Effective Inhibition of TNFalpha/mTOR Axis-Mediated Liver Inflammation and Fibrosis Induced by TAA Using a Combination of Metformin and Resveratrol in Association with the Inhibition of the Profibrotic Gene and Protein Expression / Inhibición Efectiva de la Inflamación Hepática Mediada por el Eje TNF-alfa/mTOR y la Fibrosis Inducida por TAA Utilizando una Combinación de Metformina y Resveratrol en Asociación con la Inhibición del Gen Profibrótico y la Expresión de Proteínas

SUMMARY: The response of the immune system to harmful stimuli leads to inflammation, and the adverse effects of the toxic hepatitis chemical, thioacetamide (TAA) on the human body are well documented. This article investigated the degree of protection provided by the combined pleotropic drug, metformin (Met) and the plant polyphenolic and the antiinflammatory compound, resveratrol (Res) on liver tissue exposed to TAA possibly via the inhibition of the inflammatory cytokine, tumor necrosis factor-α (TNF-α) / mammalian target of rapamycin (mTOR) axis-mediated liver fibrosis, as well as amelioration of profibrotic gene and protein expression. Rats were either given TAA (200 mg/kg via intraperitoneal injection) for 8 weeks beginning at the third week (experimental group) or received during the first two weeks of the experiment combined doses of metformin (200 mg/kg) and resveratrol (20 mg/kg) and continued receiving these agents and TAA until experiment completion at week 10 (treated group). A considerable damage to hepatic tissue in the experimental rats was observed as revealed by tissue collagen deposition in the portal area of the liver and a substantial increase (p<0.0001) in hepatic levels of the inflammatory marker, tumor necrosis factor-α (TNF-α), as well as blood levels of hepatocellular injury biomarkers, alanine aminotransferase (ALT) and aspartate aminotransferase (AST). TAA also augmented hepatic tissue levels of the signalling molecule that promotes liver fibrosis (mTOR), and profibrogenic markers; alpha-smooth muscle actin (α-SMA) protein, tissue inhibitor of metalloproteinases-1 (TIMP-1) mRNA, and matrix metalloproteinase-9 (MMP-9) mRNA. All these parameters were protected (p≤0.0016) by Met+Res. In addition, a significant correlation was detected between liver fibrosis score and inflammation, liver injury enzymes, mTOR, and profibrogenesis markers. Thus, these findings suggest that Met+Res effectively protect the liver against damage induced by thioacetamide in association with the downregulation of the TNF-α/mTOR/fibrosis axis.

La respuesta del sistema inmunológico a estímulos dañinos conduce a la inflamación y los efectos adversos de la tioacetamida (TAA), una sustancia química tóxica para el hígado, están bien documentadas. Este artículo investigó el grado de protección proporcionado por el fármaco pleotrópico combinado metformina (Met), el polifenólico vegetal y el compuesto antiinflamatorio resveratrol (Res) en el tejido hepático expuesto a TAA, posiblemente a través de la inhibición de la citoquina inflamatoria, factor de necrosis tumoral α (TNF-α)/objetivo de la fibrosis hepática mediada por el eje de rapamicina (mTOR), así como mejora de la expresión de genes y proteínas profibróticas. Las ratas recibieron TAA (200 mg/kg mediante inyección intraperitoneal) durante 8 semanas a partir de la tercera semana (grupo experimental) o recibieron durante las dos primeras semanas del experimento dosis combinadas de metformina (200 mg/kg) y resveratrol (20 mg/kg) y continuaron recibiendo estos agentes y TAA hasta completar el experimento en la semana 10 (grupo tratado). Se observó un daño considerable al tejido hepático en las ratas experimentales, como lo revela el depósito de colágeno tisular en el área portal del hígado y un aumento sustancial (p<0,0001) en los niveles hepáticos del marcador inflamatorio, el factor de necrosis tumoral-α (TNF- α), así como los niveles sanguíneos de biomarcadores de lesión hepatocelular, alanina aminotransferasa (ALT) y aspartato aminotransferasa (AST). TAA también aumentó los niveles en el tejido hepático de la molécula de señalización que promueve la fibrosis hepática (mTOR) y marcadores profibrogénicos; proteína actina del músculo liso alfa (α- SMA), inhibidor tisular de las metaloproteinasas-1 (TIMP-1) mRNA y matriz metaloproteinasa-9 (MMP-9) mRNA. Todos estos parámetros fueron protegidos (p≤0.0016) por Met+Res. Además, se detectó una correlación significativa entre la puntuación de fibrosis hepática y la inflamación, las enzimas de lesión hepática, mTOR y los marcadores de profibrogénesis. Por lo tanto, estos hallazgos sugieren que Met+Res protege eficazmente el hígado contra el daño inducido por la tioacetamida en asociación con la regulación negativa del eje TNF-α/mTOR/fibrosis.

Metformin Inhibits ROS/TNF-alpha Axis-Mediated Chronic Kidney Disease Induced by TAA Independent of Leukocyte Infiltration in Association with the Inhibition of Kidney Injury Biomarkers / La Metformina Inhibe la Enfermedad Renal Crónica Mediada por el Eje ROS/TNF-alfa Inducida por TAA Independientemente de la Infiltración de Leucocitos en Asociación con la Inhibición de Biomarcadores de Lesión Renal

SUMMARY: The toxic effects of thioacetamide (TAA) and carbon tetrachloride on the human body are well recognized. In this study, we examined whether TAA intoxication can induce kidney leukocyte infiltration (measured as leukocyte common antigen CD45) associated with the augmentation of the reactive oxygen species (ROS)/tumor necrosis factor-alpha (TNF-α) axis, as well as biomarkers of kidney injury with and without metformin treatment. Rats were either injected with TAA (200 mg/kg; twice a week for 8 weeks) before being sacrificed after 10 weeks (experimental group) or were pre-treated with metformin (200 mg/kg) daily for two weeks prior to TAA injections and continued receiving both agents until the end of the experiment, at week 10 (protective group). Using basic histology staining, immunohistochemistry methods, and blood chemistry analysis, we observed profound kidney tissue injury such as glomerular and tubular damage in the experimental group, which were substantially ameliorated by metformin. Metformin also significantly (p0.05) increase in kidney expression of CD45 positive immunostaining cells. In conclusion, we found that TAA induces kidney injury in association with the augmentation of ROS/TNF-α axis, independent of leukocyte infiltration, which is protected by metformin.

