Oxidative stress indices in the erythrocytes from lactating cows after treatment for subclinical ketosis with antioxidant incorporated in the therapeutic regime

Thioredoxin-2 suppresses hydrogen peroxide-activated nuclear factor kappa B signaling via alleviating oxidative stress in bovine adipocytes

During the periparturient period, both oxidative stress, and inflammation of adipose tissue are considered high risk factors for metabolic disorder of dairy cows. Oxidative stress can activate transcription factor nuclear factor kappa B (NF-κB), which lead to the upregulation of genes involved in inflammatory pathways. Thioredoxin-2 (TXN2) is a mitochondrial protein that regulates cellular redox by suppressing mitochondrial reactive oxygen species (ROS) generation in nonruminant, whereas the function of TXN2 in bovine adipocytes was unclear. Thus, the objective of this study was to evaluate how or by which mechanisms TXN2 regulates oxidative stress and NF-κB signaling pathway in bovine adipocytes. Bovine pre-adipocytes isolated from 5 healthy Holstein cows were differentiated and used for (1) treatment with different concentrations of hydrogen peroxide (H2O2; 0, 25, 50, 100, 200, or 400 μM) for 2 h; (2) transfection with or without TXN2 small interfering RNA (si-TXN2) for 48 h and then treated with or without 200 μM H2O2 for 2 h; (3) transfection with scrambled negative control siRNA (si-control) or si-TXN2 for 48 h, and then treatment with or without 10 mM N-acetylcysteine (NAC) for 2 h; (4) transfection with or without TXN2-overexpressing plasmid for 48 h and then treatment with or without 200 μM H2O2 for 2 h. High concentrations of H2O2 (200 and 400 μM) decreased protein and mRNA abundance of TXN2, reduced total antioxidant capacity (T-AOC) and ATP content in adipocytes. Moreover, 200 and 400 μM H2O2 reduced protein abundance of inhibitor of kappa B α (IκBα), increased phosphorylation of NF-κB and upregulated mRNA abundance of tumor necrosis factor-α (TNFA) and interleukin-1B (IL-1B), suggesting that H2O2-induced oxidative stress and activated NF-κB signaling pathway. Silencing of TXN2 increased intracellular ROS content, phosphorylation of NF-κB and mRNA abundance of TNFA and IL-1B, decreased ATP content and protein abundance of IκBα in bovine adipocytes. Knockdown of TXN2 aggravated H2O2-induced oxidative stress and inflammation. In addition, treatment with antioxidant NAC ameliorated oxidative stress and inhibited NF-κB signaling pathway in adipocytes transfected with si-TXN2. In bovine adipocytes treated with H2O2, overexpression of TXN2 reduced the content of ROS and elevated the content of ATP and T-AOC. Overexpression of TXN2 alleviated H2O2-induced inflammatory response in adipocytes, as demonstrated by decreased expression of phosphorylated NF-κB, TNFA, IL-1B, as well as increased expression of IκBα. Furthermore, the protein and mRNA abundance of TXN2 was lower in adipose tissue of dairy cows with clinical ketosis. Overall, our studies contribute to the understanding of the role of TXN2 in adipocyte oxidative stress and inflammatory response.

Comparative therapeutic efficacy of oral administration of gluconeogenic precursors with nicotinamide and intravenous hypertonic dextrose solution for management of subclinical ketosis in Chilika buffaloes

