The Protective Effect of SLNP on Hepatic Fibrosis Induced by Thioacetamide in Rats.

INTRODUCTION: The incidence of non-alcoholic fatty liver disease (NAFLD) has increased in recent years. Hepatic fibrosis (HF) is an important step in the progression of NAFLD to cirrhosis and even carcinoma and is also recognized as a possible reversal phase. AIMS: We previously found that the aqueous extract of Sedum Lineare Thunb. has hepatoprotective effects. This study investigated the hepatoprotective effect and mechanism of the Sedum Lineare Thunb. n-butanol phase (SLNP) on HF in rats. METHODS: Animals were intraperitoneally injected with thioacetamide solution twice a week for 8 weeks to prepare an HF model and were administered the corresponding drugs or an equal volume of normal saline by intragastric administration once a day for 8 weeks. Liver function, hydroxyproline and malondialdehyde (MDA) content, superoxide dismutase (SOD), Na+-K+-ATPase, and Ca2+-Mg2+-ATPase were analyzed using colorimetric methods. Moreover, mRNA expression and protein levels in the liver tissue were detected via quantitative polymerase chain reaction and western blotting, respectively. RESULTS: The results showed that SLNP could effectively improve the liver function of rats with HF and significantly reduce the content of hydroxyproline; the mRNA expression and protein levels of alpha-smooth muscle actin (α-SMA), collagen I, III, and IV, transforming growth factor beta 1 (TGF-ß1), Smad2/3, and Smad4 were also significantly reduced. Simultaneously, SLNP significantly increased the activities of SOD, Na+-K+- ATPase, and Ca2+-Mg2+-ATPase in the rat liver tissues, whereas it reduced the levels of MDA and SOD in the serum and liver tissues. CONCLUSION: This study revealed that SLNP elicits an anti-fibrotic effect by inhibiting oxidative stress and stellate cell activation, thereby reducing the formation and deposition of the extracellular matrix. The TGF-ß1/Smads signaling pathway may be involved in this process.

Topical Administration of ACE Inhibitor Interrupts the Progression of Cataract in Two Kidney One Clip Induced Hypertensive Cataract Model.

PURPOSE: Previously, we assessed that hypertension increases cataractogenesis. In the present study, we evaluated the effect of oral and topical administration of enalapril on two kidney one clip (2K1C)-induced hypertensive cataract model by evaluating the biochemical alteration of lenticular antioxidants, ionic content, ATPase activity, protein content and careful examination of the lenticular opacity. MATERIALS AND METHOD: Animals were divided into normal and hypertensive animals. Hypertensive animals were divided into hypertensive control group (0.3% CMC), enalapril (oral) treatment group (20 mg/kg/day; p.o), and enalapril (topical) treatment group (0.1% w/v on the eye cornea) for a period of twelve weeks. During experimental study blood pressure, heart rate and morphology of the eyes were monitored biweekly. After twelve weeks, lenses were photographed and various catractogenic biochemical parameters were assessed. RESULTS: Enalapril (oral) treatment conserved the blood pressure (systolic and diastolic), restored the level of antioxidants, restored the lipid peroxidation marker, nitrite content, ionic content, ATPase function, protein content, and thus delayed the cataract formation. While, enalapril (topical) treatment exhibited anti-cataract effect without affecting the systolic and diastolic blood pressure that could be by restoring the antioxidant level, maintaining the ionic balance, balancing the protein levels, and by inhibiting the upregulated ocular renin angiotensin system. The overall results suggest that enalapril (topical) treatment showed conspicuous effect than enalapril (oral) treatment in adjourning the cataract formation. CONCLUSION: Based on the results, it may be concluded that upregulated ocular RAS by increasing oxidative stress and by misbalancing the lenticular ionic and protein content may lead to cataract formation in hypertensive condition.

E-NTPDase (ecto-nucleoside triphosphate diphosphohydrolase) of Leishmania amazonensis inhibits macrophage activation.

