Fermentation enhances the in vitro antioxidative effect of onion (Allium cepa) via an increase in quercetin content

Liquid submerged fermentation by selected microbial strains for onion skins valorization and its effects on polyphenols

Onion skins, actually recycled as organic fertilizers, could be used as a substrate in environmental-friendly bioprocesses to recover high-value bioactive compounds and food ingredients.In this work, a bioprospecting method was carried out including 94 bacterial and 45 yeast strains from several agri-food and environmental niches to verify their ability to grow on onion skins as unique nutrients source.Red and yellow onion skins were assessed by newly selected starter-driven liquid submerged fermentation assays mainly aimed at the release and modification of polyphenols through microbial activities. Fermented onion skins were also investigated as a inexpensive favourable source of microbial enzymes (amylases, proteases, lipases, esterases, cellulases, xylanases).In red onion skins, the treatment with Lactiplantibacillus plantarum TB 11-32 produced a slight increase of bioactive compounds in terms of total phenolics, whereas with the yeast strain Zygosaccharomyces mrakii CL 30 - 29 the quercetin aglycone content increased of about 25% of the initial raw material.In yellow onion skins inoculated, the highest content of phenolic compounds was detected with the yeast strain Saccharomyces cerevisiae En SC, while quercetin aglycone increased of about 60% of the initial raw material in presence of the bacterial strain L. plantarum C 180 - 34.In conclusion, the proposed microbial pre-treatment method can be a potential strategy to re-use onion skins as a fermentation substrate, and as a first step in the development of a biorefinery process to produce value-added products from onion by-products.

Bioconverted Fruit Extract of Akebia Quinata Exhibits Anti-Obesity Effects in High-Fat Diet-Induced Obese Rats

Akebia quinata, commonly called chocolate vine, has various bioactivities, including antioxidant and anti-obesity properties. However, the anti-obesity effects of bioconverted extracts of A. quinate have not been examined. In this study, A. quinata fruit extracts was bioconverted using the enzyme isolated from the soybean paste fungi Aspergillus kawachii. To determine whether the bioconversion process could influence the anti-obesity effects of A. quinata fruit extracts, we employed 3T3-L1 adipocytes and HFD-induced obese rats. We observed that the bioconverted fruit extract of A. quinata (BFE) afforded anti-obesity effects, which were stronger than that for the non-bioconverted fruit extract (FE) of A. quinata. In 3T3-L1 adipocytes, treatment with BFE at concentrations of 20 and 40 μg reduced intracellular lipids by 74.8 (p < 0.05) and 54.9% (p < 0.01), respectively, without inducing cytotoxicity in preadipocytes. Moreover, the oral administration of BFE at the concentration of 300 mg/kg/day significantly reduced body and adipose tissue weights (p < 0.01) in HFD-induced obese rats. Plasma cholesterol values were reduced, whereas HDL was increased in BFE receiving rats. Although FE could exert anti-obesity effects, BFE supplementation induced more robust effects than FE. These results could be attributed to the bioconversion-induced alteration of bioactive compound content within the extract.

Tryptamine, a Microbial Metabolite in Fermented Rice Bran Suppressed Lipopolysaccharide-Induced Inflammation in a Murine Macrophage Model

Fermentation is thought to alter the composition and bioavailability of bioactive compounds in rice bran. However, how this process affects the anti-inflammatory effects of rice bran and the bioactive compounds that might participate in this function is yet to be elucidated. This study aimed to isolate bioactive compounds in fermented rice bran that play a key role in its anti-inflammatory function. The fermented rice bran was fractionated using a succession of solvent and solid-phase extractions. The fermented rice bran fractions were then applied to lipopolysaccharide (LPS)-activated murine macrophages to evaluate their anti-inflammatory activity. The hot water fractions (FRBA), 50% ethanol fractions (FRBB), and n-hexane fractions (FRBC) were all shown to be able to suppress the pro-inflammatory cytokine expression from LPS-stimulated RAW 264.7 cells. Subsequent fractions from the hot water fraction (FRBF and FRBE) were also able to reduce the inflammatory response of these cells to LPS. Further investigation revealed that tryptamine, a bacterial metabolite of tryptophan, was abundantly present in these extracts. These results indicate that tryptamine may play an important role in the anti-inflammatory effects of fermented rice bran. Furthermore, the anti-inflammatory effects of FRBE and tryptamine may depend on the activity of the aryl hydrocarbon receptor.

