d-Tetramethrin causes zebrafish hepatotoxicity by inducing oxidative stress and inhibiting cell proliferation.

d-Tetramethrin is one of the main components of mosquito control products, and is widely used for the control of dengue fever and insecticide production. Due to its widespread use, d-tetramethrin is a ubiquitous environmental pollutant and poses potential risks to human health. However, the effects of d-tetramethrin on liver morphology and function are not clearly established. In this study, we used zebrafish as an animal model to analyze the acute and chronic effects of d-tetramethrin exposure on the liver. We exposed zebrafish larvae and adults to different concentrations of d-tetramethrin and examined the impact of d-tetramethrin on lipid and glycogen metabolism, cellular properties, oxidative stress, cell proliferation, and apoptosis in the liver. We also analyzed transcriptional changes in genes related to apoptosis, inflammation, and cell proliferation using qPCR. Zebrafish exposed to d-tetramethrin exhibited severe liver damage, as evidenced by the presence of vacuoles and nuclear distortion in liver cells. The liver area in zebrafish larvae of the treatment group was significantly smaller than that of the control group. Significant lipid accumulation and decreased glycogen levels were observed in the livers of both zebrafish larvae and adults exposed to d-tetramethrin. Furthermore, d-tetramethrin exposure induced apoptosis and inflammation in zebrafish embryos. Additionally, d-tetramethrin caused liver damage, metabolic dysfunction, and impaired liver function. These results suggest that d-tetramethrin induces liver toxicity in zebrafish, by inducing oxidative stress and inhibiting cell proliferation.

[Mechanism of Gegen Qinlian Decoction in improving glucose metabolism in vitro and in vivo by alleviating hepatic endoplasmic reticulum stress].

This study investigated the mechanism of Gegen Qinlian Decoction(GQD) in improving glucose metabolism in vitro and in vivo by alleviating endoplasmic reticulum stress(ERS). Molecular docking was used to predict the binding affinity between the main effective plasma components of GQD and ERS-related targets. Liver tissue samples were obtained from normal rats, high-fat-induced diabetic rats, rats treated with metformin, and rats treated with GQD. RNA and protein were extracted. qPCR was used to measure the mRNA expression of ERS marker glucose-regulated protein 78(GRP78), and unfolded protein response(UPR) genes inositol requiring enzyme 1(Ire1), activating transcription factor 6(Atf6), Atf4, C/EBP-homologous protein(Chop), and caspase-12. Western blot was used to detect the protein expression of GRP78, IRE1, protein kinase R-like ER kinase(PERK), ATF6, X-box binding protein 1(XBP1), ATF4, CHOP, caspase-12, caspase-9, and caspase-3. The calcium ion content in liver tissues was determined by the colorimetric assay. The ERS-HepG2 cell model was established in vitro by inducing with tunicamycin for 6 hours, and 2.5%, 5%, and 10% GQD-containing serum were administered for 9 hours. The glucose oxidase method was used to measure extracellular glucose levels, flow cytometry to detect cell apoptosis, glycogen staining to measure cellular glycogen content, and immunofluorescence to detect the expression of GRP78. The intracellular calcium ion content was measured by the colorimetric assay. Whereas Western blot was used to detect GRP78 and ERS-induced IRE1, PERK, ATF6, and eukaryotic translation initiation factor 2α(eIF2α) phosphorylation. Additionally, the phosphorylation levels of insulin receptor substrate 1(IRS1), phosphatidylinositol 3-kinase regulatory subunit p85(PI3Kp85), and protein kinase B(Akt), which were involved in the insulin signaling pathway, were also measured. In addition, the phosphorylation levels of c-Jun N-terminal kinases(JNKs), which were involved in both the ERS and insulin signaling pathways, were measured by Western blot. Molecular docking results showed that GRP78, IRE1, PERK, ATF4, and various compounds such as baicalein, berberine, daidzein, jateorhizine, liquiritin, palmatine, puerarin and wogonoside had strong binding affinities, indicating that GQD might interfere with ERS-induced UPR. In vivo results showed that GQD down-regulated the mRNA transcription of Ire1, Atf6, Atf4, Grp78, caspase-12, and Chop in diabetic rats, and down-regulated GRP78, IRE1, PERK, as well as ERS-induced apoptotic factors ATF4 and CHOP, caspase-12, caspase-9, and caspase-3, while up-regulating XBP1 to enhance adaptive UPR. In addition, GQD increased the calcium ion content in liver tissues, which facilitated correct protein folding. In vitro results showed that GQD increased glucose consumption in ERS-induced HepG2 cells without significantly affecting cell viability, increased liver glycogen synthesis, down-regulated ATF6 and p-eIF2α(Ser51), and down-regulated IRE1, PERK, and GRP78, as well as p-IRS1(Ser312) and p-JNKs(Thr183/Tyr185), while up-regulating p-PI3Kp85(Tyr607) and p-Akt(Ser473). These findings suggested that GQD alleviates excessive ERS in the liver, reduces insulin resistance, and improves hepatic glucose metabolism in vivo and in vitro.