Son bien conocidosos los efectos tóxicos de la tioacetamida (TAA) y el tetracloruro de carbono en el cuerpo humano. En este estudio, examinamos si la intoxicación por TAA puede inducir la infiltración de leucocitos renales (medida como antígeno leucocitario común CD45) asociada con el aumento de las especies reactivas de oxígeno (ROS)/factor de necrosis tumoral-alfa (TNF-α), así como biomarcadores de daño renal con y sin tratamiento con metformina. A las ratas se les inyectó TAA (200 mg/kg; dos veces por semana durante 8 semanas) antes de sacrificarlas a las 10 semanas (grupo experimental) o se les pretrató con metformina (200 mg/kg) diariamente durante dos semanas antes de las inyecciones de TAA y continuaron recibiendo ambos agentes hasta el final del experimento, en la semana 10 (grupo protector). Usando tinción histológica básica, métodos de inmunohistoquímica y análisis químico de la sangre, observamos una lesión profunda del tejido renal, como daño glomerular y tubular en el grupo experimental, que mejoraron sustancialmente con la metformina. La metformina también inhibió significativamente (p0,05) en la expresión renal de células de inmunotinción positivas para CD45. En conclusión, encontramos que el TAA induce la lesión renal en asociación con el aumento del eje ROS/TNF-α, independientemente de la infiltración de leucocitos, que está protegida por metformina.

Captopril inhibits thioacetamide-induced chronic liver injury associated with the suppression of inflammation / hypoxia- inducible factor 1-alpha / profibrogenic axis-mediated hepatotoxicity in rats / Captopril inhibe la lesión hepática crónica inducida por tioacetamida asociada con la supresión de la inflamación/factor 1-alfa inducible por hipoxia/hepatotoxicidad mediada por el eje profibrogénico en rata

SUMMARY: Liver transplantation is the only available method to treat liver failure induced by chronic liver injury. We sought to determine whether the angiotensin-converting enzyme inhibitor, captopril, can inhibit the development of chronic liver injury induced by the hepatotoxic agent thioacetamide (TAA) in association with the suppression of inflammation (hsCRP, TNF-α, and IL-6) / hypoxia- inducible factor 1-alpha (HIF-1α) / profibrosis (TIMP-1, MMP-9, and α-SMA) axis that mediates liver injury. Therefore, the model group of rats was injected for eight weeks with 200 mg/kg TAA starting at week two. The protective group was pretreated with 150 mg/ kg captopril daily for two weeks prior to TAA injections and continued receiving both capropril and TAA agents until being humanely scrificed at week 10. We observed a substantial damage to liver tissue in the model group as demonstrated by a significant (p<0.0001) increase in blood and hepatic tissue levels of high sensitivity C-reactive protein (hsCRP), tumor necrosis factor-a (TNF-α), interleukin- 6 (L-6), HIF-1α, tissue inhibitor of metalloproteinases-1 (TIMP-1), matrix metalloproteinase-9 (MMP-9), alpha-smooth muscle actin (α-SMA), alanine aminotransferase (ALT), and aspartate aminotransferase (AST). All these parameters were significantly (p<0.0244) protected by captopril. Also, a significant (p<0.0001) positive correlation was observed between a-SMA (profibrosis) and the serum and tissue levels of hsCRP, TNF-α, HIF-1α, TIMP-1, MMP-9, and ALT. Thus, these findings suggest that the induction of chronic liver injury by the hepatotoxic compound, TAA is associated with the upregulation of inflammation/HIF-1α/profibrosis, with captopril exhibiting beneficial hepatic pleotropic effects.

El trasplante de hígado es el único método disponible para tratar la insuficiencia hepática inducida por una lesión hepática crónica. Buscamos determinar si el inhibidor de la enzima convertidora de angiotensina, captopril, puede inhibir el desarrollo de lesión hepática crónica inducida por el agente hepatotóxico tioacetamida (TAA) en asociación con la supresión de la inflamación (hsCRP, TNF-α e IL-6) / factor inducible por hipoxia 1-alfa (HIF-1α) / profibrosis (TIMP-1, MMP-9 y α- SMA) eje que media la lesión hepática. Por lo tanto, al grupo modelo de ratas se le inyectó durante ocho semanas 200 mg/kg de TAA a partir de la semana dos. El grupo protector fue pretratado con 150 mg/kg de captopril al día durante dos semanas antes de las inyecciones de TAA y continuó recibiendo capropril y agentes TAA hasta que fue sacrificado en la semana 10. Observamos un daño sustancial en el tejido hepático en el grupo modelo, como lo demuestra un aumento significativo (p<0,0001) de los niveles en sangre y tejido hepático de proteína C reactiva de alta sensibilidad (hsCRP), factor de necrosis tumoral-α (TNF-a), interleucina-6 (L-6), HIF-1α, inhibidor tisular de metaloproteinasas-1 (TIMP-1), metaloproteinasa de matriz-9 (MMP-9), actina de músculo liso alfa (α-SMA), alanina aminotransferasa (ALT) y aspartato aminotransferasa (AST). Todos estos parámetros estaban significativamente (p<0,0244) protegidos por captopril. Además, se observó una correlación positiva significativa (p<0,0001) entre α-SMA (profibrosis) y los niveles séricos y tisulares de hsCRP, TNF-α, HIF-1α, TIMP- 1, MMP-9 y ALT. Por lo tanto, estos hallazgos sugieren que la inducción de daño hepático crónico por el compuesto hepatotóxico, TAA, está asociada con la regulación al alza de la inflamación/HIF-1α/profibrosis, con captopril exhibiendo efectos pleotrópicos hepáticos beneficiosos.

