Exploring Molecular Insights of Cereal Peptidic Antioxidants in Metabolic Syndrome Prevention

Fractionation and characterisation of sialylated-mucin glycoprotein from edible birds' nest hydrolysates through anion exchange chromatography

Edible bird's nest (EBN) is made up of sialylated-mucin glycoprotein with various health benefits due to its high antioxidative activity. However, as a macromolecule with distinct charged sialic acid and amino acids, fractions with different charges would have varied physicochemical properties and antioxidant activity, which have not been studied. Therefore, this study aimed to fractionate and purify the enzymatic hydrolysed of cleaned EBN (EBNhc) and EBN by-product (EBNhbyp) through anion exchange chromatography (AEC), and determine their molecular weights, physicochemical properties, and antioxidative activities. Overall, 26 fractionates were collected from enzymatic hydrolysate by AEC, which were classified into 5 fractions. It was found that the positively charged fraction of EBNhc (CF 1) and EBNhbyp (DF 1) showed the significantly highest (p < 0.05) soluble protein contents (22.86 and 18.40 mg/g), total peptide contents (511.13 and 800.47 mg/g) and ferric reducing antioxidant power (17.44 and 6.96 mg/g) among the fractionates. In conclusion, a positively charged fraction (CF 1 and DF 1) showed more desired physicochemical properties and antioxidative activities. This research suggests the potential of AEC fractionation as a technology to purify EBN and produce positively charged EBN fractionates with antioxidative potential that could be applied as food components to provide health benefits.

Improving the Treatment Effect of Carotenoids on Alzheimer's Disease through Various Nano-Delivery Systems

Natural bioactive compounds have recently emerged as a current strategy for Alzheimer's disease treatment. Carotenoids, including astaxanthin, lycopene, lutein, fucoxanthin, crocin and others are natural pigments and antioxidants, and can be used to treat a variety of diseases, including Alzheimer's disease. However, carotenoids, as oil-soluble substances with additional unsaturated groups, suffer from low solubility, poor stability and poor bioavailability. Therefore, the preparation of various nano-drug delivery systems from carotenoids is a current measure to achieve efficient application of carotenoids. Different carotenoid delivery systems can improve the solubility, stability, permeability and bioavailability of carotenoids to a certain extent to achieve Alzheimer's disease efficacy. This review summarizes recent data on different carotenoid nano-drug delivery systems for the treatment of Alzheimer's disease, including polymer, lipid, inorganic and hybrid nano-drug delivery systems. These drug delivery systems have been shown to have a beneficial therapeutic effect on Alzheimer's disease to a certain extent.

Millet Bran Protein Hydrolysate Displays the Anti-non-alcoholic Fatty Liver Disease Effect via Activating Peroxisome Proliferator-Activated Receptor γ to Restrain Fatty Acid Uptake

Non-alcoholic fatty liver disease (NAFLD) is a serious health problem worldwide. Impeding fatty acid uptake may be an attractive therapeutic strategy for NAFLD. In the current study, we found that millet bran protein hydrolysate (MBPH) prepared by in vitro gastrointestinal bionic digestion exhibits the potential of anti-NAFLD in vitro and in vivo, characterized by the alleviation of hepatic steatosis and the reduction of lipid accumulation. Further, MBPH significantly decreased the expression levels of fatty acid uptake related genes (FABP1, FABP2, FABP4, CD36, and CPT-1α) of liver tissue in a NAFLD mice model through activating peroxisome proliferator-activated receptor γ (PPARγ) and efficiently restrained the fatty acid uptake of liver tissue, thus exerting anti-NAFLD activity. As expected, the anti-NAFLD effect induced by MBPH, characterized by the alleviation of hepatic vacuolar degeneration, hepatic steatosis, and fibrosis, was effectively abrogated with PPARγ inhibitor (GW9662) treatment. These results indicate that the retardant of fatty acid uptake induced by PPARγ activation may be the critical factor for the anti-NAFLD effect of MBPH. Collectively, MBPH has the potential as a next-generation dietary supplementation for the prevention and treatment of NAFLD.

Simultaneous effect of different chromatographic conditions on the chromatographic retention of pentapeptide derivatives (HGRFG and NPNPT)

Introduction: Oligopeptides exhibit great prospects for clinical application and its separation is of great importance in new drug development. Methods: To accurately predict the retention of pentapeptides with analogous structures in chromatography, the retention times of 57 pentapeptide derivatives in seven buffers at three temperatures and four mobile phase compositions were measured via reversed-phase high-performance liquid chromatography. The parameters ( k H A , k A , and p K a ) of the acid-base equilibrium were obtained by fitting the data corresponding to a sigmoidal function. We then studied the dependence of these parameters on the temperature (T), organic modifier composition (φ, methanol volume fraction), and polarity ( P m N parameter). Finally, we proposed two six-parameter models with (1) pH and T and (2) pH and φ or P m N as the independent variables. These models were validated for their prediction capacities by linearly fitting the predicted retention factor k-value and the experimental k-value. Results: The results showed that log k H A and log k A exhibited linear relationships with 1 / T , φ or P m N for all pentapeptides, especially for the acid pentapeptides. In the model of pH and T, the correlation coefficient (R²) of the acid pentapeptides was 0.8603, suggesting a certain prediction capability of chromatographic retention. Moreover, in the model of pH and φ or P m N , the R² values of the acid and neutral pentapeptides were greater than 0.93, and the average root mean squared error was approximately 0.3, indicating that the k-values could be effectively predicted. Discussion: In summary, the two six-parameter models were appropriate to characterize the chromatographic retention of amphoteric compounds, especially the acid or neutral pentapeptides, and could predict the chromatographic retention of pentapeptide compounds.

