Mechanisms of probiotic modulation of ovarian sex hormone production and metabolism: a review.

Sex hormones play a pivotal role in the growth and development of the skeletal, neurological, and reproductive systems. In women, the dysregulation of sex hormones can result in various health complications such as acne, hirsutism, and irregular menstruation. One of the most prevalent diseases associated with excess androgens is polycystic ovary syndrome with a hyperandrogenic phenotype. Probiotics have shown the potential to enhance the secretion of ovarian sex hormones. However, the underlying mechanism of action remains unclear. Furthermore, comprehensive reviews detailing how probiotics modulate ovarian sex hormones are scarce. This review seeks to shed light on the potential mechanisms through which probiotics influence the production of ovarian sex hormones. The role of probiotics across various biological axes, including the gut-ovarian, gut-brain-ovarian, gut-liver-ovarian, gut-pancreas-ovarian, and gut-fat-ovarian axes, with a focus on the direct impact of probiotics on the ovaries via the gut and their effects on brain gonadotropins is discussed. It is also proposed herein that probiotics can significantly influence the onset, progression, and complications of ovarian sex hormone abnormalities. In addition, this review provides a theoretical basis for the therapeutic application of probiotics in managing sex hormone-related health conditions.

Promoting Effect and Potential Mechanism of Lactobacillus pentosus LPQ1-Produced Active Compounds on the Secretion of 5-Hydroxytryptophan.

5-hydroxytryptophan (5-HTP) is an important substance thought to improve depression. It has been shown that Lactobacillus can promote the secretion of 5-HTP in the body and thus ameliorate depression-like behavior in mice. However, the mechanism by which Lactobacillus promotes the secretion of 5-HTP is unclear. In this study, we investigated the promoting effect and mechanism of Lactobacillus, isolated from Chinese fermented foods, on the secretion of 5-HTP. The results showed that Lactobacillus (L.) pentosus LPQ1 exhibited the strongest 5-HTP secretion-promoting effect ((9.44 ± 0.69)-fold), which was dependent on the mixture of compounds secreted by L. pentosus LPQ1 (termed SLPQ1). In addition, the results of the RNA sequencing (RNA-seq) and quantitative real-time polymerase chain reaction (qRT-PCR) analyses indicated that SLPQ1 alters the TNF and oxidative phosphorylation signaling pathways. Moreover, the SLPQ1 ultrafiltration fraction (>10 kDa) showed a similar 5-HTP promoting effect as SLPQ1. Furthermore, reverse-phase liquid chromatography-tandem mass spectrometry (RPLC-MS/MS) identified 29 compounds of >10 kDa in SLPQ1, including DUF488 domain-containing protein, BspA family leucine-rich repeat surface protein, and 30S ribosomal protein S5, which together accounted for up to 62.51%. This study reports new findings on the mechanism by which L. pentosus LPQ1 promotes 5-HTP production in some cell lines in vitro.

Development of an Immunochromatographic Test Based on Rhoptry Protein 14 for Serological Detection of Toxoplasma gondii Infection in Swine.

Toxoplasma gondii, a worldwide distributed apicomplexan protozoan, can infect almost all warm-blooded animals and may cause toxoplasmosis. In order to provide a point-of-care detection method for T. gondii infection, an immunochromatographic test (ICT) was established. The proposed test uses recombinant T. gondii rhoptry protein 14 (ROP14) conjugated with 20 nm gold particles, recombinant protein A as the detection line and monoclonal antibody TgROP14-5D5 as the control line. The specificity, sensitivity, positive predictive value, negative predictive value and stability of this new ICT were evaluated. rTgROP14 was specifically recognized by positive serum of T. gondii but not negative serum. mAb TgROP14-5D5 showed higher specific recognition of T. gondii antigens and was therefore selected for subsequent colloidal gold strip construction. The new ICT based on TgROP14 exhibited good diagnostic performance with high specificity (86.9%) and sensitivity (90.9%) using IHA as a "reference standard". Among 436 field porcine sera, ICT and IHA detected 134 (30.7%) and 99 (22.7%) positive samples, respectively. The relative agreement was 87.8%. These data indicate that this new ICT based on TgROP14 is a suitable candidate for routine testing of T. gondii in the field.

Lactobacillus plantarum SHY130 isolated from yak yogurt attenuates hyperglycemia in C57BL/6J mice by regulating the enteroinsular axis.

Diabetes, one of the most serious and common chronic metabolic diseases affecting people worldwide in the 21st century, has become a major problem that needs to be addressed urgently. This study was designed to elucidate the anti-diabetic effect of yak yogurt-derived Lactobacillus (L.) plantarum SHY130 on C57BL/6J mice fed high-fat diet and streptozotocin (HFD/STZ), and the potential regulatory mechanisms involved. Mice were divided into 3 groups: normal control, diabetes, and diabetes treated with L. plantarum SHY130 (SHY130). Treatment with L. plantarum SHY130 had a regulatory effect on blood glucose and clearly ameliorated insulin resistance in T2DM mice. L. plantarum SHY130 inhibited the reduction in ß-cell mass and α-cell proliferation in the pancreas and increased the expression of the short-chain fatty acid (SCFA) receptors GPR43 and GPR41 in the colon of T2DM mice. Furthermore, L. plantarum SHY130 treatment readjusted intestinal flora structure, enhanced the abundance of SCFA-producing bacteria, such as Faecalibaculum, Odoribacter, Alistipes, and increased the levels of SCFAs in diabetic mice. In summary, L. plantarum SHY130 ameliorated hyperglycemia in HFD/STZ-induced diabetic mice by regulating the enteroinsular axis.

