The Effect of Retinol Acetate on Liver Fibrosis Depends on the Temporal Features of the Development of Pathology

Background

The effect of vitamin A on the manifestations of liver fibrosis is controversial and establishing the causes of its multidirectional influence is an urgent problem. In the work, the functional characteristics of the liver with Cu-induced fibrosis were determined after the restoration of vitamin A to the control level at the F0/F1 stage.

Methods

In animals with liver fibrosis, classical indicators of physiology, functional activity of the liver, histological, and hematological characteristics were determined; the content of calcium and ROS was determined in bone marrow cells.

Results

It was shown that in the liver with Cu-induced fibrosis, the restoration of vitamin A content to control values after per os injections of a retinol acetate solution at a dose of 0.10 mg (300 IU)/100 g of body weight in the early stages of this pathology development (Fо/F1) was accompanied by: a decrease in the number of immunocompetent cells in the bloodstream to control values; normalization of the amount of calcium ions and ROS in bone marrow cells; restoration to the control level of activity of alkaline phosphatase; an increase in the number of binuclear hepatocytes; and restoration of the dynamics of body weight growth in experimental animals, even against the background of the ongoing action of the hepatotoxic factor.

Conclusion

We came to the conclusion that the multidirectional action of vitamin A, which occurs in liver fibrosis, depends not only on the concentration of vitamin A in the liver but also on temporal characteristics of cellular and metabolic links involved in the adaptive response formation. It was suggested that knowledge of the initial temporal metabolic characteristics and the amount of vitamin A in the liver, taking into account the stages of fibrosis development, can be an effective way to restore the altered homeostatic parameters of the body.

Fatty Liver Change in Korean Adults in a Systematic Social Distancing System Amid the COVID-19 Pandemic: A Multicenter Analysis

In response to the COVID-19 pandemic, the Korean government implemented policies including the systematic social distancing (SSD) system which started on 28 June 2020. The present study investigated the development and aggravation of fatty liver measured using ultrasonography during the transition period (from pre-SSD to SSD) compared to the fatty liver changes during the pre-SSD period. Changes in fatty liver and liver enzymes were assessed in different groups stratified by alcohol consumption. Our retrospective cohort analysis included 5668 participants who underwent health checkups at 13 university hospitals during the SSD period and two or more checkups before the SSD period. Fatty liver developed and aggravated more in the transition period (13.6% development and 12.0% aggravation) than in the pre-SSD period (10.8% development and 10.1% aggravation) in the alcohol consumption group. This finding was more prominent in women than in men. Abnormal alanine transaminase levels were more often developed in the transition period than in the pre-SSD period, especially in men (11.1% vs. 8.6% in each period). In conclusion, the SSD system may contribute to fatty liver changes in individuals who regularly consume alcohol. Further research of the post-pandemic period is needed to assess long-term changes in fatty liver disease.

The protective role of ascorbic acid in the hepatotoxicity of cadmium and mercury in rabbits

The liver is one of the vital and sensitive organs which are usually exposed against the toxicity of mercury (Hg) and cadmium (Cd). The main objective of the current study was to evaluate the potential toxicological effects of both Cd and Hg as individual and combined. Hepatotoxicity was evaluated by monitoring the biochemical parameters of the liver and their accumulation in the liver as well as therapeutic role of vitamin C in said toxicity in rabbits (Oryctolagus cuniculus). In this research, cadmium chloride (1.5 mg/kg), mercuric chloride (1.2 mg/kg), and vitamin C (150 mg/kg of body weight) were orally administered to treatment groups of the rabbits for 28 alternative days. Various biochemical parameters of the liver such as lactate dehydrogenase (LDH), aspartate aminotransferase (ASAT), bilirubin, alanine aminotransferase (ALAT), total protein, and gamma glutamyl transferase (GGT) were estimated using blood samples. Some biochemical parameters like ASAT, ALAT, LDH, GGT, and bilirubin were significantly elevated (P ≤ 0.001) in individual Cd and Hg treatment groups, while the level of total protein was found to be significantly declined. The effects of Cd and Hg in the presence of vitamin C on these biochemical parameters were low as compared to metals-treated groups. Similar results were found when rabbits were treated with co-administration of both metals and vitamin C. Accumulation of Cd and Hg found to be higher in the liver. However, chemoprevention and chemotreatment with vitamin C significantly (P ≤ 0.01) minimized the toxicological effects of both metals but not regained the accumulation similar to that of the control group. The findings of this study provide awareness on accumulation of metals in the liver in rabbits and their toxicity tested through biochemical parameters as well as the therapeutic role of vitamin C in such alterations.

Naringin regulates glutamate-nitric oxide cGMP pathway in ammonium chloride induced neurotoxicity

Naringin, plant bioflavonoid extracted mainly from grapefruit and other related citrus species. This study was designed to assess the neuroprotective effect of naringin on ammonium chloride (NH₄Cl) induced hyperammonemic rats. Experimental hyperammonemia was induced by intraperitonial injection (i.p) of NH₄Cl (100mg/kg body weight (b.w.)) thrice a week for 8 consecutive weeks. Hyperammonemic rats were treated with naringin (80mg/kg b.w.) via oral gavage. Naringin administration drastically restored the levels of blood ammonia, plasma urea, nitric oxide (NO), glutamate, glutamine, lipid peroxidation, lipid profile, activities of liver marker enzymes, antioxidant status and sodium/potassium-ATPase (Na⁺/K⁺-ATPase). In addition, naringin supplementation reverted back the pathological changes of liver, brain and kidney tissues, the expressions of Glutamine synthetase (GS), Na⁺/K⁺-ATPase, neuronal nitric oxide (nNOS) and soluble guanylate cyclase (sGC) in hyperammonemic rats. Hence, this study suggested that nargingin exhibited their protective effect against NH₄Cl induced toxicity via enhancing the activities of antioxidant enzymes and inhibiting the lipid peroxidation process. Take together, this study provides data that naingin effectively reduced neurotoxicity by attenuating hyperammonemia, suggesting that naringin act as a potential therapeutic agent to treat hyperammonemic rats.