Effects of melatonin against thioacetamide-induced testicular toxicity in rats / Efectos de la melatonina contra la toxicidad testicular inducida por tioacetamida en ratas

SUMMARY: This study aimed to investigate the changes in testis tissue of thioacetamide-induced rats and the effect of melatonin on these changes. Thirty-five male Wistar Albino rats were divided into five groups. Group I; Control (n=7), Group II; Melatonin (Mel) (10 mg/kg) a single dose (i.p)(n=7), Group III; Thioacetamide (TAA) (300 mg/kg) (i.p) 2 times with 24 hour intervals (n=7), Group IV; TAA (300 mg/kg) was administered at 24-hour intervals, afterwards of 10 mg/kg single dose of Mel (n=7), Group V; Mel was administered 10 mg/kg a single dose 24 hours before the administration of TAA (n=7). Testis was evaluated histologically, immunohistochemically (Heat Shock Proteins (HSP) 70 and 90), blood serum testosterone, total antioxidant status(TAS) and total oxidant status(TOS) in tissue. The tissue sections of Group III decreased seminiferous tubule diameters, and germinal epithelium spills were observed. HSP70 and HSP90 expressions were increased. There wasn't a statistically significant change in testosterone levels among the groups. While TAS levels decreased in Group III compared to control, TOS levels didn't change. HSP70 and HSP90 decreased in groups with Mel-treated. Mel was found to have both protective and therapeutic effects. According to our results, the therapeutic effect of Mel in thioacetamide-induced acute testicular injury is greater than its protective effect.

RESUMEN: Este estudio tuvo como objetivo investigar los cambios en el tejido testicular de ratas inducidas por tioacetamida y el efecto de la melatonina en estos cambios. Treinta y cinco ratas macho Wistar Albino se dividieron en cinco grupos. Grupo I; Control (n = 7), Grupo II; Melatonina (Mel) (10 mg / kg) una dosis única (i.p) (n = 7), Grupo III; Tioacetamida (TAA) (300 mg / kg) (i.p) 2 veces con intervalos de 24 horas (n = 7), Grupo IV; TAA (300 mg / kg) se administró a intervalos de 24 horas, luego de una dosis única de 10 mg / kg de Mel (n = 7), Grupo V; Mel recibió 10 mg / kg de una dosis única 24 horas antes de la administración de TAA (n = 7). Los testículos se evaluaron histológicamente, inmunohistoquímicamente (proteínas de choque térmico (PCT) 70 y 90), testosterona en suero sanguíneo, estado antioxidante total (EAT) y estado oxidante total (EOT) en el tejido. En secciones de tejido del Grupo III se observó disminución de los diámetros de los túbulos seminíferos y derrames en el epitelio germinal. Se aumentaron las expresiones HSP70 y HSP90. No hubo un cambio estadísticamente significativo en los niveles de testosterona entre los grupos. Mientras que los niveles de EAT disminuyeron en el Grupo III en comparación con el control, los niveles de EOT no cambiaron. HSP70 y HSP90 disminuyeron en los grupos tratados con Mel. Se descubrió que Mel tenía efectos protectores y terapéuticos. Según nuestros resultados, el efecto terapéutico de Mel en la lesión testicular aguda inducida por tioacetamida es mayor que su efecto protector.

Suppression of thioacetamide-induced hepatic injury in rats treatment with resveratrol: role of mammalian target of rapamycin (mTOR) cell signaling / Supresión de la lesión hepática inducida por tioacetamida en ratas tratadas con resveratrol: rol de la vía de señalización mTOR (mammalian target of rapamycin)

Chronic hepatotoxicity is a debilitating and frequently life-threatening disease resulting in progressive liver failure. The toxic chemical, thioacetamide (TAA) is used to evaluate hepatoprotective agents, and the polyphenolic compound, resveratrol was proposed as a novel treatment for diseases with hyperactivation of the mammalian target of rapamycin (mTOR) cell signaling pathway. This analysis sought to investigate the potential protective effect of resveratrol against liver injury induced by TAA via the inhibition of hepatic mTOR. Model group rats received several injections of TAA (200 mg/kg; twice a week for 8 weeks) before being sacrificed at week 10 and the protective group was pretreated with resveratrol (20 mg/kg) daily for two weeks prior to TAA injections and continued receiving both agents until the end of the experiment. Harvested liver tissues were examined using light microscopy and liver homogenates were assayed for biomarkers of inflammation and assessed the levels of mTOR protein in all animal groups. In addition, blood samples were assayed for biomarkers of liver injury enzyme. TAA substantially damaged the hepatic tissue of the model group such as infiltration of inflammatory cells, vacuolated cytoplasm, dark pyknotic nuclei, and dilated congested blood vessel that were effectively protected by resveratrol. Resveratrol also significantly (p<0.05) inhibited TAA-induced mTOR, high sensitivity c-reactive protein (hs-CRP), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in harvested liver homogenates and blood samples. Thus, we conclude that resveratrol effectively protects against TAA-induced hepatotoxicity in rats, possibly due to the inhibition of mTOR and inflammation.

La hepatotoxicidad crónica es una enfermedad debilitante y potencialmente mortal que produce insuficiencia hepática progresiva. La toxicidad del químico de la tioacetamida (TAA) se utiliza para evaluar los agentes hepatoprotectores y el compuesto polifenólico, resveratrol, se propuso como un nuevo tratamiento para enfermedades con hiperactivación de la vía de señalización celular mTOR (mammalian Target of Rapamycin). Aquí buscamos investigar el posible efecto protector del resveratrol contra la lesión hepática inducida por TAA a través de la inhibición de la vía de señalización mTOR en hepatocitos. Las ratas del grupo modelo recibieron varias inyecciones de TAA (200 mg / kg; dos veces por semana durante 8 semanas) antes de ser sacrificadas en la semana 10 y el grupo protector se trató previamente con resveratrol (20 mg / kg) diariamente durante dos semanas antes de las inyecciones de TAA y continuó recibiendo ambos agentes hasta el final del experimento. Se examinaron los tejidos hepáticos recolectados usando microscopía óptica y se analizaron los homogeneizados hepáticos para detectar biomarcadores de inflamación y se evaluaron los niveles de proteína mTOR en todos los grupos de animales. Además, se analizaron muestras de sangre para detectar biomarcadores de la enzima de lesión hepática. TAA dañó sustancialmente el tejido hepático del grupo modelo, con infiltración de células inflamatorias, citoplasma vacuolado, núcleos picnóticos oscuros y vasos sanguíneos congestionados dilatados que estaban efectivamente protegidos por el resveratrol. El resveratrol también inhibió significativamente (p <0.05) mTOR, proteína C-reactiva (hs-CRP), factor de necrosis tumoral alfa (TNF-α), interleucina-6 (IL-6), alanina aminotransferasa (ALT ) y aspartato aminotransferasa (AST) en las muestras de sangre y de hígados recolectados. En conclusión, el resveratrol protege eficazmente contra la hepatotoxicidad inducida por TAA en ratas, posiblemente debido a la inhibición de mTOR y de la inflamación.

