolites produced by filamentous fungi, and include aflatoxins, ochratoxins, patulin, fumonisins, zearalenone, trichothecenes, and ergot alkaloids. Insuring the absence or low levels of mycotoxins is critical for food and feed safety. Currently, the studies in this field have illuminated the adverse effects of mycotoxins on gut health including intestinal integrity and the gut-associated immune system. By affecting the proteins and peptides that serve vital functions in the immune system and host metabolism, mycotoxins are able to attack intestinal epithelium, which leads to poor intestinal health and integrity. This review focuses on the effects of exposure to mycotoxins on the intestinal barrier, especially the gut microbiome, intestinal local immune system, and tight junction proteins, which in return influence digestion, absorption, metabolism and transport of the nutrients in intestinal lumen. The crucial role of mycotoxins on microbial metabolism and antimicrobial properties is also assessed, which elucidates the relationship between exposure to mycotoxins and the intestinal microbiome. We hypothesize that the key small peptides and proteins regulate the causal relationship between mycotoxins and gut microbiome.

It was explored that CYP1 family of cytochromes P450 were over-expressed in several types of cancer. Our study aimed to characterize anti-proliferative activity and metabolism of the natural flavonoid diosmetin in the human hepatoma cell HepG2, expressing CYP1 family. Diosinduced cell apoptosis could be reversed due to p53 blockade and the cellular P53 and CYP1A1/CYP1A2 proteins levels were examined. P53 and CYP1A1/CYP1A2 proteins were upregulated by Dios; when PFT-α was added into cells, the P53 levels were down-regulated accompanied with up-regulated CYP1A1/CYP1A2. Meanwhile, when cells were co-treated with Dios and PFT-α, P53 was down-regulated and CYP1A1/CYP1A2 up-regulated controlled with that of Dios treated cells. The data reveal the new evidence that cytochrome P450 CYP1A regulation by P53 enzyme plays an important role in Diosmetin anti-cancer activity of HepG2 cells.

Natural antineoplastic drug development is crucial to treatment of clinical oncology. Dihydromyricetin, a bioactive flavonoid compound was extracted from the stems and leaves of Ampelopsis grossedentata. It exhibited anticancer activity and induced apoptosis in human hepatocellular carcinoma cells according to our previous studies. In this study, we demonstrated that DHM could significantly inhibit proliferation and induce apoptosis in HepG2 cells with MTT and Flow Cytometry methods. It is very interesting that we found DHM could regulate TGF-β signal pathway and which has a crosstalk with P53, Smad3 and P-Smad2/3 proteins. Meanwhile, we confirmed that DHM showed antitumor activity by regulating the activation of the p53-dependent pathways (MDM2, P-MDM2, BAX and Bcl-2). These findings defined and supported a novel mechanism that DHM could induce cell apoptosis by reducing TGF-β via p53 signal pathway in HepG2 cells.

This study aimed to evaluate the effect of temperature and dietary fat level on growth performance, heat production, nutrient oxidation and nitrogen balance in growing pigs. Thirty-two pigs (Duroc x Landrace x Large White) with initial weight of 25±1.91 kg were assigned to treatments in 2x4 factorial design. All pigs were fed with two isoenergetic and isoproteic diets of different fat levels (low fat level: 3.68% fat of dry matter (DM) and high fat level: 8.39% fat of DM) under four environmental temperatures (23, 18, 13 and 8 ºC). Heat production (HP) and nutrient oxidation were calculated from gas exchange via measurement with respiration chambers. The results showed that there was no interaction effect on growth performance by the temperature and dietary fat level. The average daily feed intake (ADFI) was lower (P < 0.001), the average daily gain (ADG) was higher (P < 0.001) and feed utilization was more efficient at 23 ºC than 13 and 8 ºC (P < 0.001). Dietary fat had no effect on growth performance and feed utilization at the four different temperatures. A significant interaction (P < 0.001) between temperature and dietary fat level on oxidation of carbohydrate (OXCHO) and fat (OXF) was observed. HP, OXF and OXCHO were significantly increased (P < 0.001) as environment temperatures decreased. Increasing dietary fat generated an increase in the OXF and decrease in the OXCHO (P < 0.001). No significant difference was observed in protein oxidation (OXP) of two factors. The intakes of nitrogen, nitrogen excretion in feces (FN) and urine (UN) by the pigs kept in 8 ºC environment were highest. Nitrogen digestibility decreased as environmental temperature decreased, with the most efficient gains obtained at 23 ºC. However, nitrogen retention was not influenced by environmental temperature. Dietary fat level did not affect nitrogen balance. No significant interaction between temperature and dietary fat level was observed for nitrogen balance. These results indicated that the rate of growth and nutrition utilization in pigs fed ad libitum are influenced by the environmental temperatures in which they are maintained, and the oxidation of nutrition utilization of the pig to different environmental temperatures is altered by the dietary fat supplementation.

Antibodies have become the preferred therapeutic treatment option for cancers. Antibody therapy is associated with low toxic profile and specific in its activity, unlike chemotherapy and radiotherapy. Types of tumor are known to express multiple receptors that cross-talk to activate perpetual growth, proliferation and metastasis, and inhibit apoptosis in such tumors. Bispecific antibodies (BsAbs) are therefore the preferred agent for the treatment of such cancers due to its unique characteristics. This review discusses up to date therapeutic potentials of BsAbs.

The aim of the present study was to examine the potential role and applicability of dietary supplements in reducing the risk of development of amyloid diseases associated with the gastrointestinal tract, such as type II diabetes. Trypsin, a well-known serine protease was used as a model protein in our experiments. The effect of various red wines on the formation of amyloid-like fibrils of trypsin was studied in vitro, in aqueous ethanol, at pH 7.0. Turbidity measurements, aggregation kinetics experiments, Congo red binding assays and electronic circular dichroism spectroscopic measurements were used to follow the aggregation process in the presence or absence of various red wines. The results suggest that red wines effectively inhibit the formation of amyloid-like fibrils of trypsin and the inhibitory effect is dose-dependent. The extent of inhibition was found to be proportional to the total concentration of phenolic compounds.