High Dietary Folic Acid Supplementation Reduced the Composition of Fatty Acids and Amino Acids in Fortified Eggs.

AIMS: The study aimed to evaluate the effects of dietary folic acid (FA) on the production performance of laying hens, egg quality, and the nutritional differences between eggs fortified with FA and ordinary eggs. METHODS: A total of 288 26-week-old Hy-Line Brown laying hens (initial body weights 1.65 ± 0.10 kg) with a similar weight and genetic background were used. A completely randomized design divided the birds into a control group and three treatment groups. Each group consisted of six replicates, with twelve chickens per replicate. Initially, all birds were fed a basal diet for 1 week. Subsequently, they were fed a basal diet supplemented with 0, 5, 10, or 15 mg/kg FA in a premix for a duration of 6 weeks. RESULTS: Supplementation of FA could significantly (p < 0.05) enhance the FA content in egg yolks, particularly when 10 mg/kg was used, as it had the most effective enrichment effect. Compared to the control group, the Glu content in the 10 and 15 mg/kg FA groups showed a significant (p < 0.05) decrease. Additionally, the contents of Asp, Ile, Tyr, Phe, Cys, and Met in the 15 mg/kg FA group were significantly (p < 0.05) lower compared to the other groups. Adding FA did not have significant effects on the levels of vitamin A and vitamin E in egg yolk, but the vitamin D content in the 5 and 10 mg/kg FA groups showed a significant (p < 0.05) increase. Furthermore, the addition of FA did not have a significant effect on the levels of Cu, Fe, Mn, Se, and Zn in egg yolk. The dietary FA did not have a significant effect on the total saturated fatty acids (SFA) and polyunsaturated fatty acid (PUFA) content in egg yolk. However, the total monounsaturated fatty acid (MUFA) content in the 5 and 10 mg/kg groups significantly (p < 0.05) increased. These changes in nutritional content might be attributed to the increased very low-density lipoprotein (VLDL) protein content. The significant decrease in solute carrier family 1 Member 1 (SLC1A1), solute carrier family 1 Member 2 (SLC1A2), and solute carrier family 1 Member 3 (SLC1A3) gene expression compared to the control group appeared to be the reason for the decrease in amino acid content in egg yolk within the dietary FA group. CONCLUSION: The findings suggest that the appropriate addition of FA can enhance the levels of MUFA and vitamin D in egg yolks, thereby improving their nutritional value. Excessive intake of FA can decrease the effectiveness of enriching FA in egg yolk and impact the enrichment of certain amino acids. The yolk of eggs produced by adding 10 mg/kg of FA to the feed contains the optimal amount of nutrients. This study informs consumers purchasing FA-fortified eggs.

The mechanism of curcumin to protect mouse ovaries from oxidative damage by regulating AMPK/mTOR mediated autophagy.

BACKGROUND: Oxidative stress is considered the main cause of granulosa cell apoptosis in ovarian disease. Curcumin has various biological roles, but its potential role in protecting granulosa cells from oxidative damage remains unidentified. PURPOSE: The study revealed the protective effect of curcumin on granulosa cell survival under oxidative stress, and explored its mode of action. STUDY DESIGN: The protective effect of curcumin on oxidative stress-induced ovarian cell apoptosis was evaluated in vivo and in vitro, and the role of autophagy and AMPK/mTOR signaling pathway in this process was also demonstrated. METHODS: First, mice were injected to 3-nitropropionic acid (3-NPA, 20 mg/kg/day) for 14 consecutive days to establish the ovarian oxidative stress model, at same time, curcumin (50, 100, 200 mg/kg/day) was given orally. Thereafter, functional changes, cell apoptosis, and autophagy in ovarian tissue were evaluated by hematoxylin-eosin staining, enzyme-linked immunosorbent assay, western blotting, TUNEL assays, and transmission electron microscopy. Finally, oxidative stress model of granulosa cells was established with H2O2in vitro and treated with curcumin. The underlying mechanisms of curcumin to protect the apoptosis under oxidative stress in vitro were determined using western blotting and TUNEL assays. RESULTS: In our study, after curcumin treatment, the mouse ovarian function disorder under 3-nitropropionic acid-induced oxidative stress recovered significantly, and ovarian cell apoptosis decreased. H2O2 induced granulosa cell apoptosis in vitro, and curcumin antagonized this process. Autophagy contributes to tissue and cell survival under stress. We therefore examined the role of autophagy in this process. According to the in vivo and in vitro results, curcumin restored autophagy under oxidative stress. The autophagy inhibitor (chloroquine) exhibited the same effect as curcumin, whereas the autophagy activator (rapamycin) antagonized the effect of curcumin. In addition, the study found that the AMPK/mTOR pathway plays a crucial role in curcumin- mediated autophagy to protect against oxidative stress-induced apoptosis. CONCLUSION: Our findings for the first time systematically revealed a new mechanism through which curcumin protects ovarian granulosa cells from oxidative stress-induced damage through AMPK/mTOR-mediated autophagy and suggested that it can be a new therapeutic direction for female ovarian diseases.

