Organochlorine pesticide residues in raw and grilled freshwater fish (Oreochromis niloticus) collected from various locations along the Nile basin in Egypt.

The current study aimed to assess meat quality of samples of Nile tilapia fish (Oreochromis niloticus), along with examining organochlorine pesticide (OCP) residues in these samples and their potential risks to humans. About 55 samples were collected from eleven sites on the Nile River in Egypt: Damietta, El-Behera, El-Dakahlia, Kafrelsheikh, El-Gharbia, El-Menoufia, Cairo, El-Giza, El-Fayoum, El-Menia, and Aswan Governorates. Fish samples were analyzed fresh and grilled for meat quality characteristics and the presence of OCP residues using the QuEChERS method for extraction and cleanup accompanied by detection using GC-MS (gas chromatography-mass spectrometry) system. Then, risk hazards of OCP residues were calculated. Results showed that all quality criteria of raw and cooked meat samples were within the permissible levels set by the Egyptian Organization for Standardization and Quality (EOS). The detected residues of OCPs in fresh samples were hexachlorocyclohexanes (α-HCH, ß-HCH, and δ-HCH), heptachlor, heptachlor epoxide, aldrin, dieldrin, endrin aldehyde, endosulfan, and p,p'-DDE. Endrin aldehyde was detected in all tested sites, while heptachlor epoxide was found in eight (73%) out of the 11 tested locations. After grilling, aldrin, heptachlor epoxide, endosulfan, and endrin aldehyde compounds were found in fish meat. Cooking fish samples reduced the OCP residue amounts by at least 95% of detected amounts in fresh meat.

Papaya extract upregulates the immune and antioxidants-related genes, and proteins expression in milk somatic cells of Friesian dairy cows.

Carica papaya is a perennial plant containing bioactive constituents with free radical-scavenging and immune-modulating activities. In contrast, the immune suppression is predominant in the periparturient period, where oxidative stress has a substantial impact on the mammary gland health. The aim of the experiment reported here was to determine the potential effect of C. papaya aqueous extract (CPE) on milk production traits, and expression of genes and proteins related to immune and antioxidant status in dairy milk somatic cells (MSCs). Forty Friesian dairy cows were divided equally between a control and CPE-treated groups (orally drenched 250 µg/kg bwt, once weekly a month before expected parturition and continued until 5 months post-partum). CPE did not affect milk yield or composition but upregulated the expression of ß13-defensin (DEFB13), cathelicidin 2 (CATHL2), cathelicidin antimicrobial peptide (CATHL3), hepcidin (HAMP), lysozyme (LYZ), catalase (CAT) and glutathione peroxidase (GSH-Px) in MSCs. The environmental micro-organisms did not influence the levels of the transcripts. The DEFB13, CATHL2, CATHL3, HAMP and LYZ, but not ß1-defensin (DEFB1) transcripts and proteins were constitutively expressed in MSCs obtained from pathogen-free udders. It could be concluded that CPE has immunostimulant and antioxidant activities; thereby, it could be utilized to minimize the occurrence of mastitis.

2, 3-Dimethylsuccinic acid and fulvic acid attenuate lead-induced oxidative misbalance in brain tissues of Nile tilapia Oreochromis niloticus.

Lead has long been known as neurotoxic and immunotoxic heavy metal in human and animals including fish, whereas, 2, 3-dimethylsuccinic acid (DMSA) and fulvic acid (FA) are well-known biological chelators. The present investigation was carried out to assess the potential chelating and antioxidant effects of dietary supplementation with DMSA and FA against lead acetate (Pb)-induced oxidative stress in Nile tilapia, O. niloticus. One-hundred and eighty apparently healthy O. niloticus fish (30 ± 2.5 g) were allocated into six equal groups. The first group was fed on basal diet and served as control, while the second group was fed on DMSA-supplemented basal diets at levels of 30 mg/kg diet; the third group was fed on FA-supplemented basal diet at level of 0.3 mg/kg diet; the forth, fifths, and sixth groups were exposed to 14.4 mg Pb /L water (1/10 LC50) and feed on basal diet only, basal diet supplemented with DMSA (0.3 mg/kg diet), or basal diet supplemented with FA (0.3 mg/kg diet), respectively. Antioxidant and lipid peroxidative status, activity of glucose 6-phosphate dehydrogenase (G6PD), and lactate dehydrogenase (LDH) as well as the histopathologic findings were evaluated in brain tissues, while the Pb residues were evaluated in liver, muscles, and brain tissues. The results of the present study showed that DMSA and FA decreased malondialdehyde (MDA) and Pb residue in tissues of Pb-exposed fish and improved the histologic picture and brain contents of glutathione (GSH), glutathione-s-transferase (GST), glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT), G6PD, LDH, and total antioxidant capacity (TAC). It could be concluded that DMSA and FA supplementation exhibited potential neuroprotective effect against Pb-induced oxidative brain damages in O. niloticus through improvement of antioxidant status of the brain tissue.