Leishmania amazonensis, the causal agent of diffuse cutaneous leishmaniasis, is known for its ability to modulate the host immune response. Because a relationship between ectonucleotidase activity and the ability of Leishmania to generate injury in C57BL/6 mice has been demonstrated, in this study we evaluated the involvement of ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase) activity of L. amazonensis in the process of infection of J774-macrophages. Our results show that high-activity parasites show increased survival rate in LPS/IFN-γ-activated cells, by inhibiting the host-cell NO production. Conversely, inhibition of E-NTPDase activity reduces the parasite survival rates, an effect associated with increased macrophage NO production. E-NTPDase activity generates substrate for the production of extracellular adenosine, which binds to A2B receptors and reduces IL-12 and TNF-α produced by activated macrophages, thus inhibiting NO production. These results indicate that E-NTPDase activity is important for survival of L. amazonensis within macrophages, showing the role of the enzyme in modulating macrophage response and lower NO production, which ultimately favors infection. Our results point to a new mechanism of L. amazonensis infection that may pave the way for the development of new treatments for this neglected disease.

Enzyme kinetics and pharmacological characterization of nucleotidases released from the guinea pig isolated vas deferens during nerve stimulation: evidence for a soluble ecto-nucleoside triphosphate diphosphohydrolase-like ATPase and a soluble ecto-5'-nucleotidase-like AMPase.

Previously, we have demonstrated that stimulation of the sympathetic nerves of the guinea pig vas deferens evokes release not only of the cotransmitters ATP and norepinephrine but also of soluble nucleotidases that break down extracellular ATP, ADP, and AMP into adenosine. In this study we show that the apparent K(m) values of the releasable enzyme activity vary depending on which of these adenine nucleotides is used as initial substrate. The K(m) value for ATP was 33.6 +/- 2.3 microM, 21.0 +/- 2.3 microM for ADP, and 10.0 +/- 1.1 microM for AMP. The ratios of the V(max) values for each enzyme reaction were 4:2:3. We have also found a different sensitivity of the metabolism of ATP and AMP by releasable nucleotidases to known nucleotidase inhibitors. Suramin inhibited the breakdown of ATP by releasable nucleotidases in a noncompetitive manner and with a K(i) value of 53 microM, but had no effect on the breakdown of AMP. The 5'-nucleotidase inhibitor alpha,beta-methylene ADP inhibited the breakdown of AMP but not that of ATP. Concanavalin A inhibited the breakdown of AMP but had neither inhibitory nor facilitatory effects on the breakdown of ATP. 6-N,N-Diethyl-beta,gamma-dibromomethylene-D-ATP (ARL67156), an ecto-ATPase inhibitor, suppressed ATPase and AMPase activities, whereas NaN(3) (10 mM) affected neither reaction, but inhibited the ADP metabolism. Phosphatase- and phosphodiesterase inhibitors did not affect the activity of the releasable nucleotidases. This evidence suggests that the soluble nucleotidases released during neurogenic stimulation of the guinea pig vas deferens combine an ecto-5'-nucleotidase-like and an ecto-nucleoside triphosphate diphosphohydrolase-like activity.

Photodynamic damage induced by bilirubin on human platelets: possible relevance to newborn pathology.

Several reports have appeared showing the possibility of bilirubin-sensitized photodamage. We have extended these observations to platelets. In the presence of 300 microM bilirubin the in vitro irradiation of isolated platelets or platelet-rich plasmas with visible light induced significant lysis as determined by the release of lactate dehydrogenase (LDH). The extent of LDH release was a function of irradiation time, being about 20% after 2 h of irradiation. A loss membrane-bound ATPase activity was also observed at earlier times, indicating that membrane damage was preliminary to the lytic effect. The release of beta-thromboglobulin, induced by close cell-to-cell contact, was lower in bilirubin- and light-treated platelets with respect to controls. Our results suggest that bilirubin may act as a photodynamic agent producing some damage on human blood platelets.