Ketosis in dairy animals originates from negative energy status, associated increased absorption, and production of ketone bodies exceeding their use by the ruminants as an energy source. The present therapeutic experiment was carried out in 29 herds of Chilika buffaloes in 16 villages of three adjoining districts of Chilika Lake, Puri, Khurda, and Ganjam. Twenty Chilika buffaloes, detected positive for subclinical ketosis, were randomly selected for the study and divided into 2 groups, groups II and III, and were treated with hypertonic dextrose solution intravenously or gluconeogenic precursors along with nicotinamide orally, along with other supportive drugs in both the groups. Ten lactating Chilika buffaloes with no signs of ketosis and detected negative on Rothera test were included in the study as healthy controls (group I). Blood and milk samples were collected from all the 30 recruited buffaloes on days 0 (pre-treatment), 7, 14, and 28 for haematological and biochemical analysis. The subclinical ketosis in Chilika buffaloes did not have overt clinical signs. However, close examination revealed gradual drop in milk yield (100%), inappetence (59%), debility (46%), and uncoordinated gait (10%) without excitatory nervous signs. On day 7 following treatment, blood glucose concentration increased significantly. The mean serum triglyceride concentration of group III, treated with gluconeogenic precursors with nicotinamide, continued to decline significantly on subsequent observations. The serum enzyme activity, indicating status of liver function, declined following treatment in both the therapeutic groups. The intravenous administration of hypertonic dextrose solution compared to use of oral gluconeogenic precursors along with nicotinamide efficiently restored recovery from the subclinical ketosis in Chilika buffaloes.

Therapeutic Effects of Levocarnitine or Vitamin B Complex and E With Selenium on Glycerin-Treated Holstein Friesian Cows With Clinical Ketosis

Currently, ketosis has no fully satisfactory resolution in dairy cows. Here, we investigated the effect of levocarnitine or vitamin B complex and E with selenium on clinically ketotic cows (β-hydroxybutyrate ≥ 3.0 mmol/L and decreased milk yield), fed glycerin. In total, 18 cases of Holstein cows with clinical ketosis during the postpartum transition period were randomly assigned to three treatments (6 cases per group): (1) levocarnitine (C+G), (2) vitamin B complex and E with selenium (VBES+G), and (3) levocarnitine and vitamin B complex and E with selenium (C+VBES+G). All groups were administered glycerin. Treatments were administered daily for 4 days. Blood sampling was performed on the onset day of ketosis (day 0), day 4, and day 6. β-Hydroxybutyrate (BHBA), milk yield (MY), and serum biochemical values were measured. Half of the animals in C+G failed to overcome clinical ketosis. VBES+G treatment ameliorated BHBA (p < 0.05), MY, and glucose on day 4. However, ketosis was exacerbated following the discontinuation of the treatment. C+VBES+G treatment improved BHBA, glucose (p < 0.05), and MY and reduced ketotic cases on days 4 and 6 with greater improvements compared to the others. In conclusion, combined treatment with levocarnitine, vitamin B complex and E with selenium, and glycerin may have the therapeutic effect on clinical ketosis.

Effects of a Multicomponent Herbal Extract on the Course of Subclinical Ketosis in Dairy Cows - a Blinded Placebo-controlled Field-study

A blinded placebo-controlled multi-center on-farm trial was conducted in dairy cows with subclinical ketosis to investigate effects of a multicomponent herbal extract. Blood ketone levels were measured weekly in early lactating cows from 16 Swiss herds. Cows were subclassified based on their initial blood-β-hydroxybutyrate levels (≥ 1.0 [KET-low, 84 cows] and > 1.2 mmol/L [KET-high, 39 cows]) and randomly distributed to 3 groups treated orally with herbal extract containing Camellia sinensis, Cichcorium intybus, Gentiana lutea, Glycyrrhiza glabra, Taraxacum officinale, Trigonella foenum-graecum, and Zingiber officinale, sodium propionate, or placebo twice a day for 5 days. Milk yield, milk acetone, blood-β-hydroxybutyrate, glucose, nonesterified fatty acids, gamma-glutamyl transferase, and glutamate dehydrogenase were analyzed over 2 wk. Linear mixed effect models were used for data analysis. No effects were found for nonesterifed fatty acids, gamma-glutamyl transferase, and glucose. Significantly higher glutamate dehydrogenase (29.71 U/L) values were found in herbal extract-treated animals compared to sodium propionate on day 7 (22.33 U/L). By trend, higher blood-β-hydroxybutyrate levels (1.36 mmol/L) were found in the placebo group of KET-high-cows on day 14 compared to the sodium propionate group (0.91 mmol/L). Milk yields of all treatment groups increased. Milking time and treatment showed a significant interaction for milk acetone: sodium propionate led to an immediate decrease, whereas herbal extracts resulted in a milk acetone decrease from day 7 on, reaching significantly lower milk acetone on day 14 (3.17 mg/L) when compared to placebo (4.89 mg/L). In conclusion, herbal extracts and sodium propionate are both likely to improve subclinical ketosis in dairy cows, however, by different modes of action.

