Alanine Aminotransferase In Rats Research Articles

In vitro and in vivo hepatotoxicity study of Afriplex™ GRT through an inflammatory response

BackgroundThe focus on traditional and complementary medicine for supplementation and treatment of diseases is high. Aspalathus linearis commonly known as Rooibos showed several beneficial effects, this led to the standardized production of a pharmaceutical grade green rooibos extract (Afriplex TM GRT) with enhanced polyphenolic content. The aim of this study was to assess toxicity of Afriplex TM GRT in HepG2/C3A cells and Sprague Dawley rats. MethodsAfriplex GRT TM (0.1, 1, 10, 100, or 1000 μg/mL) in DMSO was added to the media to the final 0.01% DMSO for treatment of HepG2/C3A for 1, 24 and 48 hrs followed by MTT and ATP assays. Sprague Dawley rats were grouped to Control, Afriplex TM GRT treated (10, 100 and 300 mg/kg); and acute (24hrs tetrachloromethane (CCl 4) injected hepatotoxicity control). Serum biochemistry, histology and Western blot analysis on liver were performed. ResultsAfriplex TM GRT significantly reduced cell viability at 100 and 1000μg/mL after 48 hrs. Acute CCl 4 treatment significantly increased serum alanine aminotransferase in rats. The highest extract treatment of 300 mg/kg significantly elevated aspartate amino transferase. There was severe macro vesicular in the CCl 4 group whereas mild to moderate micro vesicular steatosis was seen in the 300 mg/kg Afriplex TM GRT treated group. Highest extract treatment significantly reduced NFkB expression on Western blot analysis. ConclusionThe beneficial effects of pharmaceutical grade Afriplex GRT TM are concentration and dosage based. Afriplex GRT TM exerts its beneficial effects via NFkB as demonstrated by the dose dependent reduction of NFkB on Western blot analysis. More work need to be done to explore the exact mechanism that occurs in the NFkB pathway.

AMELIORATION OF ARSENIC-INDUCED TOXICITY BY ETHANOL LEAF EXTRACT OF PHYLLANTUS AMARUS LINN AND VITAMIN C IN MALE ALBINO RATS

The ameliorative effect of ethanol leaf extract of Phyllantus amarus (EEPA) and vitamin C in arsenic-induced toxicity was studied. Thirty-six (36) male albino rats divided into six groups of six (6) rats each were used for the study. Arsenic toxicity was induced in three of the groups by daily intake of 100 ppm of arsenic as Dimethylarsenate (DMA) in their drinking water. Two of the arsenic-exposed groups were treated with 200 and 500 mg/kg bwt of EEPA and vitamin C respectively. The third group was not treated during arsenic exposure. The fourth and fifth groups were positive control for P. amarus and Vitamin C respectively, while another group served as the normal control. All treatments were done orally for six weeks. The effects of treatments on lipid profile, lipid peroxidation and liver function were thereafter studied. Increased levels of total cholesterol, LDL-cholesterol and malondialdehyde (MDA) were observed in plasma and lymphocytes of untreated arsenic-exposed rats compared to the control group. Arsenic increased total cholesterol and LDL-cholesterol concentrations, while triacylglycerol concentration was reduced significantly. Treatments with EEPA and Vitamin C however ameliorated the dyslipidemia observed in arsenic-exposed groups. Exposure to DMA increased plasma activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) of the animals, while plasma activity of ALT in rats treated with Vitamin C was not different compared to the control. Both treatments however, had no significant effect (p > 0.05) on the activity of plasma AST. P. amarus may therefore play a role in ameliorating arsenic-induced dyslipidemia in male albino rats.
 
