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The toxic and cellular metabolic effects of atractyloside, a diterpenoid glycoside, which causes fatal renal and hepatic necrosis in vivo in animals and humans, have been investigated in tissue slices prepared from male domestic pig kidney and liver. Precision-cut slices (200 μm thick) were incubated with atractyloside at concentrations of 200 μM, 500 μ M, 1.0 mM and 2.0 mM for 3 h at 37 °C and changes in lipid profile and pyruvate-stimulated gluconeogenesis investigated. Lipid peroxidative changes, reduced glutathione (GSH) and ATP content, the release of lactate dehydrogenase (LDH), alkaline phosphatase (ALP), alanine and aspartate aminotransferase (ALT/AST) were also assessed. After 3 h of incubation, atractyloside caused a significant (P < 0.01) and concentration-dependent leakage of LDH and ALP from kidney slices. Only LDH leakage was significantly elevated in liver slices while ALT and AST leakage showed marginal increase. Atractyloside at concentrations of ≥200 μ M caused a significant increase in lipid peroxidation, but only in liver slices. However, atractyloside at concentrations of ≥200 μ M caused a marked depletion of GSH and ATP content in both kidney and liver slices. There was a marked decrease in total and individual phospholipid in kidney but not in liver slices. However, cholesterol and triacylglycerol levels were not affected by atractyloside in both kidney and liver slices. Renal and hepatic pyruvate-stimulated gluconeogenesis were significantly (P < 0.05) inhibited at atractyloside concentrations of ≥500 μM. Accumulation of organic anion p-aminohippuric acid (PAH) was also inhibited in renal cortical slices at atractyloside concentrations of ≥500 μM. These results suggest that the observable in vivo effect of atractyloside can be reproduced in slices and that basic mechanistic differences exist in the mode of toxicity in liver and kidney tissues. The data also raise the possibility that the mechanistic basis of metabolic alterations in these tissues following treatment with atractyloside may be relevant to target selective toxicity. Received: 21 January 1998 / Accepted: 23 March 1998  相似文献   

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The objective of this study was to assess the risk of genotoxicity of d ‐phenothrin by measuring the oxidative stress it causes in rat liver and kidney. The level of 8‐oxo‐7,8‐dihydro‐2′‐deoxyguanosine (8‐oxodG)/106 2′‐deoxyguanosine (dG) was measured by using high performance liquid chromatography (HPLC) with a diode array (DAD) and an electrochemical detector (ECD). Sixty male Wistar albino rats were randomly divided into five experimental groups and one control group of 10 rats/group. d ‐phenothrin was administered intraperitoneally (IP) to the five experimental groups at 25 mg/kg (Group I), 50 mg/kg (Group II), 66.7 mg/kg (Group III), 100 mg/kg (Group IV), and 200 mg/kg (Group V) for 14 consecutive days, and the control group received only the vehicle, dimethyl sulfoxide (DMSO). DNA from samples frozen in liquid nitrogen was isolated with a DNA isolation kit. Following digestion with nuclease P1 and alkaline phosphatase (ALP), hydrolyzed DNA was subjected to HPLC. The dG and 8‐oxodG levels were analyzed with a DAD and ECD, respectively. In the experimental groups, the mean 8‐oxodG/106 dG levels were 48.15 ± 7.43, 68.92 ± 20.66, 82.07 ± 14.15, 85.08 ± 28.50, and 89.14 ± 21.73 in livers and 39.06 ± 7.63, 59.69 ± 14.22, 61.13 ± 17.46, 65.13 ± 23.40, and 72.66 ± 19.04 in kidneys of Groups I, II, III, IV, and V, respectively. The mean 8‐oxodG/106 dG levels in the control groups were 44.96 ± 12.66 for the liver and 39.07 ± 4.80 for the kidney. A statistically significant (p < 0.05), dose‐dependent increase in oxidative DNA damage was observed in both organs of animals exposed to d ‐phenothrin when compared to controls. Furthermore, the liver showed a significantly higher level of oxidative DNA damage than the kidney (p < 0.01). In conclusion, d ‐phenothrin administered to rats intraperitoneally for 14 consecutive days generated free radical species in a dose‐dependent manner and caused oxidative DNA damage in the liver and kidney. © 2013 Wiley Periodicals, Inc. Environ Toxicol 30: 607–613, 2015.  相似文献   