Artichoke (Cynara scolymus L.) water extract alleviates palmitate-induced insulin resistance in HepG2 hepatocytes via the activation of IRS1/PI3K/AKT/FoxO1 and GSK-3ß signaling pathway.

BACKGROUND: Artichoke (Cynara scolymus L.) is a typical element of a traditional Mediterranean diet and has potential health advantages for insulin resistance (IR) and type 2 diabetes mellitus (T2DM). This study aims to evaluate the effect and underlying mechanism of artichoke water extract (AWE) on palmitate (PA)-induced IR in human hepatocellular carcinoma (HepG2) cells. METHODS: The effect of AWE on cell viability was determined using CCK8 assay. Cellular glucose uptake, glucose consumption, glucose production, and glycogen content were assessed after AWE treatment. The gene expression and protein levels were examined by real-time polymerase chain reaction (qRT-PCR) and western blotting. RESULTS: The results showed that AWE dose-dependently increased cell viability in IR HepG2 cells (P < 0.01). AWE treatment significantly promoted glucose uptake and consumption, decreased glucose production, and increased the cellular glycogen content in IR HepG2 cells (P < 0.01). Mechanistically, AWE elevated the phosphorylation and total protein levels of major insulin signaling molecules in IR HepG2 cells, which resulted in a decrease in the expression of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) and the inhibition of glycogen synthase (GS) phosphorylation in IR HepG2 cells. Furthermore, the protective effect of AWE on IR HepG2 cells might be ascribed to the inhibition of the endoplasmic reticulum (ER) stress. CONCLUSION: We conclude that AWE may improve glucose metabolism by regulating IRS1/PI3K/AKT/FoxO1 and GSK-3ß signaling associated with the inhibition of ER stress in IR HepG2 cells induced by PA.

Phagocytic responses of peritoneal macrophages and neutrophils are different in rats following prolonged exercise

OBJECTIVE: To analyze the effects of exhausting long-duration physical exercise (swimming) sessions of different durations and intensities on the number and phagocytic capacity of macrophages and neutrophils in sedentary rats. INTRODUCTION: Exercise intensity, duration and frequency are important factors in determining immune response to physical effort. Thus, the effects of exhausting long-duration exercise are unclear. METHODS: Wistar rats were divided into two groups: an untreated group (macrophage study) and oyster glycogen-treated rats (neutrophil study). In each group, the animals were subdivided into five groups (10 rats per group): unexercised controls, an unadapted low-intensity exercise group, an unadapted moderate-intensity exercise group, a preadapted low-intensity exercise group and a preadapted moderate-intensity exercise group. All exercises were performed to exhaustion, and preadaptation consisted of 5, 15, 30 and 45 min sessions. RESULTS: Macrophage study: the number of peritoneal macrophages significantly decreased (9.22 ± 1.78 x 10(6)) after unadapted exercise but increased (21.50 ± 0.63 x 10(6)) after preadapted low-intensity exercise, with no changes in the moderate-intensity exercise group. Phagocytic capacity, however, increased by more than 80 percent in all exercise groups (low/moderate, unadapted/preadapted). Neutrophil study: the number of peritoneal neutrophils significantly decreased after unadapted (29.20 ± 3.34 x 10(6)) and preadapted (50.00 ± 3.53 x 10(6)) low-intensity exercise but increased after unadapted (127.60 ± 5.14 x 10(6)) and preadapted (221.80 ± 14.85 x 10(6)) moderate exercise. Neutrophil phagocytic capacity decreased by 63 percent after unadapted moderate exercise but increased by 90 percent after corresponding preadapted sessions, with no changes in the low-intensity exercise groups. CONCLUSION: Neutrophils and macrophages of sedentary rats respond differently to exercise-induced stress. Adaptation sessions reduce exercise-induced stress on the immune system.