Growth, digestive and absorptive capacity and antioxidant status in intestine and hepatopancreas of sub-adult grass carp Ctenopharyngodonidella fed graded levels of dietary threonine

Background

This study was carried out to investigate effects of threonine levels on growth, digestive and absorptive capacity and antioxidant status in intestine and hepatopancreas of sub-adult grass carp (Ctenopharyngodonidella).

Results

Weight gain, specific growth rate, feed intake and feed efficiency were significantly improved by dietary threonine (P < 0.05). Intestinal activities of trypsin, chymotrypsin, alpha-amylase, lipase, alkaline phosphatase, γ-glutamyl transpeptidase and creatine kinase took the similar trends. Contents of malondialdehyde and protein carbonyl in intestine and hepatopancreas were significantly decreased by dietary optimal threonine supplementation (P < 0.05). Anti-superoxide anion capacity, anti-hydroxyl radical capacity, glutathione content and activities of superoxide dismutase, catalase and glutathione-S-transferase in intestine and hepatopancreas were enhanced by dietary threonine (P < 0.05).

Conclusions

Dietary threonine could improve growth, enhance digestive and absorptive capacity and antioxidant status in intestine and hepatopancreas of sub-adult grass carp. The dietary threonine requirement of sub-adult grass carp (441.9-1,013.4 g) based on weight gain was 11.6 g/kg diet or 41.5 g/kg of dietary protein by quadratic regression analysis.

Lycopene attenuates dichlorvos-induced oxidative damage and hepatotoxicity in rats

Because of the widespread use of dichlorvos (DDVP) for domestic applications, evaluation of their toxic effects is of major concern to public health. Lycopene may lower oxidative stress by a mechanism that is not fully elucidated. The present study was undertaken to evaluate the protective efficacy of lycopene in terms of normalization of altered biochemical parameters following DDVP treatment in rats. Animals were divided into four groups. The first group was used as control, while groups 2, 3, and 4 were orally treated with lycopene (10 mg kg−1 body weight (b.w.)), DDVP (1.6 mg kg−1 b.w.), and DDVP plus lycopene, respectively. Results showed that oral administration of DDVP for 30 days increased the levels of lipid peroxidation markers such as malondialdehyde, 4-hydroxynonanal, and protein carbonyl content in liver. Also, a decrease in levels of vitamin C, vitamin E, and reduced glutathione was detected due to DDVP administration. These were accompanied by a decrease in the activities of antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase, and glutathione- S-transferase in the liver tissue. Moreover, DDVP increased the activities of serum transaminases, alkaline phosphatase, lactate dehydrogenase, and lipoxygenase, and the levels of bilirubin, total cholesterol, low-density lipoprotein cholesterol, triglyceride and DNA–protein crosslinks, and 8-hydroxy-2-deoxyguanosine, while decreased the level of high-density lipoprotein cholesterol. Our results provide new insights into the biochemical studies of relation between DDVP hepatotoxicity and lycopene treatment. Administration of lycopene to DDVP-treated rats reverted the status of hepatic markers to near-normal levels. These data suggest that lycopene can protect against the liver damage induced by DDVP.

Protective effects of hesperidin on oxidative stress, dyslipidaemia and histological changes in iron-induced hepatic and renal toxicity in rats

The present study was to evaluate the protective role of hesperidin (HDN) against iron-induced hepatic and renal toxicity in rats. Administration of iron (30 mg/kg body weight) intraperitoneally for 10 days, the levels of serum hepatic markers, renal functional markers, lipid profile, lipid peroxidation markers and iron concentration in blood were significantly (p < 0.05) increased. The toxic effect of iron was also indicated by significant (p < 0.05) decrease in the levels of plasma, liver and kidney of enzymatic and non-enzymatic antioxidants. Administration of hesperidin at different doses (20, 40 and 80 mg/kg body weight) significantly (p < 0.05) reversed the levels of serum hepatic markers, renal functional markers, lipid profile, lipid peroxidation markers, restored the levels of hepatic, renal enzymatic antioxidants and non-enzymatic antioxidants with decrease in iron concentration in blood. Hesperidin at a dose of 80 mg/kg body weight exhibits significant protection on hepatic and renal when compared with other two doses (20 and 40 mg/kg body weight). All these changes were corroborating by histological observations of liver and kidney. This study demonstrated the protective role of hesperidin in reducing toxic effects of iron in experimental rats.

Diallyl trisulfide ameliorates arsenic-induced hepatotoxicity by abrogation of oxidative stress, inflammation, and apoptosis in rats

The present study investigates the possible ameliorative effects of diallyl trisulfide (DATS) against arsenic (As)-induced hepatotoxicity and oxidative stress in rats. The four experimental groups evaluated include: (1) vehicle control; (2) As (5 mg/kg/day); (3) DATS (80 mg/kg/day) + As; and (4) DATS. Induction of As in rats caused severe hepatotoxicity as evidenced by an elevation of serum aspartate aminotransferase and alanine aminotransferase activities and increased total bilirubin concentration, indicating hepatic function abnormalities. Histopathological examination revealed various structural changes in the liver, characterized by hepatocyte degeneration/necrosis, congestion, sinusoidal dilatation, vacuolation, and inflammatory cell infiltration. The significant decrease in reduced glutathione content, catalase, superoxide dismutase, glutathione peroxidase, and glutathione reductase activities and the significant increase in lipid peroxidation (thiobarbituric acid reactive substance) and protein oxidation (protein carbonyl) contents indicated that As-induced hepatotoxicity was mediated through oxidative stress. As intoxication also elevated the levels of Cas-3 and nitric oxide and increased the expression of nuclear factor-κB p65 in the liver. In contrast, DATS pretreatment significantly improved As-induced serum biochemical, immunohistochemical, and histopathological alterations reflecting hepatic dysfunction. These results may contribute to a better understanding of the hepatoprotective role of DATS, emphasizing the influence of this garlic trisulfide in the diet for human health, possibly preventing the hepatic injury associated with As intoxication, presumably due to its ability to inhibit lipid peroxidation, protein oxidation, and restoration of antioxidant status.