Anti-hypercholesterolemic activity of standardized fermented Allium cepa L. var aggregatum extract: In vitro and in vivo studies

Introduction: Allium cepa extract has been reported to have anti-hypercholesterolemic activity in rats. This study was conducted to investigate the effects of standardized fermented A. cepa L. var aggregatum extract on cholesterol levels and HMG-CoA reductase enzyme. Methods: The fermented A. cepa extract was standardized by the presence of quercetin using a validated high performance liquid chromatography (HPLC) method. The activity of the extract on HMG-CoA reductase was determined using HMG-CoA Assay kits, then measured by Nano spectrophotometry. In vivo study was conducted in hypercholesterolemic rats. The extract was administered orally at doses of 100, 200, and 300 mg/kg body weight (bw) to rats for 21 days and the cholesterol levels were measured every week. Results: All doses of fermented A. cepa extract and its marker compound, quercetin, ameliorated the levels of high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) as compared to those of negative control (P<0.05). Of all the doses, fermented A. cepa extract at the dose of 200 mg/kg bw displayed the highest reduction in LDL-C levels. In addition, the extract at the dose of 200 mg/kg bw showed the strongest enhancement in HDL-C levels. The fermented A. cepa extract and quercetin also inhibited the HMG-CoA reductase enzyme with inhibitory activity of 61.78%. Conclusion: The ethanol extract of fermented A. cepa shows anti-hypercholesterolemic activity. The strong anti-hypercholesterolemic activity of the extract might be due to the high amounts of quercetin, although other constituents may also contribute.

S-Allyl cysteine in garlic (Allium sativum): Formation, biofunction, and resistance to food processing for value-added product development

S-allyl cysteine (SAC), which is the most abundant bioactive compound in black garlic (BG; Allium sativum), has been shown to have antioxidant, anti-apoptotic, anti-inflammatory, anti-obesity, cardioprotective, neuroprotective, and hepatoprotective activities. Sulfur compounds are the most distinctive bioactive elements in garlic. Previous studies have provided evidence that the concentration of SAC in fresh garlic is in the range of 19.0-1736.3 μg/g. Meanwhile, for processed garlic, such as frozen and thawed garlic, pickled garlic, fermented garlic extract, and BG, the SAC content increased to up to 8021.2 μg/g. BG is an SAC-containing product, with heat treatment being used in nearly all methods of BG production. Therefore, strategies to increase the SAC level in garlic are of great interest; however, further knowledge is required about the effect of processing factors and mechanistic changes. This review explains the formation of SAC in garlic, introduces its biological effects, and summarizes the recent advances in processing methods that can affect SAC levels in garlic, including heat treatment, enzymatic treatment, freezing, fermentation, ultrasonic treatment, and high hydrostatic pressure. Thus, the aim of this review was to summarize the outcomes of treatment aimed at maintaining or increasing SAC levels in BG. Therefore, publications from scientific databases in this field of study were examined. The effects of processing methods on SAC compounds were evaluated on the basis of the SAC content. This review provides information on the processing approaches that can assist food manufacturers in the development of value-added garlic products.

Recent advances in research on Allium plants: functional ingredients, physiological activities, and applications in agricultural and food sciences

Fruits and vegetables (FVs) have long been a major source of nutrients and dietary phytochemicals with outstanding physiological properties that are essential for protecting humans from chronic diseases. Moreover, the growing demand of consumers for nutritious and healthy foods is greatly promoting the increased intake of FVs. Allium (Alliaceae) is a perennial bulb plant genus of the Liliaceae family. They are customarily utilized as vegetable, medicinal, and ornamental plants and have an important role in agriculture, aquaculture, and the pharmaceutical industry. Allium plants produce abundant secondary metabolites, such as organosulfur compounds, flavonoids, phenols, saponins, alkaloids, and polysaccharides. Accordingly, Allium plants possess a variety of nutritional, biological, and health-promoting properties, including antimicrobial, antioxidant, antitumor, immunoregulatory, antidiabetic, and anti-inflammatory effects. This review aims to highlight the advances in the research on the bioactive components, physiological activities and clinical trials, toxicological assessment for safety, and applications of different Allium plants. It also aims to cover the direction of future research on the Allium genus. This review is expected to provide theoretical reference for the comprehensive development and utilization of Allium plants in the fields of functional foods, medicine, and cosmetics.