Improved histoarchitectural changes with angiotensin receptor blockers in early testicular and cauda toxicity in rats / Mejora de los cambios en la histoarquitectura con bloqueadores de receptores de angiotensina en la toxicidad precoz testicular y de cauda en ratas

SUMMARY: Reproductive dysfunction is a complication for many diseases and toxins. Its early diagnosis and treatment are immensely important. Here the morphological histoarchitecture changes in early testicular and cauda toxicity before and after treatment with angiotensin receptor blockers were evaluated. Low-grade testicular damage was induced using thioacetamide (TAA, 50 mg/kg/day) intraperitoneally for two weeks in rats. The rats were randomly divided into four groups (n = 8) treated daily orally for three weeks as follows: Normal control (distilled water), TAA (positive control), TAA+candesartan (0.2 mg/kg) and TAA+losartan (7.5 mg/kg). Serum testosterone and testicular malondialdehyde and glutathione were measured. The changes in histoarchitecture of testis and cauda epididymis were evaluated by hematoxylin and eosin for general structure, Masson's trichrome for collagen, periodic acid Schiff for basement membrane, and caspase-3 and proliferating cell nuclear antigen (PCNA) for immunohistochemical analysis. The TAA-rats showed decreases of serum testosterone and testicular glutathione, increases in testicular malondialdehyde, degenerative changes and apoptosis in germ cells, thickening of tubular basal lamina and increases in expression of caspase 3, and decreases in expression of PCNA. The ARBs (candesartan and losartan) significantly reversed these changes with non-significant differences in-between. Treatment with ARBs (candesartan and losartan) significantly reversed TAA-induced low-grade testicular and cauda toxicity in rats. This could be potentially useful for early treatment of male patients with occupational toxicant-induced reproductive dysfunction especially if they are using ARBs for other comorbidities.

RESUMEN: La disfunción reproductiva es una complicación por muchas enfermedades y toxinas. Su diagnóstico y tratamiento tempranos son inmensamente importantes. Aquí se evaluaron los cambios morfológicos en la histoarquitectura en la toxicidad precoz testicular y cauda antes y después del tratamiento con bloqueadores de receptores de angiotensina. Se indujo daño testicular de bajo grado usando tioacetamida (TAA, 50 mg / kg / día) por vía intraperitoneal durante dos semanas en ratas. Las ratas se dividieron aleatoriamente en cuatro grupos (n = 8) tratados diariamente por vía oral durante tres semanas de la siguiente manera: control normal (agua destilada), TAA (control positivo), TAA + candesartan (0,2 mg / kg) y TAA + losartán (7,5 mg / kg). Se midieron la testosterona sérica, el malondialdehído testicular y el glutatión. Los cambios en la histoarquitectura de los testículos y la epidermis de la cauda se evaluaron mediante Hematoxilina y Eosina para determinar la estructura general, con tricrómicro de Masson para el colágeno, ácido periódico de Schiff para la membrana basal y la caspasa-3 y el antígeno nuclear de células proliferantes (PCNA) para análisis inmunohistoquímico. Las ratas TAA mostraron disminución de la testosterona sérica y glutatión testicular, aumentos en el malondialdehído testicular, cambios degenerativos y apoptosis en células germinales, engrosamiento de la lámina basal tubular y aumentos en la expresión de la caspasa 3, y disminución en la expresión de PCNA. Los ARB (candesartán y losartán) revirtieron significativamente estos cambios con diferencias no significativas en el medio. El tratamiento con BRA (candesartán y losartán) revirtió significativamente la toxicidad testicular y cauda inducida por TAA en ratas. Esto podría ser potencialmente útil para el tratamiento temprano de pacientes con disfunción reproductiva inducida por tóxicos ocupacionales, especialmente si están usando BRA para otras comorbilidades.

Metformin protects against thioacetamide induced liver injury in rats / La metformina protege contra la lesión hepática inducida por tioacetamida en ratas

Potent heptatotoxic chemicals such as carbon tetrachloride and thioacetamide (TAA) are used to evaluate hepatoprotective agents. Here we sought to investigate the potential protective effect of the antidiabetic and antioxidant drug, metformin against liver injury induced by TAA. Model group rats received several injections of TAA (200 mg/kg) before being sacrificed after 10 weeks and the protective group started the treatment two weeks prior to TAA injections and continued receiving both agents, metformin and TAA until the end of the experiment, week 10. Harvested liver tissues were examined using light microscopy and liver homogenates were assayed for oxidative and anti-oxidative stress markers that are known to be modulated in liver injury. Profound damage in the hepatic tissue of the model group such as liver fibrosis and destruction of hepatic architectures were revealed, which were protected by metformin comparable to the control group. TAA augmented the oxidative stress biomarker, malondialdehyde (MDA) and ameliorated the antioxidant superoxide dismutase (SOD), which were significantly (p<0.05) protected by metformin treatment. These results indicate that metformin effectively protects against TAA-induced hepatotoxicity in a rat model.