Ameliorating effects of troxerutin on nickel-induced oxidative stress in rats

OBJECTIVE

This study investigates the effects of troxerutin on nickel (Ni)-induced oxidative stress in rats.

METHODS

Nickel as nickel sulfate (20 mg/kg body weight (b.w.)) was administered intraperitoneally for 20 days to induce toxicity in the subject rats. The levels of stress markers AST, ALT, ALP, LDH, and GGT in the hepatic tissue were significantly increased while a decrease in the levels of enzymic and non-enzymic antioxidants was observed in Ni intoxicated rats.

RESULTS

Oral administration of troxerutin along with Ni for 20 days in a dose-dependent manner significantly reverted the stress markers in the liver tissue to near normal level. Troxerutin exhibited significant protection at 100 mg/kg b.w. Histopathological studies also supported the above findings.

CONCLUSIONS

Thus, we conclude that troxerutin preserved the histo-architecture and ameliorated stress markers in the liver tissue of Ni-intoxicated rats.

Anticarcinogenic effect of brucine in diethylnitrosamine initiated and phenobarbital-promoted hepatocarcinogenesis in rats

We evaluated the effects of brucine on N-nitrosodiethylamine (DENA)-induced hepatocarcinogenesis in rats. Initiation of hepatocarcinogenesis was done by intraperitoneal injection of diethylnitrosamine (DENA) followed by promotion with phenobarbital. The rats were exposed to dietary brucine for 4 weeks prior to initiation, and the treatment was continued for 22 consecutive weeks. Brucine decreased the incidence, total number, multiplicity, size and volume of preneoplastic hepatic nodules in a dose-dependent manner. Administration of DENA induced hepatocellular carcinoma (HCC), as evidenced by changes in histopathological architecture, increased activity of cytochrome P450, decreased activity of glutathione Stransferase (GST) as well as decreased antioxidant status, enhanced lipid peroxidation, increased liver marker enzymes. Western blot analysis showed decreased expression of cyclin D1 and Bcl-2 with activation of caspase-3 and increased expression of Bax. Immunohistochemical demonstrated the decreased expression of the PCNA and VEGF. These results indicate that brucine prevents lipid peroxidation and hepatic cell damage and also protects the antioxidant system in DENA-induced hepatocarcinogenesis.

Epigallocatechin gallate effectively ameliorates fluoride-induced oxidative stress and DNA damage in the liver of rats

Environmental exposure to sodium fluoride (NaF) compounds is a worldwide health concern. Epigallocatechin gallate (EGCG) is a green tea catechin found in a variety of green tea preparations. The intention of this study was to investigate the hepatoprotective role of EGCG in NaF-intoxicated rats. Rats were orally treated with NaF alone (25 mg·(kg body mass)−1·day−1) or plus EGCG at different doses (20, 40, and 80 mg·(kg body mass)−1·day−1) for 4 weeks. Hepatotoxicity of NaF was determined by increased levels of serum hepatospecific markers and total bilirubin, along with increased levels of thiobarbituric acid reactive substances, lipid hydroperoxides, protein carbonyl content, and conjugated dienes. The hepatotoxic nature of NaF was further evidenced by the decreased activity of enzymatic and nonenzymatic antioxidant levels in liver. NaF-treated rats also showed increased DNA damage and fragmentation in hepatocytes. Administration of EGCG (40 mg·(kg body mass)−1) to NaF-intoxicated rats significantly recuperated the distorted biochemical indices, DNA damage, and pathological changes in the liver tissue. Thus, the results of the present study clearly demonstrate that EGCG has strong free radical scavenging, antioxidant, and antigenotoxic properties that protect against NaF-induced oxidative hepatic injury in rats.

Inhibitory effect of naringenin (citrus flavonone) on N-nitrosodiethylamine induced hepatocarcinogenesis in rats

We evaluated the effects of naringenin on N-nitrosodiethylamine (NDEA)-induced hepatocarcinogenesis in rats. Administration of NDEA induced hepatocellular carcinoma (HCC), as evidenced by changes in histopathological architecture, increased activity of cytochrome P450, decreased activity of glutathione S-transferase (GST) as well as decreased antioxidant status, enhanced lipid peroxidation and increased liver marker enzymes. Pre- and post-treatment with naringenin effectively suppressed NDEA-initiated hepatocarcinoma and the associated preneoplastic lesions by modulating xenobiotic-metabolizing enzymes (XMEs), alleviating lipid peroxidation (through both free radical scavenging and the enhanced antioxidant status), and decreased levels of liver marker enzymes. These results indicate that naringenin prevents lipid peroxidation and hepatic cell damage and also protects the antioxidant system in N-nitrosdithylamine-induced hepatocarcinogenesis.

