Impact of zinc and arginine on antioxidant status of weanling piglets raised under commercial conditions

Development and application of a multi-step porcine in vitro system to evaluate feedstuffs and feed additives for their efficacy in nutrient digestion, digesta characteristics, and intestinal immune responses

In vitro model provides alternatives to the use of live animals in research. In pig nutrition, there has been a tremendous increase in in vivo research over the decades. Proper utilization of in vitro models could provide a screening tool to reduce the needs of in vivo studies, research duration, cost, and the use of animals and feeds. This study aimed to develop a multi-step porcine in vitro system to simulate nutrient digestion and intestinal epithelial immune responses affected by feedstuffs and feed additives. Seven feedstuffs (corn, corn distillers dried grains with solubles [corn DDGS], barley, wheat, soybean meal, soy protein concentrates, and Corynebacterium glutamicum cell mass [CGCM]), feed enzymes (xylanase and phytase), and supplemental amino acids (arginine, methionine, and tryptophan), were used in this in vitro evaluation for their efficacy on digestibility, digesta characteristics, and intestinal health compared with the results from previously published in vivo studies. All in vitro evaluations were triplicated. Data were analyzed using Mixed procedure of SAS9.4. Evaluations included (1) nutrient digestibility of feedstuffs, (2) the effects of feed enzymes, xylanase and phytase, on digestibility of feedstuffs and specific substrates, and (3) the effects of amino acids, arginine, tryptophan, and methionine, on anti-inflammatory, anti-oxidative, and anti-heat stress statuses showing their effects (P < 0.05) on the measured items. Differences in dry matter and crude protein digestibility among the feedstuffs as well as effects of xylanase and phytase were detected (P < 0.05), including xylo-oligosaccharide profiles and phosphorus release from phytate. Supplementation of arginine, tryptophan, and methionine modulated (P < 0.05) cellular inflammatory and oxidative stress responses. The use of this in vitro model allowed the use of 3 experimental replications providing sufficient statistical power at P < 0.05. This indicates in vitro models can have increased precision and consistency compared with in vivo animal studies.

Zinc caproate: Ecofriendly synthesis, structural characterization, and antibacterial action

Disease-causing microorganisms such as Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) are among the primary contributors to morbidity and mortality of diarrhea in humans. Considering the challenges associated with antibiotic use, including antimicrobial resistance, this study aimed to develop a novel zinc-based agent for bacterial inactivation. To this end, zinc caproate (ZnCA) was synthesized using caproic acid (CA) and zinc oxide (ZnO) in anhydrous ethanol via the solvothermal method. Structural characterization techniques, including Fourier-transform infrared spectroscopy, single crystal X-ray diffraction analysis, and nuclear magnetic resonance spectroscopy, revealed the bidentate bridging coordination of zinc atoms with CA. The resulting two-dimensional ZnCA network was found to be composed of a distinct lamellar pattern, without any evident inter-layer interactions. Powder X-ray diffraction analysis, elemental analysis, and melting point analysis confirmed that ZnCA had an average particle size of 1.320 µm, a melting point of 147.2 °C, and a purity exceeding 98 %. Remarkably, ZnCA demonstrated potent antibacterial activity against E. coli and S. aureus, which exceeded the antibacterial efficacy of ZnO. ZnCA exerted its antibacterial effects by inhibiting biofilm formation, disrupting cell membrane integrity, increasing cell membrane permeability, and altering intracellular Ca2+-Mg2+-ATPase activity. These findings highlight the potential of ZnCA as a promising antibiotic substitute for the treatment of diarrhea in humans.

Zinc status and indicators of intestinal health in enterotoxigenic Escherichia coli F18 challenged newly weaned pigs fed diets with different levels of zinc

This study investigated the impact of an enterotoxigenic Escherichia coli (ETEC) F18 challenge on newly weaned pigs when fed one of three Zn levels (150, 1,400, or 2,500 ppm) on performance, Zn status, ETEC shedding, and diarrhea. The ETEC challenge was hypothesized to have a more pronounced negative impact on pigs fed a diet containing 150 ppm Zn compared to 1,400 or 2,500 ppm Zn for 14 d after weaning. The study included 72 ETEC F18 susceptible pigs weaned at ~28 d of age (d 0 of the study). The pigs were distributed according to initial weight and litter to one of the three dietary Zn levels. Half of the pigs were challenged with ETEC on d 1 and 2. The challenge reduced (P ≤ 0.03) feed intake and average daily gain (ADG) during d 3 to 5. Challenged pigs fed 150 ppm Zn had lower (P = 0.01) ADG during d 5 to 7 compared to those fed 1,400 or 2,500 ppm Zn, whereas control pigs' ADG were not affected by dietary Zn content. Challenged pigs fed 150 ppm Zn also showed lower (P < 0.01) fecal dry matter (DM) on d 5 compared to control pigs fed 150 ppm Zn and challenged pigs fed 1,400 or 2,500 ppm Zn. Challenge increased (P < 0.01) ETEC shedding in all groups, but challenged pigs fed 150 ppm Zn showed higher (P ≤ 0.05) fecal shedding of ETEC and toxins than when fed 1,400 or 2,500 ppm. On d 3, C-reactive protein concentration in plasma was lower (P < 0.03) for pigs fed 1,400 and 2,500 compared to 150 ppm Zn. Plasma haptoglobin and pig major acute phase protein were unaffected by dietary Zn content. On d 0, the serum Zn concentration was 586 ± 36.6 µg/L, which pigs fed 150 ppm Zn maintained throughout the study. The serum Zn concentration increased (P ≤ 0.07) in pigs fed 1,400 or 2,500 ppm Zn. The challenge decreased (P < 0.01) the serum Zn concentration in pigs fed 2,500 ppm Zn. On d 5 and 7, serum Zn concentration was similar for challenged pigs fed 1,400 and 2,500 ppm Zn, while control pigs fed 2,500 ppm Zn had higher (P < 0.01) serum Zn concentration than 1,400 ppm Zn. On d 7, serum Zn concentration tended (P = 0.08) to be lower for pigs with diarrhea (fecal DM ≤ 18%). In summary, these results indicate that newly weaned pigs fed 150 ppm Zn are more susceptible to ETEC F18 colonization and its adverse consequences such as diarrhea and reduced growth, even though challenge did not increase acute phase proteins.

