Exploring the Multimodal Role of Yucca schidigera Extract in Protection against Chronic Ammonia Exposure Targeting: Growth, Metabolic, Stress and Inflammatory Responses in Nile Tilapia (Oreochromis niloticus L.).

Zizy I Elbialy,Muyassar H Abualreesh,Ahmad El Askary,Merna Rizk,Doaa H Assar,Mohamed M Abdel-Daim,Shimaa M R Salem,Abdallah S Salah,Ahmed Elsheshtawy

doi:10.3390/ani11072072

Abstract

Simple SummaryAmmonia is a problematic environmental toxicant for aquatic species. The current study aimed to declare the modulatory effect(s) of YSE against chronic ammonia intoxication in Nile tilapia through its effects on growth performance, haemato-biochemical and antioxidant-related parameters, and histopathological changes, as well as the molecular gene expression of some genes related to appetite and growth, glucose and lipid metabolism and some inflammatory cytokines. Our results indicated that Yucca schidigera extract alleviated the adverse impacts induced by ammonia intoxication. YSE could be used as a functional water supplement in aquaculture.Ammonia is a critical hazardous nitrogen metabolic product in aquaculture. Despite trials for its control, ammonia intoxication remains one of the most critical issues to overcome. In this study, we explored the modulatory effect and potential mechanism by which Yucca schidigera extract (YSE) can ameliorate ammonia intoxication-induced adverse effects on tilapia health and metabolism. A total number of 120 Nile tilapia were evenly assigned into four groups with three replicates each. The first group served as normal control group; the second group was exposed to ammonia alone from the beginning of the experiment and for four weeks. The third group was supplied with YSE in water at a dose of 8 mg/L and exposed to ammonia. The fourth group was supplied with YSE only in water at a dose of 8 mg/L. YSE supplementation succeeded in improving water quality by reducing pH and ammonia levels. Moreover, YSE supplementation markedly alleviated chronic ammonia-induced adverse impacts on fish growth by increasing the final body weight (FBW), specific growth rate (SGR), feed intake and protein efficiency ratio (PER) while reducing the feed conversion ratio (FCR) via improvements in food intake, elevation of hepatic insulin-like growth factor (ILGF-1) and suppression of myostatin (MSTN) expression levels with the restoration of lipid reserves and the activation of lipogenic potential in adipose tissue as demonstrated by changes in the circulating metabolite levels. In addition, the levels of hepato-renal injury biomarkers were restored, hepatic lipid peroxidation was inhibited and the levels of hepatic antioxidant biomarkers were enhanced. Therefore, the current study suggests that YSE supplementation exerted an ameliorative role against chronic ammonia-induced oxidative stress and toxic effects due to its free radical-scavenging potential, potent antioxidant activities and anti-inflammatory effects.

Highlights

Increased demand for fish as food source is a consequence of pervasive population growth [1]
The first group kept as a normal control group, the second group supplied with Yucca schidigera extract (YSE) in water at a dose of 8 mg/L water every two days, the third group exposed to ammonia from the beginning of the experiment for four weeks, and the fourth group was supplied with YSE and exposed to ammonia for four weeks
In this work, stressed fish with a high ammonia level revealed a significantly elevated total ammonia nitrogen (TAN) and UIA in the water compared to the control fish group, and such results may be attributed to adverse effects of ammonia on the osmoregulation, respiration, and protein metabolism of tilapia, in addition to oxidative stress caused by the free radical production and the subsequent depletion of intracellular antioxidant enzymes [48]

Summary

Introduction

Increased demand for fish as food source is a consequence of pervasive population growth [1]. Fish farming is an ideal potential means of facing the high food and nutrition demands of human beings [2]. The intensification of aquaculture in turn causes water pollution, which is consistently related to increased levels of ammonia, and represents about 70% of nitrogenous fish wastes [3,4]. Decomposed un-eaten feed in water favors ammonia formation, and subjects fish to stress risk [5]. In addition to sewage effluents, agricultural run-off and industrial wastes are major sources that are attributed to elevating ammonia levels in water bodies [6]. NH3 can diffuse across the gill membranes due to its lipid solubility and lack of charge;

Methods

Results

Discussion

Conclusion