Regulation of transcription factors by the epigallocatechin-3-gallate in poultry reared under heat stress

Abstract

High ambient temperature is associated with decreasing growth rate, egg production, feed efficiency, nutrient utilisation, egg quality and is a major problem resulting in extensive economic losses in poultry. Poultry reared under heat stress may exhibit various metabolic disorders caused by a chronic state of oxidative stress and inflammation. Recently, nuclear factor-erythroid 2-related factor 2 (Nrf2) has emerged as an agent that plays a significant role in cellular protection against oxidative stress and inflammation. The nuclear factor kappa-B (NF-κB) signalling pathway has been associated with enhanced inflammatory response and its activation has been significantly correlated with heat stress. These transcription factors when activated can regulate antioxidant and anti-inflammatory cellular responses leading to the expression of detoxifying enzymes. Studies have shown that NF-κB and Nrf2 expression can be modulated by several factors, such as bioactive compounds. Green tea contains many polyphenolic antioxidants including the catechin, epigallocatechin-3-gallate (EGCG). As bioactive compounds, supplementing EGCG in poultry diets may improve antioxidant status in poultry. EGCG modulates signalling pathways including the NF-κB and Nrf2 that regulate antioxidant and anti-inflammatory responses. This review aims to discuss the evidence to justify a recommendation of EGCG in heat stressed poultry as a non-pharmacological option to activate the NF-κB and Nrf2 pathways.

Keywords::

• heat stress
• EGCG
• antioxidant
• anti-inflammatory
• poultry

Acknowledgements

This work was supported by the Turkish Academy of Sciences (KS).