The objective of this study was to investigate the effects of salmon gonadotropin releasing hormone analog (S-GnRH-A) and human chorionic gonadotropin (HCG) on the serum levels of gonadotropins (GtHs) and sex steroid hormones in Manchurian trout during sexual maturity. Females in the treatment group were injected with 20 µg/kg S-GnRH-A and 400 IU/kg HCG, whilst males were injected with half the amount. Blood samples were collected at 0, 5, 10, and 20 days post injection (dpi). The results showed an increase in female follicle-stimulating hormone (FSH) levels in the treatment group at 5 dpi, and from 5 dpi onwards, a difference was observed between the groups, with higher FSH levels in the treatment group compared to the control group. In males, FSH levels showed group differences at only 5 dpi (p < 0.05) and were higher in the treatment group. In females, luteinizing hormone (LH) peaked at 10 dpi in the treatment group, and there were differences between the two groups at 10 dpi and 20 dpi. In males, LH was significantly higher in the treatment group than in the control group at 5 dpi and 10 dpi (p < 0.05). In females, estradiol (E2) was significantly higher in the treatment group than in the control group at 5 dpi and 10 dpi (p < 0.05), whereas in males, the difference between the two groups was only observed at 5 dpi (p < 0.05). The female testosterone (T) level in the treatment group was significantly higher than that of the control group at 5 dpi and 10 dpi (p < 0.05), while T levels were significantly higher in the male treatment group than in the control group at 5 dpi (p < 0.05). The level of 17α–hydroxyprogesterone (17α-OHP) in the females of the treatment group was significantly higher than that of the control group at 5 dpi and 10 dpi (p < 0.05), and 17α-OHP levels were significantly higher in the male treatment group than in the control group at 10 and 20 dpi (p < 0.05). The fish were successfully spawned after S-GnRH-A and HCG injections, and brood amount, fertilization rate, and hatching rate were significantly increased (p < 0.05). This study provides a framework for a better understanding of the mechanisms of exogenous hormone-mediated control of reproduction in Manchurian trout.

Cold and hot water extracts (2, 6 and 10%) were prepared from parching green tea and its antioxidant properties studied and potential antioxidant components determined. Yields of hot water extracts (17.53-28.63%) were significantly higher than those of cold water extracts (13.34-16.14%). The half maximal effective concentration (EC(50)) values in antioxidant activity and reducing power were 2.17-2.75 and 0.22-0.30 mg/mL, respectively. Scavenging abilities on 1,1-diphenyl-2-picrylhydrazyl radicals were comparable. EC(50) values in scavenging ability on hydroxyl radicals and chelating ability on ferrous ions were 3.31-4.54 and 1.63-3.09 mg/mL, respectively. Contents of total phenols were 220.52-339.83 mg/g whereas those of total catechins in cold and hot water extracts were 130.22-146.28 mg/g and 136.40-191.33 mg/g, respectively. Based on the results obtained, hot water extracts were more effective in antioxidant activity, reducing power and scavenging ability on hydroxyl radicals but less effective in chelating ability on ferrous ions. PRACTICAL APPLICATIONS Tea is one of popular drinks in the world. The consumption of green tea is especially popular in Asia, mainly for its health benefits. Parched tea is a Chinese style green tea, which is different from the Japanese style steamed tea. Recently, the tea prepared by brewing tea leaves in cold water has become a new choice in Taiwan in addition to traditionally hot water-brewed tea. Results from this research, the cold and hot water extracts of green tea are good antioxidant. Besides, green tea is also reported to reduce serum cholesterol levels and inhibit hypertension, mutagenesis, and tumourigenesis in several experiments in vitro and in vivo. Therefore, the extract of green tea has the potential to be developed into new health foods, and the cold brewing would be a new alternative way to make a tea

Global warming poses a significant threat to aquaculture, particularly for cold-water species like rainbow trout (Oncorhynchus mykiss). Understanding the molecular mechanisms underlying stress responses is crucial for developing resilient strains. This study investigates the dual stress of salinity and temperature response of “Shuike No. 1” (SK), a pioneering commercially bred rainbow trout strain in China, using RNA-sequencing of gill, intestine, and liver tissues from fish exposed to four treatment combinations: freshwater at 16 °C, freshwater at 25 °C, saltwater (30‰) at 16 °C, and saltwater at 25 °C. Differential gene expression analysis identified a substantial number of DEGs, with the liver showing the most pronounced response and a clear synergistic effect observed under combined high-temperature and salinity stress. Weighted gene co-expression network analysis (WGCNA) revealed stress-responsive gene modules and identified hub genes, primarily associated with gene expression, endoplasmic reticulum (ER) function, disease immunity, energy metabolism, and substance transport. Key hub genes included klf9, fkbp5a, fkbp5b, ef2, cirbp, atp1b1, atp1b2, foxi3b, smoc1, and arf1. Functional enrichment analysis confirmed the prominent role of ER stress, particularly the pathway “protein processing in the endoplasmic reticulum.” Our results reveal complex, tissue-specific responses to dual stress, with high temperature exerting a stronger influence than salinity. These findings provide valuable insights into the molecular mechanisms underpinning dual stress responses in SK, informing future breeding programs for enhanced resilience in the face of climate change.