This study was performed to evaluate the antifibrotic properties of coffee in a model of liver damage induced by repeated administration of thioacetamide (TAA) in male Wistar rats. In this study, cirrhosis was induced by chronic TAA administration and the effects of co-administration of conventional caffeinated coffee or decaffeinated coffee (CC, DC, respectively) for 8 weeks were evaluated. TAA administration elevated serum alkaline phosphatase (AP), γ-glutamyl transpeptidase (γ-GTP) and alanine aminotransferase (ALAT), liver lipid peroxidation, collagen content, depleted liver glycogen and glutathione peroxidase (GPx) activity. Additionally increased levels of a number of proteins were detected including transforming growth factor-beta (TGF-β), connective tissue growth factor (CTGF) and alpha-smooth muscle actin (α-SMA), and matrix metalloproteinase (MMP)-2, 9 and 13. Coffee suppressed most of the changes produced by TAA. Histopathological analysis was in agreement with biochemical and molecular findings. These results indicate that coffee attenuates experimental cirrhosis; the action mechanisms are probably associated with its antioxidant properties and mainly by its ability to block the elevation of the profibrogenic cytokine TGF-β and its downstream effector CTGF. Various components of coffee that have been related to such a favorable effect include caffeine, coffee oils kahweol, cafestol and antioxidant substances; however, no definite evidence for the role of these components has been established. These results support earlier findings suggesting a beneficial effect of coffee on the liver. However, more basic clinical studies must be performed to confirm this hypothesis.

AIMTo study the molecular mechanisms involved in the hepatoprotective effects of naringenin (NAR) on carbon tetrachloride (CCl4)-induced liver fibrosis.METHODSThirty-two male Wistar rats (120-150 g) were randomly divided into four groups: (1) a control group (n = 8) that received 0.7% carboxy methyl-cellulose (NAR vehicle) 1 mL/daily p.o.; (2) a CCl4 group (n = 8) that received 400 mg of CCl4/kg body weight i.p. 3 times a week for 8 wk; (3) a CCl4 + NAR (n = 8) group that received 400 mg of CCl4/kg body weight i.p. 3 times a week for 8 wk and 100 mg of NAR/kg body weight daily for 8 wk p.o.; and (4) an NAR group (n = 8) that received 100 mg of NAR/kg body weight daily for 8 wk p.o. After the experimental period, animals were sacrificed under ketamine and xylazine anesthesia. Liver damage markers such as alanine aminotransferase (ALT), alkaline phosphatase (AP), γ-glutamyl transpeptidase (γ-GTP), reduced glutathione (GSH), glycogen content, lipid peroxidation (LPO) and collagen content were measured. The enzymatic activity of glutathione peroxidase (GPx) was assessed. Liver histopathology was performed utilizing Masson’s trichrome and hematoxylin-eosin stains. Zymography assays for MMP-9 and MMP-2 were carried out. Hepatic TGF-β, α-SMA, CTGF, Col-I, MMP-13, NF-κB, IL-1, IL-10, Smad7, Smad3, pSmad3 and pJNK proteins were detected via western blot.RESULTSNAR administration prevented increases in ALT, AP, γ-GTP, and GPx enzymatic activity; depletion of GSH and glycogen; and increases in LPO and collagen produced by chronic CCl4 intoxication (P < 0.05). Liver histopathology showed a decrease in collagen deposition when rats received NAR in addition to CCl4. Although zymography assays showed that CCl4 produced an increase in MMP-9 and MMP-2 gelatinase activity; interestingly, NAR administration was associated with normal MMP-9 and MMP-2 activity (P < 0.05). The anti-inflammatory, antinecrotic and antifibrotic effects of NAR may be attributed to its ability to prevent NF-κB activation and the subsequent production of IL-1 and IL-10 (P < 0.05). NAR completely prevented the increase in TGF-β, α-SMA, CTGF, Col-1, and MMP-13 proteins compared with the CCl4-treated group (P < 0.05). NAR prevented Smad3 phosphorylation in the linker region by JNK since this flavonoid blocked this kinase (P < 0.05).CONCLUSIONNAR prevents CCl4 induced liver inflammation, necrosis and fibrosis, due to its antioxidant capacity as a free radical inhibitor and by inhibiting the NF-κB, TGF-β-Smad3 and JNK-Smad3 pathways.

Our results show that caffeine prevents experimental cirrhosis; the mechanisms of action are associated with its antioxidant properties and mainly by its ability to block the elevation of the profibrogenic cytokine transforming growth factor-β, which may be associated with attenuation of the inflammatory and fibrotic processes.

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Study design: Laboratory investigation in rats submitted to experimental spinal cord injury (SCI). Objective: To determine the effect of acute SCI on the pharmacokinetics of diclofenac, a marker drug of intermediate hepatic extraction, administered by the intravenous and the oral routes. Methods: Female Wistar rats were submitted to complete section of the spinal cord at the T8 level. SCI and sham-injured rats received 3.2 mg kg À1 of diclofenac sodium either intravenously or orally, diclofenac concentration was measured in whole blood samples and pharmacokinetic parameters were estimated. Diclofenac was not selected as test drug because of its therapeutic properties, but because to its biopharmaceutical properties, that is, intermediate hepatic extraction. Results: Diclofenac bioavailability after intravenous administration was increased in injured rats compared with controls due to a reduced clearance. In contrast, oral diclofenac bioavailability was diminished in SCI animals due to a reduction in drug absorption, which overrides the effect on clearance. Conclusion: Acute SCI induces significant pharmacokinetic changes for diclofenac, a marker drug with intermediate hepatic extraction. SCI-induced pharmacokinetic changes are not only determined by injury characteristics, but also by the route of administration and the biopharmaceutical properties of the studied drug.