Protective effect of Piper betle leaf extract against cadmium-induced oxidative stress and hepatic dysfunction in rats

The present study was undertaken to examine the attenuative effect of Piper betle leaf extract (PBE) against cadmium (Cd) induced oxidative hepatic dysfunction in the liver of rats. Pre-oral supplementation of PBE (200 mg/kg BW) treated rats showed the protective efficacy against Cd induced hepatic oxidative stress. Oral administration of Cd (5 mg/kg BW) for four weeks to rats significantly (P > 0.05) elevated the level of serum hepatic markers such as serum aspartate transaminase (AST), serum alanine transaminase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), gamma-glutamyl transpeptidase (GGT), bilirubin (TBRNs), oxidative stress markers viz., thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides (LOOH), protein carbonyls (PC) and conjugated dienes (CD) and significantly (P > 0.05) reduced the enzymatic antioxidants viz., superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), glutathione reductase (GR) and glucose-6-phosphate dehydrogenase (G6PD) and non-enzymatic antioxidants Viz., reduced glutathione (GSH), total sulfhydryls (TSH), vitamin C and vitamin E in the liver. Pre-oral supplementation of PBE (200 mg/kg BW) in Cd intoxicated rats, the altered biochemical indices and pathological changes were recovered significantly (P > 0.05) which showed ameliorative effect of PBE against Cd induced hepatic oxidative stress. From the above findings, we suggested that the pre-administration of P. betle leaf extract exhibited remarkable protective effects against cadmium-induced oxidative hepatic injury in rats.

Naringenin in combination with vitamins C and E potentially protects oxidative stress-mediated hepatic injury in cadmium-intoxicated rats

Cadmium (Cd)-induced oxidative stress and hepatic injury is one of the major outcomes of chronic Cd toxicity, which can be ameliorated by numerous antioxidants. The present study was undertaken to find the therapeutic efficacy of naringenin (NGN) plus vitamins C and E on Cd-induced oxidative hepatotoxicity in Wistar rats. It has been noticed that Cd intoxication significantly elevates the levels of serum hepatic marker enzymes such as alanine amino transferase, aspartate amino transferase, alkaline phosphatase, lactate dehydrogenase, γ glutamyl transferase, total bilirubin, and hepatic thiobarbituric acid reactive substances, lipid hydroperoxides, conjugated dienes and protein carbonyls. In addition, Cd also decreases the activities of hepatic enzymatic antioxidants superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase, glutathione reductase and glucose-6-phosphate dehydrogenase and the levels of non-enzymatic antioxidants total sulphydryl groups, reduced glutathione, vitamins C and E and histopathological changes in liver. Treatment with NGN and vitamins C and E in combination more significantly improved the altered biochemical and histopathological changes in the liver of Cd-intoxicated rats than the NGN or vitamins C and E treatment alone.

CONCLUSION

The present data suggest that combined administration of NGN with vitamins C and E proved to be more beneficial in the treatment of Cd-hepatotoxicity than NGN treatment alone.

Protective role of sinapic acid against arsenic: induced toxicity in rats

Arsenic compounds are classified as toxicants and human carcinogens. Environmental exposure to arsenic imposes a big health issue worldwide. Sinapic acid is a phenylpropanoid compound and is found in various herbal materials and high-bran cereals. It has been reported that sinapic acid has antioxidant efficacy as metal chelators due to the orientation of functional groups. However, it has not yet been examined in experimental animals. In light of this fact, the purpose of this study was to characterize the protective role of sinapic acid against arsenic induced toxicity in rats. Rats were orally treated with arsenic alone (5mg/kg body weight (bw)/day) plus sinapic acid at different doses (10, 20 and 40mg/kg bw/day) for 30days. Hepatotoxicity was measured by the increased activities of serum hepatospecific enzymes namely aspartate transaminase, alanine transaminase, alkaline phosphatase, gamma glutamyl transferase, lactate dehydrogenase and total bilirubin along with increased elevation of lipid peroxidative markers, thiobarbituric acid reactive substances, lipid hydroperoxides, protein carbonyl content and conjugated dienes. The toxic effect of arsenic was also indicated by significantly decreased activities of enzymatic antioxidants like superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase, glutathione reductase and glucose-6-phosphate dehydrogenase along with non-enzymatic antioxidant like reduced glutathione. Administration of sinapic acid exhibited significant reversal of arsenic induced toxicity in hepatic tissue. The effect at a dose of 40mg/kgbw/day was more pronounced than the other two doses (10 and 20mg/kgbw/day). All these changes were supported by reduction of arsenic concentration and histopathological observations of the liver. These results suggest that sinapic acid has a protective effect over arsenic induced toxicity in rat.

Hepatoprotective effect of morin on ethanol-induced hepatotoxicity in rats

Morin is a flavonoid that exists in nature and is the major component of traditional medicinal herbs. Here we evaluated morin for its hepatoprotective effect against chronic ethanol-induced biochemical changes in male Wistar rats. Ethanol administration (7.9 g/kg bwt) for 60 days induced hepatic and renal damage by increasing oxidative stress and decreasing antioxidant levels. The status of lipid peroxidation (thiobarbituric reactive substances (TBARS) and hydroperoxides (HP)), antioxidant (vitamin C, vitamin E, GSH), serum hepatic markers (AST, ALT, ALP, GGT, bilirubin), and renal markers (urea, creatinine) were assessed as biochemical endpoints to determine the hepatic protective effect of morin. Oral administration of morin (100 mg/kg b.w) to alcohol-intoxicated rats for 30 days showed significant decreases in lipid peroxidation and restoration of antioxidant, hepatic, and renal markers to normal. Histopathologic observations of liver were also in correlation with biochemical parameters. The results indicate that morin might be beneficial in ameliorating alcohol-induced oxidative damage in rat liver.

