Efecto hepatoprotector del Noni-C® en la intoxicación experimental inducida por tetracloruro de carbono / Noni-C® hepatoprotective effect in experimental intoxication induced by carbon tetrachloride

INTRODUCCIÓN: las enfermedades hepáticas son un serio problema de salud y la carencia de un tratamiento efectivo en la medicina moderna hace que aumenten los esfuerzos por hallar medicamentos naturales apropiados. OBJETIVO: determinar el efecto hepatoprotector del producto natural Noni-C® en la intoxicación experimental por tetracloruro de carbono (CCl4). MÉTODOS: estudio experimental en ratas Wistar macho; se emplearon cuatro grupos de trabajo, uno control negativo, uno control positivo tratado con CCl4 y dos experimentales tratados con Noni-C® a las dosis 200 y 400 mg/kg de peso corporal durante 21 días, más CCl4 postratamiento con Noni-C® por 3 días a la dosis 0,5 mL/kg intraperitoneal. Se determinaron los niveles de transaminasa glutámico pirúvica y glutámico oxalacética. Se realizó análisis histopatológico para determinar lesión hepática y renal de diferente grado. RESULTADOS: se obtuvo reducción significativa de la transaminasa glutámico pirúvica al comparar las dosis de 200 y 400 mg/kg. Se observó disminución de las lesiones histopatológicas hepáticas y renales, de esteatosis hepática severa a leve y moderada, y de necrosis tubular aguda a tumefacción celular moderada, respectivamente, a la dosis 400 mg/kg de Noni-C®. CONCLUSIÓN: el tratamiento preventivo con Noni-C® a la dosis 400 mg/kg reduce la gravedad del daño hepático resultante de la intoxicación por CCl4. Por las características químico-físicas del producto y la variedad de compuestos identificados en el fruto, entre ellos vitaminas y minerales que contribuyen con su capacidad antioxidante, se recomienda su estudio en la prevención de enfermedades hepáticas.

INTRODUCTION: liver diseases are a serious health problem and the lack of effective treatment in modern medicine drives up efforts to find suitable natural medicines. OBJECTIVE: determine the hepatoprotective effect of Noni-c® natural product in experimental poisoning carbon tetrachloride (CCL4). METHODS: an experimental study was conducted in wistar male rats; four working groups were formed: one negative control, a positive control treated with CCL4 and two experimental Noni-c® treated at doses 200 and 400 mg/kg body weight for 21 days, plus CCL4 after treatment with Noni-C® for 3 days in 0.5 mL/kg dose intraperitoneally. Levels of glutamic oxaloacetic and glutamic pyruvic transaminase were determined. Histopathological analysis was performed to determine liver and kidney damage at different levels. RESULTS: significant reduction in glutamic pyruvic transaminase was observed when comparing 200 and 400 mg/kg doses. Decrease liver and kidney histopathological lesions, severe to mild and moderate hepatic steatosis were observed; acute tubular necrosis or moderate cell swelling, respectively, at 400 mg/kg Noni-c® dose was also observed. CONCLUSION: preventive treatment at 400 mg/kg Noni-c® dose reduced the severity of liver damage resulting from CCl4 poisoning. Due to the chemical-physical product features and variety of compounds identified in this fruit, including vitamins and minerals which contribute as antioxidant, its study is recommended in preventing liver diseases.

Genotoxic effects of tanshinones from Hyptis martiusii in V79 cell line.

The genotoxic effect of two tanshinones isolated from roots of Hyptis martiussi Benth (Labiatae) was studied using V79 (Chinese hamster lung) cells by the alkaline comet assay and micronucleus test. Tanshinones were incubated with the cells at concentrations of 1, 3, 6 and 12 microg/mL for 3 h. Tanshinones were shown to be quite strongly genotoxic against V79 cells at all tested concentrations. The data obtained provide support to the view that tanshinones has DNA damaging activity in cultured V79 cells under the conditions of the assays.

Preventive treatment with vitamin E alleviates the poisoning effects of carbon tetrachloride in cattle.

Fifteen yearling steers were used to study the preventive effect of vitamin E on the protection against free radicals produced by carbon tetrachloride (CCl4). The animals were randomly divided in three equal groups and treated as follows: group A--previously injected (i.m.) with 15 IU/kg BW on the 15th and second day before the trial and drenched with 0.05 ml/kg BW CCl4; group B--only drenched with the same dose of CCl4; group C--drenched with a placebo. Food intake was recorded and blood samples collected daily for 8 days after the CCl4 drenching to compare the activity of aspartate aminotransferase (AST), gamma-glutamyltransferase (gamma-GT) and the levels of erythrocyte reduced glutathione (GSH) and serum malonyldialdehyde (MDA). Food intake was reduced in group B for the first 3 days (P < 0.05); higher activities of AST and gamma-GT were observed in the poisoned groups, nevertheless the overall values were lower in the group A than B (P < 0.02); only the group A reached the basal values of AST at the seventh day; higher levels of GSH and MDA were recorded in the poisoned cattle indicating the generation of free radicals. It was concluded that the preventive use of Vitamin E lessened the damage in hepatic tissue caused by the free radicals and prevented the anorexia caused by CCl4.