Para evaluar los agentes hepatoprotectores se usan químicos heptatotóxicos potentes como el tetracloruro de carbono y la tioacetamida (TAA). En este estudio tratamos de investigar el efecto protector potencial de la droga antidiabética y antioxidante, la metformina contra la lesión hepática inducida por TAA. Las ratas del grupo modelo recibieron varias inyecciones de TAA (200 mg/kg) durante 10 semanas antes de ser sacrificadas, y el grupo protector comenzó el tratamiento dos semanas antes de las inyecciones TAA y continuó recibiendo ambos agentes, metformina y TAA, hasta el final del experimento. Los tejidos hepáticos se examinaron usando microscopía óptica y se analizaron los homogeneizados hepáticos en busca de marcadores de estrés oxidativo y antioxidante los que están modulados en la lesión hepática. Se observaron daños significativos en el tejido hepático del grupo modelo como la fibrosis hepática y destrucción de la arquitectura hepática, que estaban protegidas por la metformina comparable al grupo control. TAA aumentó el biomarcador de estrés oxidativo, malondialdehído (MDA) y mejoró la enzima antioxidante superóxido dismutasa (SOD), que fueron protegidas significativamente (p <0,05) por el tratamiento con metformina. Estos resultados indican que la metformina protege eficazmente contra la hepatotoxicidad inducida por TAA en un modelo de rata.

The ameliorative potential of probiotics and/or silymarin on thioacetamide induced hepatotoxicity in rats: histological and immunohistochemical study / El potencial de mejora de los probióticos y / o silimarina sobre la hepatotoxicidad inducida por tioacetamida en ratas: estudio histológico e inmunohistoquímico

Thioacetamide (TAA) is one of the common fungicidal agents that induce liver injury varying from inflammation, necrosis, and fibrosis to cirrhosis. Many recent studies reported the beneficial effect of probiotics and silymarin on hepatotoxicity regardless the causative agents. Therefore, the present study aimed to evaluate the ameliorative role of probiotics and/or silymarin on TAA induced hepatotoxicity in rats via histological, and immunohistochemical methods. Twenty five male albino rats were used for this experiment and were divided into five groups (n=5 rats/group); group I acts as negative control, group II was orally administrated distilled water for six weeks, then injected with TAA (200 mg/kg b.wt./ 5 ml physiological saline/ I.P.) twice a week for another six weeks, group III was treated with probiotics at a dose of 135 mg/ kg b.wt. orally in drinking water daily for six weeks, then injected with TAA (dosage of group II), twice weekly for another six weeks, group IV was treated with silymarin at a dose of 200 mg/ kg b.wt orally 4 times per week for six weeks, then injected with TAA (dosage of group II), twice weekly for another six weeks and group V was treated with combination of both probiotics and silymarin, at the same dosage in groups III and IV respectively then injected with TAA (dosage of group II), twice weekly for another six weeks. Histologically, TAA induced hepatocytes degeneration, inflammatory cells infiltration, and pseudolobular parenchyma as well as, high apoptosis and low proliferation rates that were proved by immunohistochemical staining for caspase 3 and ki-67 respectively. Probiotics and/or silymarin improved the histological feature of hepatocytes, reduced apoptosis and stimulated proliferation. Based on these results, we concluded that the use of probiotics and silymarin combination ameliorates the hepatotoxic effect of TAA in rats more than the use of probiotics or silymarin alone.

La tioacetamida (TAA) es uno de los agentes fungicidas más comunes que inducen lesiones hepáticas que varían desde inflamación, necrosis y fibrosis hasta cirrosis. Muchos estudios recientes informaron el efecto beneficioso de los probióticos y la silimarina sobre la hepatotoxicidad independientemente de los agentes causantes. Por lo tanto, el presente estudio tuvo como objetivo evaluar el papel paliativo de los probióticos y / o silimarina en la hepatotoxicidad inducida por TAA en ratas a través de métodos histológicos e inmunohistoquímicos. Para este experimento se usaron veinticinco ratas albinas y se dividieron en cinco grupos (n = 5 ratas / grupo); el grupo I se usó como control negativo; en el grupo II se administró por vía oral agua destilada durante seis semanas y luego se inyectó TAA (200 mg / kg b.wt./ 5 ml solución salina fisiológica / IP) dos veces por semana durante otras seis semanas; el grupo III se trató con probióticos, dosis diaria de 135 mg / kg b.wt. por vía oral en agua potable, durante seis semanas y luego fue inyectado con TAA (dosis del grupo II), dos veces por semana durante otras seis semanas; el grupo IV se trató con silimarina, con una dosis de 200 mg / kg b.wt por vía oral 4 veces por semana durante seis semanas, luego se inyectó TAA (dosificación del grupo II), dos veces por semana durante otras seis semanas; y el grupo V, se trató con una combinación de ambos probióticos y silimarina con la misma dosis que en los grupos III y IV, respectivamente, luego fueron inyectados con TAA (dosificación del grupo II), dos veces por semana durante otras seis semanas. Histológicamente, la TAA indujo la degeneración de los hepatocitos, la infiltración de células inflamatorias y el parénquima pseudolobular, así como también una apoptosis alta y tasas de proliferación bajas que se probaron mediante tinción inmunohistoquímica para caspasa 3 y ki-67, respectivamente. Los probióticos y / o la silimarina mejoraron la característica histológica de los hepatocitos, redujeron la apoptosis y estimularon la proliferación. En base a estos resultados, concluimos que el uso de la combinación de probióticos y silimarina mejora el efecto hepatotóxico del TAA en ratas más que el uso de probióticos o silimarina individualmente.

Effect of Kombucha tea on rat liver histopathological alterations due to thioacetamide

Kombucha [fungal] tea is a sugar sweetened black tea obtained through a fermentation process containing symbiotic culture of acetic acid bacteria and yeasts. This study was done to determine the effect of Kombucha tea on rat liver histopathological alterations due to Thioacetamide [TAA]. In this experimental study, 20 adult male Wistar rats randomly allocated into four groups as follow: 1] control, 2] TAA group, treated with [TAA], [400 mg/kg/bw] for two weeks, 3] treated with [TAA], [400 mg/kg/bw] and then with Kombucha tea [50 mg/kg] and finally 4] preventive, treated with Kombucha tea, [50 mg/kg] and then [TAA], [400 mg/kg] for three weeks. The serum level of aminotransferase [AST], Alanine transaminase [ALT], Alkaline phosphatase [ALP], Lactate dehydrogenase [LDH] and total bilirubin were meseared and liver tissue samples were stained by hematoxilin and eosin. Serum level of AST, ALT, ALP, LDH and total bilirubin significantly increased in TAA group compare to control group [P<0.05]. Serum level of AST, ALT, ALP, LDH and total bilirubin significantly reduced in treated and protective groups in comparision with TAA group [P<0.05]. Mitosis and apptosis increased in TAA group. These liver histopathological alterations reduced in terated and protective groups. Kombucha tea contains theraputic and protective effects on enzyms and liver histophatological damage due to Thioacetamide in rat