RLIP: A necessary transporter protein for translating oxidative stress into pro-obesity and pro-carcinogenic signaling

Previously, we showed that knockout mice homozygous for deficiency of the mercapturic acid pathway (MAP) transporter protein, RLIP (RLIP^-/-), are resistant to chemical carcinogenesis, inflammation, and metabolic syndrome (MetS). We also found that RLIP^-/- mice are highly resistant to obesity caused by a high-fat diet (HFD). Interestingly, these studies showed that kinase, cytokine, and adipokine signaling that are characteristics of obesity were blocked despite the presence of increased oxidative stress in RLIP^-/- mice. The deficiencies in obesity-inducing kinase, cytokine, and adipokine signaling were attributable to a lack of clathrin-dependent endocytosis (CDE), a process that is severely deficient in RLIP^-/- mice. Because CDE is also necessary for carcinogenic signaling through EGF, WNT, TGFβ and other cancer-specific peptide hormones, and because RLIP^-/- mice are cancer-resistant, we reasoned that depletion of RLIP by an antisense approach should cause cancer regression in human cancer xenografts. This prediction has been confirmed in studies of xenografts from lung, kidney, prostate, breast, and pancreatic cancers and melanoma. Because these results suggested an essential role for RLIP in carcinogenesis, and because our studies have also revealed a direct interaction between p53 and RLIP, we reasoned that if RLIP played a central role in carcinogenesis, that development of lymphoma in p53^-/- mice, which normally occurs by the time these mice are 6 months old, could be delayed or prevented by depleting RLIP. Recent studies described herein have confirmed this hypothesis, showing complete suppression of lymphomagenesis in p53^-/- mice treated with anti-RLIP antisense until the age of 8 months. All control mice developed lymphoma in the thymus or testis as expected. These findings lead to a novel paradigm predicting that under conditions of increased oxidative stress, the consequent increased flux of metabolites in the MAP causes a proportional increase in the rate of CDE. Because CDE inhibits insulin and TNF signaling but promotes EGF, TGFβ, and Wnt signaling, our model predicts that chronic stress-induced increases in RLIP (and consequently CDE) will induce insulin-resistance and enhance predisposition to cancer. Alternatively, generalized depletion of RLIP would antagonize the growth of malignant cells, and concomitantly exert therapeutic insulin-sensitizing effects. Therefore, this review focuses on how targeted depletion or inhibition of RLIP could provide a novel target for treating both obesity and cancer.

Therapeutic promise of carotenoids as antioxidants and anti-inflammatory agents in neurodegenerative disorders

Neurodegenerative disorders (NDs) including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, Huntington's disease, and multiple sclerosis have various disease-specific causal factors and pathological features. A very common characteristic of NDs is oxidative stress (OS), which takes place due to the elevated generation of reactive oxygen species during the progression of NDs. Furthermore, the pathological condition of NDs including an increased level of protein aggregates can further lead to chronic inflammation because of the microglial activation. Carotenoids (CTs) are naturally occurring pigments that play a significant role in averting brain disorders. More than 750 CTs are present in nature, and they are widely available in plants, microorganisms, and animals. CTs are accountable for the red, yellow, and orange pigments in several animals and plants, and these colors usually indicate various types of CTs. CTs exert various bioactive properties because of its characteristic structure, including anti-inflammatory and antioxidant properties. Due to the protective properties of CTs, levels of CTs in the human body have been markedly linked with the prevention and treatment of multiple diseases including NDs. In this review, we have summarized the relationship between OS, neuroinflammation, and NDs. In addition, we have also particularly focused on the antioxidants and anti-inflammatory properties of CTs in the management of NDs.

Raman Fingerprints of Rice Nutritional Quality: A Comparison between Japanese Koshihikari and Internationally Renowned Cultivars

Raman spectroscopy was applied to characterize at the molecular scale the nutritional quality of the Japanese Koshihikari rice cultivar in comparison with other renowned rice cultivars including Carnaroli from Italy, Calrose from the USA, Jasmine rice from Thailand, and Basmati from both India and Pakistan. For comparison, two glutinous (mochigome) cultivars were also investigated. Calibrated and validated Raman analytical algorithms allowed quantitative determinations of: (i) amylopectin and amylose concentrations, (ii) fractions of aromatic amino acids, and (iii) protein content and secondary structure. The Raman assessments non-destructively linked the molecular composition of grains to key nutritional parameters and revealed a complex intertwine of chemical properties. The Koshihikari cultivar was rich in proteins (but with low statistical relevance as compared to other investigated cultivars) and aromatic amino acids. However, it also induced a clearly higher glycemic impact as compared to long-grain cultivars from Asian countries. Complementary to genomics and wet-chemistry analyses, Raman spectroscopy makes non-destructively available factual and data-driven information on rice nutritional characteristics, thus providing customers, dietitian nutritionists, and producers with a solid science-consolidated platform.