Hepatoprotective role of naringin on nickel-induced toxicity in male Wistar rats

Aim of the present study was planned to determine the protective role of naringin in attenuating the toxicity induced by nickel sulfate in rat liver. In this investigation nickel sulfate (20mg/kg body weight) was administered intraperitoneally for 20days to induce toxicity. Naringin was administered orally (20, 40 and 80mg/kg body weight) for 20days with intraperitoneal administration of nickel sulfate. Liver injury was measured by the increased activities of serum hepatic enzymes namely aspartate transaminase, alanine transaminase, alkaline phosphatase, gamma glutamyl transferase, lactate dehydrogenase and total bilirubin along with increased elevation of lipid peroxidation markers, thiobarbituric reactive acid substances, lipid hydroperoxides, protein carbonyl content and conjugated dienes. The toxic effect of nickel was also indicated by significantly decreased activities of enzymatic antioxidants like superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase, glutathione reductase and glucose-6-phosphate dehydrogenase and non-enzymatic antioxidants like reduced glutathione, total sulfhydryl groups, vitamin C and vitamin E levels were significantly decreased. Naringin administered at a dose of 80mg/kg body weight significantly reversed the activities of hepatic marker enzymes, decreasing lipid peroxidative markers, increasing the antioxidant cascade and decreasing the nickel concentration in the liver. The effect at a dose of 80mg/kg body weight was more pronounced than that of other two doses (20 and 40mg/kg body weight). All these changes were supported by histopathological observations. These results clearly demonstrate that naringin has the potential in alleviating the toxic effects of nickel in rat liver.

Cadmium-induced hepatotoxicity in rats and the protective effect of naringenin

This experiment pertains to the protective role of naringenin against cadmium (Cd)-induced oxidative stress in the liver of rats. Cadmium is a major environmental pollutant and is known for its wide toxic manifestations. Naringenin is a naturally occurring citrus flavonone which has been reported to have a wide range of pharmacological properties. In the present investigation cadmium (5mg/kg) was administered orally for 4 weeks to induce hepatotoxicity. Liver damage induced by cadmium was clearly shown by the increased activities of serum hepatic marker enzymes namely aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), gamma glutamyl transferase (GGT) and serum total bilirubin (TB) along with the increased level of lipid peroxidation indices (thiobarbituric acid reactive substances (TBARS) and lipid hydroperoxides) and protein carbonyl contents in liver. The toxic effect of cadmium was also indicated by significantly decreased levels of enzymatic antioxidants (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione S-transferase (GST)) and non-enzymatic antioxidants (reduced glutathione (GSH), vitamin C and vitamin E). Administration of naringenin at a dose of (50mg/kg) significantly reversed the activities of serum hepatic marker enzymes to their near-normal levels when compared to Cd-treated rats. In addition, naringenin significantly reduced lipid peroxidation and restored the levels of antioxidant defense in the liver. The histopathological studies in the liver of rats also showed that naringenin (50mg/kg) markedly reduced the toxicity of cadmium and preserved the normal histological architecture of the tissue. The present study suggested that naringenin may be beneficial in ameliorating the cadmium-induced oxidative damage in the liver of rats.

Pattern of enzyme activity following acute myocardial infarction with special reference to gamma-glutamyl transpeptidase

The present study on 55 consecutive patients with acute myocardial infarction (AMI) draws attention to the relationship between different enzyme maxima in AMI, with special reference to serum gamma-glutamyl transpeptidase (S-GT). In more than 60% of the patients the S-GT was increased during the hospital stay. The S-GT rise nearly always began during the first days, reached a maximum within 5--8 days and normalized with 2--3 weeks. We failed to find the late increase in S-GT reported by others. The rise of S-GT is particularly common in patients with inferior infarction, with or without right ventricular involvement. We conclude that S-GT activity is not a useful early or late indicator of AMI but a very sensitive test for hepatic dysfunction in patients with AMI.

Increased activity of serum gamma-glutamyltransferase in myotonic dystrophy

The activity of serum gamma-glutamyltransferase (gamma-GT) and its determinants were studied in 17 patients with myotonic dystrophy. The gamma-GT activity was elevated in 11 patients and its mean value was five-fold higher than in healthy controls. The increase in gamma-GT could not be explained by factors generally known to result in a misleading elevation of gamma-GT. Most patients with elevated gamma-GT also had one or more other pathological laboratory tests related to hepatic function but none had a clinically significant liver disease. Serum gamma-GT activity was not related to the disability caused by dystrophy or to the level of serum creatine kinase suggesting that the elevation of serum gamma-GT is not an indication of a general cell membrane dysfunction. It is concluded that the increase in serum gamma-GT activity in patients with myotonic dystrophy is due to a real but mild liver involvement, which should be taken into account in the examination of these patients who often complain of gastrointestinal symptoms.

Efficacy of caffeic acid in preventing nickel induced oxidative damage in liver of rats

Nickel (Ni), a major environmental pollutant, is known for its wide toxic manifestations. In the present study caffeic acid (CA), one of the most commonly occurring phenolic acids in fruits, grains and dietary supplements, was evaluated for its protective effect against the Ni induced oxidative damage in liver. In this investigation, Ni (20 mg/kg body weight) was administered intraperitoneally for 20 days to induce toxicity. CA was administered orally (15, 30 and 60 mg/kg body weight) for 20 days with intraperitoneal administration of Ni. Ni induced liver damage was clearly shown by the increased activities of serum hepatic enzymes namely aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), gamma glutamyl transferase (GGT) and lactate dehydrogenase (LDH) along with increased elevation of lipid peroxidation indices (thiobarbituric reactive acid substances (TBARS) and lipid hydroperoxides). The toxic effect of Ni was also indicated by significantly decreased levels of enzymatic (superoxide dismutase (SOD), catalase (CAT) glutathione peroxidase (GPx) and glutathione S-transferase (GST)) and non-enzymatic antioxidants (glutathione (GSH), vitamin C and vitamin E). CA administered at a dose of 60 mg/kg body weight significantly reversed the activities of hepatic marker enzymes to their near normal levels when compared with other two doses. In addition, CA significantly reduced lipid peroxidation and restored the levels of antioxidant defense in the liver. All these changes were supported by histological observations. The results indicate that CA may be beneficial in ameliorating the Ni induced oxidative damage in the liver of rats.

