Antioxidant Effect of Soymilk Fermented by Lactobacillus plantarum HFY01 on D-Galactose-Induced Premature Aging Mouse Model

Research progress on the regulation of oxidative stress by phenolics: the role of gut microbiota and Nrf2 signaling pathway

In recent years, the increase in high-calorie diets and sedentary lifestyles has made obesity a global public health problem. An unbalanced diet promotes the production of proinflammatory cytokines and causes redox imbalance in the body. Phenolics have potent antioxidant activity and cytoprotective ability. They can scavenge free radicals and reactive oxygen species, and enhance the activity of antioxidant enzymes, thus combating the body's oxidative stress. They can also improve the body's inflammatory response, enhance the enzyme activity of lipid metabolism, and reduce the contents of cholesterol and triglyceride. Most phenolics are biotransformed and absorbed into the blood after the action by gut microbiota; these metabolites then undergo phase I and II metabolism and regulate oxidative stress by scavenging free radicals and increasing expression of antioxidant enzymes. Phenolics induce the expression of genes encoding antioxidant enzymes and phase II detoxification enzymes by stimulating Nrf2 to enter the nucleus and bind to the antioxidant response element after uncoupling from Keap1, thereby promoting the production of antioxidant enzymes and phase II detoxification enzymes. The absorption rate of phenolics in the small intestine is extremely low. Most phenolics reach the colon, where they interact with the microbiota and undergo a series of metabolism. Their metabolites will reach the liver via the portal vein and undergo conjugation reactions. Subsequently, the metabolites reach the whole body to exert biological activity by traveling with the systemic circulation. Phenolics can promote the growth of probiotics, reduce the ratio of Firmicutes/Bacteroidetes (F/B), and improve intestinal microecological imbalance. This paper reviews the nutritional value, bioactivity, and antioxidant mechanism of phenolics in the body, aiming to provide a scientific basis for the development and utilization of natural antioxidants and provide a reference for elucidating the mechanism of action of phenolics for regulating oxidative stress in the body. © 2023 Society of Chemical Industry.

Lactiplantibacillus plantarum fermentation enhanced the protective effect of kiwifruit on intestinal injury in rats: Based on mitochondrial morphology and function

Fermented foods have protective effects on body health. In our previously study, we found Lactiplantibacillus plantarum fermentation enhanced antioxidant activity of kiwifruit in vitro digestion. Then, in this work we explored the protective effect of fermented kiwi on intestinal injury induced by acute lipopolysaccharide (LPS) stress. Compared to non-fermented kiwi pulp (KP), Lactiplantibacillus plantarum fermented kiwi pulp (FKP-LP) contained more peptides, hormones and vitamins contents, lesser nucleic acid and carbohydrate contents. FKP-LP could relieve the intestinal injury by improving morphological of tight junction and upregulating tight junction proteins mRNA expression. Fermented kiwi maintained the mitochondrial morphology, mitochondrial respiratory function, and mitochondrial homeostasis, and relieved the LPS induced injury by regulating the contents of energy substances, and the respiratory chain complex enzyme activity through the pathway of AMPK and its downstream factors including PGC-1α, NRF1, NRF2, TFAM, and ULK2.

Lactobacillus plantarum CQPC02 intervenes in mouse lupus nephritis by regulating the NF-κB signaling pathway

A strain of Lactobacillus plantarum CQPC02 (LP-CQPC02) isolated from naturally fermented kimchi was utilized in this investigation. In order to construct an animal model of lupus nephritis, pristane was used. We then used a kit to identify markers in mouse blood and tissues and a quantitative polymerase chain reaction (qPCR) to measure the expression of genes associated to nuclear factor kappa-B (NF-κB) in mouse kidney tissue. According to the results of the experiments, oral administration of LP-CQPC02 LP-CQPC02 may lessen the lupus nephritis-related rise in urine protein as well as the cytokine levels that were rising in the serum and renal tissues, including IL-6, IL-12, tumor necrosis factor alpha, and interferon. Additionally, in mice with nephritis, LP-CQPC02 can lower serum creatinine (SCr), blood urea nitrogen (BUN), total cholesterol (TC), triglyceride (TG), and raise total protein (TP) and albumin (ALB) levels. In mice with nephritis, LP-CQPC02 can also reduce the positive rate of double-stranded deoxyribonucleic acid (dsDNA). Pathological sections were examined, and it was shown that LP-CQPC02 can lessen tissue damage such incomplete glomerular morphology and inflammatory infiltration brought on by nephritis. In the kidneys of mice with lupus nephritis, LP-CQPC02 can upregulate the expression of inhibitor of NF-κB (IκB-α), downregulate the expression of NF-κB, transforming growth factor-β1 (TGF-β1), vascular endothelial growth factor (VEGF), intercellular cell adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1). Lactobacillus plantarum CQPC02 has been confirmed to have an intervention effect on nephritis in mice and has the potential as a probiotic.

