Headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry (HS-SPME-GC-MS) offers an alternative analysis method for isoeugenol (an active ingredient in fish sedatives) that avoids the use of organic solvents, simplifies sample preparation, and can be fully automated. This work focuses on developing and evaluating an HS-SPME-GC-MS method for isoeugenol in aquaculture samples and testing the stability of isoeugenol itself. Because of isoeugenol\'s relatively low volatility, more polar SPME fiber coatings (polyacrylate and polydimethylsiloxane/divinylbenzene) had better performance and the headspace extractions took over 30 min to reach equilibrium. Additionally, it was found that isoeugenol was relatively unstable compared to a deuterated standard (d3-eugenol) in the presence of water. To address this, after the fish samples were homogenized with water, they were heated at 50 °C for 1 h prior to analysis for equilibration. By using the method developed in this work, isoeugenol\'s detection limits in multiple aquaculture matrices (shrimp, tilapia, and salmon) were in the low ng/g range (<15 ng/g), well below the target testing level (200 ng/g). Additionally, by adding d3-eugenol as an internal standard, excellent linearity (R2 > 0.98), accuracy (97-99% recoveries), and precision (5-13% RSDs) were all achieved.

The aim of this study was to investigate microplastic (MP) exposure by Nile tilapia (Oreochromis niloticus) in laboratory conditions. A total of 150 tilapia fishes were equally distributed randomly in 15 different glass tanks with five experimental conditions. Observed results depicted that the presence of MPs in different organs was mainly accumulated from the fish feed rather than externally added MPs in the culture tanks. It was also revealed that the gastrointestinal tract (GIT) was found to be the most susceptible to MPs accumulation followed by gills and muscles in order. However, muscle contained the least size of MPs followed by GITs and gills. A statistical test showed significant correlations among the average length and weight of fish with MP exposure. A filamentous shape was found to be dominant in both GITs and gills while fragment shape was dominant in muscles. FTIR results revealed a total of 12 different polymers in the fish of which two polymers (polyvinyl alcohol and ethylene vinyl acetate) were not detected in the feed-only tanks. Polypropylene (PP) and polyethylene terephthalate (PET) were found to be dominant polymers in all the experimental GIT, gills, and muscle organs. FESEM results indicated the presence of different textures including cracks, edges, flakes, scratches, grooves, and adhering particles. EDX results exhibited the presence of Na, Si, K, Ni, Cu, Zn, As, and Cd in the analyzed samples that may pose additional health risks. Thus, this study could act as baseline data for laboratory-based studies of aquaculture species in future research.

Biphasic calcium phosphate (BCP), consisting of bioceramics such as HAp + β-TCP and Ca10(PO4)6(OH)2 + Ca3(PO4)2, is a popular choice for optimizing performance due to its superior biological reabsorption and osseointegration. In this study, BCP was produced by calcining the bones of tilapia fish (Oreochromis niloticus) reared in net cages and slaughtered at an age ranging from 15 to 420 days. The bones were cleaned and dried, calcined at 900 °C for 8 h, and then subjected to high-energy grinding for 3 h to produce BCP powders. After the calcination process, the crystalline phase\'s hydroxyapatite (HAp) and/or beta-tricalcium phosphate (β-TCP) were present in the composition of the bioceramic. The age-dependent variation in phase composition was confirmed by complementary vibrational spectroscopy techniques, revealing characteristic peaks and bands of the bioceramic. This variation was marked by an increase in HAp phase and a decrease in β-TCP phase. Thermogravimetric Analysis (TGA) and Differential Thermal Analysis (DTA) from 25 to 1400 °C showed the characteristic mass losses of the material, with a greater loss observed for younger fish, indicating the complete removal of organic components at temperatures above 600 °C. Comparison of the results obtained by X-Ray Diffraction (XRD) and Rietveld refinement with Raman spectroscopy showed excellent agreement. These results showed that with temperature and environment control and adequate fish feeding, it is possible to achieve the desired amounts of each phase by choosing the ideal age of the fish. This bioceramic enables precise measurement of HAp and β-TCP concentrations and Ca/P molar ratio, suitable for medical orthopedics and dentistry.