 

Effects of cembrane-type diterpenes on proliferation of PC12 cells and their antagonistic effects on neurotoxicity induced by glutamate

To investigate the effects of cembrane-type diterpenes extracted from Sinularia flexibilis on the proliferation of PC12 cells and their protective effects on PC12 cells exposed to glutamate. Methyl thiazolyl tetrazolium (MTT) method was adopted to observe the effects of cembrane-type diterpenes (compound 1, compound 2 and compound 3) on the proliferation of PC12 cells. And the protective effects of the three compounds on PC12 cells exposed to glutamate were also detected by MTT. Furthermore, the influence of compound 1 on intracellular concentration of calcium in PC12 cells exposed to glutamate was detected by laser confocal microscopy. After 72-hour PC12 cell culture, OD values in the 2, 10 and 50 micromol/L compound 1 groups were significantly higher than that in the normal group (P<0.05, P<0.01). After 24-hour glutamate damage, OD values in the 0.4, 2 and 50 micromol/L compound 1 groups, the 0.4, 2 and 100 micromol/L compound 2 groups and the 2 micromol/L compound 3 group were obviously increased as compared with the untreated group (P<0.01, P<0.05). After 48-hour glutamate damage, OD values in the compound 1 group were approximate to those in the normal control and the positive control group while were significantly higher than that in the untreated group (P<0.01, P<0.05), but no dose-dependent effect was observed. Compound 1 of 0.4, 2, 50 micromol/L could significantly reduce the intracellular concentration of calcium in PC12 cells exposed to glutamate (P<0.05, P<0.01), which was also approximate to the effect of nimodipine (positive control drug). Cembrane-type diterpenes (compound 1, compound 2 and compound 3) extracted from Sinularia flexibilis have obvious protective effects on PC12 cells damaged by glutamate, and compound 1 has the best neuroprotective effect. The mechanism of the neuroprotective effect of compound 1 may lie in reducing the intracellular concentration of calcium in PC12 cells exposed to glutamate and relieving the calcium overload.

Effect of the Inducer of Interleukin‐6 (ME3738) on Rat Liver Treated With Ethanol

Recently, ME3738, a derivative of soyasapogenol B, was developed as an inducer of interleukin (IL)-6. It has been demonstrated that ME3738 is stimulate to produce IL-6 and that it protects against concanavalin A-induced liver failure. It has also been reported that IL-6 prevents alcoholic fatty liver in mice. These results suggest that ME3738 may prevent alcoholic liver injury. In the present study, we investigated whether ME3738 prevents fatty liver in ethanol-fed rats. Twenty-four male rats were fed with liquid diets containing ethanol or carbohydrates for 8 weeks. Liquid diets were prepared with or without ME3738 (0.8 mg/mL). Liver sections were stained for histology and IL-6 expression. Fatty changes of liver were classified into 4 grades: 0, 1+, 2+, and 3+. Plasma levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transpeptidase (GGT), triglyceride, total cholesterol, and IL-6 were measured, as was hepatic ATP content. The extent of fatty degeneration in ethanol-fed rats was significantly greater (p=0.023) than that in controls. Fatty changes in rats fed ethanol containing ME3738 decreased, but were not significantly different from those in rats fed ethanol. Immunohistochemical staining of IL-6 was observed in perivenular hepatocytes of all rats, with its intensity becoming stronger in the order of controls, controls containing ME3738, ethanol, and ethanol-containing ME3738-fed rats. Plasma levels of AST and ALT in rats fed ethanol were significantly higher than those in controls. In rats fed ethanol-containing ME3738, these levels decreased to those of control-fed rats, but were not significantly different from those in rats fed ethanol. Plasma IL-6 was not detected in any rats. Hepatic ATP content in rats fed ethanol was significantly (p<0.05) lower than that in control-fed rats; however, in rats fed ethanol-containing ME3738, it increased to that in control-fed rats. Oral administration of ME3738, inducer of IL-6 may prevent the development of fatty liver caused by chronic ethanol consumption.