Quercetin: A Bioactive Compound Imparting Cardiovascular and Neuroprotective Benefits: Scope for Exploring Fresh Produce, Their Wastes, and By-Products

Quercetin, a bioactive secondary metabolite, holds incredible importance in terms of bioactivities, which has been proved by in vivo and in vitro studies. The treatment of cardiovascular and neurological diseases by quercetin has been extensively investigated over the past decade. Quercetin is present naturally in appreciable amounts in fresh produce (fruits and vegetables). However, today, corresponding to the growing population and global demand for fresh fruits and vegetables, a paradigm shift and focus is laid towards exploring industrial food wastes and/or byproducts as a new resource to obtain bioactive compounds such as quercetin. Based on the available research reports over the last decade, quercetin has been suggested as a reliable therapeutic candidate for either treating or alleviating health issues, mainly those of cardiovascular and neurological diseases. In the present review, we have summarized some of the critical findings and hypotheses of quercetin from the available databases foreseeing its future use as a potential therapeutic agent to treat cardiovascular and neurological diseases. It is anticipated that this review will be a potential reference material for future research activities to be undertaken on quercetin obtained from fresh produce as well as their respective processing wastes/byproducts that rely on the circular concept.

Phenolic composition and biological activities of stingless bee honey: An overview based on its aglycone and glycoside compounds

Stingless bees are native to tropical and subtropical countries, such as Brazil. The wide variety of species, the sources of food collection (nectar and pollen), and the climate conditions strongly affect the chemical composition of the honey, making this a unique product with peculiar characteristics. Stingless bee honey presents higher water content, higher acidity, and a lower sugar concentration when compared to Apis mellifera honey. Moreover, there is a wide variety of microorganisms in stingless bees' environment, which leads their honey to go through a natural fermentative process during its production in the hive. Besides, fermentation and hydrolysis are effective ways to convert glycosides into aglycones, thus increasing the bioavailability of compounds. In this sense, stingless bee honey may possess a greater concentration of phenolic compounds aglycones than glycosides, which would increase its potential benefits. Therefore, this review aims to compile the most recent studies of stingless bee honey phenolic profile and its biological potential (antioxidant, antimicrobial, and anti-inflammatory activities) and a possible connection to its natural fermentation process.

[Inhibitory effect of Xinhui citrus fermentation liquor on liver fibrosis in mice]

OBJECTIVE

To investigate the inhibitory effect of Xinhui citrus fermentation liquor on liver fibrosis in mice.

OBJECTIVE

Mouse models of liver fibrosis were established by intraperitoneal injection of CCl₄ in 105 male C57BL/6 mice, followed by gavage of 0.1 mL 40% CCl₄ olive oil 3 times a week (model group, n=49) or daily gavage of citrus liquor at the dose of 0.26 mL (citrus liquor group, n=56) for 8 weeks. Seven mice receiving only olive oil treatment (0.1 mL, 3 times a week) and another 7 treated with citrus liquor served as the control group. Liver tissues and serum samples were collected from 7 mice in the citrus liquor group and model group each week and from the mice in the two control groups at the 8th week for pathological examination of the liver tissues using HE staining and Sirius red staining and for determination of the biochemical indexes of liver function.

OBJECTIVE

The mice in the model group showed progressively worsened liver fibrosis with obvious hepatic steatosis, necrosis and inflammatory cell infiltration. These liver pathologies were much ameliorated in citrus liquor group, which showed significantly reduced vacuolation, inflammatory cell infiltration, collagen deposition and the Ishak score of the liver tissue (P < 0.05). Serum levels of cholyglycine, alanine aminotransferase, transglutaminase and alanine aminotransferase were all significantly lower in citrus liquor group than in the model group (P < 0.05).

OBJECTIVE

Xinhui citrus fermentation liquor has protective effect on the liver and can significantly ameliorate liver fibrosis in mice.

Research progress in use of traditional Chinese medicine monomer for treatment of non-alcoholic fatty liver disease

With the improvement of people's living standards and the change of eating habits, non-alcoholic fatty liver disease (NAFLD) has gradually become one of the most common chronic liver diseases in the world. However, there are no effective drugs for the treatment of NAFLD. Therefore, it is urgent to find safe, efficient, and economical anti-NAFLD drugs. Compared with western medicines that possess fast lipid-lowering effect, traditional Chinese medicines (TCM) have attracted increasing attention for the treatment of NAFLD due to their unique advantages such as multi-targets and multi-channel mechanisms of action. TCM monomers have been proved to treat NAFLD through regulating various pathways, including inflammation, lipid production, insulin sensitivity, mitochondrial dysfunction, autophagy, and intestinal microbiota. In particular, peroxisome proliferator-activated receptor α (PPAR-α), sterol regulatory element-binding protein 1c (SREBP-1c), nuclear transcription factor kappa (NF-κB), phosphoinositide 3-kinase (PI3K), sirtuin1 (SIRT1), AMP-activated protein kinase (AMPK), p53 and nuclear factor erythroid 2-related factor 2 (Nrf2) are considered as important molecular targets for ameliorating NAFLD by TCM monomers. Therefore, by searching PubMed, Web of Science and SciFinder databases, this paper updates and summarizes the experimental and clinical evidence of TCM monomers for the treatment of NAFLD in the past six years (2015-2020), thus providing thoughts and prospects for further exploring the pathogenesis of NAFLD and TCM monomer therapies.