Oxidative stress, NF-κB signaling, NLRP3 inflammasome, and caspase apoptotic pathways are activated in mammary gland of ketotic Holstein cows

Ketosis is a serious metabolic disorder characterized by systemic and hepatic oxidative stress, inflammation, and apoptosis, as well as reduced milk yield. Because of the paucity of data on mammary responses during ketosis, the aim of this study was to evaluate alterations in oxidative stress, NF-κB signaling, NLRP3 inflammasome, and caspase apoptotic pathways in mammary gland of dairy cows with ketosis. Blood, mammary gland tissue, and milk samples were collected from healthy cows [Control, blood concentration of β-hydroxybutyrate (BHB) <0.6 mM, n = 10] and cows with subclinical ketosis (SCK, blood concentration of BHB >1.2 mM and <3 mM, n = 10) or clinical ketosis (CK, blood concentration of BHB >3 mM, n = 10) at median 8 d in milk (range = 6-12). Compared with Control, serum concentration of glucose was lower (3.91 vs. 2.86 or 2.12 mM) in cows with SCK or CK, whereas concentrations of fatty acids (0.25 vs. 0.57 or 1.09 mM) and BHB (0.42 vs. 1.81 or 3.85 mM) were greater. Compared with Control, the percentage of milk fat was greater in cows with SCK or CK. In contrast, the percentage of milk protein was lower in cows with SCK or CK. We detected no differences in milk lactose content across groups. Compared with Control, activities of glutathione peroxidase, superoxide dismutase, and catalase were lower in mammary gland tissue of cows with SCK or CK. In contrast, concentrations of hydrogen peroxide and malondialdehyde were greater in cows with SCK or CK. Compared with Control, mRNA abundances of TNFA, IL6, and IL1B were greater in mammary tissues of cows with SCK or CK. In addition, activity of IKKβ and the ratio of phosphorylated inhibitor of κBα to IκBα, and of phosphorylated NF-κB p65 to NF-κB p65, were also greater in mammary tissues of cows with SCK or CK. Subclinical or clinical ketosis also led to greater activity of caspase 1 and protein abundance of caspase 1, NLRP3, Bax, caspase 3, and caspase 9. In contrast, abundance of the antiapoptotic protein was lower in SCK or CK cows. The data indicate that the mammary gland of SKC or CK cows undergoes severe oxidative stress, inflammation, and cell death.

Changes in cardiac biomarkers in goats naturally affected by pregnancy toxemia

Pregnancy toxemia (PT) is considered one of the most common metabolic diseases with high impact on the production of small ruminants. The objective of this study was investigate possible myocardial damage in goats affected with PT by the determination of serum myocardial biomarkers CK-MB and cTnI. A total of 44 goats affected with PT, and 10 apparently healthy goats (control group or CG) were used in the study. In goats with PT, the serum concentrations of cTnI (0.43 ng/mL) were significantly higher than that in CG goats (0.06 ng/mL). Although CK-MB showed no significant difference, it was approximately three times higher in animals with PT. The serum concentrations of insulin were significantly lower in PT goats (5.03 ppmol/L) compared to CG goats (10.66 pmol/L). The serum concentrations of cortisol in PT goats (155.41 nmol/L) were significantly higher than that in CG goats (36.58 nmol/L). Results of this study indicate that a clinically significant myocardial damage might occur in goats affected with PT leading to significant elevations in values of cTnI and CK-MB. Therefore, these parameters could be used as a potential prognostic indicator in goats affected with this important disease.