Antioxidant effects in the quinone fraction from Auxemma oncocalyx TAUB.

In previous studies in vitro we showed that the quinone fraction (QF) from the heartwood of Auxemma oncocalyx TAUB. presented antiplatelet and antioxidant activities. In the present work, the QF antioxidant property was evaluated in models of CCl(4)-induced hepatotoxicity in rats, and prolongation of pentobarbital-induced sleeping time in mice. Our results showed that levels of plasma glutamate-pyruvate-transaminase (GPT), as well as glutamate-oxalate-transaminase (GOT), were increased by the administration of CCl(4). On the other hand, only GPT levels were reduced by the QF treatment. Pentobarbital sleeping time was prolonged by the administration of CCl(4) and reduced by the QF treatment. Moreover, QF did not alter the pentobarbital-induced sleeping time. In conclusion, we showed that QF, represented mainly by oncocalyxone A, has hepatoprotective activity, and this effect is at least in part due to the antioxidant activity of this quinone.

Oxidative preconditioning affords protection against carbon tetrachloride-induced glycogen depletion and oxidative stress in rats.

The rectal insufflation of a judicious dose of ozone, selected from that used in clinical practice, is able to promote oxidative preconditioning or oxidative stress tolerance preventing the hepatocellular damage mediated by free radicals. In order to evaluate the effects of ozone oxidative preconditioning on carbon tetrachloride-mediated hepatotoxicity, the following experimental protocol was designed: group 1 (negative control, sunflower oil i.p.); group 2 (CCl(4) in sunflower oil, 1 ml kg(-1) i.p.); group 3 (15 ozone-oxygen pretreatments at a dose of 1 mg kg(-1) via rectal insufflation + CCl(4) as in group 2); group 4 (ozone control group, 15 ozone-oxygen pretreatments + sunflower oil i.p.). Ozone pretreatment prevented glycogen depletion (as demonstrated by biochemical and histopathological findings) and avoided lactate overproduction associated with the hepatotoxic effects of CCl(4). The administration of CCl(4) increased lipid peroxidation (as measured by thiobarbituric acid-reactive substances) and uric acid levels and inhibited superoxide dismutase activity. All these deleterious effects induced by CCl(4) were prevented by ozone pretreatment. The administration of ozone without CCl(4) (ozone control group) did not produce any changes in the evaluated parameters. Our results showed that ozone treatment, in our experimental conditions, was able to prevent anaerobic glycolysis and oxidative stress induced by CCl(4).

Effect of colchicine in a biochemical model of liver injury and fibrosis

Background. The accummulation of collagen is a salient feature of chronic liver injury. The objetive of this study was to investigate and compare the therapeutic effectiveness of colchicine and one of its metabolites, colchiceine, to protect rats from developing liver injury and fibrosis. Methods. To accomplish this, the authors used a procedure developed by other to produce liver injury and firosis by chronic administration of CCl4 in rats. The effect of both compounds on collagen metabolism and liver injury was analyzed. Results. Althought both compounds prevented increase in collagen synthesis, animals treated with colchicine did not show a reduction in collagen content compared with animals treated with CCl4. On the other hand, the animals treated with colchiceine along with CCl4, showed a 50 percent reduction in hepatic collagen content as well as an improvement in histological architecture. Both compound, colchicine and colchiceine, increased the intracellular degradation of collagen in addition to increasing collagenase activity as compared to non-treated rats. However, collagenase activity was lower in animals treated with colchicine and colchiceine than in the fibrotic livers treated with CCl4. The changes in collagen metabolism correlated with changes in parameters of liver injury. Conclusions. In conclusion, the compound colchiceine may be recommended in the treatment of chronic liver diseases rather than its precursor, colchicine, due to the fact that it showed a lower accumulation of collagen content and has a better anti-fibrogenic effect than does colchicine

Trifluopromazine late preventive effects on carbon tetrachloride-induced liver necrosis.

Trifluopromazine (TFPro) administration to rats (50 mg/kg, ip) 30 min before or 6 or 10 hr after CCl4 treatment (1 ml/kg ip in olive oil) partially prevented necrogenic effects of this compound at 24 hr. TFPro has only minor effects on the covalent binding (CB) of CCl4-reactive metabolites to cellular constituents and even an enhancing action on CCl4-promoted lipid peroxidation (LP). Determination of TFPro levels in liver 1 and 3 hr after administration by gas chromatography/mass spectrometry showed its presence in that tissue at concentrations well above those needed for calmodulin (CaM) inhibitory effects of this drug. TFPro lowered body temperature in CCl4-treated animals during the 24-hr observation period. Protective effects of TFPro at 6 or 10 hr, when most of the CB and all of the LP has already occurred, suggest but do not prove a role for CaM in late stages of CCl4-induced necrogenic effects. Decreases in the body temperature of CCl4-poisoned animals provoked by TFPro might also play a role in the preventive actions of this drug.