Allium Flavonols: Health Benefits, Molecular Targets, and Bioavailability

Allium species are revered worldwide as vegetables, condiments, and spices as well as the therapeutic agents in traditional medicine. The bioactive compounds in alliums mainly include organosulfur compounds, polyphenols, dietary fibers, and saponins. Flavonoids, particularly flavonols from alliums, have been demonstrated to have the antioxidant, anticancer, hypolipidemic, anti-diabetic, cardioprotective, neuroprotective, and antimicrobial activities. However, flavonols are mostly characterized from onions and have not been comprehensively reviewed across different species. This article therefore focuses on flavonol profiles from different Allium species, their health effects, underlying molecular mechanisms, and bioavailability. Intriguingly, the functional health effects of flavonols were mainly ascribed to their antioxidant and anti-inflammatory activities involving a cascade of multiple signaling pathways. Although the Allium-derived flavonols offer tremendous potential in preventing chronic disease risks, in-depth studies are needed to translate their clinical application.

Controlled Fermentation Using Autochthonous Lactobacillus plantarum Improves Antimicrobial Potential of Chinese Chives against Poultry Pathogens

Chinese chives (CC) are rich in several antimicrobial constituents including organosulfur compounds, phenolics, and saponins, among others. Herein, we fermented CC juice using an autochthonous isolate, Lactobacillus plantarum having antimicrobial effects against poultry pathogens toward formulating an antimicrobial feed additive. Following 24 h of fermentation, the antimicrobial and antiviral activities of CC juice were significantly enhanced against poultry pathogens. However, the antioxidant activity of CC juice was significantly decreased following fermentation. Meanwhile, the compositional changes of CC juice following fermentation were also investigated. The total polyphenol, thiol, and allicin contents were significantly decreased in L. plantarum 24 h-fermented CC juice (LpCC) extract; however, total flavonoids increased significantly following fermentation. The untargeted metabolite profiling of nonfermented CC juice (NCC) and LpCC extracts was carried out using the ultra-high-performance liquid chromatography-linear trap quadrupole-orbitrap-tandem mass spectrometry (UHPLC-LTQ-Orbitrap-MS/MS) followed by multivariate analyses. The score plots of principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) based on UHPLC-LTQ-Orbitrap-MS/MS datasets displayed a clear segregation between the LpCC and NCC samples, which suggests their marked metabolomic disparity. Based on the multivariate analysis, we selected 17 significantly discriminant metabolites belonging to the different chemical classes including alkaloid, flavonols, saponins, fatty acids, amino acids, and organic acids. Notably, the flavonols including the glycosides of quercetin, kaempferol, and isorhamnetin as well as the saponins displayed significantly higher relative abundance in LpCC as compared with NCC. This study provides useful insights for the development of a fermented CC juice based antimicrobial feed additive to combat poultry infections.

Effects of a Fermented Beverage of Changbai Mountain Fruit and Vegetables on the Composition of Gut Microbiota in Mice

Evidence suggests that fermented foods and beverages made from fruits and vegetables benefit human health, including in the prevention of cardiovascular disease, cancer, diabetes and gastrointestinal disorders. However, there are few studies on the effects of fermented fruits and vegetables on intestinal microbiota. In this study, we investigated the changes in the composition of the intestinal microbial community after short-term treatment with a fermented beverage of Changbai Mountain fruit and vegetables (FB). Forty male ICR mice, weighing 17-19 g, were fed diets with different concentrations of the FB or distilled water for 15 days. 16S rDNA gene sequences were used to analyze the gut microbiota with the Illumina sequencing platform and a paired-end method. FB had no effect on weight gain, the adiposity index, or food intake in the treated mice compared with the control group. The cecal index was significantly higher in the FB-administered groups than in the control group. Firmicutes and Bacteroidetes were the dominant phyla in the mice ceca. The Firmicutes/Bacteroidetes ratio was reduced in the FB-administered mice, and proportions of the family Prevotellaceae, Bacteroidales_S24-7_group, family Bacteroidaceae, and genus Bacteroides increased, and these increases were correlated positively with intake of fermented beverage. The FB also altered the diversity of the cecal microbiota in the mice. Graphical Abstract.

