Ginseng Extract Ameliorates the Negative Physiological Effects of Heat Stress by Supporting Heat Shock Response and Improving Intestinal Barrier Integrity: Evidence from Studies with Heat-Stressed Caco-2 Cells, C. elegans and Growing Broilers.

Georg Sandner,Klaus Maenner,Clemens Schwarzinger,Andreas S Mueller,Tobias Aumiller,Stefan Hirtenlehner,Julian Weghuber,Jan Dirk Van Der Klis,Xiaodan Zhou,Bettina Schwarzinger,Verena Stadlbauer,Uwe Wenzel

doi:10.3390/molecules25040835

Abstract

Climatic changes and heat stress have become a great challenge in the livestock industry, negatively affecting, in particular, poultry feed intake and intestinal barrier malfunction. Recently, phytogenic feed additives were applied to reduce heat stress effects on animal farming. Here, we investigated the effects of ginseng extract using various in vitro and in vivo experiments. Quantitative real-time PCR, transepithelial electrical resistance measurements and survival assays under heat stress conditions were carried out in various model systems, including Caco-2 cells, Caenorhabditis elegans and jejunum samples of broilers. Under heat stress conditions, ginseng treatment lowered the expression of HSPA1A (Caco-2) and the heat shock protein genes hsp-1 and hsp-16.2 (both in C. elegans), while all three of the tested genes encoding tight junction proteins, CLDN3, OCLN and CLDN1 (Caco-2), were upregulated. In addition, we observed prolonged survival under heat stress in Caenorhabditis elegans, and a better performance of growing ginseng-fed broilers by the increased gene expression of selected heat shock and tight junction proteins. The presence of ginseng extract resulted in a reduced decrease in transepithelial resistance under heat shock conditions. Finally, LC-MS analysis was performed to quantitate the most prominent ginsenosides in the extract used for this study, being Re, Rg1, Rc, Rb2 and Rd. In conclusion, ginseng extract was found to be a suitable feed additive in animal nutrition to reduce the negative physiological effects caused by heat stress.

Highlights

Global warming and the growing consumer demand for animal-derived food and meat, in newly industrializing countries with hot climates, have increased public concerns regarding animal welfare, long-term sustainable livestock production and food and consumer safety [1,2].Heat stress is an important environmental challenge for the livestock industry, representing the reaction of animals to high-temperature and high-humidity environments, and produces unfavorable consequences, ranging from discomfort to death [3]
To investigate the influence of ginseng extract on the heat shock response in intestinal epithelial cells, the dose-response relationship between ginseng extract (0, 22.5, 45, 90, and 135 mg/L) and the mRNA concentrations of the known heat shock protein genes HSPA1A and HSPB1 and the tight junction protein genes CLDN1, CLDN3 and OCLN in Caco-2 cells were studied
HSPD1 and 2.9-fold higher HSPB1 mRNA levels under heat stress than under normal temperature conditions. This finding indicates that incubating cells at 41 ◦ C for 3 h produced sufficient heat stress in Caco-2 cells

Summary

Introduction

Heat stress is an important environmental challenge for the livestock industry, representing the reaction of animals to high-temperature and high-humidity environments, and produces unfavorable consequences, ranging from discomfort to death [3]. Animals change their behavior and physiology for body heat dissipation; they spend less time feeding and moving and more time resting, drinking and panting. The importance of animal responses to environmental challenges applies to all species. Poultry are more susceptible to heat stress than other farm animals due to their fast metabolic rates [4]. Obvious signs of heat stress in poultry include poor production performance (e.g., decreased feed intake and daily weight gain), poor meat and egg quality, and high morbidity and mortality rates [5,6,7]

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Results

Discussion

Conclusion