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CYP1A2 is one of the main Cytochrome P450 enzymes in the human liver associated with the metabolism of several xenobiotics. CYP1A2 is especially involved in the metabolic activation of different procarcinogens. Therefore, the development of cancer may be inhibited by inhibiting CYP1A2 activity. Here, the inhibitory effect of HYIpro‐3‐1 and its derivatives on CYP1A2 activity in human liver microsomes (HLM) was studied through LC‐MS/MS using a cocktail assay. Among the four compounds, HYIpro‐3‐1 showed the most selective and strongest inhibitory effect on CYP1A2 at IC50 values of 0.1 µM in HLMs and inhibition was confirmed using purified human CYP1A2. It was determined that inhibition is reversible because the inhibitory effect of HYIpro‐3‐1 is not dependent on preincubation time. HYIpro‐3‐1 showed a typical pattern of competitive inhibition for CYP1A2‐catalyzed phenacetin O‐deethylation, based on the Lineweaver‐Burk plot, with a Ki value of 0.05 μM in HLMs; the secondary plot also showed a linear pattern. In our study, HYIpro‐3‐1 was proposed as a novel inhibitor with the capacity to selectively inhibit CYP1A activity in HLMs.  相似文献   

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We explored biomarkers suitable for monitoring sub‐chronic kidney injury using the three rat models of cisplatin (CDDP)‐induced kidney injury, which were designed to extend the current knowledge beyond the sub‐acute exposure period. In the pilot study, a single intravenous administration of 1.5 mg kg–1 CDDP to rats was confirmed to result in no histopathological changes. Subsequently, CDDP was intravenously administered to rats at a dose of 1.5 mg kg–1 for 4 days at 24‐h intervals (Experimental model 1) and for up to 10 weeks at weekly intervals (Experimental models 2 and 3), and the changes in blood and urine components, such as recently recommended urinary biomarkers (Kim‐1, clusterin and so on) and traditional blood biomarkers (blood urea nitrogen and serum creatinine), were examined together with the histopathological changes in renal tissues during the development of the kidney injury in each model. In these experimental models, a significant increase in urinary Kim‐1 was observed prior to the histopathological changes in renal tissues, and these changes were retained after the adverse histopathological changes. Significant changes in all of the other urinary biomarkers examined occurred along with the histopathological changes. In addition, the increase in urinary Kim‐1 after weekly treatment with CDDP for 4 weeks was reduced in a time‐dependent manner after cessation of the drug. The present findings indicate that urinary Kim‐1 is the most useful biomarker for CDDP‐induced rat sub‐chronic kidney injury among the biomarkers examined. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

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Tocopherol is used not only as an ethical drug but also as a supplement. In 2008, it was reported that α‐tocopherol is partly transported via an intestinal cholesterol transporter, Niemann‐Pick C1‐Like 1 (NPC1L1). Ezetimibe, a selective inhibitor of NPC1L1, is administered for a long time to inhibit cholesterol absorption and there is a possibility that the absorption of α‐tocopherol is also inhibited by ezetimibe. This study investigated the influence of ezetimibe on the absorption of α‐tocopherol with single administration and long‐term administration. An approach to avoid its undesirable consequence was also examined. α‐Tocopherol (10 mg/kg) and ezetimibe (0.1 mg/kg) were administered to rats, and the plasma concentration profiles of α‐tocopherol and tissue concentrations were investigated. The plasma concentration of α‐tocopherol was decreased by the combination use of ezetimibe in the case of concurrent single administration. On the other hand, inhibition of the absorption of α‐tocopherol was prevented by an administration interval of 4 h. In a group of rats administered for 2 months with a 4 h interval, not only the plasma concentration but also the liver concentration was increased compared with those in a group with concurrent combination intake of α‐tocopherol and ezetimibe. The absorption of α‐tocopherol was inhibited by ezetimibe. The inhibitory effect of ezetimibe can be prevented by an administration interval of 4 h, although ezetimibe is a medicine of enterohepatic circulation. Attention should be paid to the use of ezetimibe and components of NPC1L1 substrates such as α‐tocopherol. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

