Tea Polyphenols Enhanced the Antioxidant Capacity and Induced Hsps to Relieve Heat Stress Injury

Abstract

Keap1-Nrf2-ARE and heat shock proteins (Hsps) are important endogenous protection mechanisms initiated by heat stress to play a double protective role for cell adaptation and survival. H9C2 cells and 80 300-day-old specific pathogen-free chickens were randomly divided into the control and tea polyphenol groups and used to establish a heat stress model in vitro and in vivo. This task was conducted to explore the protection and mechanism of tea polyphenols in relieving thermal injury. A supplement with 10 μg/mL tea polyphenols could effectively relieve the heat damage of H9C2 cells at 42°C. Accordingly, weaker granular degeneration, vacuolar degeneration, and nucleus deep staining were shown. A strong antioxidant capacity was manifested in the upregulation of the total antioxidant capacity (T-AOC) (at 5 h, P < 0.05 ), Hemeoxygenase-1 mRNA (at 2 h, P < 0.01 ), superoxide dismutase (SOD) (at 2, 3, and 5 h, P < 0.05 ), and Nrf2 (at 0 and 5 h, P < 0.01 ). A high expression of Hsps was reflected in CRYAB at 3 h; Hsp27 at 0, 2, and 3 h ( P < 0.01 ); and Hsp70 at 3 and 5 h ( P < 0.01 ). The supplement with 0.2 g/L tea polyphenols in the drinking water also had a good effect in alleviating the heat stress damage of the myocardial cells of hens at 38°C. Accordingly, light pathological lesions and downregulation of the myocardial injury-related indicators (LDH, CK, CK-MB, and TNF-α) were shown. The mechanism was related to the upregulation of T-AOC (at 0 h, P < 0.05 ), GSH-PX (at 0.5 d, P < 0.01 ), SOD (at 0.5 d), and Nrf2 (at 0 d with P < 0.01 and 2 d with P < 0.05 ) and the induced expression of CRYAB (at 0.5 and 2 d), Hsp27 (at 0, 0.5, and 5 d), and Hsp70 (at 0 and 0.5 d). In conclusion, the tea polyphenols enhanced the antioxidant capacity and induced Hsps to relieve heat stress injury.

Effects of Dietary Tea Powder on the Growth Performance, Carcass Traits, and Meat Quality of Tibetan Pig × Bama Miniature Pigs

“…By improving the activity of the ALP enzyme, it helps to increase the feed intake of the pigs [ 36 ]. T-AOC, SOD, and GSH-Px are important indicators that reflect the body’s antioxidant level, also known as the body’s antioxidant enzyme system [ 37 ]. Among them, GSH-Px catalyzes peroxides to produce alcohol or water through a reduction reaction.…”

Polysaccharides From Abrus cantoniensis Hance Modulate Intestinal Microflora and Improve Intestinal Mucosal Barrier and Liver Oxidative Damage Induced by Heat Stress

“…That is, exposure to extreme heat acts as a stimulus, triggering the activation and accumulation of HSP to protect functional proteins from degeneration ( 34 ). In the study, after 0,.5, and 2 h heat treatment, the level of HSP70 in the H9C2 cells was significantly higher than that in the normal temperature control group ( 30 ). This is consistent with our findings that HSP70 levels were significantly elevated after HS treatment and HSP70 levels were reversed to normal by ACP.…”

“…Keap1-Nrf2 and HSPs are important endogenous protective mechanisms of HS initiation, participating in the regulation of antioxidant enzymes and playing a dual protective role in cell adaptation and survival ( 30 ). Nrf2 is a key factor in the Keap1-Nrf2 pathway, which plays an important role in activating antioxidant signaling pathways to prevent oxidative stress-induced cell and tissue damage and to maintain redox balance ( 31 ); it can also boost the production of other antioxidants ( 32 ); Keap1 is a negative regulator of Nrf2 ( 33 , 34 ).…”

Evaluation of a Dietary Grape Extract on Oxidative Status, Intestinal Morphology, Plasma Acute-Phase Proteins and Inflammation Parameters of Weaning Piglets at Various Points of Time

“…The potential of polyphenols in the prevention of excessive ROS production is interesting with regard to increased antioxidant enzyme production and in the regulation of heat shock proteins (HSPs). Both are associated with cytoprotection, as shown by Yin et al [ 90 ]. Antioxidant genes are upregulated in order to convert the superoxide anion radical to H 2 O 2 (e.g., SOD1) or they are involved in modulating of glutathione homeostasis (e.g., GPX1, GPX2, and CAT) [ 91 ].…”

“…Moreover, another study showed reduced HSP70 expression in organs after longer period (6 h) of transportation stress, thus suggesting a certain adaptability to the expression of this gene [ 94 ]. The role of polyphenols in the presence of heat stress and their potential in stimulation of HSPs was explored in chickens by Yin et al [ 90 ], who showed no clear direction of effects of tea-derived phenolic compounds on different HSPs in the presence of heat stress. The results from our analyses in the liver, without changes in the expression of HSP70 and HSP90AA1 by the diets, suggest an absence of acute stress on day 27/28 and day 55/56 that could allow polyphenols to alleviate the expression of these genes.…”