The Genus Allium as Poultry Feed Additive: A Review

The genus Allium, belonging to the family Amaryllidaceae has been known since ancient times for their therapeutic potentials. As the number of multi-drug resistant infections has increased due to in-feed antibiotic usage in poultry, the relevance of alliums as feed additives has been critically assessed. Garlic and the other Allium species, such as onions, leek, shallot, scallion, and chives, have been characterized to contain a plethora of bioactive compounds such as organosulfur compounds, polyphenols, saponins, fructans, and fructo-oligosaccharides. Consequently, alliums have been validated to confer antioxidant, antibacterial, antiviral, immunostimulatory, gut homeostasis, and lipid- as well as cholesterol-lowering properties in poultry. This review intends to summarize recent progress on the use of edible alliums as poultry feed additives, their beneficial effects, and the underlying mechanisms of their involvement in poultry nutrition. Perspectives for future research and limitations are also briefly discussed.

Effect of Aged and Fermented Garlic Extracts as Natural Antioxidants on Lipid Oxidation in Pork Patties

The aim of this study was to investigate the natural antioxidant activity of raw garlic (RG), aged black garlic (AG), and garlic fermented with Bacillus subtilis (FG) extracts on pork patty lipid oxidation throughout refrigerated storage. The total polyphenol, total flavonoid content, 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging activity of three different types of garlic extracts were measured. The total phenolic and flavonoid content of AG was significantly higher than that of FG and RG; FG also showed a significantly higher total phenolic content than that of RG (p<0.05). The DPPH and ABTS radical scavenging activity of AG and FG was significantly higher than that of RG and that of AG was significantly higher than that of FG (p<0.05). To investigate the effect of processed garlic extracts on pork patty lipid oxidation, freeze-dried extracts of RG, FG, and AG were added to the patties at levels of 0.5% (w/w). Patties containing 0.01% (w/w) ascorbic acid (AA) and patties without treatment (CON) were compared with patties containing garlic extracts. The pH value, 2-thiobarbituric acid reactive substances value, and volatile basic nitrogen value of pork patties containing AG and FG extracts were significantly decreased compared to the other groups (CON, AA, and RG; p<0.05). Taken together, these results suggest that AG and FG extracts possess strong antioxidative activity and can serve as natural antioxidative additives to prevent pork patty lipid oxidation.

Effects of different processing methods on the antioxidant and immune stimulating abilities of garlic

In this study, we determined the antioxidant and immune stimulating abilities of a garlic product developed by freeze drying, heat drying, and solid-state fermentation of heat-dried garlic. Lactobacillus plantarum KCTC21004 and Leuconostoc mesenteroides KCTC13302 were used for the sample fermentation. The optimum conditions for fermentation were 50% (v/w) moisture, a fermentation time of 48 hr and a temperature of 37°C. Heat-dried garlic samples fermented with L. plantarum KCTC21004 (HD21004) and L. mesenteroides KCTC13302 (HD13302) showed the highest flavonoid contents while heat-dried garlic (HD) had the lowest flavonoid content. HD21004 contained the highest phenolic compounds, showed the highest antioxidant activity and demonstrated a strong immune stimulating effect while freeze-dried garlic showed the lowest flavonoid and polyphenolic contents. Overall, the heat-dried garlic samples (fermented and unfermented) contained about three times more S-Allylcysteine (SAC) than the freeze-dried samples (FD). The current study demonstrates that heat drying and subsequent fermentation of garlic with L. plantarum KCTC21004 can improve its therapeutic effects.

Ginger fermented with Schizosaccharomyces pombe alleviates memory impairment via protecting hippocampal neuronal cells in amyloid beta1-42 plaque injected mice

Ginger, which has been widely used for dietary condiment, has been reported to improve memory dysfunction in an animal model of Alzheimer's disease (AD). Recently, a few trials have been carried out to enhance the effects of ginger by improving the bioavailability of its relevant components via fermentation. Some reports have suggested that the fermented ginger has the ability to affect the AD in vitro systems; however, its anti-amnesic effects on an in vivo model still remain to be investigated. In the present study, we aimed to investigate the neuroprotective effects of ginger fermented with Schizosaccharomyces pombe (FG) in the in vivo models of AD. The neuroprotective effects were investigated by employing behavioral, western blotting, and immunohistochemical assays. The administration of FG improved recognition memory, impaired by scopolamine injection, than that of non-fermented ginger. In addition, FG ameliorated memory impairment in amyloid beta1-42 (Aβ1-42) plaque-injected mice via protecting neuronal cells in the CA3 area of the mouse hippocampus. Moreover, FG reinstated the pre- and postsynaptic protein levels decreased by Aβ1-42 plaque-toxicity. Overall, these data suggest that FG attenuates memory impairment in Aβ1-42 plaque-induced AD mice through inhibition of neuronal cell loss and synaptic disruption.