Antioxidative Properties of Fermented Soymilk Using Lactiplantibacillus plantarum LP95

In recent times, there has been a growing consumer interest in replacing animal foods with alternative plant-based products. Starting from this assumption, for its functional properties, soymilk fermented with lactic acid bacteria is gaining an important position in the food industry. In the present study, soymilk was fermented with Lactiplantibacillus plantarum LP95 at 37 °C, without the use of stabilizers as well as thickeners and acidity regulators. We evaluated the antioxidant capacity of fermented soymilk along with its enrichment in aglycone isoflavones. The conversion of isoflavone glucosides to aglycones (genistein, glycitein, and daidzein) was analyzed together with antioxidant activity (ABTS) measurements, lipid peroxidation measurements obtained by a thiobarbituric acid reactive substance (TBARS) assay, and apparent viscosity measurements. From these investigations, soymilk fermentation using Lp. plantarum LP95 as a starter significantly increased isoflavones' transformation to their aglycone forms. The content of daidzein, glycitein, and genistein increased after 24 h of fermentation, reaching levels of 48.45 ± 1.30, 5.10 ± 0.16, and 56.35 ± 1.02 μmol/100 g of dry weight, respectively. Furthermore, the antioxidant activity increased after 6 h with a reduction in MDA (malondialdehyde). The apparent viscosity was found to increase after 24 h of fermentation, while it slightly decreased, starting from 21 days of storage. Based on this evidence, Lp. plantarum LP95 appears to be a promising candidate as a starter for fermented soymilk production.

Isoflavones Mediate Dendritogenesis Mainly through Estrogen Receptor α

The nuclear estrogen receptor (ER) and G-protein-coupled ER (GPER1) play a crucial role during brain development and are involved in dendrite and spine growth as well as synapse formation. Soybean isoflavones, such as genistein, daidzein, and S-equol, a daidzein metabolite, exert their action through ER and GPER1. However, the mechanisms of action of isoflavones on brain development, particularly during dendritogenesis and neuritogenesis, have not yet been extensively studied. We evaluated the effects of isoflavones using mouse primary cerebellar culture, astrocyte-enriched culture, Neuro-2A clonal cells, and co-culture with neurons and astrocytes. Soybean isoflavone-augmented estradiol mediated dendrite arborization in Purkinje cells. Such augmentation was suppressed by co-exposure with ICI 182,780, an antagonist for ERs, or G15, a selective GPER1 antagonist. The knockdown of nuclear ERs or GPER1 also significantly reduced the arborization of dendrites. Particularly, the knockdown of ERα showed the greatest effect. To further examine the specific molecular mechanism, we used Neuro-2A clonal cells. Isoflavones also induced neurite outgrowth of Neuro-2A cells. The knockdown of ERα most strongly reduced isoflavone-induced neurite outgrowth compared with ERβ or GPER1 knockdown. The knockdown of ERα also reduced the mRNA levels of ER-responsive genes (i.e., Bdnf, Camk2b, Rbfox3, Tubb3, Syn1, Dlg4, and Syp). Furthermore, isoflavones increased ERα levels, but not ERβ or GPER1 levels, in Neuro-2A cells. The co-culture study of Neuro-2A cells and astrocytes also showed an increase in isoflavone-induced neurite growth, and co-exposure with ICI 182,780 or G15 significantly reduced the effects. In addition, isoflavones increased astrocyte proliferation via ER and GPER1. These results indicate that ERα plays an essential role in isoflavone-induced neuritogenesis. However, GPER1 signaling is also necessary for astrocyte proliferation and astrocyte-neuron communication, which may lead to isoflavone-induced neuritogenesis.