Effect of quality protein maize diet on liver integrity and serum aminotransferases of albino wistar rats

The study was designed to evaluate the effect of quality protein maize (QPM) diet on the histology of the liver and on the activities of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in albino wistar rats. The AST level in rats fed QPM diet was 57.4 ± 8.92U/L which compared favourably with that in rats fed the reference casein diet (46.0 ± 8.48U/L) at p>0.05. There was also no significant difference (p>0.05) in the serum AST levels in rats fed the basal diet (61.2 ± 4.63U/L), common maize diet (60.2 ±8.59U/L) and the reference diet. Similarly, there was no significant difference (p>0.05) in the levels of serum ALT in rats fed the basal diet (33.5 ±6.50U/L), QPM diet (21.6 ±3.98U/L), common maize diet (27.4 ± 6.13U/L) and the reference case in diet (21.6 ± 2.11U/L). Histological examination of the livers of rats fed the experimental diets showed mild degeneration of the hepatic vessels and a small central vein in the group fed the basal (protein-free) diet while the livers of the rats fed the QPM diet showed a smaller central vein but generally gave the same picture as that of the group fed the reference casein diet. The results indicate that consumption of QPM diet by rats does not have adverse effect on the liver. Keywords: quality protein maize, liver integrity, serum aminotransferasesGlobal Journal of Pure and Applied Sciences Vol. 12(2) 2006: 189-192

Role of Zinc in Regulating the Levels of Hepatic Elements Following Nickel Toxicity in Rats

This study was designed to determine the protective effects of zinc on the hepatotoxicity induced by nickel in rats. Female Sprague-Dawley (SD) rats received either nickel sulfate alone in the dose of 800 mg/L nickel in drinking water, zinc sulfate alone in the dose of 227 mg/L zinc in drinking water, and nickel plus zinc or drinking water alone for a total duration of 8 wk. The effects of different treatments were studied on activities of rat liver marker enzymes like alkaline phosphatase (ALP), alanine aminotransferase (ALT), and aspartate aminotransferases (AST) and on the status of essential elements in rat liver. The study revealed a significant increase in the activities of enzymes ALP and ALT in rats subjected to nickel treatment. Interestingly, zinc supplementation to rats treated with nickel brought back the raised activities of these enzymes to within normal limits. Further, the levels of elements in liver that include zinc, copper, selenium, and potassium were found to be significantly suppressed following nickel treatment, whereas the levels of iron and sulfur were elevated. However, zinc treatment alone did not cause any appreciable change in the concentration of these elements. To the contrary, when zinc was given to nickel-treated rats, the concentrations of zinc, copper, potassium, and phosphorus were not significantly different from that of normal controls, whereas the levels of iron, selenium, and sulfur were improved in comparison to nickel-treated rats but were not within the normal limits. The present study concludes that zinc has the ability to maintain the levels of hepatic elements and has bearing in regulating the liver functions by maintaining the activities of marker enzymes in conditions of nickel toxicity.

Transcript analysis of the genes encoding aminopeptidase N and alanine aminotransferase, two enzymes involved in protein turnover, in the Pacific oyster, Crassostrea gigas

Molecular probes have been developed to detect aminopeptidase N (ApN) and alanine aminotransferase (ALAT) transcripts in the Pacific oyster Crassostrea gigas. Degenerate primers were designed using ApN and ALAT sequences stored in the EMBL database. Amplification of C. gigas genomic DNA using these primers resulted in amplification of a 344-bp ApN fragment and a 530-bp alanine aminotransferase fragment. The deduced amino acid sequence of the ApN fragment displayed 75 and 73% identities with sequences of ApN from human and mouse, respectively. The deduced amino acid sequence of the ALAT fragment displayed 57% identity both with human and rat ALAT. An ApN transcript of approximately 3.1 kb was detected by northern blotting in larvae and in adult digestive gland and gonadal tissue. No transcript was detected in adult adductor muscle. An ALAT transcript of approximately 2 kb was similarly detected in larvae and in adult gonadal tissue, but was undetectable in adult digestive gland and adductor muscle. Transcript detection employing RT-PCR demonstrated low-level expression of both ApN and ALAT in all studied tissues, in both larvae and adults.

