OBJECTIVE: To investigate whether auraptene (AUR) exerts a protective effect on acute diquat (DQ)-induced liver injury in mice and explore its underlying mechanisms. METHODS: Forty SPF-grade healthy male C57BL/6 mice were randomly divided into normal control group (Control group), DQ poisoning model group (DQ group), AUR treatment group (DQ+AUR group), and AUR control group (AUR group), with 10 mice in each group. The DQ poisoning model was established via a single intraperitoneal injection of 40 mg/kg DQ aqueous solution (0.5 mL); Control group and AUR group received an equal volume of pure water intraperitoneally. Four hours post-modeling, DQ+AUR group and AUR group were administered 0.5 mg/kg AUR aqueous solution (0.2 mL) by gavage once daily for 7 consecutive days, while Control group and DQ group received pure water. Blood and liver tissues were collected after anesthesia on day 7. Liver ultrastructure was observed by transmission electron microscopy. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were measured via enzyme-linked immunosorbent assay (ELISA). Hepatic glutathione (GSH), superoxide dismutase (SOD), and malondialdehyde (MDA) levels were detected using WST-1, thiobarbituric acid (TBA), and enzymatic reaction methods, respectively. Protein expression of nuclear factor-erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), Kelch-like ECH-associated protein 1 (Keap1), and activated caspase-9 in liver tissues was analyzed by Western blotting. RESULTS: Transmission electron microscopy revealed that mitochondria in the Control group exhibited mild swelling, uneven distribution of matrix, and a small number of cristae fractures. In the AUR group, mitochondria showed mild swelling, with no obvious disruption of cristae structure. In the DQ group, mitochondria demonstrated marked swelling and increased volume, matrix dissolution, loss and fragmentation of cristae, and extensive vacuolization. In contrast, the DQ+AUR group showed significantly reduced mitochondrial swelling, volume increase, matrix dissolution, cristae loss and fragmentation, and vacuolization compared to the DQ group. Compared with the DQ group, the DQ+AUR group exhibited significantly lower serum AST levels (U/L: 173.45±23.60 vs. 255.33±41.51), ALT levels (U/L: 51.77±21.63 vs. 100.70±32.35), and hepatic MDA levels (μmol/g: 12.40±2.76 vs. 19.74±4.10), along with higher hepatic GSH levels (mmol/g: 37.65±14.95 vs. 20.58±8.52) and SOD levels (kU/g: 124.10±33.77 vs. 82.81±22.00), the differences were statistically significant (all P < 0.05). Western blotting showed upregulated Nrf2 expression (Nrf2/β-actin: 0.87±0.37 vs. 0.53±0.22) and HO-1 expression (HO-1/β-actin: 1.06±0.22 vs. 0.49±0.08), and downregulated Keap1 expression (Keap1/β-actin: 0.82±0.12 vs. 1.52±0.76) and activated caspase-9 expression (activated caspase-9/β-actin: 1.16±0.28 vs. 1.71±0.30) in the DQ+AUR group compared to the DQ group (all P < 0.05). CONCLUSION AUR attenuates DQ-induced acute liver injury in mice by activating the Keap1/Nrf2 signaling pathway.
Animals ; Male ; Mice ; Mice, Inbred C57BL ; Liver/pathology* ; Chemical and Drug Induced Liver Injury/drug therapy* ; Diquat/poisoning* ; NF-E2-Related Factor 2/metabolism* ; Oxidative Stress ; Apoptosis ; Coumarins

Objective:To investigate the protective effect of quercetin (QR) on acute liver injury induced by diquat (DQ) poisoning in mice and its mechanism.Methods:Eighty healthy male C57BL/6 mice with SPF grade were randomly divided into control group, DQ model group, QR treatment group, and QR control group, with 20 mice in each group. The DQ poisoning model was established by a one-time intraperitoneal injection of DQ solution (40 mg/kg); the control and QR control groups received equivalent amounts of distilled water through intraperitoneal injection. Four hours after modeling, the QR treatment group and the QR control group received 0.5 mL QR solution (50 mg/kg) through gavage. Meanwhile, an equivalent amount of distilled water was given orally to the control group and the DQ model group. The treatments above were administered once daily for seven consecutive days. Afterwards, the mice were anesthetized, blood and liver tissues were collected for following tests: changes in the structure of mice liver tissue were observed using transmission electron microscopy; the levels of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were detected using enzyme linked immunosorbent assay (ELISA); the levels of glutathione (GSH), superoxide dismutase (SOD), and malondialdehyde (MDA) in liver tissues were measured using the water-soluble tetrazolium-1 (WST-1) method, the thiobarbituric acid (TBA) method, and enzymatic methods, respectively; the protein expressions of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), Kelch-like ECH-associated protein 1 (Keap1), and activated caspase-9 in liver tissues were detected using Western blotting.Results:Severe mitochondrial damage was observed in the liver tissues of mice in the DQ model group using transmission electron microscopy, yet mitochondrial damage in the QR treatment group showed significant alleviation. Compared to the control group, the DQ model group had significantly increased levels of MDA in liver tissue, serum AST, and ALT, yet had significantly decreased levels of GSH and SOD in liver tissue. In comparison to the DQ model group, the QR treatment group exhibited significant reductions in serum levels of ALT and AST, as well as MDA levels in liver tissue [ALT (U/L): 52.60±6.44 vs. 95.70±8.00, AST (U/L): 170.45±19.33 vs. 251.10±13.09, MDA (nmol/mg): 12.63±3.41 vs. 18.04±3.72], and notable increases in GSH and SOD levels in liver tissue [GSH (μmol/mg): 39.49±6.33 vs. 20.26±3.96, SOD (U/mg): 121.40±11.75 vs. 81.67±10.01], all the differences were statistically significant (all P < 0.01). Western blotting results indicated that the protein expressions of Nrf2 and HO-1 in liver tissues of the DQ model group were significantly decreased compared to the control group. On the other hand, the protein expressions of Keap1 and activated caspase-9 were conspicuously higher when compared to the control group. In comparison to the DQ model group, the QR treatment group showed a significant increase in the protein expressions of Nrf2 and HO-1 in liver tissues (Nrf2/β-actin: 1.17±0.08 vs. 0.92±0.45, HO-1/β-actin: 1.53±0.17 vs. 0.84±0.09). By contrast, there was a notable decrease in the protein expressions of Keap1 and activated caspase-9 (Keap1/β-actin: 0.48±0.06 vs. 1.22±0.09, activated caspase-9/β-actin: 1.17±0.12 vs. 1.59±0.30), the differences were statistically significant (all P < 0.01). Conclusion:QR may reduce acute liver injury induced by DQ poisoning in mice via activating Keap1/Nrf2 signaling pathway.