Thioacetamide-Induced acute hepatic encephalopathy in rat: behavioral, biochemical and histological changes

As a serious neuropsychiatric disease, hepatic encephalopathy [HE] is a clinical condition with several types regarding chronicity and clinical diversity that can develop as a complication of both acute and chronic liver failure. This study evaluates changes in thioacetamide [TAA]-induced acute hepatic encephalopathy [AHE] in rat as an animal model. Both genders of C57BL6, BALB/C mice and Sprague Dawley rats; [10 animals in each group] were compared for induction of AHE to clarify which animal and gender were appropriate. The animals [10 male rats in each group] were categorized in 4 groups according to the dose of the TAA administered [200, 300 and 400 mg/kg of TAA at 24 h intervals for 4 days]. A control group was treated with solvent of TAA which was water [5 ml/kg/day]. The behavioral, biochemical markers of hepatic failure and histological aspects of thioacetamide [TAA] induced AHE and the correlation between the clinical severity and liver failure biomarkers were evaluated. Rat was shown to be an animal model of choice for AHE while the optimum dosage of TAA to induce AHE was 300 mg/kg/day at 24 h intervals for 4 days. The behavioral score was partially correlated with the rising of some biomarkers and pathological findings. Rat can be introduced as the animal of choice for AHE to study the pathophysiology, pharmacology and the survival rate of disease in liver transplant patients

Parthenolide-induced apoptosis of hepatic stellate cells and anti-fibrotic effects in an in vivo rat model

Parthenolide (PT), a sesquiterpene lactone derived from the plant feverfew, has pro-apoptotic activity in a number of cancer cell types. We assessed whether PT induces the apoptosis of hepatic stellate cells (HCSs) and examined its effects on hepatic fibrosis in an in vivo model. The effects of PT on rat HSCs were investigated in relation to cell growth inhibition, apoptosis, NF-kappaB binding activity, intracellular reactive oxygen species (ROS) generation, and glutathione (GSH) levels. In addition, the anti-fibrotic effects of PT were investigated in a thioacetamide-treated rat model. PT induced growth inhibition and apoptosis in HSCs, as evidenced by cell growth inhibition and apoptosis assays. PT increased the expression of Bax proteins during apoptosis, but decreased the expression of Bcl-2 and Bcl-XL proteins. PT also induced a reduction in mitochondrial membrane potential, poly(ADP-ribose) polymerase cleavage, and caspase-3 activation. PT inhibited TNF-alpha-stimulated NF-kappaB binding activity in HSCs. The pro-apoptotic activity of PT in HSCs was associated with increased intracellular oxidative stress as evidenced by increased intracellular ROS levels and depleted intracellular GSH levels. Furthermore, PT ameliorated hepatic fibrosis significantly in a thioacetamide-treated rat model. In conclusion, PT exhibited pro-apoptotic effects in rat HSCs and ameliorated hepatic fibrosis in a thioacetamide-induced rat model.

Distribution of Hepatic Myofibroblasts and Type I and III Collagen in Rat Liver Cirrhosis Induced by Thioacetamide / Distribución de Miofibroblastos y Colágeno Tipo I y III en Hígado de Ratas con Cirrosis Inducida por Tioacetamida

Thioacetamide (TAA) can induce various types of cirrhosis in the rat, including bridging fibrosis, biliary fibrosis, perisinusoidal/pericellular fibrosis and centrilobular fibrosis, in which different populations of hepatic myofibroblasts (MFs) are involved. The hepatic MFs can be classified into 3 groups: (a) portal/septal MFs; (b) activated hepatic stellate cell myofibroblasts (HSC/MFs); and (c) interface myofibroblasts (IF/MFs). The present study was carried out to examine the morphology and localization of hepatic MFs in relation to the distribution of type I and III collagen in rat cirrhotic livers. Immunohistochemistry to a-smooth muscle actin was employed to demonstrate the morphology and localization of the subpopulations of hepatic MFs. The distribution of type I and III collagen was investigated by using specific antibodies. Portal and septal MFs were windmill in shape and localized around tributaries of the portal and hepatic veins where type I and III collagen was accumulated. HSC/MFs with arachnoid in shape were localized in the spaces of Disse and spaces between neighboring hepatocytes where type I collagen was formed. IF/MFs showed arachnoid shapes and distributed along the margin of fibrous septa where type I collagen was condensed. MFs with polygonal shapes were also found around the wall of hepatic sinusoids, margin of fibrous septa and around the portal tract. They were probably transitional cells to the mature MFs. Our data suggest that each subpopulation of hepatic MFs shows characteristic morphology and localization, which correlates with localization of type I and/or type III collagen.

La tioacetamida (TAA) puede provocar diversos tipos de cirrosis hepática en la rata, incluyendo fibrosis en puente, fibrosis biliar, fibrosis perisinusoidal/pericelular y fibrosis centrolobulillar, en los que diferentes poblaciones de miofibroblastos hepáticos (MFs) están involucrados. Los MFs hepáticos se pueden clasificar en tres grupos: (a) MFs portal/ septal; (b) células estrelladas hepática activada miofibroblásticas (HSC/MFs), y (c) miofibroblastos de interface (IF/MFs). El presente estudio se realizó para examinar la morfología y localización de los MFs hepáticos en relación con la distribución de colágeno Tipos I y III en el hígado de ratas cirróticas. Se utilizó inmunohistoquímica de a-actina de músculo liso para demostrar la morfología y localización de las subpoblaciones de MFs hepática. La distribución de colágenos Tipos I y III se investigó utilizando anticuerpos específicos. FMs portales y septales mostraron forma de molino de viento y se localizaron cerca de afluentes de las venas porta y hepática donde los colágenos Tipos I y III se acumularon. HSC/MFs con forma aracnoide se localizaron en los espacios de Disse y los espacios entre hepatocitos vecinos, donde se formó el colágeno Tipo I. IF/MFs mostraron formas aracnoides y se distribuyeron a lo largo del margen de los septos fibrosos donde se condensó el colágeno Tipo I . MFs con formas poligonales también fueron encontrados alrededor de la pared de los sinusoides hepáticos, en el margen de los septos fibrosos y en todo el tracto portal. Probablemente fueron células de transición a los MFs maduros. Nuestros datos sugieren que cada subpoblación de MFs hepáticos muestra una morfología y localización característica, que se correlaciona con la localización de colágenos Tipo I y o III.