Bioconverted Orostachys japonicas Extracts Suppress Angiogenic Activity of Ms-1 Endothelial Cells

Orostachys japonicus A. Berger (), known as Wa-song in Korea, has been reported to exert various biological effects, such as anti-tumor, anti-oxidant, and anti-febrile effects. However, the anti-angiogenic effects of O.japonicus extracts remain to be investigated. In the present study, we demonstrated the anti-angiogenic effects of bioconverted O. japonicus extract (BOE) in Ms-1 mouse endothelial cells and compared them with the bioactivities of O. japonicus extract (OE). BOE, but not OE, were found to exert anti-angiogenic effects, including inhibition of cell migration, cell adhesion, tube formation of Ms-1 cells, and blood vessel formation of matrigel plug assay in vivo. Furthermore, protein levels of phosphorylated Src kinase were lower in BOE-treated cells than in OE-treated cells. Treatment with OE or BOE did not influence cell viability during the experimental period. Bioconverted extract of O.japonicus have anti-angiogenic effects in vitro and vivo, but non-bioconverted extract do not. We suggest that these observed anti-angiogenic effects are caused by the changes in the composition of bioactive compounds in the extracts as a result of biological conversion.

The Glycosidase Treatment of Gentianae Scabrae Radix Converts Trifloroside into Deglucosyltrifloroside with an Enhancement of Antioxidative Effects

Herbal medicines were subjected to enzyme reaction by using a commercial glycosidase AMG-300L, and were evaluated for enhancement of their antioxidative activities. The methanolic extract of Gentianae Scabrae Radix (GSR) showed the most dramatic changes after enzyme reaction, as seen in the high-performance liquid chromatography profiles and an increase in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging effect. Trifloroside (1, TF) was identified as being significantly decreased by enzyme reaction, whereas deglucosyltrifloroside (2, DTF) increased. The optimal reaction time to induce DTF was 24 h at 30°C. The content increased from 1.00 ± 0.29 mg/g of extract (g_ex) to 2.80 ± 0.85 mg/g_ex after 24 h of enzyme reaction. DTF showed better antioxidative effect than TF in the DPPH, Trolox equivalent antioxidant capacity, and reactive oxygen species (ROS) in HT22 cell assays. In addition, when HT22 cells were stressed by 5 mM glutamate, 50 μM of DTF significantly inhibited the glutamate-induced lactate dehydrogenase leakage, Ca²⁺ influx, lipid peroxidation, and intracellular ROS production. These data demonstrated that the enzyme-treated GSR and its increased level of antioxidant DTF could be useful as a starting point in the discovery of functional foods to prevent various oxidative stresses, especially neurodegenerative disorders.

A Review of Fermented Foods with Beneficial Effects on Brain and Cognitive Function

Around the world, fermentation of foods has been adopted over many generations, primarily due to their commercial significance with enriched flavors and high-profile nutrients. The increasing application of fermented foods is further promoted by recent evidence on their health benefits, beyond the traditionally recognized effects on the digestive system. With recent advances in the understanding of gut-brain interactions, there have also been reports suggesting the fermented food's efficacy, particularly for cognitive function improvements. These results are strengthened by the proposed biological effects of fermented foods, including neuroprotection against neurotoxicity and reactive oxygen species. This paper reviews the beneficial health effects of fermented foods with particular emphasis on cognitive enhancement and neuroprotective effects. With an extensive review of fermented foods and their potential cognitive benefits, this paper may promote commercially feasible applications of fermented foods as natural remedies to cognitive problems.

Effectiveness of Periodic Treatment of Quercetin against Influenza A Virus H1N1 through Modulation of Protein Expression

Kimchi, a traditional fermented food regularly consumed in Korea, contains various types of antimicrobial compounds. Among the tested compounds present in common spices used in Kimchi, quercetin showed the highest selectivity index against influenza A virus (IAV) H1N1. In this study, the effect of pretreatment and periodic treatment with quercetin against IAV in Madin-Darby canine kidney cells was observed. Compared to pretreatment, periodic treatment resulted in significantly higher cell viability but lower relative expression of the IAV PA gene and total apoptosis and cell death. To explain the mechanisms underlying the antiviral effects of quercetin treatment, a comparative proteomic analysis was performed in four samples (mock, quercetin-treated, IAV-infected, and quercetin-treated IAV-infected). Among the 220 proteins, 56 proteins were classified nonhierarchically into three clusters and were differentially modulated by quercetin treatment in IAV-infected cells. Post-translational modifications were identified in 68 proteins. In conclusion, periodic treatment with quercetin is effective in reducing IAV infection, and differentially regulates the expression of key proteins, including heat shock proteins, fibronectin 1, and prohibitin to reduce IAV replication.

