Correction to: Effect of wheat germ on metabolic markers: a systematic review and meta-analysis of randomized controlled trials.

[This corrects the article DOI: 10.1007/s10068-020-00769-9.].

Quantification of lactoferrin in human milk using monolithic cation exchange HPLC.

Human lactoferrin (hLF) is one of the most important whey proteins in human milk, known for its ability to modulate innate host immunity and multifunctional activities for neonatal growth. The objective of this study was to validate an efficient method for the detection and quantification of hLF using a unique technology of cation-exchange high-performance liquid chromatography (HPLC) on CIM® monolithic columns. Human milk samples were collected using manual expression or a breast pump, at different weeks of lactation. After sample preparation, hLF was detected and measured by HPLC method and further confirmed by SDS-PAGE. Selected fractions were analysed also by LC-MS/MS. Presumably, due to the high density of positive charge on the surface of the N-terminal domain, hLF binds strongly to the column and elutes last, enabling the high specificity of this method. The LC-MS/MS analysis indicated that hLF eluted in two clearly separated peaks, presumably representing two different molecular species of hLF. hLF concentration in the human milk samples ranged from 2.03 mg/mL to 5.79 mg/mL and was not significantly affected by the sample collection method whereas it was negatively correlated with the stage of lactation. These results suggest that cation exchange chromatography is an accurate, efficient, and robust method for the detection and quantification of hLF.

Antidepressive Effect of Natural Products and Their Derivatives Targeting BDNF-TrkB in Gut-Brain Axis.

Modern neurological approaches enable detailed studies on the pathophysiology and treatment of depression. An imbalance in the microbiota-gut-brain axis contributes to the pathogenesis of depression. This extensive review aimed to elucidate the antidepressive effects of brain-derived neurotrophic factor (BDNF)-targeting therapeutic natural products and their derivatives on the gut-brain axis. This information could facilitate the development of novel antidepressant drugs. BDNF is crucial for neuronal genesis, growth, differentiation, survival, plasticity, and synaptic transmission. Signaling via BDNF and its receptor tropomyosin receptor kinase B (TrkB) plays a vital role in the etiopathogenesis of depression and the therapeutic mechanism of antidepressants. This comprehensive review provides information to researchers and scientists for the identification of novel therapeutic approaches for neuropsychiatric disorders, especially depression and stress. Future research should aim to determine the possible causative role of BDNF-TrkB in the gut-brain axis in depression, which will require further animal and clinical research as well as the development of analytical approaches.

Neuroprotective Natural Products' Regulatory Effects on Depression via Gut-Brain Axis Targeting Tryptophan.

L-tryptophan (Trp) contributes to regulating bilateral communication of the gut-brain axis. It undergoes three major metabolic pathways, which lead to formation of kynurenine, serotonin (5-HT), and indole derivatives (under the control of the microbiota). Metabolites from the principal Trp pathway, kynurenic acid and quinolinic acid, exhibit neuroprotective activity, while picolinic acid exhibits antioxidant activity, and 5-HT modulates appetite, sleep cycle, and pain. Abnormality in Trp plays crucial roles in diseases, including depression, colitis, ulcer, and gut microbiota-related dysfunctions. To address these diseases, the use of natural products could be a favorable alternative because they are a rich source of compounds that can modulate the activity of Trp and combat various diseases through modulating different signaling pathways, including the gut microbiota, kynurenine pathway, and serotonin pathway. Alterations in the signaling cascade pathways via different phytochemicals may help us explore the deep relationships of the gut-brain axis to study neuroprotection. This review highlights the roles of natural products and their metabolites targeting Trp in different diseases. Additionally, the role of Trp metabolites in the regulation of neuroprotective and gastroprotective activities is discussed. This study compiles the literature on novel, potent neuroprotective agents and their action mechanisms in the gut-brain axis and proposes prospective future studies to identify more pharmaceuticals based on signaling pathways targeting Trp.

Antioxidant Effect of Wheat Germ Extracts and Their Antilipidemic Effect in Palmitic Acid-Induced Steatosis in HepG2 and 3T3-L1 Cells.

Wheat germ (WG) is a by-product of wheat milling and comprises many bioactive compounds. This study aimed to compare the antioxidant and antilipidemic effects of different WG extracts (WGEs) by analyzing candidate bioactive compounds such as carotenoids, tocopherols, γ-oryzanol, and biogenic amines by reversed-phase high-performance liquid chromatography. Antioxidant activity was determined using the ABTS, DPPH, and FRAP assays. The antilipidemic effect was evaluated in palmitic acid-induced steatosis in HepG2 hepatocytes and 3T3-L1 adipocytes. Cellular lipid accumulation was assessed by Oil Red O staining and a cellular triglyceride content assay. All analyzed WGEs showed significant antioxidant potential, although some bioactive compounds, such as carotenoids, tocopherols, and γ-oryzanol, were the highest in the ethanol extract. Correlation analysis revealed the antioxidant potential of all identified biogenic amines except for spermidine. Ethanol and n-hexane extracts significantly inhibited cellular lipid accumulation in cell models. These results suggest that WGEs exhibit promising antioxidant potential, with a variety of bioactive compounds. Collectively, the findings of this study suggest that bioactive compounds in WGEs attenuate plasma lipid and oxidation levels. In conclusion, WG can be used as a natural antioxidant and nutraceutical using appropriate solvents and extraction methods.

Millet: A review of its nutritional and functional changes during processing.

Millets are a major source of human food, and their production has been steadily increasing in the last decades to meet the dietary requirements of the increasing world population. Millets are an excellent source of all essential nutrients like protein, carbohydrates, fat, minerals, vitamins, and bioactive compounds. However, the nutrients, bioactive compounds, and functions of cereal grains can be influenced by the food preparation techniques such as decortication/dehulling, soaking, germination/malting, milling, fermentation, etc. This study discusses the nutritional and functional changes in millet during different traditional/modern processing techniques, based on more than 100 articles between 2013 and 2020 from Web of Science, Google Scholar, FAO, and USDA databases. Our results concluded that processing techniques could be useful to combat undernourishment and other health issues. Moreover, this review provides detailed information about millet processing, which is advantageous for industry, consumers, and researchers in this area.

Effect of wheat germ on metabolic markers: a systematic review and meta-analysis of randomized controlled trials.

This systematic review and meta-analysis aim to evaluate the association of wheat germ interventions and metabolic markers. An electronic search was performed by mid-May 2019 in the PubMed, Google Scholar, and Web of Science databases. Quality was evaluated using the risk of bias assessment tools. Thirty-three randomized controlled trials (RCTs) were identified, among which ten were suitable and systematically reviewed based on biomarkers (cholesterol, triglycerides, glucose, and oxidative stress). Three biomarkers in five eligible studies were investigated by meta-analysis. Total cholesterol showed non-significant results (p = 0.98), with standard mean difference (SMD) of - 0.01 (95% confidence interval; - 0.17, 0.16). The SMD was - 0.06 (95% CI - 0.41, 0.29, n = 4) for triglycerides and - 0.09 (95% CI - 0.62, 0.45, n = 2) for glucose. No biomarkers showed heterogeneity (0%). This review revealed non-significant association between wheat germ interventions and metabolic markers. Sensitive analysis with high-quality RCTs may be worth trying.