Protective role of caffeic acid against alcohol-induced biochemical changes in rats

Caffeic acid is a well-known phenolic compound mainly present in plants. In this study, caffeic acid was evaluated for its protective effect against chronic ethanol-induced biochemical changes in male Wistar rats. Administration of ethanol (7.9 g/kg/day) for 45 days induced liver and kidney damage as manifested by a significant increase in the levels of serum hepatic and renal markers namely aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), gamma glutamyl transferase (GGT), bilirubin, urea, creatinine, and a significant decrease in creatinine clearance and levels of hemoglobin. Plasma thiobarbituric acid-reactive substances and hydroperoxide were significantly elevated where as the levels of nonenzymic antioxidants [reduced glutathione, vitamin E and vitamin C] were significantly decreased in alcohol-intoxicated rats. Administration of caffeic acid along with alcohol significantly decreased the serum levels of liver and kidney markers to near-normal levels. In addition, administration of caffeic acid significantly decreased the levels of lipid peroxidation markers while the levels of antioxidants were significantly increased in circulation of alcohol-fed rats. All these results were accompanied by histological observations in liver. The results demonstrate that caffeic acid has a beneficial effect in reducing the adverse effect of alcohol.

Hepatoprotective effect ofHygrophila spinosa andCassia occidentalis on carbon tetrachloride induced liver damage in experimental rats

The present study was undertaken to analyze the levels of some known antioxidant (both enzymic and non enzymic) activities in the rootsof Hygrophila spinosa andCassia occidentalis also to find out the hepatoprotective effect of the same in carbon tetrachloride induced liver damage in albino rats. The roots were found to be rich in antioxidants. Liver damage in rats were induced by carbon tetrachloride. To find out the hepatoprotective activity, the aqueous extract of the plant root samples were administrated to rats for 15 days. The serum marker enzymes Aspartate transaminase, Alanine transaminase and Gama Glutamyl were measured in experimental animals. The increased enzyme levels after liver damage with carbon tetrachloride were nearing to normal value when treated with aqueous extract of the root samples. Histopathological observation also proved the hepatoprotectivity of the root samples.

Colorimetric coupled enzyme assay for γ-glutamyltransferase activity using glutathione as substrate

A colorimetric coupled enzyme assay for the determination of gamma-glutamyltransferase (GGT) activity using glutathione as substrate is described. The cysteine released from glutathione upon sequential action of GGT and leucine aminopeptidase is spectrophotometrically detected through its reaction with ninhydrin at 100 degrees C in acidic conditions. The method was applied to the determination of the activity of both bovine kidney and human serum GGT. In the described assay conditions with final GGT concentrations ranging from 0.18 to 4 mU/ml, a linear relationship between produced cysteine and incubation times up to 90 min was observed. When a standard chromogenic assay for GGT using L-gamma-glutamyl-3-carboxy-4-nitroanilide as substrate and the proposed assay were applied on the same serum sample a linear relationship between the two method was observed. Since the use of GSH as substrate, the proposed method can be usefully adopted for enzymological studies on GGT-related enzymes, a class of enzymes which is still waiting to be characterized.

Role of diallyl tetrasulfide in ameliorating the cadmium induced biochemical changes in rats

Cadmium (Cd) is an ubiquitous environmental and occupational toxic metal concerned with a variety of adverse effects. The present study was undertaken to evaluate the role of diallyl tetrasulfide (DTS), an organosulfur compound in alleviating the Cd induced biochemical changes in male Wistar rats. During the experiment, rats were injected with Cd (3mg/(kgday)) subcutaneously alone or with oral administration of DTS at different doses (10, 20 and 40mg/(kgday)) for 3 weeks. In Cd treated rats, the activities of aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and gamma glutamyl transferase (GGT) were significantly increased in serum with elevated levels of bilirubin, urea and creatinine. The hemoglobin level and creatinine clearance were also significantly decreased in Cd treated rats. In addition, the levels of plasma lipid peroxidation markers: thiobarbituric acid reactive substances and lipid hydroperoxides were significantly increased while the levels of plasma reduced glutathione (GSH), Vitamins C and E were significantly decreased in Cd administered rats. Administration of DTS along with Cd significantly decreased the serum, liver and kidney markers towards near normal level in a dose dependent manner. DTS at a dose of 40mg/(kgday) was highly effective when compared to other doses (10 and 20mg/(kgday)). DTS also significantly reduced the accumulation of Cd in blood and tissues as well as decreased the level of lipid peroxidation markers with elevation of antioxidants in plasma. All these changes were accompanied by histological observations in liver. The obtained results demonstrated the beneficial effect of DTS in reducing the harmful effects of Cd.