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Fluorosis, caused by drinking water contaminated with inorganic fluoride, is a public health problem in many areas around the world. The aim of this study was to evaluate oxidative stress in spermatozoa caused by fluoride and NADPH oxidase in relationship to fluoride. Four experimental groups of male Wistar rats were administered with deionized water, NaF, at a dose equivalent to 5 mg fluoride kg?1 per 24 h, NaF plus 20 mg kg?1 per 24 h α‐tocopherol, or α‐tocopherol alone for 60 days. We evaluated several spermatozoa parameters in the four groups: standard quality analysis, superoxide dismutase (SOD) activity, the generation of reactive oxygen species (ROS), NADPH oxidase activity, TBARS formation, ultrastructural analyses of spermatozoa using transmission electron microscopy and in vitro fertilization (IVF) capacity. After 60 days of treatment, urinary excretion of fluoride was not modified by α‐tocopherol. Spermatozoa from fluoride‐treated rats exhibited a significant increase in the generation of ROS, accompanied by a significant increase in NADPH oxidase activity. The increase in ROS generation was significantly diminished by diphenylene iodonium, an inhibitor of NADPH oxidase activity. In contrast, a decrease in the generation of ROS, an increase in SOD activity and the prevention of TBARS formation process were observed in spermatozoa of rats exposed to fluoride plus α‐tocopherol. Finally, α‐tocopherol treatment prevented the IVF incapacity observed in the spermatozoa from fluoride‐treated rats. These results suggest that NADPH oxidase participates in the oxidative stress damage caused by subchronic exposure to fluoride. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

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Hexaammine cobalt (III) chloride is a trivalent complex cation of Co(III) and amine that has previously been shown to act as an inhibitor of insulin secretion, radiosensitizing agent, and an antiviral agent. We have recently reported the anticancer potential of the compound against diethylnitrosamine-induced carcinogenesis in mice. However, there is no report on the potential toxicity of the compound. The present study was conducted to evaluate the tissue distribution of the compound and its potential toxicity following acute administration of the compound through intraperitoneal route in Balb/c mice. Our results showed that cobalt accumulated maximally in kidney, followed by liver, spleen, blood, and lung in a decreasing order and in a dose-dependent manner. Evaluation of liver and kidney function tests revealed that the compound exerted a relatively higher toxicity in kidney, as compared to liver, as evidenced by the sharp enhancement in the serum levels of urea and creatinine in a dose-dependent manner. Examination of levels of lipid peroxidation and selected oxidative stress–related parameters in kidney, liver, and lung suggest that higher accumulation of cobalt in kidney may promote higher oxidative stress in the organ, as compared to liver and lung, which may eventually impair kidney function.  相似文献   