Valorization of fish processing waste to obtain value-added products such as collagen and bioactive peptides is a vital strategy to increase the economic value, reduce disposal problems, and prevent harmful impacts on both environment and health. This study aims to isolate two collagen peptides from Taiwan Tilapia skin and prepare 12 nanopeptides including nanoemulsion (NE), nanoliposome (NL), and nanogold (NG) without and with folic acid/chitosan (FA/CH) or FA ligand conjugation for comparison of their inhibition efficiency towards lung cancer cells A549 and normal lung cells MRC5. Acid-soluble collagen (yield, 21.58 %) was extracted using 0.5 M acetic acid and hydrolyzed to obtain two tilapia skin collagen peptides TSCP1 (482 Da) and TSCP2 (172 Da) respectively using 2.5 % and 12.5 % alcalase, with sample-to-water ratio at 1:30 (w/v), pH 8, temperature 50 °C, and hydrolysis time 6 h. Characterization of collagen peptides revealed the presence of type 1 collagen with a high amount of amino acids including glycine (32.6-33.1 %), alanine (13.6-14.0 %), proline (10.0-10.5 %), and hydroxyproline (7.3-7.6 %). TSCP1, TSCP2, and 12 nanopeptides showed a higher cytotoxicity towards A549 cells than MRC5 cells, with TSCP2 and its 6 nanopeptides exhibiting a lower IC50 compared to TSCP1 and its 6 nanopeptides. The mean particle size was 15.7, 33.6, and 16.0 nm respectively for TSCP2-NE, TSCP2-NL, and TSCP2-NG, but changed to 14.4, 36.3, and 17.9 nm following ligand conjugation with a shift in zeta potential from negative to positive for TSCP2-NE-FA/CH and TSCP2-NL-FA/CH. All nanopeptides were more effective than peptides in inhibiting the growth of A549 cells, with the lowest IC50 value being shown for TSCP2-NL-FA/CH (5.32 μg/mL), followed by TSCP2-NE-FA/CH (8.3 μg/mL), TSCP2-NE (22.4 μg/mL), TSCP2-NL (82.7 μg/mL), TSCP2-NG-FA (159.8 μg/mL), TSCP2-NG (234.0 μg/mL) and TSCP2 (359.7 μg/mL). Cell proportions of sub-G1, S, and G2/M phases increased dose-dependently, with a possible cell cycle arrest at G2/M phase. The proportion of necrotic cells was the highest for TSCP2, TSCP2-NE, TSCP2-NE-FA/CH, and TSCP2-NL, while that of late apoptotic cells dominated for TSCP2-NL-FA/CH, TSCP2-NG, and TSCP2-NG-FA. Similarly, TSCP2 and its 6 nanopeptides showed a dose-dependent rise in caspase-3, caspase-8, and caspase-9 activities for execution of apoptosis, with the ligand-conjugated nanopeptides being the most efficient, followed by nanopeptides and peptides. The outcome of this study demonstrated an effective strategy for valorization of Taiwan tilapia skin to obtain collagen peptides and their nanopeptides possessing anticancer activity and form a basis for in vivo study in the future.

Microplastics play a significant role in interactions between organisms and hydrophobic organic contaminants (HOCs), leading to a joint toxic effect on aquatic organisms. This study extensively investigated the tissue-specific accumulation of polychlorinated biphenyls (PCBs) resulting from different sized microplastics in tilapia (Oreochromis mossambicus) using a passive dosing device. Based on biological feeding behavior considerations, 1 mm and 2 μm polystyrene (PS) microplastics with concentrations of 2 and 5 mg L-1 were investigated. A physiologically based toxicokinetic (PBTK) model was applied to evaluate the exchange kinetics and fluxes among the tissues. Moreover, an in vitro simulation experiment was conducted to theoretically validate the vector effect. The findings demonstrated that the effects caused by HOCs and microplastics on organisms were influenced by multiple factors such as size and surface properties. The mass transfer kinetics of HOCs in specific tissues were closely related to their adsorption capacity and position microplastics could reach. Specifically, although 2 μm microplastics exhibited high adsorption capacity for PCBs, they were only retained in the intestines and did not significantly contribute to the bioaccumulation of PCBs in gills or muscle. While 1 mm microplastics were ingested but just paused in the mouth and subsequently flew through the gills with oral mucus. Their vector effects increased the desorption of microplastic-bound PCB-118 in the gill mucus microcosm, thereby facilitating the mass transfer and accumulation of PCB-118 in gills and muscle. This study sheds new light on how the size-dependent vector generated by microplastics affects the tissue-specific accumulation of HOCs in aquatic organisms.

