Armenian Hamster Anti-glutathione S-transferase Monoclonal antibody, clone PIP Functional Grade

Antioxidant peptides are naturally present in food, especially in fishes, and are considered to contain rich source of various bioactive compounds that are structurally heterogeneous. This study aims to identify and characterize the antioxidant property of the WL15 peptide, derived from Cysteine and glycine-rich protein 2 (CSRP2) identified from the transcriptome of a freshwater food fish, Channa striatus. C. striatus is already studied to contain high levels of amino acids and fatty acids, besides traditionally known for its pharmacological benefits in the Southeast Asian region. In our study, in vitro analysis of WL15 peptide exhibited strong free radical scavenging activity in 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), superoxide anion radical and hydrogen peroxide (H2O2) scavenging assay. Further, to evaluate the cytotoxicity and dose-response, the Human dermal fibroblast (HDF) cells were used. Results showed that the treatment of HDF cells with varying concentrations (10, 20, 30, 40 and 50 mu M) of WL15 peptide was not cytotoxic. However, the treatment concentrations showed enhanced antioxidant properties by significantly inhibiting the levels of free radicals. For in vivo assessment, we have used zebrafish larvae for evaluating the developmental toxicity and for determining the antioxidant property of the WL15 peptide. Zebrafish embryos were treated with the WL15 peptide from 4 h of post-fertilization (hpf) to 96 hpf covering the embryo-larval developmental period. At the end of the exposure period, the larvae were exposed to H2O2 (1 mM) for inducing generic oxidative stress. The exposure of WL15 peptide during the embryo-larval period showed no developmental toxicity even in higher concentrations of the peptide. Besides, the WL15 peptide considerably decreased the intracellular reactive oxygen species (ROS) levels induced by H2O2 exposure. WL15 peptide also inhibited the H2O2-induced caspase 3-dependent apoptotic response in zebrafish larvae was observed using the whole-mount immunofluorescence staining. Overall results from our study showed that the pre-treatment of WL15 (50 mu M) in the H2O2-exposed zebrafish larvae, attenuated the expression of activated caspase 3 expressions, reduced Malondialdehyde (MDA) levels, and enhanced antioxidant enzymes, including superoxide dismutase (SOD) and catalase (CAT). The gene expression of antioxidant enzymes such as glutathione 5-transferase (GST), glutathione peroxide (GPx) and gamma-glutamyl cysteine synthetase (GCS) was found to be upregulated. In conclusion, it can be conceived that pretreatment with WL15 could mitigate H2O2-induced oxidative injury by elevating the activity and expression of antioxidant enzymes, thereby decreasing MDA levels and cellular apoptosis by enhancing the antioxidant response, demonstrated by the in vitro and in vivo experiments.

Aflatoxin B-1 (AFB(1)) is a mycotoxin that is commonly detected in aquatic feed in tropical and subtropical regions. The toxic effects in shrimp and fish tissues following exposure to chronic AFB(1) exposure has been studied but there is no information on tolerance between different species. This study was designed to compare the tolerance of AFB(1) between invertebrate Litopenaeus vannamei and vertebrate Oreochromis niloticus. The emphasis was on growth profile, biotransformation, histopathology and AFB(1) accumulation following exposure to increasing doses of AFB(1). 182 shrimps and 146 tilapia were used and divided into control and AFB(1) exposure groups. Shrimp were exposed to 1.5-fold increasing doses of 1.2, 1.8, 2.7, 4, 6 mg/kg AFB(1) and tilapia to 3.2, 4.8, 7.2, 10.8, 16.2 mg/kg of AFB(1) for 20 d with a 4-day exposure to each AFB(1) with the shrimp/fish sacrificed on the last day of exposed dose(s). At each time point the controls were also sacrificed. A significant decrease in survival rate and weight gain (WG) was observed in shrimp. Higher AFB(1) doses caused a decline in tilapia WG. Dose responsive AFB(1) accumulation was evident in muscle and shrimp hepatopancreas /tilapia liver. The concentration of AFB(1) was significantly higher in shrimp hepatopancreas (22.76-72.89 ng/g) than in tilapia liver (6.68-19.45 ng/g) in spite of exposure to a higher dose regime. The muscle AFB(1) concentration in both species ranged from 0 to 20 ng/g. The shrimp hepatopancreas cytochrome b5 (Cyt b5) concentration increased initially but declined after> 4 mg/kg AFB(1) exposure. The tilapia liver Cyt b5 content declined after> 10.8 mg/kg AFB(1). In the shrimp hepatopancreas, a marked induction of enzymes, aniline hydroxylase (AH), NADPH-cytochrome P450 reductase (NCCR), 7-ethoxyresorufin O-deethylase (EROD), glutathione-S-transferase (GST), sulfotransferase (SULT) and uridinediphosphate glucuronyltransferase (UGT) were observed. Only some of these enzymes, namely, EROD, GST, UGT and SULT but not AH or NCCR were induced in tilapia liver. Hepatopancreas/liver damage in shrimp/fish was marked at higher AFB(1) doses. Marked changes in the shrimp hepatopancreatic cell structure was observed in shrimp at concentrations> 6 mg/kg AFB(1). This study showed that shrimp are more susceptible to AFB(1) than tilapia and further studies are required to determine the role of AH and NCCR enzymes in species differences to AFB(1) toxicity.