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Combined recirculation of the rat liver (L) and kidney (IPK) at 10 ml min–1 per organ (LK) was developed to examine the hepatorenal handling of the precursor-metabolite pair: [14C]-enalapril and [3H]enalaprilat. Loading doses followed by constant infusion of [14C]enalapril and preformed [3H]enalaprilat to the reservoirs of the IPK or the LK preparation was used to achieve steady stale conditions. In both organs, enalapril was mostly metabolized to its dicarboxylic acid metabolite, enalaprilat, which was excreted unchanged. At steady state, the fractional excretion for [14C]enalapril (FE=0.45 to 0.48) and preformed [3H]enalaprilat (FE{pmi}=1.1) were constant and similar for both the IPK and LK. The additivity of clearance was demonstrated in the LK preparation, namely, the total clearance of enalapril was the sum of its hepatic and renal clearances. However, the apparent fractional excretion for fanned [14C]enalaprilat, FE{mi} and the apparent urinary clearance were time-dependent and higher than the corresponding values for preformed [3H]enalaprilat in both the IPK and LK. The FE{mi} and urinary clearance values further differed between the IPK and LK. Biliary clearance of formed vs. preformed enalaprilat displayed the same discrepant trends as observed for FE{mi} vs. FE{pmi} for the LK. These observations on the time-dependent and variable excretory clearance (urinary or biliary) of the formed metabolite vs. the constant, and much reduced, excretory clearance of the preformed metabolite are due to dual contributions to formed metabolite excretion: the nascently formed, intracellular metabolite which immediately underwent excretion and the formed metabolite which reentered the circulation, behaved as a preformed species. When data for the IPK and LK preparations were modeled with a physiological model with parameters previously reported for the L and IPK, all data, including metabolite excretory clearances, were well predicted. Model simulations revealed that the apparent FE{mi} differed between the LK and IPK preparations when the liver was present as an additional metabolite formation organ; the apparent excretory (urinary orGlossary k0 infusion rate into the reservoir - CR reservoir concentration - COut,k and COut,L venous concentrations for the kidney and liver - Cp,k and cP,L concentrations in renal and hepatic plasma, respectively - Ck and CL concentrations in kidney and liver tissue, respectively - CU and CBile concentrations in urine and bile, respectively - CL b in andCL b ef influx and efflux clearances, respectively, at the basolateral membrane of the renal tubular cell - C l in and CL l ef influx and efflux clearances, respectively, at the luminal membrane of the renal tubular cell - CL int,K m renal metabolic intrinsic clearance of the drug - CL d in and CL d ef influx and efflux clearances, respectively, at the sinusoidal membrane - CL int m,L hepatic metabolic intrinsic clearance of the drug - CL int,L b biliary intrinsic clearance - VR plasma reservoir volume - VP,K and VP,L plasma volumes of the kidney and liver, respectively - VK and VL tissue volumes of the kidney and liver, respectively - VU and VBile volumes of urine and bile, respectively - QK and QL total renal and hepatic plasma flow rates, respectively - GFR glomerular filtration rate - QU and QBile urine and bile flow rates, respectively - fP, fK, and fL unbound fractions in plasma and kidney and liver tissue, respectively This work was supported by the Medical Research Council of Canada. I. A. M. de Lannoy was a recipient of the Ontario Graduate Scholarship from the Ontario Ministry of Health; K. S. Pang was a recipient of the Faculty Development Award, Medical Research Council.  相似文献   

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Acute kidney injury (AKI) occurs in 5% of hospitalized patients and in 50% of sepsis patients with acute renal dysfunction. However, there have been no safe and effective therapeutic strategies. The hypoxia condition is closely related to renal injury and function under AKI. As hypoxia‐inducible factor 1α (HIF‐1α) is critical for the cellular response to hypoxia, we investigated the protective effect of HIF‐1α in a rat AKI model. We found that HIF‐1α injection improved the survival of rat with AKI, and the level of creatinine and blood urea nitrogen (BUN) was also increased. Our data showed that HIF‐1α treatment significantly alleviated ischaemic/reperfusion injury to kidney tubules and nephrocytes. We also found the downstream factors, such as EPOR, VEGF, and PHD3, were also upregulated by HIF‐1α. Finally, it was observed that HIF‐1α treatment also increased the percentage of adult resident progenitor cells (ARPC) in vitro and in vivo. In conclusion, HIF‐1α plays a protective role in the ischaemic AKI model through stimulating the proliferation of ARPC, and our study provided a potential therapeutic strategy for AKI.  相似文献   

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《Environmental toxicology》2018,33(3):315-324
Overexposure to manganese (Mn) has been known to induce alpha‐synuclein (α‐Syn) oligomerization, which is degraded mainly depending on endoplasmic reticulum stress (ER stress) and autophagy pathways. However, little data reported the cross‐talk between ER stress and autophagy on Mn‐induced α‐Syn oligomerization. To explore the relationship between ER stress and autophagy, we used 4‐phenylbutyric acid (4‐PBA, the ER stress inhibitor), rapamycin (Rap, autophagy activator) and 3‐methyladenine (3‐MA, autophagy inhibitor) in mice model of manganism. After 4 weeks of treatment with Mn, both ER stress and autophagy were activated. Exposed to Mn also resulted in α‐Syn oligomerization and neuronal cell damage in the brain tissue of mice, which could be relieved by 4‐PBA pretreatment. Moreover, when the ER stress was inhibited, the activation of autophagy was also inhibited. Rap pretreatment significantly activated autophagy and decreased α‐Syn oligomers. However, 3‐MA pretreatment inhibited autophagy resulting in increase of α‐Syn oligomers, and compensatorily activated PERK signaling pathway. Our results also demonstrated that the inhibition of autophagy by 3‐MA aggravated neuronal cell damage. The findings clearly demonstrated that the cross‐talking between autophagy and ER stress might play an important role in the α‐Syn oligomerization and neurotoxicity by Mn.  相似文献   