α-Linolenic acid-regulated testosterone biosynthesis via activation of the JNK-SF-1 signaling pathway in primary rooster Leydig cells.

As a functional fatty acid, α-linolenic acid (ALA) is essential in promoting animal testosterone biosynthesis. This study investigated the effects of ALA on testosterone biosynthesis and the possible mechanism underlying the signaling pathway in primary Leydig cells of the rooster. METHODS: Primary rooster Leydig cells were treated with ALA (0, 20, 40, or 80 µmol/L) or pretreated with a p38 inhibitor (50 µmol/L), a c-Jun NH2-terminal kinase (JNK) inhibitor (20 µmol/L), or an extracellular signal-regulated kinase (ERK) inhibitor (20 µmol/L) before ALA treatment. Testosterone content in the conditioned culture medium was detected using an enzyme-linked immunosorbent assay (ELISA). The expression of steroidogenic enzymes and JNK-SF-1 signaling pathway factors was detected using real-time fluorescence quantitative PCR (qRT-PCR). RESULTS: Supplementation with ALA significantly increased testosterone secretion within culture media (P < 0.05), and the optimized dose was 40 µmol/L. Compared with the control group, steroidogenic acute regulatory protein (StAR), cholesterol side-chain cleavage enzyme (P450scc), and 3ß-hydroxysteroid dehydrogenase (3ß-HSD) mRNA expression significantly increased (P < 0.05) in the 40 µmol/L ALA group; 17-hydroxylase/c17-20 lyase (P450c17) and p38 mRNA expressions were not significantly different in the 40 µmol/L ALA group; ERK and JNK mRNA expressions were significantly upregulated (P < 0.05) in 40 µmol/L ALA group. In the inhibitor group, testosterone levels were significantly downregulated (P < 0.05). Compared with the 40 µmol/L ALA group, StAR, P450scc, and P450c17 mRNA expressions were significantly decreased (P < 0.05), and 3ß-HSD mRNA expression in the p38 inhibitor group did not change; StAR, P450scc, and 3ß-HSD mRNA expressions were significantly decreased (P < 0.05), and P450c17 mRNA expression in ERK inhibitor group did not change; StAR, P450scc, 3ß-HSD, and P450c17 mRNA expressions were significantly decreased (P < 0.05) in JNK inhibitor group. Additionally, the increased steroidogenic factor 1 (SF-1) gene expression levels induced by ALA were reversed when the cells were pre-incubated with JNK and ERK inhibitors. The levels in the JNK inhibitor group were significantly lower than those in the control group (P < 0.05). CONCLUSION: ALA may promote testosterone biosynthesis by activating the JNK-SF-1 signaling pathway to upregulate StAR, P450scc, 3ß-HSD, and P450c17 expression in primary rooster Leydig cells.

Effects of dietary pretreated Chinese herbal medicine supplementation on production performance, egg quality, uterine histopathological changes, and antioxidant capacity in late-phase laying hens.

Aims: The study aimed to evaluate the effects of pretreated Chinese herbal medicine (PCHM) on egg quality, production performance, histopathological changes in the uterus, antiox idant capacity, and antioxidant gene expression in late-phase layers. Methods: Jinghong No.1 layers (n = 360, 68 weeks old) were assigned randomly to one of f our dietary interventions. Each treatment was replicated six times. Repeat 15 chickens per g roup. All birds were fed a diet composed of a corn-soybean meal-based diet supplemented with 0, 0.2, 0.4, or 0.8% PCHM for 6 weeks. Results: Dietary PCHM supplementation had no significant effects on laying rate, feed con sumption, yolk color, and shape index. With increasing PCHM level the Haugh unit linearly increased (P < 0.05). Supplementation of 0.8% PCHM increased egg weight, compared with the control (P < 0.05). PCHM can effectively alleviated the pathological changes caused by aging in the uterus including hemorrhage, and many inflammatory cell infiltrations. Supplementation of 0.4% PCHM increased glutathione peroxidase (GSHPx) in liver, magnum, and plasm considerably, compared with the control (P < 0.05). Supplementation of PCHM decr ease in the liver, magnum, and uterus on malondialdehyde (MDA) content, compared with the control (P < 0.05). Compared with the control group, mRNA expressions of glutathione peroxidase 1 (GPX1), peroxidase 4 (GPX4), catalase (CAT), and nuclear factor E2-related factor 2 (Nrf2) in the magnum, liver, and uterus were dramatically rose in the 0.4% PCHM supplementation group (P < 0.05). In summary, dietary supplementation after PCHM increased egg weight and quality in late-phase laying hens. Conclusion: Dietary PCHM increased the antioxidative capacity of late-phase laying hens, which could be associated with increased mRNA expression of antioxidant enzymes and Nrf2. These findings provide potential for using PCHM to increase the production performance in late-phase laying hens.