Change in Flavonoid Composition and Antioxidative Activity during Fermentation of Onion (Allium cepa L.) by Leuconostoc mesenteroides with Different Salt Concentrations

The aim of this study is to investigate the change in flavonoid composition and antioxidative activity during fermentation of onion (Allium cepa L.) by Leuconostoc mesenteroides with different NaCl concentrations. In order to qualify and quantify the flavonoids during fermentation of onion, 7 flavonoids, [quercetin 3,7-O-β-d-diglucopyranoside (Q3,7G), quercetin 3,4'-O-β-d-diglucopyranoside (Q3,4'G), quercetin 3-O-β-d-glucopyranoside (Q3G), quercetin 4'-O-β-d-glucopyranoside (Q4'G), isorhamnetin 3-O-β-d-glucopyranoside (IR3G), quercetin (Q), and isorhamnetin (IR)], were isolated and identified from onion. During fermentation, the contents of flavonoid glucosides (Q3,7G, Q3,4'G, Q3G, Q4'G, and IR3G) gradually decreased, whereas the contents of flavonoid aglycones (Q, IR) gradually increased. Decline rates of the flavonoid glucosides increased with the addition of L. mesenteroides. Furthermore, the activity of β-glucosidase, which is produced by L. mesenteroides, is dose-dependently inhibited with different NaCl concentrations during fermentation. The presence of L. mesenteroides enhanced the antioxidative activity of onion as demonstrated using the 1,1-diphenyl-2-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), and reducing power assays. The enhancement of antioxidative activity was considered because the content of flavonoid aglycones increased during fermentation. However, the addition of NaCl may decrease the antioxidative activity; we surmise that this phenomenon occurs because of the inhibition of β-glucosidase by NaCl. Therefore, we conclude that the addition of NaCl may be useful for the regulation of antioxidative activity via the control of β-glucosidase action, during the fermentation of flavonoid glucoside-rich foods.

Isolation and antioxidative activity of amino acid derivatives produced by Leuconostoc mesenteroides

One new phenyl lactic acid derivative, N-(5-amino-2-hydroxy-1-oxopentyl)-tyrosine (2), and three known metabolites [(S)-8-hydroxy-4-hydroxy-phenylpropanoic acid (1), (S)-8-hydroxy-phenylpropanoic acid (3), and indole-(S)-3-lactic acid (4)] were isolated from the culture medium of Leuconostoc mesenteroides guided with DPPH radical-scavenging assay. The chemical structures of the isolated compounds were determined by NMR and electrospray ionization mass spectroscopy. The isolated four compounds were assumed to be metabolites formed by the transformation of amino acids. The DPPH radical-scavenging activities of 1 and 2 were significantly higher than those of 3 and 4. This result may provide meaningful information of antioxidative metabolites from lactic acid bacteria.

Soy products fermented with sprouted garlic have increased neuroprotective activities and restore cognitive functions

Enhanced antioxidant activities of sprouted garlic over garlic were considered. The popular Korean traditional fermented soybean product cheonggukjang (CGJ) was prepared as normal CGJ and prepared with fermentation of a mixture of cooked soybeans and sprouted garlic. Different varieties were investigated for anti-oxidative and protective activities against oxidative stress in neuronal cells. Normal CGJ was compared with CGJ prepared with garlic and sprouted garlic for anti-oxidative and neuroprotective activities and protection of cognitive function. CGJ prepared with sprouted garlic during fermentation exhibited higher anti-oxidative and neuroprotective activities in a mouse hippocampal model than the normal fermented soy product with enhanced cognitive function in the mouse model. Sprouted garlic can be used to improve the health benefits of fermented soy products.

The cadmium binding characteristics of a lactic acid bacterium in aqueous solutions and its application for removal of cadmium from fruit and vegetable juices

A lactic acid bacterium with good cadmium binding ability can remove this heavy metal from fruit and vegetable juices efficiently.

Enhanced anti-oxidative effect of fermented Korean mistletoe is originated from an increase in the contents of caffeic acid and lyoniresinol

The crude enzyme extract derived from Aspergillus kawachii increased the anti-oxidants, caffeic acid and lyoniresinol, in Korean mistletoe.

Comparison of clinical and histological effects between lactobacillus-fermented Chamaecyparis obtusa and tea tree oil for the treatment of acne: an eight-week double-blind randomized controlled split-face study

BACKGROUND

Screening of natural compounds for the development of anti-acne therapeutic agents has been steadily required considering various side effects of acne medications. However, previous studies have mainly focused on experimental tests without clinical trials and histopathological analysis.

