Subchronic toxicity study of GH transgenic carp

The food safety assessment of all-female common carp (Cyprinus carpio) (cyp17a1+/-;XX genotype) generated using genome editing technology

There are several technical challenges and public issues concerning genome editing applications before they become viable in commercial aquaculture. Recently, we developed a novel strategy to generate all-female (AF) common carp, which exhibited a growth advantage over the control carp, using genetic editing through single gene-targeting manipulation. Here, we found that the body weight of the AF common carp was higher by 22.58% than that of the control common carp. Because the genotype of the AF common carp was cyp17a1+/-;XX, the contents of sex steroids were normally synthesized, as they were comparable to that of the control female carp. To evaluate the food safety of the AF carp, Wistar rats were fed a diet containing control female carp (control, C) or all-female (AF) carp at an incorporation rate of 5, 10 and 20% (w/w) for 90 days. Compared with those fed control carp, the rats fed AF common carp exhibited no significant difference in body weight, food intake, feed conversion ratio, hematology, serum biochemistry, urine test, relative organ weight, gross necropsy, and histopathological examination. This is the first food safety assessment of the farmed fish strain cultured using CRISPR/Cas9, which will further advance the fishery development of genome-edited animals.

A 90-Day Subchronic Toxicity Study of Consumption of GH-Transgenic Triploid Carp in Wistar Rats

Genetic modification (GM) offers an alternative strategy to conventional animal breeding. The present study was carried out to investigate the potential health effects of the consumption of growth hormone-transgenic triploid carp (GH-ttc) through a 90-day subchronic rodent feeding study. Wistar rats (n = 10/sex/group) were given formulated diets containing GH-ttc or non-GM carp at an incorporated rate of 2.5%, 5%, or 10% (w/w) for 90 days. An additional control group of rats (n = 10/sex/group) was fed a basic rodent diet. During the 90-day study, clinical observation, ophthalmic examination, body weight, and food intake were evaluated. At the end of the study, rats were killed, and the hematology, serum chemistry, urine test, necropsy, and histopathology were assessed. Compared with the non-GM carp and the basic control groups, no biologically significant differences were observed on clinical signs of toxicity, body weights, food intake, hematology, serum chemistry, urinalysis, organ weight, and histopathology on selected organs for the GH-ttc group. The results of this 90-day subchronic feeding study indicated that, at the dose level used in this study, consumption of GH-ttc showed no subchronic toxicity to Wistar rats.

Poloxamer188-based nanoparticles improve the anti-oxidation and anti-degradation of curcumin

Curcumin (CUR) is a food additive approved by World Health Organization. But the shortcomings, such as poor water solubility, easy oxidation and degradation, limit its application. In this study, the CUR-loaded poloxamer₁₈₈-based nanoparticles (CUR/PTT NPs) were fabricated to improve the stability and water solubility of CUR. Studies found the spherical CUR/PTT NPs had an average size of 98.71 ± 0.64 nm. Stability experiments displayed CUR/PTT NPs were extremely stable in different conditions. XRD analysis indicated the changes of crystal structures of CUR might be the main cause of the improved water solubility. Reducing power and anti-degradation tests suggested CUR/PTT NPs could improve the anti-oxidation and anti-degradation of CUR. Additionally, the results of body weight gains, hematological examination, organ coefficients, hematoxylin and eosin staining demonstrated CUR/PTT NPs bearing the excellent in vivo bio-security. Therefore, this study may provide a new idea for the combination of food industry and nanoparticles.

Dietary Safety Assessment of Flk1-Transgenic Fish

Genetic engineering, also called genetic modification, is facing with growing demands of aquaculture and aquatic products. Although various genetically modified (GM) aquatics have been generated, it is important to evaluate biosafety of GM organisms on the human health before entering into our food chain. For this purpose, we establish a zebrafish wild adult feeding Flk1-transgenic larvae model to examine the predatory fish's histology in multiple tissues, and the global gene expression profile in the liver. 180 days of feeding trial show that there are no significantly morphological changes in intestine, liver, kidney, and sex gonads between fish fed with Flk1 transgenic fish diet (TFD) and fish fed with regular food meal (RFM). However, a characteristic skin spot and autofluorescence increase in the theca of follicle are observed in F1 generation of TFD fish. Liver RNA-sequencing analyses demonstrate that 53 out of 56712 genes or isoforms are differentially transcribed, and mostly involved in proteolysis in extracellular region. According to GO enrichment terms these deregulated genes function in catalytic activity, steroid storing, lipid metabolic process and N-Glycan biosynthesis. These results suggest that a long term of Flk1-transgenic fish diet could alter certain metabolic pathways and possibly cause related tissue deformation. Compared to the previous reports, our feasible transgenic dietary assess system could evaluate subchronic and potential health impact of transgenic fish diet by combining multi-tissue histology and liver transcriptome analyses.

Endotoxin exposure and puberty in female rats: the role of nitric oxide and caspase-1 inhibition in neonates

Bacterial toxins are widespread in the environment as well as in the digestive system of humans and animals. Toxin from Gram-negative bacteria (endotoxin or lipopolysaccharide; LPS) has a life-long programming effect on reproduction in rats, but the mediators have not been well-documented, so we investigated the effects of LPS on the timing of puberty in female rats. Because the levels of nitric oxide (NO) and interleukin 1β (IL-1β) increase following injection of LPS, we injected neonates (post-natal day (pnd) 7) with LPS, with or without NO or IL-1β inhibitors. Half of the prepubescent (pnd 30) animals received an additional LPS injection. Vaginal opening, number of ovarian follicles, and serum anti-LPS antibodies were determined. A single LPS injection was sufficient to reduce the primordial follicle pool, but puberty was delayed when rats received 2 LPS injections (at pnd 7 and 30). NO or IL-1β inhibitors improved both of these parameters, suggesting that the early detrimental effects of LPS on puberty and primordial follicle pool are mediated by NO and IL-1β.