Intramuscular administration of l-arginine boosts testicular hemodynamics, plasma concentrations of testosterone and nitric oxide in heat-stressed rams

The current study aimed to assess, for the first time, the effects of intramuscular injection of l-arginine (L-arg) on testicular hemodynamics, echogenicity, and plasma concentrations of testosterone, total antioxidant capacity, and nitric oxide (NO) in Ossimi rams. Twelve sexually matured heat-stressed rams were randomly assigned to one of two groups: the L-arg group (n = 6) received 5 mg/kg L-arg dissolved in 2 ml normal saline 0.9%, or the control group (n = 6) received merely 2 ml of normal saline 0.9%. Blood sampling, B-mode ultrasound assessment of the testicular parenchyma, and pulsed-wave Doppler ultrasound of the testicular artery for both right and left testis were performed immediately before 0 min and 1, 4, 24, 48, 72, and 168 h after L-arg or saline administration. In the L-arg group, resistive index (RI) and pulsatility index (PI) means were significantly lower compared to the control group at 4-168 h post-treatment. Plasma testosterone concentrations were higher (P < 0.05) at 4 h and onward in the L-arg treated compared to the control rams, the same for NO levels however its increase (P < 0.05) was observed as soon as 1 h post-treatment. In L-arg treated rams, NO concentrations were positively correlated to plasma testosterone concentrations (r = 0.7, p < .01), but negatively correlated to both RI and PI (r = -0.8 and -0.6, respectively, p < .01). In conclusion, l-arginine administration enhanced testicular blood flow and increased plasma testosterone and nitric oxide concentrations in heat-stressed rams.

The use of oral and enteral tube-fed arginine supplementation in pressure injury care: A systematic review and meta-analysis

AIM

Pressure injuries (PIs) are one of the most common complications related to immobility, especially in hospitalized patients, which lead to increased morbidity, infection and overall decreased quality of life. Arginine supplementation may prevent the development of PIs. This study has summarized the findings of studies on the effect of arginine supplementation on PI healing.

DESIGN

Systematic review and meta-analysis.

METHODS

This study was conducted on online electronic databases including PubMed, Scopus, Web of Science, Google Scholar and Embase to identify relevant clinical trial studies up to September 2020. The pooled effect size of arginine supplement effects on PI was evaluated with standard mean difference (SMD) with 95% confidence interval (CI).

RESULTS

Eight studies met the inclusion criteria for this meta-analysis with 196 patients. PIs were significantly improved with Arginine supplementation (SMD: -0.6; CI 95%: -0.9 to -0.3, I² : 72.5%, p = .001). Subgroup analysis showed that administering Arginine supplement more than 15 g/day had more beneficial effects on the healing of PIs (SMD: -2.8; CI 95%: -4.08 to -1.52, I² : 54.7%, p = .138).

CONCLUSIONS

Our findings suggest that the administration of Arginine supplement in patients with PIs can accelerate the healing of this type of ulcer. Arginine is a supplement, and primary treatment is still needed to optimize PI healing. Therefore, arginine supplementation in addition to primary treatment seems to be an appropriate approach for the healing of PIs. Further well-designed studies are necessary to prevent the development of PIs compared to their primary treatment.

Synthesis of Zinc Oxide Eudragit FS30D Nanohybrids: Structure, Characterization, and Their Application as an Intestinal Drug Delivery System

The present study was designed to develop multifunctional zinc oxide-encapsulated Eudragit FS30D (ZnO/EFS) nanohybrid structures as a biodegradable drug delivery system and as a promising successful carrier for targeting sites. The solvent evaporation method was used to fabricate the ZnO/EFS nanohybrids and the size, shape, stability, and antioxidant activity were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), thermogravimetric analysis (TGA), and an antioxidant (1,1-diphenyl-2-picrylhydrazyl (DPPH)). Zinc oxide-encapsulated Eudragit FS30D (ZnO/EFS) nanohybrid structures consisted of irregularly shaped, 297.65 nm-sized ZnO/EFS microcapsule, enduring thermal stability from 251.17 to 385.67 °C. Nano-ZnO was encapsulated in EFS through the formation of hydrogen bonds, and the average encapsulation efficiency for nano-ZnO was determined to be 96.12%. In vitro intestinal-targeted drug release assay provided 91.86% with free nano-ZnO, only 9.5% in acidified ZnO/EFS nanohybrid structure but the rate ZnO/EFS nanohybrids reached 93.11% in succus entericus resultantly modified nano-ZnO was proven proficient intestinal-specific delivery system. The stability of the ZnO/EFS nanohybrid structures was confirmed using ζ-potential and antioxidant activity analysis. Hence, the EFS nanoencapsulation strategy of ZnO provided a stable, nontoxic, and pharmacokinetically active intestine-specific system that can become the best choice for an effective oral feed additive in future.