OBJECTIVE: To investigate the protective effect and mechanism of tumor necrosis factor receptor-associated factor 6 (TRAF6) inhibitor C25-140 on acute kidney injury (AKI) induced by acute diquat (DQ) poisoning in mice. METHODS: A total of 80 SPF grade healthy male C57BL/6 mice were randomly divided into the normal control group, DQ model group, C25-140 intervention group, and C25-140 control group, with 20 mice in each group. The DQ poisoning mouse model was established by using one-time intraperitoneal injection of 1 mL of 40 mg/kg DQ solution. The normal control group and C25-140 control group were injected with an equal amount of pure water into the peritoneal cavity. After 4 hours of model establishment, the C25-140 intervention group and C25-140 control group were given intraperitoneal injection of C25-140 5 mg/kg. The normal control group and DQ model group were given equal amounts of pure water, once a day for 7 consecutive days. After 7 days, the mice were anesthetized, eye blood was collected, and renal tissue was collected after sacrifice. The pathological changes of renal tissue were observed under a light microscope and renal tissue structure and mitochondrial changes were observed under transmission electron microscopy. The levels of serum creatinine (SCr) and blood urea nitrogen (BUN) were measured. Enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of serum interleukins (IL-6, IL-1β) and tumor necrosis factor-α (TNF-α). Western blotting was used to detect the protein expression levels of TRAF6, myeloid differentiation factor 88 (MyD88), and nuclear factor-κB (NF-κB) in renal tissue. Chemical method was used to determine the content of serum malondialdehyde (MDA) and superoxide dismutase (SOD). RESULTS: During the observation period, there were no abnormal behaviors in the normal control group mice. The DQ model group mice gradually showed symptoms such as mental fatigue, fluffy fur, reduced activity, and low food intake after being exposed to the toxin, and severe cases resulted in death. The above symptoms were alleviated in the C25-140 intervention group compared to the DQ model group. Under light microscopy, HE staining showed infiltration of inflammatory cells, glomerulosclerosis, proximal tubular dilation, and vacuolization in the DQ model group, while the inflammatory response was reduced in the C25-140 intervention group compared to the DQ model group. Under transmission electron microscopy, the DQ model group showed relatively high levels of mitochondrial damage, severe swelling, increased volume, matrix dissolution, ridge fracture and loss. The degree of mitochondrial damage in the C25-140 intervention group was reduced compared to the DQ model group. Compared with the normal control group, the levels of serum SCr, BUN, IL-6, IL-1β, TNF-α, and MDA in the DQ model group were significantly increased, while the serum SOD level was significantly decreased. Compared with the DQ model group, the levels of serum SCr, BUN, IL-6, IL-1β, TNF-α, and MDA in the C25-140 intervention group were significantly reduced [SCr (μmol/L): 59.07±13.11 vs. 83.61±20.13, BUN (mmol/L): 25.83±9.95 vs. 40.78±11.53, IL-6 (ng/L): 40.76±7.03 vs. 83.33±21.83, IL-1β (ng/L): 53.87±7.82 vs. 91.74±12.53, TNF-α (ng/L): 102.52±32.13 vs. 150.92±31.75, MDA (μmol/L): 3.57±1.06 vs. 5.75±1.83], and the serum SOD level was significantly increased (kU/g: 162.52±36.13 vs. 122.72±22.13), and the differences were statistically significant (all P < 0.01). Western blotting results showed that the protein expression levels of TRAF6, NF-κB, and MyD88 in the renal tissue of DQ model group mice were significantly higher than those in the normal control group. The expression levels of the above-mentioned proteins in the C25-140 intervention group of mice were significantly lower than those in the DQ model group (TRAF6/β-actin: 1.05±0.36 vs. 1.74±0.80, NF-κB/β-actin: 0.57±0.07 vs. 1.03±0.75, MyD88/β-actin: 0.58±0.07 vs. 1.03±0.33, all P < 0.05). CONCLUSIONS TRAF6 inhibitor C25-140 can alleviate AKI induced by DQ poisoning in mice by regulating the Toll-like receptor 4 (TLR4)/TRAF6/NF-κB signaling pathway and downregulating the levels of inflammatory cytokines IL-1β, IL-6, and TNF-α.
Animals ; Male ; Acute Kidney Injury/prevention & control* ; Mice ; Mice, Inbred C57BL ; Diquat ; TNF Receptor-Associated Factor 6/metabolism* ; Interleukin-6/blood* ; Kidney/pathology* ; NF-kappa B/metabolism* ; Peptide Fragments