Interaction between ß-lactoglobulin and EGCG under high-pressure by molecular dynamics simulation.

The binding between ß-lactoglobulin and epigallocatechin gallate (EGCG) under the pressure of 600 MPa was explored using molecular docking and molecular dynamics (MD) simulation. EGCG bound mainly in two regions with site 1 in internal cavity of the ß-barrel and site 2 on the surface of protein. 150 ns MD was performed starting from the structure with the optimal binding energy at the two sites in molecular docking, respectively. It was found that the protein fluctuated greatly when small molecule bound to site 2 at 0.1 MPa, and the protein fluctuation and solvent accessible surface area became smaller under high-pressure. The binding of small molecules made the protein structure more stable with increasing of α-helix and ß-sheet, while high-pressure destroyed α-helix of protein. The binding energy of small molecules at site 1was stronger than that at site 2 under 0.1 MPa, with stronger van der Waals and hydrophobic interaction at site 1 while more hydrogen bonds were present at site 2. The binding energy of both sites weakened under high-pressure, especially at site 1, causing the binding force to be weaker at site 1 than that at site 2 under high-pressure.

Inhibitory Effect and Potential Mechanism of Lactobacillus plantarum YE4 against Dipeptidyl Peptidase-4.

This study investigated the inhibitory effect and mechanism of 12 LAB strains isolated from Chinese fermented foods on dipeptidyl peptidase-4 (DPP-4) using the Caco-2 cell model. The results showed that the inhibitory effect of cell-free extracts (CFEs) collected from each LAB strain on DPP-4 was higher than that of the cell-free excretory supernatants. The CFEs from Lactobacillus plantarum YE4 (YE4-CFE) exhibited the strongest DPP-4 inhibitory activity (24.33% inhibition). Furthermore, YE4-CFE altered the TNF and MAPK signaling pathways. Additionally, the YE4-CFE ultrafiltration fraction (<3 kDa) displayed a similar DPP-4 inhibitory activity to YE4-CFE. UHPLC-MS/MS identified 19 compounds with a relative proportion of more than 1% in the <3 kDa fraction, and adenine, acetylcholine, and L-phenylalanine were the top three substances in terms of proportion. Altogether, the inhibitory effect of YE4-CFE on DPP-4 was associated with the TNF and MAPK signaling pathways, and with the high proportion of adenine, acetylcholine, and L-phenylalanine.

Targeted overexpression of cyclic AMP-dependent protein kinase subunit in Toxoplasma gondii promotes replication and virulence in host cells.

Toxoplasma gondii (T. gondii) is one of the most common parasite that can infect almost any warm-blooded animals including humans. The cyclic nucleotide-dependent protein kinase (PKA) regulates a spectrum of intracellular signal pathways in many organisms. Protein kinase catalytic subunit (PKAC) is the core of the whole protein, and plays an important role in the life cycle of T.gondii. Here, T.gondii PKAC (TgPKAC) overexpression strain (TgPKAC-OE) was constructed. The growth of the TgPKAC-OE, RH△Ku80, and TgPKAC inhibition strains (TgPKAC-H89) were analysed by SYBR-green real-time PCR, and the ultrastructure was observed by transmission electron microscopy. The survival rate in mice was also recorded to analyse the virulence of the parasites. We also investigated the subcellular localization of TgPKAC in Vero cells by laser scanning microscope. We found that TgPKAC-OE strain exhibited obviously increased growth rate in Vero cells in vitro, and infected mice survived for a shorter time compared to wild type strain. Ultrastructural analysis found more autophagosomes-like structures in TgPKAC-H89 parasite compared to RH△Ku80 strain, and the relative expression level of Toxoplasma gondii autophagy-related protein (ATG8) in TgPKAC-H89 parasite was higher than wild type parasite. Laser confocal results showed that TgPKAC was mainly expressed in the cytoplasm of Vero cells. In conclusion, we hypothesized that inhibition of TgPKAC could cause autophagy of Toxoplasma gondii and then influence the replication of the parasite. TgPKAC plays an important role in parasite virulence in vivo, and the subcellular localization was successfully detected in Vero cells. Our data will provide a basis for further study of TgPKAC function and help screen drug targets of T. gondii.

Property and structure changes of myofibril protein in pork treated by high pressure combined with heat.