Effect of heat-shock protein B7 on oxidative stress in adipocytes from preruminant calves

Dairy cows with ketosis display excessive lipolysis in adipose tissue. Heat-shock protein B7 (HSPB7), a small heat-shock protein, plays important roles in mediating cytoprotective responses to oxidative stress in rodent adipose tissue. Accordingly, it is assumed that HSPB7 may also play important roles in the antioxidant response in adipose tissue of ketotic cows. Therefore, the aim of this study is to investigate (1) the redox state of adipose tissue in ketotic cows and (2) the role and mechanism of HSPB7 on the regulation of oxidative stress in adipocytes from preruminant calves. An in vivo study consisting of 15 healthy and 15 clinically ketotic cows was performed to harvest subcutaneous adipose tissue and blood samples. In addition, adipocytes isolated from calves were treated with different concentrations of H₂O₂ (0, 12.5, 25, 50, 100, or 200 μM) for 2 h, transfected with adenovirus-mediated overexpression of HSPB7 for 48 h, or transfected with small interfering RNA of HSPB7 for 48 h followed by exposure to H₂O₂ (200 μM) for 2 h. Serum concentrations of nonesterified fatty acids and β-hydroxybutyrate were greater in cows with clinical ketosis, whereas serum concentration of glucose was lower. Compared with healthy cows, the malondialdehyde content was greater but the activity of glutathione peroxidase and superoxide dismutase was lower in adipose tissue of clinically ketotic cows. The abundance of HSPB7 and nuclear factor, erythroid 2 like 2 (NFE2L2) was greater in adipose tissue of clinically ketotic cows. In vitro, H₂O₂ treatment induced the overproduction of reactive oxygen species and malondialdehyde, and inhibited the activity of antioxidant enzymes glutathione peroxidase and superoxide dismutase in adipocytes from preruminant calves. The low concentration of H₂O₂ (12.5, 25, and 50 μM) increased the abundance of HSPB7 and NFE2L2, but high concentrations of H₂O₂ (100 or 200 μM) reduced the abundance of HSPB7 and NFE2L2. The overexpression of HSPB7 improved the H₂O₂-induced oxidative stress in adipocytes via increasing the abundance of NFE2L2 and its downstream target genes heme oxygenase-1 (HMOX1) and NADH quinone oxidoreductase 1 (NQO1). Knockdown of HSPB7 markedly inhibited the expression of NFE2L2, HMOX1, and NQO1 and further exacerbated H₂O₂-induced oxidative stress. Overall, these results indicate that activation of the HSPB7-NFE2L2 pathway increases cellular antioxidant capacity, thereby alleviating oxidative stress in bovine adipocytes.

Exploration of serum sensitive biomarkers of fatty liver in dairy cows

Serum proteins are sensitive with diseases in dairy cows, and some of them could be used as biomarkers for fatty liver. This study aimed to explore serum biomarkers for fatty liver in dairy cows. A total of 28 early lactating dairy cows were chosen from a commercial dairy herds, liver samples were collected for determining concentration of triacylglycerol (TAG), and serum samples were collected for measuring fibroblast growth factor-21 (FGF-21), adiponectin, Lipoprotein-associated phospholipase A2 (LP-PLA2), and hemoglobin (Hb). Dairy cows were divided into fatty liver (liver TAG > 5%, wet weight) and control group (liver TAG < 5%, wet weight). Concentration of FGF-21 was greater in fatty liver cows, while the concentration of LP-PLA2 and Hb was less. The concentration of FGF-21 and total Hb had strong correlation with the liver TAG as well as good prediction power (kappa value = 0.79 and 0.58, respectively). These results suggested that the serum concentration of FGF-21 and total Hb could be potentially used as fatty liver biomarkers in lactating dairy cows.