Melatonin through blockade of Hif-1α signaling mediates the anti-fibrosis under hypoxia in canine Sertoli cells.

The hypoxic microenvironment of cryptorchidism is an important factor in the impairment and fibrosis of Sertoli cells which result in blood-testis barrier (BTB) destruction and spermatogenesis loss. Recent studies have shown that melatonin, a well-known pineal hormone exerts beneficial effects against pathological fibrosis in a various of organs. However, it is still unknown whether melatonin can regulate hypoxia-induced fibrosis of Sertoli cells. In this study we evaluate melatonin levels, and its synthesizing enzymes, AANAT and HIOMT expression patterns in canine cryptorchidism and contralateral normal testis. Results show abdominal testes presented low melatonin levels and AANAT and HIOMT expression compared with testes located in the scrotum. Moreover, we established a hypoxia-induced fibrosis model in canine Sertoli cells induced by cobalt chloride (CoCl2) and found that melatonin inhibited the EMT markers expression and ECM production as well as Hif-1α expression of Sertoli cells in a dose-dependent manner. Furthermore, use of Lificiguat (synonyms YC-1, Hif-1α inhibitor) to interfere with the Hif-1α pathway showed a similar effect with melatonin suppression of the fibrosis in Sertoli cells. The results indicate that melatonin supplementation can alleviate the fibrosis process of Sertoli cells caused by hypoxia, which is associated with regulating the inhibition of Hif-1α signaling.

Dietary supplementation with selenomethionine enhances antioxidant capacity and selenoprotein gene expression in layer breeder roosters.

This study's objective was to investigate the effects of dietary Se (in the form of selenomethionine) on the antioxidant activity and selenoprotein gene expressions in layer breeder roosters. One hundred and eighty, 36-wk-old Jingfen layer breeder roosters were randomly allocated to one of 5 dietary treatments (0, 0.25, 0.5, 1, or 2 mg/kg Se) for 6 wk on a corn-soybean meal-based diet. Antioxidant parameters and selenoprotein gene expressions were assessed at the end of the experiment. The results showed that Se supplementation significantly increased the activity of T-SOD, CAT, GSH-Px, and superoxide anion scavenging ability in plasma (P ≤ 0.05), and activities of T-SOD, CAT, GSH-Px, superoxide anion scavenging ability, and hydroxyl radical scavenging ability in the liver, kidney, and testis (P < 0.05). Moreover, MDA levels were significantly reduced in plasma, liver, kidney, and testis (P < 0.01), compared to the control group. Furthermore, the dietary administration of Se significantly increased TrxR2 and GPx4 mRNA levels in kidney and testis, and ID1 mRNA levels in liver and kidney. Most of the antioxidant parameters and selenoprotein-related gene expressions significantly increased, and MDA significantly decreased at dietary supplementation with 0.5 mg/kg Se. Whereas a higher dose of Se level (1 or 2 mg/kg) inhibited the activities of some of the antioxidant enzymes and selenoprotein-related gene expressions in selected tissues. In conclusion, dietary Se supplementation with 0.5 mg/kg significantly improved roosters' antioxidant status and selenoprotein-related gene expression in liver, kidney, and testis, while higher doses led to inhibit these; dietary Se might increase reproductive performance by enhancing their antioxidant status in roosters.

Research Note: Dietary supplementation with pyrroloquinoline quinone disodium (PQQ.Na2) improves oxidative status and semen quality in aging layer breeder roosters.