The effect of preconditioning on liver regeneration after hepatic resection in cirrhotic rats / 대한간학회지

BACKGROUND/AIMS: Ischemic preconditioning (IP) decreases severity of liver necrosis and has anti-apoptotic effects in previous studies using liver regeneration in normal rats. This study assessed the effect of IP on liver regeneration after hepatic resection in cirrhotic rats. METHODS: To induce liver cirrhosis, thioacetamide (300 mg/kg) was injected intraperitoneally into Sprague-Dawley rats twice per week for 16 weeks. Animals were divided into four groups: non-clamping (NC), total clamping (TC), IP, and intermittent clamping (IC). Ischemic injury was induced by clamping the left portal pedicle including the portal vein and hepatic artery. Liver enzymes alanine transaminase (ALT) and aspartate aminotransferase (AST) were measured to assess liver damage. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) staining for apoptosis and proliferating cell nuclear antigen (PCNA) staining for cell replication were also performed. RESULTS: Day-1 ALT and AST were highest in IP, however, levels in NC and IC were comparably low on days 1-7. There was no significant correlation of AST or ALT with experimental groups (P=0.615 and P=0.186). On TUNEL, numbers of apoptotic cells at 100x magnification (cells/field) were 31.8+/-24.2 in NC, 69.0+/-72.3 in TC, 80.2+/-63.1 in IP, and 21.2+/-20.8 in IC (P<0.05). When regeneration capacity was assessed by PCNA staining, PCNA-positive cells (cells/field) at 400x were 3.4+/-6.0 in NC, 16.9+/-69 in TC, 17.0+/-7.8 in IP and 7.4+/-7.6 in IC (P<0.05). CONCLUSIONS: Although regeneration capacity in IP is higher than IC, the liver is vulnerable to ischemic damage in cirrhotic rats. Careful consideration is needed in applying IP in the clinical setting.

A thioacetamide-induced hepatic encephalopathy model in C57BL/6 mice: a behavioral and neurochemical study / Modelo de encefalopatia hepática induzida por tioacetamida em camundongos C57BL/6: estudo comportamental e neuroquímico

OBJECTIVE: Hepatic encephalopathy (HE) is a neuropsychiatric syndrome resulting from liver failure. In the present study, we aimed to standardize an animal model of HE induced by thioacetamide (TAA) in C57BL/6 mice evaluating behavioral symptoms in association with liver damage and alterations in neurotransmitter release. METHOD: HE was induced by an intraperitoneal single dose of TAA (200 mg/kg, 600 mg/kg or 1,200 mg/kg). Behavioral symptoms were evaluated using the SHIRPA battery. Liver damage was confirmed by histopathological analysis. The glutamate release was measured using fluorimetric assay. RESULTS: The neuropsychiatric state, motor behavior and reflex and sensory functions were significantly altered in the group receiving 600 mg/kg of TAA. Biochemical analysis revealed an increase in the glutamate release in the cerebral cortex of HE mice. CONCLUSION: HE induced by 600mg/kg TAA injection in C57BL/6 mice seems to be a suitable model to investigate the pathogenesis and clinical disorders of HE.

OBJETIVO: A encefalopatia hepática (EH) é uma síndrome neuropsiquiátrica resultante da falência hepática. O objetivo do presente estudo foi estabelecer um modelo de EH induzida por tioacetamida (TAA) em camundongos C57BL/6 avaliando transtornos comportamentais, falência hepática e alterações na liberação de neurotransmissores. MÉTODO: A EH foi induzida por meio de uma única dose intraperitoneal de TAA (200 mg/kg, 600 mg/kg, 1.200 mg/kg). As alterações comportamentais foram avaliadas utilizando a bateria SHIRPA. A falência hepática foi confirmada através de análises histopatológicas e a liberação de glutamato medida, por ensaio fluorimétrico. RESULTADOS: Foram encontradas alterações significativas no estado neuropsiquiátrico, comportamento motor e função reflexa e sensorial no grupo que recebeu 600 mg/kg de TAA. Análises bioquímicas revelaram aumento na liberação de glutamato no córtex cerebral dos camundongos com EH. CONCLUSÃO: A EH induzida por 600 mg/kg de TAA em camundongos C57BL/6 parece ser um modelo apropriado para a investigação da patogênese e dos transtornos clínicos da EH.

Differential Expression of Matrix Metalloproteinases and Tissue Inhibitors of Metalloproteinases in Thioacetamide-Induced Chronic Liver Injury

Hepatic fibrogenesis, a complex process that involves a marked accumulation of extracellular matrix components, activation of cells capable of producing matrix materials, cytokine release, and tissue remodeling, is regulated by matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). The MMP-TIMP balance can regulate liver fibrogenesis. The aim of this study was to evaluate the expression patterns of MMPs and TIMPs during thioacetamide (TAA)-induced liver fibrogenesis. Chronic liver injury was induced with TAA (200 mg/kg i.p.) for 4 or 7 weeks in male Sprague-Dawley rats. Hepatic injury and fibrosis were assessed by hematoxylin-eosin (H&E) staining, and collagen deposition was confirmed by Sirius Red staining. The level of hepatic injury was quantified by serological analysis. The transcriptional and translational levels of alpha-smooth muscle actin (alpha-SMA), MMPs, and TIMPs in the liver were measured by Western blotting, RT-PCR, and immunohistochemistry. MMP, TIMP, and alpha-SMA were observed along fibrotic septa and portal spaces around the lobules. TAA treatment increased transcription of both MMPs and TIMPs, but only TIMPs showed increased translation. The dominant expression of TIMPs may regulate the function of MMPs to maintain liver fibrosis induced by TAA.