Full-thickness cutaneous trauma, due to the lack of dermis, leads to difficulty in epithelialization by keratinocytes, developing a fibrotic scar, with less elasticity than the original skin, which may have disorders in predisposed individuals, resulting in hypertrophic scar and keloids. Biomedical materials have excellent characteristics, such as good biocompatibility and low immunogenicity, which can temporarily replace traditional materials used as primary dressings. In this work, we developed two dermal matrices based on Nile tilapia collagen, with (M_GAG) and without (M) glycosaminoglycans, using a sugarcane polymer membrane as a matrix support. To assess the molecular mechanisms driving wound healing, we performed qualitative proteomic analysis on the wound bed in an in vivo study involving immunocompetent murine models at 14 and 21 days post-full-thickness skin injury. Gene Ontology and Pathway analysis revealed that both skins were markedly represented by modulation of the immune system, emphasizing controlling the acute inflammation response at 14 and 21 days post-injury. Furthermore, both groups showed significant enrichment of pathways related to RNA and protein metabolism, suggesting an increase in protein synthesis required for tissue repair and proper wound closure. Other pathways, such as keratinization and vitamin D3 metabolism, were also enriched in the groups treated with M matrix. Finally, both matrices improved wound healing in a full post-thick skin lesion. However, our preliminary molecular data reveals that the collagen-mediated healing matrix lacking glycosaminoglycan (M) exhibited a phenotype more favorable to tissue repair, making it more suitable for use before skin grafts.

The widespread use of pesticides in some areas where fish species such as tilapia are farmed may cause damage to the environment and affect commercial fish and therefore, human health. Water leaching with the pesticide trichlorfon, during the fumigation season in the field, can affect water quality in fish farms and consequently affect fish health. At the same time, the use of immunomodulatory compounds such as β-glucan supplied in the diet has become widespread in fish farms as it has been shown that improves the overall immune response. The present research examines the immunomodulatory impacts observed in macrophages of Nile tilapia (Oreochromis niloticus) after being fed a diet supplemented with β-glucan for 15 days, followed by their in vitro exposure to trichlorfon, an organophosphate pesticide, at concentrations of 100 and 500 µg mL-1 for 24 h. The results showed that β-glucan diet improved the viability of cells exposed to trichlorfon and their antioxidant capacity. However, β-glucan did not counteract the effects of the pesticide as for the ability to protect against bacterial infection. From the present results, it can be concluded that β-glucan feeding exerted a protective role against oxidative damage in cells, but it was not enough to reduce the deleterious effects of trichlorfon on the microbicidal capacity of macrophages exposed to this pesticide.

Neoergasilus japonicus, a fish ectoparasite indigenous to eastern and southern Asia, has been introduced to various regions, including Europe and North and South America, where it spreads at an alarming rate. The parasite is not host-specific. It was also collected from the Vaal-Orange and Limpopo river systems in South Africa. This report describes the morphology of the wound-inflecting structures in N. japonicus and relates their morphology to the pathological effect on Tilapia sparrmanii. Host tissue with parasites attached was imbedded in resin for histological sectioning and stained with haematoxylin and eosin. Additional specimens were prepared for scanning electron microscopy. Adult female parasites attach by inserting the hooked tips of the antennae into the epidermis. The maxillulae are minute but have sharp tips. The maxillae have sharp tips on the endopod and brush-like setae on the exopod. The mandibles are armed with sharp tips. These structures are used to remove the epidermis of the host and brush it into the buccal cavity. Host tissue in the intestine confirms that adult females consume host tissue leaving the dermis exposed to opportunistic diseases. The microscopic size of the parasite prevents casual observation, and its occurrence in Africa is, therefore, probably underreported.

