Noni (Morinda citrifolia) modulates the hypothalamic expression of stress- and metabolic-related genes in broilers exposed to acute heat stress

Authors: RAJAEI-SHARIFABADI, HOSSEIN - University Of Arkansas; ELLESTAD, LAURA - University Of Maryland; PORTER, TOM - University Of Maryland; Donoghue, Ann - Annie; BOTTJE, WALTER - University Of Arkansas; DRIDI, SAMI - University Of Arkansas

Submitted to: Frontiers in Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/27/2017
Publication Date: 12/5/2017
Citation: Rajaei-Sharifabadi, H., Greene, E., Piekarski, A., Lassiter, K., Cook, D., Blankenship, K., Falcon, D., Nguyen, P., Decker, A., Gramlich, L., Thaxton, Y., Liang, Y., Hazen, K., Ellestad, L., Porter, T., Donoghue, A.M., Bottje, W., Dridi, S. 2017. Noni (Morinda citrifolia) modulates the hypothalamic expression of stress- and metabolic-related genes in broilers exposed to acute heat stress. Frontiers in Genetics. 8:192.
DOI: https://doi.org/10.3389/fgene.2017.00192

Interpretive Summary: Commercial poultry production is facing substantial challenges from a steep projected increases in global demand for nutritional needs and the necessity to adapt to global environmental changes, increasing pressures on water and land availability and the prohibition of sub-therapeutic use of antibiotics in animal food industry. There is, therefore, a critical need to identify new alternative approaches to sustainably meet demand for animal product. The tropic medicinal plant Morinda Citrifolia L (Noni) has gained considerable popularity in animal nutrition and has been reported to improve growth performance in poultry, yet its underlying molecular mechanisms are still unknown. The present study aimed to determine the effect of Noni on the hypothalamic expression of stress- and metabolic-related genes in broiler chickens exposed to acute heat stress (HS). A total of 480 one day-old male broiler chicks were randomly assigned to 12 controlled environmental chambers. Each chamber was divided into 2 floor pens and chicks were fed corn-soy based diet (C) or a diet containing 2 g dried noni plant/kg feed (N). At 21 days of age, chickens were exposed to two thermal conditions: acute heat stress (HS, 35°C, for 2h) or thermoneutral condition (TN, 25°C) resulting in a total of 4 experimental groups (C-TN, C-HS, N-TN, and N-HS). Feed intake and core body temperature (BT) were recorded. Blood was collected and hypothalamic tissues were harvested for target gene and protein analyses. Acute heat stressed-broilers exhibited higher BT (~1°C), spent less time eating with a significant decrease in feed intake, and spent more time drinking along with higher drinking frequency compared to those maintained under TN conditions. Although dietary supplementation of Noni did not improve feed intake, it significantly increased plasma corticosterone levels in broilers maintained under both TN and HS conditions. At molecular levels and under HS conditions, Noni supplementation down regulated the hypothalamic expression of HSP90 and its related transcription factors HSF1, 2, and 4, increased orexin mRNA levels, and decreased the phosphorylation levels of AMPKa1/2 and mTOR at Thr172 and Ser2481 sites, respectively. Together, these data indicated that Noni supplementation might modulate HS response in broilers through central orexin-AMPK-mTOR pathways.

Technical Abstract: Commercial poultry production is facing substantial challenges from a steep projected increases in global demand for nutritional needs and the necessity to adapt to global environmental changes, increasing pressures on water and land availability and the prohibition of sub-therapeutic use of antibiotics in animal food industry. There is, therefore, a critical need to identify new alternative approaches to sustainably meet demand for animal product. The tropic medicinal plant Morinda Citrifolia L (Noni) has gained considerable popularity in animal nutrition and has been reported to improve growth performance in poultry, yet its underlying molecular mechanisms are still unknown. The present study aimed to determine the effect of Noni on the hypothalamic expression of stress- and metabolic-related genes in broiler chickens exposed to acute heat stress (HS). A total of 480 one day-old male broiler chicks were randomly assigned to 12 controlled environmental chambers. Each chamber was divided into 2 floor pens and chicks were fed corn-soy based diet (C) or a diet containing 2 g dried noni plant/kg feed (N). At 21 days of age, chickens were exposed to two thermal conditions: acute heat stress (HS, 35°C, for 2h) or thermoneutral condition (TN, 25°C) resulting in a total of 4 experimental groups (C-TN, C-HS, N-TN, and N-HS). Feed intake and core body temperature (BT) were recorded. Blood was collected and hypothalamic tissues were harvested for target gene and protein analyses. Acute heat stressed-broilers exhibited higher BT (~1°C), spent less time eating with a significant decrease in feed intake, and spent more time drinking along with higher drinking frequency compared to those maintained under TN conditions. Although dietary supplementation of Noni did not improve feed intake, it significantly increased plasma corticosterone levels in broilers maintained under both TN and HS conditions. At molecular levels and under HS conditions, Noni supplementation down regulated the hypothalamic expression of HSP90 and its related transcription factors HSF1, 2, and 4, increased orexin mRNA levels, and decreased the phosphorylation levels of AMPKa1/2 and mTOR at Thr172 and Ser2481 sites, respectively. Together, these data indicated that Noni supplementation might modulate HS response in broilers through central orexin-AMPK-mTOR pathways.