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The characteristics of the β-adrenergic signal transduction system were analyzed in kidney and liver membrane preparations from neonatal (2–3 days), mature (2 months), and old (2 years) rats. When comparing kidneys from adult to neonatal rats, we found a higher β-receptor density and a higher percentage of β1-receptor subtype, lower immunoreactive Gs-protein, a lower ratio between the high and low molecular weight splice variant of Gs, lower immunoreactive Gi-protein, and lower basal adenylate cyclase activity. When comparing livers from adult to neonatal rats, we found lower β-receptor density and basal adenylate cyclase activity. Very few differences could be detected when comparing mature to old kidneys or livers. Stimulated adenosine 3′,5′-cyclic monophosphate (cAMP) synthesis was tissue- and age-dependent. In liver, G-protein- and β-receptor-stimulated cAMP synthesis mirrored basal adenylate cyclase activity and was highest in liver from neonatal animals. In contrast, cAMP synthesis was significantly more stimulated in kidneys from mature animals than from neonatal and senescent rats. We conclude that: (i) the stoichiometry of the components within the β-receptor/G-protein/adenylate cyclase complex is not fixed but is both tissue- and age-dependent; (ii) adenylate cyclase enzyme activity is possibly but not necessarily the rate-limiting step in the β-receptor-mediated synthesis of cAMP; and (iii) there is in vivo evidence for a preferential co-expression of the large splice variant of the Gs-protein and β2-receptor subtype. It is speculated that this could have important physiological consequences for the development of the kidney.  相似文献   

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This research was conducted to investigate the biochemical effects of thymosin alpha‐1 using human lung cancer cells (A549). The A549 cells were treated with different concentrations of Thα1 for 24 h and the growth, inhibition of cells was determined. Thα1 revealed anti‐proliferative effect at 24 and 48 μg/ml after 24 h. Furthermore, it indicated antioxidant properties by significantly enhancing the activity of catalase (12 μg/ml), superoxide dismutase (6 and 12 μg/ml), and glutathione peroxidase (3, 6 and 12 μg/ml) and reducing the production of cellular ROS. Our results showed that Thα1 inhibits the migration of A549 cells in a concentration‐dependent manner after 24 and 48 h. Moreover, the effect of Thα1 on apoptosis was investigated by Hoechst 33342 staining and cell cycle analysis. Results demonstrated no significant effect on the induction of apoptosis in A549 cells. In conclusion, our results showed the antioxidant properties of Thα1 on A549 cancer cells.  相似文献   

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《Environmental toxicology》2018,33(3):361-369
This study was designed to assess the potential antifibrotic effect of D‐Limonene—a component of volatile oils extracted from citrus plants. D‐limonene is reported to have numerous therapeutic properties. CCl4‐intduced model of liver fibrosis in Wistar rats is most widely used model to study chemopreventive studies. CCl4‐intoxication significantly increased serum aminotransferases and total cholesterol these effects were prevented by cotreatment with D‐Limonene. Also, CCl4‐intoxication caused depletion of glutathione and other antioxidant enzymes while D‐Limonene preserved them within normal values. Hydroxyproline and malondialdehyde content was increased markedly by CCl4 treatment while D‐Limonene prevented these alterations. Levels of TNF‐α, TGF‐β, and α‐SMA were also assessed; CCl4 increased the expression of α‐SMA, NF‐κB and other downstream inflammatory cascade while D‐Limonene co‐treatment inhibited them. Collectively these findings indicate that D‐Limonene possesses potent antifibrotic effect which may be attributed to its antioxidant and anti‐inflammatory properties.  相似文献   