As the antioxidant capacity of sperm declines with age in roosters, the objective of the present study was to determine the effects of different levels of pyrroloquinoline quinone disodium (PQQ.Na2) on antioxidative and sperm quality parameters of aging layer breeder roosters. A total of ninety-six 63-wk-old Jinghong No. 1 layer breeder roosters were randomly assigned to 4 treatments (0, 0.5, 1, 2 mg/kg PQQ.Na2) for 6 wk. Antioxidant activity and semen parameters were assessed biweekly. The dietary administration of PQQ.Na2 significantly increased semen quality (semen volume, sperm motility, straightness, progressive motility, curvilinear velocity, straight-line velocity, and amplitude of lateral head displacement) and antioxidant capacity (T-SOD, GSH-Px, hydroxyl radical scavenging ability, and/or superoxide scavenging capacity) in seminal plasma in aging layer breeder roosters. Whereas, PQQ.Na2 supplementations significantly decreased malondialdehyde (MDA) concentration in seminal plasma in aging layer breeder roosters. Supplementation with 1 mg/kg dietary PQQ.Na2 as an antioxidant supplement could increase sperm quality and antioxidant activity of aging layer breeder roosters, while a higher dose (2 mg/kg) did not result in further increment.

Dietary supplementation with natural astaxanthin from Haematococcus pluvialis improves antioxidant enzyme activity, free radical scavenging ability, and gene expression of antioxidant enzymes in laying hens.

The objective of this study was to evaluate the effects of natural astaxanthin (ASTA) from Haematococcus pluvialis on production performance, egg quality, antioxidant enzyme activity, free radical scavenging ability, and gene expression of antioxidant enzymes in laying hens. Nongda No. 3 laying hens (n = 450) were randomly allocated to 1 of 5 dietary treatments. Each treatment had 6 replicates of 15 hens each. All birds were assigned to a corn-soybean meal-based diet containing 0, 20, 40, 80, or 160 mg/kg ASTA for 4 wk. With increasing dietary ASTA, no significant effects were observed on egg weight, feed consumption, feed efficiency, laying rate, Haugh unit, or eggshell strength. Yolk color darkened linearly with increasing dose of ASTA (P < 0.05). Glutathione peroxidase activity was improved in the kidney with dietary ASTA at levels of 40 mg/kg. Total superoxide dismutase (SOD) was significantly increased in the liver, kidney, and plasma with dietary ASTA supplementation at 40 mg/kg. With increasing dietary ASTA, the scavenging abilities of hydroxyl radicals and superoxide anions were linearly increased (P < 0.05), and the malondialdehyde content decreased linearly (P < 0.05). Compared with the control group, mRNA expression of Cu-Zn SOD (SOD1), Mn SOD (SOD2), and nuclear factor E2-related factor 2 (NRF2) in the liver and kidney was significantly increased in the 40 mg/kg ASTA group (P < 0.05). The level of GPX4 mRNA in the liver and kidney was significantly increased with ASTA supplementation at 40 and 80 mg/kg (P < 0.05). The results demonstrate that dietary ASTA improves free radical scavenging ability and antioxidant enzyme activity, which may be related in part to the upregulated mRNA expression of genes encoding antioxidant enzymes and NRF2.

Effects of supplementing natural astaxanthin from Haematococcus pluvialis to laying hens on egg quality during storage at 4°C and 25°C.

The objective of this study was to evaluate the effects of different levels of dietary natural astaxanthin (ASTA) (from the microalga Haematococcus pluvialis) and storage at 4°C and 25°C on the quality of eggs from laying hens. Nongda No. 3 laying hens (n = 450) were randomly allocated to 1 of 5 dietary treatments. Each treatment had 6 replicates of 15 hens each. All birds were assigned to a corn-soybean meal-based diet containing 0, 20, 40, 80, or 160 mg/kg natural ASTA for 4 wk. A total of 540 eggs were collected at the end of the 4-week feeding trial. Sixty fresh eggs were collected and measured for egg quality within 24 h after collection. The other 480 eggs were used in a factorial arrangement with 5 dietary ASTA levels, 4 storage times, and 2 storage temperatures. During the 8-week storage period at 4°C and 25°C, egg quality measurements were performed every 2 wk on 12 eggs per treatment. No significant effects (P > 0.05) on yolk index, yolk pH, Haugh units, weight loss, or eggshell strength were observed with increasing concentrations of dietary ASTA. Yolk color darkened linearly with increasing dose of ASTA (P < 0.05). During storage of eggs, yolk index and Haugh units decreased significantly (P < 0.05), whereas yolk pH and weight loss increased (P < 0.05). An interaction was observed between dietary ASTA level and storage time on yolk index, yolk color, and Haugh units (P < 0.05). These results demonstrated that dietary ASTA from H. pluvialis delayed the decrease in yolk index and yolk color during storage at 4°C and 25°C. Therefore, we speculate that there may be a combined effect of dietary ASTA level and storage time on egg internal quality; this information may provide additional options by which to extend the storage time of eggs.