Induction of endogenous pathways by antiepileptics and clinical implications

The aim of this study was to review modifications of the endogenous pathways (e.g. enzyme elevations, normal body constituent depletion or higher formation/excretion of endogenous metabolites) which could be ascribed to enzyme induction by antiepileptic drugs (AEDs). Information on older (e.g. phenobarbital, phenytoin and carbamazepine) and newer drugs (where information is available) is discussed together with clinical implications. The enzymes involved in the endogenous pathways and induced by the AEDs will not be limited to the hepatic microsomal enzymes; extrahepatic enzymes and/or enzymes present in other subcellular fractions will also be discussed, if pertinent. The induction of endogenous pathways by AEDs has been taken into account in the past, but much less emphasis has been given compared with the extensive literature on induction by AEDs of the metabolism of concomitantly administered drugs, either of the same or of different classes. Not all of the endogenous pathways examined and induced by AEDs appear to result in serious clinical consequences (e.g. induction of hepatic ALP, increased excretion of d-glucaric acid or of 6 beta-hydroxycortisol). In some cases, induction of some pathways (e.g. increase of high-density lipoprotein cholesterol or of conjugated bilirubin) might even be a beneficial side-effect, however enzyme induction is considered rather a detrimental aspect for an AED, as induction is generally a broad and a non-specific phenomenon. The new AEDs have generally less induction potential than the older agents. Yet some (felbamate, topiramate, oxcarbazepine and lamotrigine) have the potential for inducing enzymes, whereas others (levetiracetam, gabapentin and vigabatrin) appear to be completely devoid of enzyme inducing characteristics, at least as far as the enzymes investigated are concerned.

Oxidative status in patients with alcohol dependence: a clinical study in Taiwan

The aim of this study is to examine the relationship between alcohol dependence and oxidative status. The biochemical parameters and antioxidants status were measured among 28 patients with alcohol dependence. Nineteen healthy persons without drinking problem were recruited as the control subjects. The activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyltransferase (gamma-GT), and levels of cholesterol, triglyceride (TG), and uric acid were significantly increased in the specimen of patients compared with control. Serum malondialdehyde (MDA) levels of the patients were found to be significantly increased compared with controls and decreased after abstinence. Superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities were, respectively, 86% and 37% lower in alcoholic patients. After 14 d of abstinence, SOD activity was significantly reduced by 85%, CAT by 52%, and GPX by 54%, whereas no change was found in activity of glutathione reductase (GR). The duration of alcohol dependence is significantly correlated with the levels of MDA. In addition, the activity of CAT was significantly correlated with MDA levels. The results of this study suggest that oxidative stress occurred during alcohol dependence and subsequently affected the antioxidants mechanisms.

Traditional markers of excessive alcohol use

AIMS

The blood tests used traditionally as markers of excessive drinking are the liver enzymes, gamma glutamyltransferase (GGT), aspartate aminotransferase (AST) and alanine aminotransferase (ALT), and the red blood cell volume (mean corpuscular volume: MCV). Here we review the nature of these markers' association with alcohol use, their practical application in detecting, assessing or monitoring drinking and increases in understanding of these markers in the past 10 years.

DESIGN

Articles were identified via Medline search and perusal of bibliographies.

FINDINGS

The conventional markers have imperfect sensitivity and specificity, but have an added clinical role in the detection of complications of drinking, and of comorbid conditions that may increase risk of drinking. GGT may in part be a marker of the oxidative stress associated with ethanol metabolism. Markers are more likely to be elevated in those aged more than 30 years and in regular drinkers with a longer drinking history. The markers may be useful in opportunistic case finding, in motivating patients to change drinking and in monitoring treatment response. Increased prevalence of obesity and hepatitis C must be considered in interpretation of liver enzyme results. The liver enzymes are prognostic indicators for several medical conditions and for mortality.

CONCLUSIONS

These conventional tests are widely available and relatively inexpensive. While having limited sensitivity and specificity in detection of excessive drinking, they also provide valuable data on complications of drinking, comorbid conditions that may be affected by drinking and, in some cases, prognosis.

Kinetic study of gamma-glutamyltransferase activity by electrophoretically mediated microanalysis combined with micellar electrokinetic capillary chromatography

The use of capillary electrophoresis for the determination of gamma-glutamyltransferase (GGT) activity with gamma-glutamyl-p-nitroanilide (Glu-p-NA) as a substrate was investigated. The reaction velocity was quantified spectrophotometrically by the corrected peak area of the product p-nitroaniline (pNA) at 380 nm. Micelles composed of sodium deoxycholic acid were used in the background electrolyte in order to obtain a baseline separation between the substrate and the product. The presence of the micelles did not influence the enzymatic reaction. The electrophoretic system was used, not only for the separation and quantitation of the different reaction compounds but also for the in-capillary mixing of the enzyme and substrate plugs. This methodology is known as electrophoretically mediated microanalysis (EMMA). With the developed in-capillary activity assay an average Michaelis constant (K(M)) for GGT was calculated to be 2.09 mM (RSD = 7.3%, n = 3), a value consistent with previously reported values.

Indicators of inflammation and cellular damage in chronic asymptomatic or oligosymptomatic alcoholics: correlation with alteration of bilirubin and hepatic and pancreatic enzymes

Biochemical and hematimetric indicators of inflammation and cell damage were correlated with bilirubin and hepatic and pancreatic enzymes in 30 chronic male alcoholics admitted into psychiatric hospital for detoxification and treatment of alcoholism. Aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase, alkaline phosphatase, and total bilirubin were altered, respectively, in 90%, 63%, 87%, 23% and 23% of the cases. None of the indicators of inflammation (lactic dehydrogenase, altered in 16% of the cases; alpha-1 globulin, 24%; alpha-2 globulin, 88%; leucocyte counts, 28%) was correlated with alterations of bilirubin or liver enzymes. Lactic dehydrogenase was poorly sensitive for detection of hepatocytic or muscular damage. Alterations of alpha-globulins seemed to have been due more to alcohol metabolism-induced increase of lipoproteins than to inflammation. Among indicators of cell damage, serum iron, increased in 40% of the cases, seemed to be related to liver damage while creatine phosphokinase, increased in 84% of the cases, related to muscle damage. Hyperamylasemia was found in 20% of the cases and significantly correlated with levels of bilirubin, alkaline phosphatase and gamma-glutamyltransferase. It was indicated that injuries of liver, pancreas, salivary glands, and muscle occurred in asymptomatic or oligosymptomatic chronic alcoholics.