OBJECTIVES

To compare the clinical efficacy, safety and histopathological changes between Lactobacillus-fermented Chamaecyparis obtusa (LFCO) and existing tea tree oil (TTO).

METHODS

A total of 34 patients were instructed to apply 5% LFCO to the involved areas of a randomly allocated side and 5% TTO extract to the other side for 8 weeks in a double-blind split-face clinical trial.

RESULTS

After 8 weeks, inflammatory acne lesions were reduced by 65.3% on the LFCO side and by 38.2% on the TTO side. LFCO was also superior to TTO in the onset time of efficacy (p < 0.05). The LFCO side further demonstrated improvement for non-inflammatory lesions (52.6%, p < 0.05), decreased size of sebaceous glands and sebum output reductions. Patients' subjective satisfaction was also higher without severe adverse reactions. Protein expressions of nuclear factor κB decreased earlier on the LFCO side, and those of interleukin-1α (IL-1α), IL-8, insulin-like growth factor 1 receptor and sterol regulatory element-binding protein 1 decreased subsequently. Ultra-performance liquid chromatography/high-resolution mass spectrometry further demonstrated that the contents of dihydroxybenzoic acid, taxifolin and quercetin were increased in LFCO after fermentation.

CONCLUSIONS

LFCO treatment was rapid and effective for treating acne lesions compared to TTO. Histopathological findings correlated well with the clinical acne grade and treatment response. This novel natural compound appears to be effective and safe for acne treatment.

Effect of alcoholic fermentation on the carotenoid composition and provitamin A content of orange juice

Orange juice is considered a rich source of carotenoids, which are thought to have diverse biological functions. In recent years, a fermentation process has been carried out in fruits resulting in products that provide higher concentrations of bioactive compounds than their original substrates. The aim of this study was to evaluate the effect of a controlled alcoholic fermentation process (15 days) on the carotenoid composition of orange juice. Twenty-two carotenoids were identified in samples. The carotenoid profile was not modified as result of the fermentation. Total carotenoid content and provitamin A value significantly increased from day 0 (5.37 mg/L and 75.32 RAEs/L, respectively) until day 15 (6.65 mg/L and 90.57 RAEs/L, respectively), probably due to a better extractability of the carotenoids from the food matrix as a result of processing. Therefore, the novel beverage produced could provide a rich source of carotenoids and exert healthy effects similar to those of orange juice.

Fermented orange juice: source of higher carotenoid and flavanone contents

The intake of bioactive compounds and moderate alcohol decreases the risk of cardiovascular diseases. These effects could be joined in a beverage created by a controlled alcoholic fermentation of orange juice. The influence of controlled alcoholic fermentation on the bioactive compound profile of orange juice has not been previously evaluated, and this is the purpose of the present study. Total and individual flavanones and carotenoids significantly increased throughout the fermentation. The reason for this was an enhanced extraction of these compounds from the pulp. Besides, the potential bioavailability of flavanones increased due to a higher content of hesperetin-7-O-glucoside (2-fold higher at the end of the fermentation process). Ascorbic acid did not undergo a significant change, and only total phenolics decreased. Antioxidant capacity was also evaluated. TEAC and FRAP values remained constant throughout the process. However, ORAC and DPPH values significantly increased. Correlation analysis concluded that the increase in ORAC and DPPH values could be due to enhancement of flavanones.

Hepatotoxicity evaluation of aqueous extract from Scutia buxifolia

Nowadays there is an increase in the number of people taking herbals worldwide. Scutia buxifolia is used for the treatment of hypertension, but little is known about its action on liver. Thirty-two Wistar rats were divided into four groups: control and groups treated during 30 days with 100, 200 and 400 mg of lyophilized aqueous extract of S. buxifolia (SBSB)/kg of body weight. This study was planned to explore hepatotoxic effect of SBSB, which was assessed by serum transaminases (ALT and AST). Thiobarbituric acid reactive substances (TBARS) levels were determined in liver, along with thiols content (NPSH), catalase (CAT) activity and, superoxide dismutase (SOD) enzymes. Histopathological studies of liver tissue were performed. Flavonoids and phenolics were quantified in SBSB by high performance liquid chromatography with diode array detection (HPLC/DAD). We did not observe alterations on redox status (TBARS, NPSH, CAT and, SOD) in the control and experimental groups. An increase on AST activity was only observed at 200 mg of SBSB, whereas ALT score was not affected by SBSB. Moreover, no morphological alterations were observed on the hepatocytes, matching the analysed biochemical parameters. This way, we conclude that SBSB was not toxic.