Expression of G1 Cell Cycle Regulators in Rat Liver upon Repeated Exposure to Thioacetamide / 대한간학회지

BACKGROUND/AIMS: Eukaryotic cell cycle is regulated by signal transduction pathways mediated by complexes of cyclin dependent kinases (CDKs) and their partner cyclins, or by interaction with CDK inhibitors. Thioacetamide (TA) is a weak hepatocarcinogen causing several types of liver damage in a dose dependent manner and ultimately producing malignant transformation. We investigated alterations of expression of cell cycle regulators in the rat liver, involved in G1 entry and progression during TA administration. METHODS: We studied expression patterns of cyclin D1, CDK4, CDK6, p21(CIP1) and p16(INK4a) during daily intraperitoneal injection of low dose TA (50 mg/kg) till 7 day. We used western blot and immunohistochemistry for detection. RESULTS: Expression of cyclin D1, CDK4, CDK6 and p21(CIP1) increased from 6 hour and peaked at 2, 3 day, then decreased next 2 days, and re-increased at 6 day. Cytoplasmo-nuclear translocation of cyclin D1 and p21(CIP1) was evident within 1 day and prominent at 2 and 7 day. Expression of p16(INK4a) increased immediately after TA treatment and remarkably increased from 3 day and progressed till 7 day, showing cytoplasmic location, suggestive of inactive form. Most of in situ immunoreactions occurred at the centrilobular hepatocytes. Concomitant nuclear translocation of p21(CIP1) and cyclin D1, different with p16(INK4a) suggests that p21(CIP1) might be a transporter for nuclear translocation rather than cell cycle inhibitor. CONCLUSIONS: Daily administration of low dose TA makes cell cycle open and G1 progress, possibly due to cyclin D1, CDK4 and CDK 6, their transporter p21(CIP1), and inactive p16(INK4a), which occur at quiescent hepatocytes, not stem cells.

Protective effect of Panax ginseng against thioacetamide cytotoxicity in liver and kidney of albino rat

Thioacetamide [TA] has a deleterious effect on hepatocytes and kidney cells. TA administration is an established technique for generating rat models of liver fibrosis and cirrhosis. Panax ginseng root has an antioxidant and protective effect against many chemical and physical agents. In this study Panax gensing roots with a dose of 117mg/kg was used for a period of 10 days prior to TA oral administration of 300 mg/kg sublethal dose. TA highly affected liver and kidney of rats. Previous starvation for 24, 48 and 72 hours immediately to TA administration strongly potentiated the effect of TA on the tissue injury of liver and kidney. The histopathological observations indicated highly disturbed hepatic portal area and marked hyperplasia in liver of rats while the damage of kidney involved areas of internal haemorrhage, disrupted and swollen cells of convoluted tubules and lobulated atrophied glomeruli. The obtained results showed that pre-treatment with Panax ginseng roots partially improved or modulated the pathological changes induced by TA intoxication in the liver while no significant protective effect in kidney cells has been detected against cellular damages of TA. This work aimed to evaluate the protective effect of Panax ginseng roots against the destructive effect of TA. Histochemical analysis of total protein showed that administration of TA induced depletion of liver and kidney proteins while pretreatment with ginseng improved the protein contents

Hepatoprotective effect of silybum marianum [L] gaertn and glycyrrhiza glabra L. in the rats

One of the major role of liver is metabolism of xenobiotics and detoxification. But sometimes during metabolism of xenobiotics produce active and more toxic agents which cause liver damage and disease. Use of nature products from vegetables. In the treatment of diseases and liver diseases have a long history, especially in Eastern medicine in this study we have investigate the protective effects of polyphenolic extracts of Silybum marianum and Cichorium intybus. Liver damage induced with hepatotoxin, thioacethamide. Extracts was injected every day for a duration of 3 days, to rats, at a doses of 25 mmg/kg body weight together with thioacetamide at a doses of 50 mg/kg body weight. In order to investigate the hepatoprotective effect of extracts against thioacetamide activities of serum aminotrasferases [SGOT and SGPT], alkalline Pbosphatase bilirubin, Na[+] and K[+] were measured.Activities of serum aminotrasferases [SGOT and SGPT], alkaline phosphatase and bilirubin were decreased significantly to rats treated with extracts compared to thioacetamide group. The results showed potent protective effects of these extracts against the thioacetamide induced hepatotoxicity that are due to antioxidant effect of polyphenolic compound

Ameliorative efficacy of a triple antioxidant combination of silymarin, selenium and vitamin E on thioacetamide induced liver cirrhosis in rats

This study was carried out to investigate the curative and protective efficacy of the triple antioxidant combination of silymarin, selenium [Se] and vitamin E [Vit.E] in thioacetamide-induced liver cirrhotic rats. Thioactamide [TAA] at a dose of 200 mg/kg, twice weekly, produced liver cirrhosis in rats as manifested by the significant [P<0.05] levation of hepatic marker enzymes and disturbances in antioxidant defense when compared with normal rats. Also, histopathologic evaluation of liver samples-demonstrated cirrhotic changes in TAA treated group. Oral administration of silymarin [20 mg/kg body weight], Se [10 micro mol/kg body weight] and vit. E in diet [1 g/kg diet] for 14 consecutive days, pre and post cirrhosis induction, significantly [P<0.05] decreased alanine and aspartate aminotransferase [ALT and AST, respectively], gamma-glutamyl transferase [GGT] and malondialdehyde [MDA] inthioacetamide treated rats. These ameliorative effects were more apparent in the post-treated group. The triple antioxidant also improved the activities of free radical detoxifying enzymes by increasing the activities of glutathione peroxidase [GSH-Px], glucose 6 phosphate dehydrogenase [G6P-DH], erythrocyte copper, zinc-superoxide dismutase [Cu, Zn-SOD] and the levels of reduced glutathione [GSH], plasma ceruloplasmin [Cp] and total protein in thioacetamide treated rats. A conclusion was made that the triple antioxidant induced marked improvement of biochemical and histopathological liver changes caused by thioactamide induction. Also, the results indicated that the potential therapeutic action of the triple antioxidant against TAA induction was more effective than its curative action