Ameliorative Hematological and Histomorphological Effects of Dietary Trigonella foenum-graecum Seeds in Common Carp (Cyprinus carpio) Exposed to Copper Oxide Nanoparticles

Abstract

Different types of metal oxide nanoparticles (NPs) are being used for wastewater treatment worldwide but concerns have been raised regarding their potential toxicities, especially toward non-targeted aquatic organisms including fishes. Therefore, the present study aimed to evaluate the toxicity of copper oxide (CuO) NPs (1.5 mg/L; positive control group) in a total of 130 common carp (Cyprinus carpio), as well as the potential ameliorative effects of fenugreek (Trigonella foenum-graecum) seed extracts (100 mg/L as G-1 group, 125 mg/L as G-2 group, and 150 mg/L as G-3 group) administered to fish for 28 days. Significant changes were observed in the morphometric parameters: the body weight and length of the CuO-NP-treated fish respectively decreased from 45.28 ± 0.34 g and 14.40 ± 0.56 cm at day one to 43.75 ± 0.41 g and 13.57 ± 0.67 cm at day 28. Conversely, fish treated with T. foenum-graecum seed extract showed significant improvements in body weight and length. After exposure to CuO NPs, a significant accumulation of Cu was recorded in the gills, livers, and kidneys (1.18 ± 0.006 µg/kg ww, 1.38 ± 0.006 µg/kg ww, and 0.05 ± 0.006 µg/kg ww, respectively) of the exposed common carp, and significant alterations in fish hematological parameters and oxidative stress biomarkers (lipid peroxidation (LPO), glutathione (GSH), and catalase (CAT)) were also observed. However, supplementing diets with fenugreek extracts modulated the blood parameters and the oxidative stress enzymes. Similarly, histological observations revealed that sub-lethal exposure to CuO NPs caused severe histomorphological changes in fish gills (i.e., degenerative epithelium, fused lamellae, necrotic lamellae, necrosis of primary lamellae, complete degeneration, and complete lamellar fusion), liver (i.e., degenerative hepatocytes, vacuolization, damaged central vein, dilated sinusoid, vacuolated degeneration, and complete degeneration), and kidney (i.e., necrosis and tubular degeneration, abnormal glomerulus, swollen tubules, and complete degeneration), while the treatment with the fenugreek extract significantly decreased tissue damage in a dose-dependent manner by lowering the accumulation of Cu in the selected fish tissues. Overall, this work demonstrated the ameliorative effects of dietary supplementation with T. foenum-graecum seed extract against the toxicity of NPs in aquatic organisms. The findings of this study therefore provided evidence of the promising nutraceutical value of fenugreek and enhanced its applicative potential in the sector of fish aquaculture, as it was shown to improve the growth performance and wellness of organisms.

Histomorphological Changes in Fish Gut in Response to Prebiotics and Probiotics Treatment to Improve Their Health Status: A Review

“…Nevertheless, the formulation of optimal feeding diets for the wide variety of aquaculture fish species requires the implementation of different types of analyses to verify their impact on the health status of the specimens [ 251 ]. Among the different approaches employed [ 194 , 252 ], histomorphological assays represent a good biomarker for the assessment of the welfare of aquatic organisms [ 253 , 254 , 255 , 256 , 257 ] since it is able to promptly provide insights into the overall health status of individuals under examination. In particular, in the histological assays of fish guts, endpoints such as mucosal fold length (villi), muscle thickness (MT), and crypt depth (CD) might provide useful information regarding the efficiency of the gut in terms of nutrient absorption [ 223 ], while evaluation of the number of goblet cells and leukocytes may be useful for estimating the state of the immune system response, which is crucial for gut microbiota balance [ 222 ].…”

“…Besides enhancing the general wellness of aquaculture fish species, feed additives (prebiotics and probiotics) play a pivotal role in challenging infections, providing a valid alternative to the use of antibiotics that may lead to antibiotic resistance after a prolonged period of time [ 175 , 256 , 257 , 269 ]. In [ 175 ], the efficiency of three Bacillus species in O. niloticus against A. hydrophila infection was assessed, resulting in improvements in some histological parameters of the fish gut (i.e., villus length and width, goblet cells count, intestinal epithelial muscle thickness).…”

Differential Cell Metabolic Pathways in Gills and Liver of Fish (White Seabream Diplodus sargus) Coping with Dietary Methylmercury Exposure

“…Although Hg toxicity has been the topic of several studies [ 17 , 18 , 19 ], clarifying the mechanisms of dietary MeHg toxicity in fish remains challenging. Fish have been widely used in ecotoxicological studies as worthy sentinel organisms [ 6 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ] due to their ability to accumulate and metabolize different contaminants in their tissues and to produce valid and measurable responses (biomarkers) when exposed to stressful conditions, such as the presence of Hg.…”