Late protective effects against CCl4-induced liver necrosis by the radioprotective agent 2-aminoethyl-isothiouronium bromide hydrobromide (AET).

Administration of the radioprotective agent 2-aminoethyl-isothiouronium bromide hydrobromide (AET) (240 mg/kg, i.p. in saline 30 min before or 6 or 10 h after CCl4 (1 ml/kg i.p. as a 20% v/v solution in olive oil) significantly prevented the necrogenic effect of the hepatotoxin at 24 h. Protection was more intense when the drug was given 6 h after CCl4 than when administered 30 min before. CCl4-induced fat accumulation was prevented only when AET was given 30 min before. AET did not prevent the CCl4-induced initiation of a lipid peroxidation (LP) process as evidenced by diene hyperconjugation of microsomal lipids. AET pretreatment 30 min before CCl4 did not significantly modify the CCl4 levels reaching the liver and only exerted a transient significant effect on the covalent binding of [14C]Cl4 reactive metabolites to microsomal lipids (CB) at 1 h but not at 3 h. The markedly intense protective effects of AET when given 6 or 10 h after CCl4 can not be attributed to decreased amounts of CCl4 reaching the liver or to decreasing effects in CB or to chain breaking effects in LP. Really, protection might be due to a favorable modulation of late events occurring after CB or LP, events that remain to be elucidated.

Prevention of CCl4-induced liver necrosis by the calcium chelator arsenazo III.

Arsenazo III (AIII) (100 mg/kg ip in saline) administration to Sprague-Dawley male rats 30 min before or 6 or 10 hr after CCl4 [1 ml/kg ip as a 20% (v/v) solution in olive oil] significantly prevented liver necrosis but not fatty liver caused by the hepatotoxin at 24 hr as demonstrated either by histology or by determination of isocitric acid dehydrogenase in plasma. AIII did not modify the CCl4 concentrations reaching the liver, the intensity of the covalent binding of CCl4-reactive metabolites to hepatic microsomal lipids, or the CCl4-promoted lipid peroxidation process at either 1 or 3 hr of poisoning. AIII administration enhanced glutathione (GSH) levels in liver and significantly prevented the CCl4-induced minor decreases in GSH content and the CCl4-induced increases in calcium content at 24 hr of intoxication. AIII treatment further enhanced the CCl4-induced decreases in body temperature of the poisoned rats. Results suggest that AIII's preventive effects might be related to its very well-known calcium-chelating properties, but that additional factors related to AIII's ability to increase GSH content in liver or to decrease body temperature of CCl4-intoxicated animals may also play a role.

Antioxidative stress therapy with dithiothreitol tetraacetate. I. Protection against carbon tetrachloride induced liver necrosis.

Dithiothreitol (DTT) is known to prevent or even reverse several deleterious effects of radiation or of chemical agents operating via free radical and oxidative stress. However, its use has been hampered by its chemical instability and toxic properties. In this work, we synthesized and characterized dithiothreitol tetraacetate (DTT-Ac) which is less toxic and chemically stable, and we provided GLC/MS evidence that it is able to rapidly generate fully deacetylated DTT in liver after its administration to rats. Treatment with DTT-Ac simultaneously with CCl4 or 3 h after the hepatotoxin was able to significantly prevent the CCl4-induced liver necrosis at 24 h after poisoning. DTT-Ac administration was able to significantly reduce the intensity of the covalent binding of CCl4 reactive metabolites to microsomal lipids (CB), but it did not prevent the CCl4-induced initiation of a lipid peroxidation (LP) process as evidenced by diene hyperconjugation of microsomal lipids. Results suggest that DTT-Ac protective effects might be due to its in vivo conversion to DTT which in turn would decrease the intensity of CB via different potential mechanisms to be explored. Protection cannot be attributed to decreases in levels of CCl4 reaching the liver or to chain breaking effects on LP.

Late preventive effects against carbon tetrachloride-induced liver necrosis of the calcium chelating agent Calcion.

In agreement with the hypothesis that changes in calcium homeostasis might be significant in late stages of chemically-induced liver cell injury, a calcium chelating agent, Calcion, was able to partially prevent CCl4-induced liver necrosis observed at 24 h, when treatment was given as late as 6 or 10 h after the hepatotoxin. Calcion had minor or no effects on covalent binding of reactive metabolites to cellular components, or on lipid peroxidation or on CCl4 levels reaching the liver. Calcion treatment of CCl4-poisoned animals decreased CCl4-induced calcium increases in liver and increased glutathione levels decreased by hepatotoxin at 24 h. Calcion treatment was not able to prevent CCl4-induced fatty liver. Calcion protective effects were body temperature dependent but they were cancelled when Calcion-treated poisoned animals were kept normothermic. Results suggest that Calcion protective effects might be linked to calcium chelation or alternatively that they might derive from decreases in body temperature.