The effects of myofibril protein in pork treated by high hydrostatic pressure combined with heat were investigated. The solubility of myofibril protein significantly increased up to 400 MPa but since then began to decrease up to 600 MPa. The best solubility was shown under all pressure at 35 ℃ and the lowest solubility was observed at 55 ℃. The carbonyl group value, disulfide bond and surface hydrophobicity exhibited pressure-dependent increase in the same manner. Particle size decreased up to 400 MPa and then increased up to 600 MPa, but the turbidity always reduced. The increase of intrinsic fluorescence intensity with red shift and decrease of absorbance around 278 nm with blue shift indicated that protein unfolding and exposure of hydrophobic amino acid occurred with increase of pressure. The second derivative infrared spectra and curve fittings suggested that high pressure induced reduction of ß-sheet structures, enhancement of α-helix and random coil and ß-turns segments, which was opposite to the effects of temperature. Emission scanning electron microscope assay further demonstrated protein unfolding and aggregation process induced by different pressure and temperature. The data suggested that cooperative effect of moderate pressure and temperature could improve physical-chemical and processing properties of meat.

Combined effects of high-pressure and thermal treatments on lipid oxidation and enzymes in pork.

The relationship between lipid oxidation and related enzymes in pork during combined pressure-heat treatments was investigated. Minced pork was treated under a pressure range of 0.1-750 MPa and a temperature range of 30-60°C for 20 min. Thiobarbituric acid-reactive substances (TBARS) values and activities of acid lipase (AL), neutral lipase (NL), phospholipase (PL), and lipoxygenase (LOX) in pork were evaluated. NL and LOX were completely inactivated at 600 MPa-50°C and 450 MPa-60°C, and AL at 600MPa-55°C. PL had the greatest stability and was completely inactivated at 600 MPa-60°C and 750 MPa-50°C. PL activity was strongly related to lipid oxidation caused by high pressure, followed by AL and LOX. TBARS values at 600 and 750 MPa were strongly related to the inactivation rate and the ratio of PL during treatment. PL was the most important enzyme related to lipid oxidation induced by pressure.

Lipolysis and lipid oxidation during processing of Chinese traditional smoke-cured bacon.

Lipolysis and lipid oxidation as well as the relationship between them during processing of Chinese traditional smoke-cured bacon were studied by evaluating the changes in physicochemical parameters, lipase and lipoxygenase (LOX) activities, lipid content, fatty acid composition, peroxide value (POV), and thiobarbituric acid reactive substances (TBARS). Besides phospholipids, triacylglycerols (TAG) were an important source of free fatty acids in bacon, resulting in an increase in free fatty acid content in the mid-late stage of processing, whilst phospholipids hydrolysed intensely in the early stage. Preferential lipolysis was observed for polyunsaturated fatty acids in phospholipids and for linoleic and palmitic acids in TAG. The lipolysis of TAG and phospholipids was independent and catalysed by acid lipase and phospholipase, respectively. ANOVA-partial least squares regression (APLSR) analysis showed that POV and TBARS were poorly related to LOX and closely associated with phospholipid degradation. Therefore, autoxidation may be the main cause of muscle lipid oxidation in smoke-cured bacon, which was promoted by phospholipid hydrolysis.

Effect of antioxidant on the fatty acid composition and lipid oxidation of intramuscular lipid in pressurized pork.

To investigate the effect of antioxidants on lipid oxidation and fatty acid composition in pressurized pork, minced pork with or without 1% Na(2)EDTA was pressurized at 500MPa before 7days storage at 4°C. TBARS value, lipid content and fatty acid composition in untreated and high-pressure (HP) treated samples were analyzed. HP treatment induced marked increases in TBARS values and lipolysis of partial phospholipids causing an increase of free fatty acid content. Preferential hydrolysis for polyunsaturated fatty acids (PUFA) in phospholipids resulted in the percentage of PUFA in phospholipids decreasing markedly and thereby that in free fatty acids increasing significantly. Addition of 1% Na(2)EDTA to minced pork before HP significantly decreased the TBARS values in pressurized samples, but did not inhibit the lipolysis of phospholipids, causing the fatty acid composition of phospholipids and free fatty acids to change similarly to those samples without Na(2)EDTA.

Effect of high-pressure treatment on the fatty acid composition of intramuscular lipid in pork.

To investigate the effect of high-pressure (HP) treatment on lipid oxidation and fatty acid composition of intramuscular lipid in pork, the longissimus muscles from Rongchang (RC) pig were pressurized at 200, 350 and 500 MPa for 20 min at 20°C prior to 7 days storage at 4°C. The changes in TBARS number, lipid content and fatty acid composition of total intramuscular lipids, phospholipids, triglycerides and free fatty acids in untreated and HP treated samples were analyzed. HP treatment had no significant effect on the content and fatty acid composition of total lipids and triglycerides in the samples, but treatment at 350 MPa and above led to marked increases in TBARS values and lipolysis of partial phospholipids causing a correlative increase of free fatty acid content. A preferential hydrolysis for polyunsaturated fatty acids (PUFA) in phospholipids was observed, which resulted in the percentage of PUFA in phospholipids decreasing markedly and thereby that in free fatty acids increasing significantly.