Supplementation of orotic acid to the casein, but not to egg protein, soy protein, or wheat gluten diets, increases serum ornithine carbamoyltransferase activity

Effects of dietary supplementation of orotic acid to a diet containing the casein protein were compared with diets containing egg protein, soy protein, or wheat gluten on lipid levels in the liver and serum and activities of ornithine carbamoyltransferase (OCT) and alanine aminotransferase in the serum of rats. We found that supplementation of orotic acid to each diet increased the contents of the liver total lipids, triacylglycerol, and phospholipids compared with those not supplemented. The contents of liver total lipids, triacylglycerol, cholesterol, and phospholipids in rats fed the casein diet were significantly higher than those of rats fed the other three diets when orotic acid was supplemented. The levels of triacylglycerol, cholesterol, and phospholipids in the serum of rats fed the casein diet were markedly decreased by addition of orotic acid. The supplementation of orotic acid significantly increased the activities of both serum OCT and alanine aminotransferase in rats fed the casein diet, but not in rats fed the other diets. In conclusion, liver lipid accumulation induced by dietary orotic acid depends on the type of dietary protein. The enhancement of serum OCT activity may result from liver lipid accumulation in rats fed the casein diet supplemented with orotic acid, demonstrating hepatic damage.

Complete amino acid sequence of rat liver cytosolic alanine aminotransferase

The complete amino acid sequence of rat liver cytosolic alanine aminotransferase (EC 2.6.1.2) is presented. Two primary sets of overlapping fragments were obtained by cleavage of the pyridylethylated protein at methionyl and lysyl bonds with cyanogen bromide and Achromobacter protease I, respectively. The protein was found to be acetylated at the amino terminus and contained 495 amino acid residues. The molecular weight of the subunit was calculated to be 55,018 which was in good agreement with a molecular weight of 55,000 determined by SDS-PAGE and also indicated that the active enzyme with a molecular weight of 114,000 was a homodimer composed of two identical subunits. No highly homologous sequence was found in protein sequence databases except for a 20-residue sequence around the pyridoxal 5'-phosphate binding site of the pig heart enzyme [Tanase, S., Kojima, H., & Morino, Y. (1979) Biochemistry 18, 3002-3007], which was almost identical with that of residues 303-322 of the rat liver enzyme. In spite of rather low homology scores, rat alanine aminotransferase is clearly homologous to those of other aminotransferases from the same species, e.g., cytosolic tyrosine aminotransferase (24.7% identity), cytosolic aspartate aminotransferase (17.0%), and mitochondrial aspartate aminotransferase (16.0%). Most of the crucial amino acid residues hydrogen-bonding to pyridoxal 5'-phosphate identified in aspartate aminotransferase by X-ray crystallography are conserved in alanine aminotransferase. This suggests that the topology of secondary structures characteristic in the large domain of other alpha-aminotransferases with known tertiary structure may also be conserved in alanine aminotransferase.

Effects of Putrescine on D–Galactosamine-Induced Acute Liver Failure in Rats

We studied the effect of putrescine on acute liver failure caused in rats by two injections of 1 gm/kg D-galactosamine. The hepatic polyamine level rose only slightly in the D-galactosamine-injected rats treated with glucagon and insulin, and [3H]thymidine incorporation into DNA increased little; these hormones did not improve the survival rate. When D-galactosamine-injected rats were given putrescine, the putrescine concentration in the liver increased and the survival rate of the rats was significantly higher than that of control rats given only D-galactosamine. Putrescine administration tended to lower the serum level of alanine aminotransferase in rats injected with D-galactosamine, so the polyamine might have a protective effect on hepatocytes. Putrescine significantly increased [3H]thymidine incorporation in the liver; thus it accelerated liver regeneration. Difluoromethylornithine decreased the level of putrescine in the liver, decreasing both [3H]thymidine uptake and the survival rate. In the rats treated with D-galactosamine, in which liver damage was so severe that treatment with glucagon and insulin was ineffective, the intraperitoneal administration of putrescine increased the survival rate in acute liver failure. This probably resulted mainly from activation of liver regeneration and possibly from a protective effect of putrescine on the liver.