جستجوی مقالات مرتبط با کلیدواژه « Tilapia » در نشریات گروه « پزشکی »

Tilapia Piscidin 4 (TP4) showed potential anti-tumor effects against various cancer cells. Lycosine-1 (LYC1), is another Antimicrobial Peptides (AMP) from spider venom with targeted penetration to cancer cells without any adverse effects on normal cells. The aim of this study was to produce a soluble recombinant fusion peptide in order to diminish the cytotoxicity of TP4 against normal cells.

In order to express of TP4-LYC-1, TP4, and LYC1 in fusion to the inteins1/2 of pTWIN-1 vector, induction condition was optimized to earn soluble peptides. Autocleavage induction of inteins1/2 was performed based on IMPACT® manual and their effect on cell viability of HeLa and HUVEC cells was surveyed by MTT assay.

The best condition for accessing the most soluble peptide in fusion to the inteins was approximately similar for all three peptides (0.1 mM of IPTG, at 22°C). After the induction of self-cleavage of inteins, a band in 3, 3, and 6 kDa was observed on tricine- SDS-PAGE. The IC50 values of TP4-LYC1 and TP4 against HeLa cells were calculated as 0.83, and 2.75 μM, respectively.

In the present study, a novel chimeric peptide, TP4-LYC1, was successfully produced. This fusion protein can act as a safe bio-molecule with potent cytotoxic effects against cancer cells, but the penetration ability and determination of cell death mechanism must be performed in order to have more precise view on the apoptosis induction of this recombinant peptide.

Preserving the quality and safety of fish and its products is a critical concern for food industry. In the present study, the effect of green tea extract and olive leaves extract-based preservative coatings on chemical, microbial, and sensory quality of wild type Nile tilapia (Oreochromis niloticus) was determined during pre-freezing ice and subsequent frozen storage.

Forty-eight ponds raised tilapia, freshly caught in April, 2021, which were divided into three groups: group CT with no coating, group GTE with green tea extract-based coating, and group OLE with olive leaves extract-based coating. Fish samples in all groups were kept in ice for five days (1±2 °C) and then subjected to freezing (-18±2 °C) for 105 days. Chemical (moisture, ash, protein, fat, Total Volatile Basic-Nitrogen (TVB-N), pH) and microbial (Aerobic Plate Count (APC), Total Coliform (TC), Faecal Coliform (FC), Escherichia coli) parameters as well as sensory attributes (appearance, odour, acceptability, flesh color, Total Quality Index (TQI)) of tilapia in all groups were analysed after five days of ice storage and 15, 45, 75, and 105 days of frozen storage.

APC of tilapia treated with preservative coatings remained below the permissible limit (<5×105 Colony Forming Unit (CFU)/g) throughout the storage period. After five days, content of TVB-N in untreated samples of tilapia was 32.94±2.30 mg/100 g compared to 5.05±2.19 and 7.24±2.89 mg/100 g in tilapia treated with green tea and olive leaves extract-based coating, respectively. Fat content of untreated tilapia was significantly (p<0.05) reduced to 0.05±0.01% at the end of the study period from the the initial content of 0.24±0.04%. However, the tilapia treated with preservative coatings achieved significantly (p<0.05) lower scores of TQI compared with the untreated one owing to the coloration of fish with extract solution.

Green tea extract and olive leaves extract-based coatings can, therefore, be used to improve fish quality and safety during storage. However, there is a need to change consumer’s perception about the sensory attributes of fish.

Few studies have been published about the quality of freshwater fish in Algeria. This study determined the chemical composition and the fatty acid of six species of freshwater fish cultivated in the North region of Algeria (Nile tilapia, red tilapia, common carp, Algerian barb, crucian carp, and mirror carp) as well as the nutritional quality of the lipids in these freshwater fish species.

One hundred and ten freshwater fish were randomly caught in the spring of 2021 from Achor Ali farm (Jijel), Beni-Haroun Dam (Mila), and EL-Agrem Dam (Jijel) from Algeria. Moisture, ash, protein, lipid, and fatty acids were measured according to standard laboratory procedures and protocols of previous studies. Statistical analysis was performed using ANOVA (XLSTAT 2014), and the pair wise comparison of the means was done by Tukeys test at the 5% significance level (p<0.05).

Regarding freshwater fish species, fatty acid profiles were discovered to have 38.94 to 57.75% Saturated Fatty Acids (SFAs), 29.35 to 46.63% Monounsaturated Fatty Acids (MUFAs), and 6.79 to 26.55% Polyunsaturated Fatty Acids (PUFAs). Common carp was a rich resource of Eicosapentaenoic Acid and Docosahexaenoic Acid (EPA+DHA) (5.38%); the highest concentration of ω-3 was recorded in crusian carp (10.63%); and Nile tilapia contained significant levels of ω-6 PUFA. Results demonstrated that the examined freshwater fish species appeared to have a good nutritional value and be a source of important fatty acids with positive effects on consumer health. On the other hand, results revealed low levels of PUFAs.

The examined freshwater fish species appeared to have a good nutritional value, but, it is important to provide diets rich in fatty acids, in particular PUFAs, to these freshwater fish to improve the nutritional quality of their lipids.

The present study aimed to investigate the effects of freezing speed and time on the deterioration indices such as Total Volatile Basic Nitrogen (TVB-N), Peroxide Value (PV), Thiobarbituric acid value (TBA), and pH, as well as the histological changes. Eighty Nile tilapias (Oreochromis niloticus) with approximate weight of 700 ± 50 g were caught from the saline water fish in research centre of Yazd, Iran in 2012. Then, the fillets were harvested and exposed to slow and quick freezing at 0.2 cm/h speed in the freezer at -18 °C during 18 hours, and 0.8 cm/h speed at -30 °C for 25 minutes, respectively. Finally, the fillets were transferred to -18 °C freezer where they were kept for 180 days. Based on the results, the changes in TVB-N, PV, TBA, pH and histological changes were less dramatic in the samples treated by quick freezing, compared to the slow freezing samples (p≤0.5).