Serum Paraoxonase as an Indicator for Fatty Liver in Sheep

INTRODUCTION

A model of fatty liver in postpartum sheep was established to measure blood paraoxonase 1 (PON1) and other biochemical indicators, which were used to predict fatty liver in sheep.

MATERIAL AND METHODS

Sheep were assigned into two experimental groups: a fatty liver group (T, n = 10) and a healthy control group (C, n = 5). PON1 enzyme activity towards paraoxon as a substrate was quantified spectrophotometrically. The results were analysed by t-test and pearson correlation coefficient. Disease was predicted by binary logistic analysis, and diagnostic thresholds were determined by receiver operatingcharacteristic (ROC) analysis.

RESULTS

The activity of serum PON1 in group T was significantly decreased (P < 0.05) when compared with C group, and liver lipid content and the levels of serum BHBA, NEFA, and TG were significantly increased (P < 0.05). Thresholds were lower than 74.0 U/mL for PON1, higher than 0.97 mmol/L for β-hydroxybutyrate, higher than 1.29 mmol/L for non-esterified fatty acids, higher than 0.24 mmol/L for triglycerides, and lower than 71.35 g/L for total protein.

CONCLUSION

This study verified that PON1, BHBA, NEFA, TG, and TP could be used to predict the risk of fatty liver in sheep.

The cardiac biomarkers troponin I and CK-MB in nonpregnant and pregnant goats, goats with normal birth, goats with prolonged birth, and goats with pregnancy toxemia

This study was designed to establish the reference range for the cardiac biomarkers cardiac troponin I (cTnI) and creatine kinase myocardial band (CK-MB) in nonpregnant and pregnant goats, goats with normal birth, goats with prolonged birth associated with dystocia, and goats with pregnancy toxemia. Fifty-seven does, categorized into three groups (G1 to G3), were used. These groups were comprised of 20 healthy does (G1), 19 does with prolonged birth (G2), and 18 does with pregnancy toxemia (G3). Six blood samples (T0 to T5) were collected from G1. The first blood sample (T0) was taken before insemination, the second (T1) at the first trimester, the third (T2) at the second trimester, the fourth (T3) at the last trimester, the fifth (T4) within 12 h of parturition, and the sixth blood sample (T5) was taken 10 days after parturition. A sample of blood was obtained from G2 and G3 upon admission to the hospital. At T0 to T3, no cTnI was detected in any of the 20 does in G1. At parturition (T4), seven of the 20 goats (35%) exhibited slightly elevated cTnI concentrations (range, 0.01 to 0.04 ng/mL). Ten days after parturition (T5), cTnI was not detected in any of the 20 goats. In 10 of the 19 goats (53%) with prolonged birth (G2), the cTnI was significantly elevated to a mean value of 0.094 ± 0.155 ng/mL, with a maximum value of 0.61 ng/mL. In 16 of the 18 goats (89%) with pregnancy toxemia (G3), the cTnI was significantly elevated to a value of 0.852 ± 1.472 ng/mL, with a maximum value of 5.219 ng/mL. Comparing the values of CK-MB in G1 (T0 to T5), G2 and G3 revealed nonsignificant differences. Only a slight elevation in the CK-MB levels in goats with prolonged birth (G2) was noted. We concluded that in healthy does, the cardiac biomarker cTnI is not elevated during normal pregnancy. The serum cTnI concentration may be elevated in a number of goats at normal vaginal or cesarean delivery. Finally, cTnI is significantly elevated in does with pregnancy toxemia and could be used as a prognostic indicator in such cases. The cardiac biomarker CK-MB is not a good indicator of parturition stress in does. Serum cTnI is elevated in goats with pregnancy toxemia, indicating some degree of cardiac dysfunction.