The antioxidant effect of salidroside has been proven, but its role in liver injury is poorly understood. In this study, we aimed to evaluate the protective effects and mechanism of salidroside on liver injury induced by carbon tetrachloride (CCl₄) in vivo. Mice were pretreated with salidroside (60 mg/kg, intraperitoneally injected, i.p.) once per day for 14 consecutive days and then administered with CCl₄ (15.95 g/kg, i.p.) for 24 h to produce a liver injury model. Salidroside attenuated hepatic transaminase elevation in serum and ameliorated liver steatosis and necrosis, thereby suggesting its protective effect on the liver. Salidroside antagonized CCl₄-induced toxicity by equilibrating antioxidation system, thereby inhibiting reactive oxygen species accumulation, and restoring mitochondrial structure and function. Salidroside exerts antioxidant and liver-protective effects by selectively inhibiting the activation of genes, including growth arrest and DNA -damage-inducible 45 α (Gadd45a), mitogen-activated protein kinase 7 (Mapk7), and related RAS viral oncogene homolog 2 (Rras2), which induce oxidative stress in the mitogen-activated protein kinase pathway. These results revealed that salidroside can protect the liver from CCl₄-induced injury by resisting oxidative stress and protecting mitochondrial function.

Lipopolysaccharide (LPS) is an endotoxin that can cause an imbalance between the oxidation and antioxidant defense systems and then induces hepatic damages. Ferulic acid (FA) has multiple biological functions including antibacterial and antioxidant activities; however, the effect of FA on lipopolysaccharide-induced hepatic injury remains unknown. The purpose of this study was to investigate the mechanism of action of dietary Ferulic acid against Lipopolysaccharide-induced hepatic injuries in Tianfu broiler chickens. The results showed that supplementation of FA in daily feed increased body weight (BW) and decreased the feed conversion ratio (FCR) in LPS treatment broilers significantly (p < 0.05). Additionally, supplement of FA alleviated histological changes and apoptosis of hepatocytes in LPS treatment broilers. Supplement of FA significantly decreases the activities of ROS. Interestingly, the levels of antioxidant parameters including total superoxide dismutase (T-SOD), total antioxidant capacity (T-AOC), and glutathione (GSH) in LPS group were significantly increased by the FA supplementation (p < 0.05). Nevertheless, administration of LPS to broilers decreased the expressions of Nrf2, NQO1, SOD, GSH-Px, CAT and Bcl-2, whereas it increased the expressions of Bax and Caspase-3 (p < 0.05). Moreover, the expressions of Nrf2, NQO1, SOD, CAT, Bcl-2 were significantly upregulated and Caspase-3 were significantly downregulated in the FL group when compared to LPS group (p < 0.05). In conclusion, supplementation of FA in daily feed improves growth performance and alleviates LPS-induced oxidative stress, histopathologic changes, and apoptosis of hepatocytes in Tianfu broilers.

Lipopolysaccharide (LPS) has been considered the primary agent to establish animal models of inflammation, immunological stress, and organ injury. Previous studies have demonstrated that LPS impaired gastrointestinal development and disrupted intestinal microbial composition and metabolism. Ferulic acid (FA) isolated from multiple plants exhibits multiple biological activities. This study investigated whether FA ameliorated intestinal function and microflora in LPS-challenged Tianfu broilers. The results showed that LPS challenge impaired intestinal function, as evidenced by decreased antioxidant functions (p < 0.05), disrupted morphological structure (p < 0.05), and increased intestinal permeability (p < 0.05); however, these adverse effects were improved by FA supplementation. Additionally, FA supplementation preserved sIgA levels (p < 0.05), increased mRNA expression levels of CLDN and ZO-1 (p < 0.05), and enhanced epithelial proliferation (p < 0.05) in the ileal mucosa in LPS-challenged chickens. Moreover, FA supplementation rectified the ileal microflora disturbances in the LPS-challenged broilers. The results demonstrate that dietary FA supplementation decreased LPS-induced intestinal damage by enhancing antioxidant capacity and maintaining intestinal integrity. Furthermore, FA supplementation protects intestinal tight junctions (TJs), elevates secretory immunoglobulin A (sIgA) levels, and modulates ileal microflora composition in LPS-challenged broilers.