Antioxidant properties of fermented soymilk and its anti-inflammatory effect on DSS-induced colitis in mice

Lactic acid-fermented soymilk as a new plant-based food has aroused extensive attention because of its effects on nutrition and health. This study was conducted to delve into the antioxidative and anti-inflammatory activities of lactic acid-fermented soymilk. To elucidate the key factors that affect the antioxidant properties of fermented soymilk, the strains and preparation process were investigated. Findings show that the fermented soymilk prepared using hot-water blanching method (BT-80) demonstrated a better antioxidant activity than that using conventional method (CN-20). Besides, a huge difference was observed among the soymilks fermented with different strains. Among them, the YF-L903 fermented soymilk demonstrated the highest ABTS radical scavenging ability, which is about twofold of that of unfermented soymilk and 1.8-fold of that of L571 fermented soy milk. In vitro antioxidant experiments and the analysis of H₂O₂-induced oxidative damage model in Caco-2 cells showed that lactic acid-fermentation could improve the DPPH radical scavenging ability, ABTS radical scavenging ability, while reducing the content of reactive oxygen species (ROS) and malondialdehyde (MDA) in Caco-2 cells induced by H₂O₂, and increasing the content of superoxide dismutase (SOD). Consequently, cells are protected from the damage caused by active oxidation, and the repair ability of cells is enhanced. To identify the role of fermented soymilk in intestinal health, we investigate its preventive effect on dextran sodium sulfate-induced colitis mouse models. Results revealed that the fermented soymilk can significantly improve the health conditions of the mice, including alleviated of weight loss, relieved colonic injury, balanced the spleen-to-body weight ratio, reduced the disease index, and suppressed the inflammatory cytokines and oxidant indexes release. These results suggest that YF-L903 fermented soymilk is a promising natural antioxidant sources and anti-inflammatory agents for the food industry. We believe this work paves the way for elucidating the effect of lactic acid-fermented soymilk on intestinal health, and provides a reference for the preparation of fermented soymilk with higher nutritional and health value.

Effect of pretreatments of camellia seeds on the quality, phenolic profile, and antioxidant capacity of camellia oil

Camellia oil is one of the four major woody oils in the world and has high nutritional value due to its richness in monounsaturated fatty acids (MUFAs) and bioactive substances. In order to compare the effects of pretreatments of camellia seeds on the quality, phenolic profile, and antioxidant capacity of camellia oil, three different pretreatment methods, i.e., hot air (HA), steam (ST) and puffing (PU), were used to treat the seed powder in the present study. All three pretreatments changed the internal structure of the camellia seeds. The oil yield was increased after all three pretreatments, with the highest oil yield increased by PU pretreatment (Based on the oil yield, we screened out the best conditions of the three pretreatments, HA pretreatment is 60°C for 40 min, ST pretreatment is 100°C for 15 min, PU pretreatment is 800 rpm). The fatty acids (FAs) of the oil were relatively stable, with no significant changes after three pretreatments. However, all three pretreatments had a significant effect on the acid value (AV), peroxide value (PV), and benzo(a)pyrene (Ba P) of the camellia oil. The PU and HA pretreatments could increase the tocopherol content and the total sterols content in the camellia oil. The ST and PU pretreatments significantly increased the free phenolics (FP) content, all three pretreatments reduced the contents of conjugated phenolics (CP) and insoluble-bound phenolics (IBP) in the camellia oil. The IBP made the most significant contribution to the antioxidant capacities of camellia oil. ST and PU prtreatments increased the antioxidant capacities of the total phenolics in the camellia oil. Eight phenolics in FP, CP, and IBP were significantly correlated with the antioxidant capacities of camellia oil. The results of the present study could provide some theoretical guidance for the pretreatment of camellia seeds for higher oil yield, phenolic content and enhanced antioxidant capacities of camellia oil.

Antioxidative potential of Lactobacillus sp. in ameliorating D-galactose-induced aging

Aging is a progressive, unalterable physiological degradation process of living organisms, which leads to deterioration of biological function and eventually to senescence. The most prevalent factor responsible for aging is the accumulation of damages resulting from oxidative stress and dysbiosis. D-galactose-induced aging has become a hot topic, and extensive research is being conducted in this area. Published literature has reported that the continuous administration of D-galactose leads to the deterioration of motor and cognitive skills, resembling symptoms of aging. Hence, this procedure is employed as a model for accelerated aging. This review aims to emphasize the effect of D-galactose on various bodily organs and underline the role of the Lactobacillus sp. in the aging process, along with its anti-oxidative potential. A critical consideration to the literature describing animal models that have used the Lactobacillus sp. in amending D-galactose-induced aging is also given. KEY POINTS: • D-Galactose induces the aging process via decreasing the respiratory chain enzyme activity as well as ATP synthesis, mitochondrial dysfunction, and increased ROS production. • D-Galactose induced aging primarily affects the brain, heart, lung, liver, kidney, and skin. • The anti-oxidative potential of Lactobacillus sp. in improving D-galactose-induced aging in animal models via direct feeding and feeding of Lactobacillus-fermented food.