OBJECTIVE: Study the possible mechanism and delayed effect of tilapia skin collagen on skin aging for mice.
METHODS: Kunming (KM) mice were randomly divided into the aging model group, the normal group, the positive control group (vitamin E) and the low, medium, high dose tilapia skin collagen groups (2.0, 4.0, 8.0 mg/g). The normal group was only injected with saline at the back and the neck. The other groups were injected subcutaneously with 5% D-galactose and ultraviolet light jointly to establish the aging model. After modeling, the positive control group was treated with a dose of 10% vitamin E once a day, and the low, medium, high dose tilapia skin collagen group was separately applied 2.0, 4.0, 8.0 mg/g of tilapia skin collagen for 40 days. The changes of skin tissue morphology, water content, hydroxyproline (Hyp) content, and superoxide dismutase (SOD) activity in mice were studied at the day 10, 20, 30, 40, 50.
RESULTS: Compared with the normal group, the skin of mice in the aging model group was thinner, looser, and the skin moisture content, Hyp content, SOD activity were all decreased. For mice of the low, medium, high dose tilapia skin collagen group, the thickness of dermis increased, possessing close arrangement, and the moisture content, Hyp content, SOD activity were up-regulated significantly, which effectively alleviated the aging process of skin. The dose of tilapia skin collagen was directly proportional to the anti-aging effect.
CONCLUSIONS: Tilapia skin collagen has an obvious effect on improving skin aging.

A 12-wk trial was conducted to compare the tolerance of tilapia to high carbohydrate and high lipid diets. Three isonitrogenous and isoenergetic diets, whose carbohydrate and lipid levels were the following: 35.0% and 8% (control), 44.2% and 4% (D1, high carbohydrate), and 25.8% and 12% (D2, high lipid), respectively. Three hundred tilapias (27 ± 0.11 g) were fed the diets for 10 wk (4 replicates per group); 72 fish from the D1 group were continually fed the D1 (D1D1) and 72 fish from the D2 were continually fed the D2 (D2D2) diet for 2 wk (3 replicates each group) to evaluate the tilapia\'s capacity to tolerate high carbohydrate and high lipid diets, respectively. Another 36 fish from D1 group were continually fed D2 (D1D2) for comparison with D1D1 and D2D2 groups. In phase 1, hepatosomatic index, liver triglycerides (TG), glucose tolerance (GT) and crude protein in the whole body in D1 group were higher than those in D2 group (P < 0.05). During phase 2, D1D1 group had lower feed intake and weight gain, as well as lower serum total protein and albumin than that of D2D2 group (P < 0.05), while its liver glycogen was significantly higher than that in D1D2 and D2D2 groups (P < 0.05). Moreover, serum glucose and GT were higher in D1D1 and D1D2 groups than those in D2D2 group (P < 0.05). By contrast, D2D2 group had significantly higher intraperitoneal fat, subcutaneous adipose tissue (SCAT) and liver TG than those in D1D1 group (P < 0.05). The mRNA expression of brain npy, hepatic nrf2, gst1 and hepatic transcriptomic data showed that immune-related genes (gama, mrc2, mhc2 and cd163), were downregulated in D1D1 group compared to D2D2 and D1D2 groups. Taken together: 1) tilapia have higher tolerance to a high lipid diet than high carbohydrate diet; 2) despite retention of glucose tolerance, the continuous feeding of D1 diet impaired tilapia\'s appetite, weight gain rate and host immune response; 3) specific distribution of fat in intraperitoneal regions, SCAT and liver may be a risk-avoidance strategy in tilapia in response to a continuous D2 diet.