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A liposome formulation of the enzyme paraoxonase‐1 (PON1) was prepared for purposes of prolonging and maintaining its activity in vivo. Following purification of PON1 from rabbit serum, liposomes containing PON1 (L‐PON1) were prepared using a film‐dispersion method with a soybean phospholipid–cholesterol mixture (5 : 1, w/w). The pharmacokinetic behaviour of conventional injectable PON1 and L‐PON1 was compared following a single intravenous injection in rats. The enzyme activity of PON1 and its pharmacokinetic parameters were calculated based on a two‐compartment model following conventional injection. The level of PON1 encapsulation in L‐PON1 was 86.20 ± 3.12%. The particle size distribution of L‐PON1 was a narrow unimodal form, with an average diameter of 126 nm. The results suggest that compared with conventional injectable PON1, L‐PON1 has an improved half‐life and enhanced enzyme activity in rats. In conclusion, PON1 can be encapsulated into a lipid bilayer for enhanced stability.  相似文献   

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Potassium dichromate (K2Cr2O7) is an environmental contaminant widely recognized as a carcinogen, mutagen, and teratogen toward humans and animals. This study investigated the effects of K2Cr2O7 on the hepatic function of pregnant and lactating rats and their suckling pups. Experiments were carried out on female Wistar rats given 700 ppm of K2Cr2O7 in their drinking water from the 14th day of pregnancy until day 14 after delivery. Hepatotoxicity was objectified by the significant increase in liver malondialdehyde content and a significant accumulation of chromium in this soft tissue. Moreover, exposure to K2Cr2O7 induced a decrease of glutathione, nonprotein thiols, and vitamin C in the liver of mothers and their suckling pups. Alteration of the antioxidant system in the treated group was confirmed by the significant decline of antioxidant enzyme activities such as catalase, glutathione peroxidase, while liver superoxide dismutase activity increased in mothers and decreased in their offspring. It was found that K2Cr2O7 induced liver damages as evidenced by the elevation of plasma aminotransferases, lactate dehydrogenase activities, and bilirubin levels. Impairment of the hepatic function corresponded histologically. Our investigation revealed hemorrhage, leukocytes infiltration cells, and necrosis, which were more pronounced in the hepatocytes of mothers than in those of their suckling pups. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2013.  相似文献   

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The therapeutic potential of the chelator tiferron (sodium-4,5-dihydroxy-1,3-benzene disulphonate; 300 mg kg(-1), i.p.) and adjuvants, i.e. alpha-tocopherol (25 mg kg(-1), p.o.), propolis (a honey-bee hive product; 200 mg kg(-1), p.o.) and piperine (10 mg kg(-1), p.o.) were evaluated individually and in combination against beryllium induced biochemical alterations and oxidative stress consequences. Female albino rats were exposed to beryllium nitrate (1 mg kg(-1), i.p.) daily for 28 days followed by treatment with the above mentioned therapeutic agents for 5 consecutive days. Administration of beryllium altered blood biochemical variables with significant depletion in hemoglobin, blood sugar, total serum protein, albumin and significant enhancement in the release of serum transaminases. A significantly increased lipid peroxidation and a decreased level of glutathione after beryllium exposure indicated oxidative stress in the liver and kidney. Beryllium exposure decreased total protein and glycogen contents, whereas triglycerides and cholesterol increased significantly in liver and kidney. Individual administration of all the four compounds showed significant therapeutic potential in reverse of some of the biochemical parameters mentioned above. Furthermore, the combination of tiferron with alpha-tocopherol, propolis or piperine, respectively, could reverse all the variables significantly more towards the control. None of the test compounds showed any significant change in choleretic activity (bile flow and bile solids), indicating that these compounds had no adverse effects at these dose levels. It was concluded that all the combinations of tiferron and adjuvants played a beneficial role in reducing beryllium induced systemic toxicity at relatively lower doses and the combination of tiferron and propolis showed a more pronounced therapeutic potential.  相似文献   

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