To understand the characteristics of the fish community structure and biomass particle-size spectrum in the upper reaches of the Jinsha River, fish and environmental surveys were conducted in 21 segments of the upper reaches of the Jinsha River in September 2019 and June 2020. A total of 4062 fish belonging to 2 orders, 5 families, 18 genera, and 28 species were collected. Among them, Cyprinidae fish were the most abundant (14 species), accounting for 50.00%. The Shannon index and Pielou evenness index values varied from 0.402–1.770 and 0.254–0.680, respectively. The dominant species of fish were Triplophysa stenura, Schizothorax wangchiachii, and Schizopygopsis malacanthus. Redundancy analysis (RDA) was used to analyse the relationship between the fish community and environmental factors. Velocity, altitude, and dissolved oxygen were the main influencing factors of fish community structure differences in the upper reaches of the Jinsha River. The abundance/biomass curves showed that the fish communities in the upper reaches of the Jinsha River were moderately or severely disturbed. The standardized biomass particle-size spectrum of fish showed that the degree of disturbance of fish in tributaries was much lower than that in the main stream. Compared with the historical data, the fish community structure in the Jinsha River has changed significantly, with the number of exotic species increasing, and the individual fish showing miniaturization and younger ages. It is suggested that habitat conservation strategies be adopted in the upper tributaries of the Jinsha River to provide a reference for the restoration of fishery resources and the conservation of fish diversity in the Yangtze River.

Apoptosis plays a key role in the effective removal of excessive and defective germ cells, which is essential for sequential hermaphroditism and sex change in vertebrates. The ricefield eel, Monopterus albus is a protogynous hermaphroditic fish that undergoes a sequential sex change from female to male. Previous studies have demonstrated that apoptosis is involved in sex change in M. albus. However, the apoptotic signaling pathway is unclear. In the current study, we explored the underlying mechanism of apoptosis during gonadal development and focused on the role of the mitochondrial apoptosis signaling pathway in sex change in M. albus. Flow cytometry was performed to detect apoptosis in gonads at five sexual stages and ovary tissues exposed to hydrogen peroxide (H₂O₂) in vitro. Then the expression patterns of key genes and proteins in the mitochondrial pathway, death receptor pathway and endoplasmic reticulum (ER) pathway were examined. The results showed that the apoptosis rate was significantly increased in the early intersexual stage and then decreased with the natural sex change from female to male. Quantitative real-time PCR revealed that bax, tnfr1, and calpain were mainly expressed in the five stages. ELISA demonstrated that the relative content of cytochrome-c (cyt-c) in the mitochondrial pathway was significantly higher than that of caspase8 and caspase12, with a peak in the early intersexual stage, while the levels of caspase8 and caspase12 peaked in the late intersexual stage. Interestingly, the Pearson’s coefficient between cyt-c and the apoptosis rate was 0.705, which suggests that these factors are closely related during the gonadal development of M. albus. Furthermore, the cyt-c signal was found to be increased in the intersexual stage by immunohistochemistry. After incubation with H₂O₂, the mRNA expression of mitochondrial pathway molecules such as bax, apaf-1, and caspase3 increased in ovary tissues. In conclusion, the present results suggest that the mitochondrial apoptotic pathway may play a more important role than the other apoptotic pathways in sex change in M. albus.

Bmpr2 plays a central role in the regulation of reproductive development in mammals, but its role during ovarian development in fish is still unclear. To ascertain the function of bmpr2 in ovarian development in the ricefield eel, we isolated and characterized the bmpr2 cDNA sequence; the localization of Bmpr2 protein was determined by immunohistochemical staining; and the expression patterns of bmpr2 in ovarian tissue incubated with FSH and hCG in vitro were analyzed. The full-length bmpr2 cDNA was 3311 bp, with 1061 amino acids encoded. Compared to other tissues, bmpr2 was abundantly expressed in the ovary and highly expressed in the early yolk accumulation (EV) stages of the ovary. In addition, a positive signal for Bmpr2 was detected in the cytoplasm of oocytes in primary growth (PG) and EV stages. In vitro, the expression level of gdf9, the ligand of bmpr2, in the 10 ng/mL FSH treatment group was significantly higher after incubation for 4 h than after incubation for different durations. However, bmpr2 expression in the 10 ng/mL FSH treatment group at 2 h, 4 h and 10 h was significantly lower. Importantly, the expression level of bmpr2 and gdf9 in the 100 IU/mL hCG group had similar changes that were significantly decreased at 4 h and 10 h. In summary, Bmpr2 might play a pivotal role in ovarian growth in the ricefield eel, and these results provide a better understanding of the function of bmpr2 in ovarian development and the basic data for further exploration of the regulatory mechanism of gdf9 in oocyte development.