Posthatch development of small intestinal function in the poult

The size, morphology, and mucosal enzyme activity of small intestines in poults were determined from hatch to 12 d of age. Mass and length of the small intestines increased at different rates in the duodenum, jejunum, and ileum and mass increased more than length. Intestinal weight increased more rapidly then other body organs, reaching a peak at about Day 6, and then decreased. Examination of the morphology of the small intestine showed that villus height and area increased several fold in the jejunum and duodenum and less in the ileum over the period examined. Enterocyte size increased slightly in the initial posthatch period. Activities of mucosal enzymes also increased at different rates in the different intestinal segments and sucrase, maltase, and gamma-glutamyltransferase activities per gram of intestine peaked at 2 to 5 d posthatch before decreasing. Regional mucosal intestine activities exhibited a steady increase, which was highly correlated with BW and thus mucosal hydrolysis may be a determining step in digestion. Poult villus size and area were smaller and mucosal enzyme activity was lower than that found in broilers and this may explain the initial slower growth rate in poults.

The effects of cigarette smoking and alcohol consumption on serum liver enzyme activities: a dose-related study in men

The separate and joint effects of cigarette smoking and alcohol consumption on serum activities of the enzymes aspartate aminotransferase (AST), alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT) were investigated in 46,775 men attending the BUPA Health Screening Centre in London during the period 1983-1987, after allowing for differences in age, body mass index and exercise level. As expected, all showed a significant positive correlation with alcohol consumption. Cigarette smoking produced a significant increase in GGT activity in all drinking categories bar teetotallers, particularly for those smoking more than 20 cigarettes per day. There were no changes of clinical significance in AST or ALT activities with smoking. We postulate that the combined effects of alcohol and smoking on GGT activity are a result of induction of the enzyme by both alcohol and nicotine. Smoking as well as drinking habits should be taken into account when assessing the significance of an individual's enzyme activities.

[Drunkenness in traffic in Geneva: occasional abuse or alcoholism?]

The main aim of the study is to measure the importance of alcoholism amongst alcohol intoxication (up to the Swiss legal BAC: 0.8 gr/kg) in traffic. The method used describes the characteristics of all cases of inebriety (amongst pedestrians and drivers) recorded by the police during one year and relates this with complementary data such as the determination of a biological marker of alcohol consumption (Gamma Glutamyl Transferase), or DWI recidivism. Results of general interest are: 22% of recorded cases of alcohol intoxication are recidivists; about one third of the cases of alcohol intoxication registered are due to alcoholism rather than to social drinking. A preventive policy in road traffic safety must integrate the problems, caused by alcoholism, on Public Health.

Contrast nephrotoxicity: predictive value of urinary enzyme markers in a rat model

RATIONALE AND OBJECTIVES

We tested whether urinary enzymes are an accurate and useful marker of renal damage in a rat model of contrast media nephrotoxicity.

METHODS

Thirty rats were pretreated with a combination of salt depletion, indomethacin, and contrast material. Alanine aminopeptidase (AAP), gamma-glutamyltranspeptidase (GGT), and N-acetyl-beta-D-glucosaminidase (NAG) were measured before and 24 hr after injection of contrast material. Enzyme concentrations were correlated with glomerular filtration rate (GFR) and histology.

RESULTS

Decreasing GFR and histopathologic changes were found only in rats treated with all three variables. NAG levels increased from baseline for both diatrizoate meglumine- and ioversol-treated animals (from 83.9 +/- 48.6 to 145.5 +/- 55.4 and from 69.41 +/- 43.6 to 123.1 +/- 50.7, respectively; P < 0.05 from baseline for ioversol) and declined in other groups. GGT and AAP levels did not correlate well with structural and functional changes.

CONCLUSIONS

In this model of contrast nephrotoxicity, NAG concentration appears to correlate with structural and functional changes associated with contrast media nephrotoxicity. However, the large range of baseline values makes this of dubious clinical use. AAP and GGT levels appear less helpful in detecting renal damage.

Enzymes and circulating proteins as markers of alcohol abuse

The identification of alcohol abuse is an important social and clinical objective for which various biochemical procedures have been utilized, serum enzymes and circulating proteins being predominant. Tests are required to detect alcohol abuse as screening procedures in the general population as well as for the specific diagnosis of those presenting as hospital inpatients or outpatients, especially when liver disease is present or suspected. The amino-transferases are of limited value, although the mitochondrial isoenzyme of aspartate amino-transferase has been strongly advocated and is quite useful in detecting alcoholics among patients with liver disease. Gammaglutamyl transferase, by contrast, is raised in all forms of liver disease but can identify 30-50% of those consuming excessive amounts of alcohol before organic damage becomes manifest. Serum carbohydrate-deficient transferrin (CDT) is raised in many alcohol abusers without and most with liver damage, but is rarely elevated in other forms of liver disease. Haemoglobin-associated acetaldehyde, the newest biochemical index to be evaluated in alcoholics, is one of several adducts formed by the reaction of acetaldehyde with various proteins, and antibodies to these adducts may contribute, at least in part, to immunological tissue damage provoked by chronic excessive consumption of alcohol. Its assay is technically complex and it appears to be present in higher concentrations in heavy drinkers than in those who fulfill the criteria of addictive alcohol abuse. Many other markers have been introduced in the last decade but the search for a reliable index continues. CDT comes closest at the present time to matching the desired specificity, although it is of limited value in screening unselected non-hospitalized subjects.