Histomorphological, Histochemical and Ultrastructural Studies on the Healthy Liver of Yemen Veiled Chameleon (Chamaeleo calyptratus) in Southern Saudi Arabia / Estudios Histomorfológicos, Histoquímicos y Ultraestructurales en el Hígado Sano del Camaleón Velado de Yemen (Chamaeleo calyptratus) en el Sur de Arabia Saudita

SUMMARY: The livers of reptiles are being studied as a model for the link between the environment and hepatic tissue. There have been few investigations on the histology of reptile livers, and very few or no studies have examined the histology of liver of veiled chameleon (Chamaeleo calyptratus). This paper describes the histomorphological, histochemical and ultrastructural characterization of the liver of veiled chameleons in southern Saudi Arabia. Seven Chamaeleo calyptratus were captured in the summer season in Abha City, Aseer region, southern Saudi Arabia. Chamaeleon liver samples were processed for histomorphology, histochemistry and ultrastructure analyses. Morphologically liver of Chamaeleo calyptratus was observed as a large dark brown organ with lighter speckles, which represent melanin deposits. It located at the ventral part of abdominal cavity forward of the stomach. Its dimensions approximately were 3.7 x 2 cm. The liver was a bilobed organ divided into two lobes, right and left lobes. The right one was bigger than the others. The gallbladder was well developed and had an elongated shape, situated between the two lobes and contained the bile for the digestion. Microscopically, the liver was found to be covered by a thick layer of connective tissue, which formed the hepatic capsule. Hepatic parenchyma probably appeared in cross sections as hepatic glandular-like alveoli "acini" or follicular structures with various diameters, each acinus contains approximately four to six hepatocytes, surrounded by sinusoidal capillaries filled with abundant melanomacrophages, which are absent in birds and mammals. Melanomacrophages are common in the hepatic parenchyma's perisinusoidal areas, particularly near portal spaces. Hepatocytes are polyhedral or pyramidal with and mostly contained large, rounded nuclei mostly peripherally located, with prominent dark oval nucleoli. Some of nuclei are eccentric or central position. The cytoplasm appeared spongy or vacuolated and more eosinophilic when stained by hematoxylin-eosin and strongly reactive to PAS staining technique, indicating abundant glycogen content. The reticular fibers that surround hepatocytes, blood arteries, and sinusoids supported the hepatic parenchyma. The blood sinusoids are seen interspersed among hepatocytes of varying sizes. The sinusoidal lumen was bordered by flattened endothelial cells and includes elliptical nucleated erythrocytes and liver macrophages as phagocytes, which are also known as Kupffer cells. Branches of the portal vein, hepatic artery, small bile duct, and lymph vessels were detected in the hepatic portal area "tract" or triad which made up of connective. Hematopoietic tissue was observed in subcapsular region and portal triads. Ultrastructurally, the hepatocyte appeared polyhedric containing a single large rounded basal or eccentric vesicular nucleus with prominent nucleolus. Extensive network of rough endoplasmic reticulum (RER) often arranged in an array parallel to the nuclear membrane with many mitochondria, and Golgi apparatus were described. The cytoplasm contained glycogen granules, vesicles or vacuoles scattered throughout the cytoplasm especially at the apical region were reported. The bile canaliculi and the hepatic "Kupffer" cells were also discussed. This is the first study on the histological characterization of the healthy liver of Yemen veiled chameleon in southern Saudi Arabia. The findings reported here should be used as a reference to compare with the pathological abnormalities of the liver in this animal.

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Hepatotoxicity-induced by the therapeutic dose of acetaminophen and the ameliorative effect of oral co-administration of selenium/Tribulus terrestris extract in rats / Hepatotoxicidad inducida por la dosis terapéutica de acetaminofén y el efecto de mejora de la administración conjunta de extracto de selenio Tribulus terrestris en ratas

SUMMARY: Over dose or long-term clinical use of therapeutic doses of acetaminophen (APAP) causes hepatotoxicity. Various strategies attempted to ameliorate APAP-hepatotoxicity have been found to be unsuitable for clinical practice. This study was aimed to illustrate the histopathological changes induced by therapeutic dose of APAP and investigate the hepatoprotective role of oral co-administration of selenium/ Tribulus terrestris (TT) extract concurrently against hepatotoxicity induced by APAP in rats. Fifty-four healthy male albino Wistar rats were randomized into nine groups (G1-G9) of six rats each, and administered with APAP and TT orally for 30 days as follows: Control (2ml normal saline), APAP (470 mg/kg), APAP (470 mg/kg) + selenium (2 mg/kg), APAP (470 mg/kg) + TT (98 mg/kg), APAP (470 mg/kg) + selenium (2mg/kg) + TT (98 mg/kg), APAP (470 mg/kg) + silymarin (200 mg/kg), selenium (2 mg/ kg), TT (98 mg/kg) and silymarin (200 mg/kg) groups. The results demonstrated that exposure of rats to therapeutic dose of APAP for 30 days caused significant histopathological changes parallel to elevated blood chemistry parameters. Co-administration of selenium/TT extract showed significantly reduced histopathological lesions and, restored or decreased levels of the examined blood chemistry parameters. Liver histology in selenium/TT extract showed normal hepatic architecture with mild changes and silymarin treated rats showed no histopathological changes. Histochemically PAS staining, showed that APAP-induced hepatotoxicity was characterized by hepatocytes glycogen depletion. Selenium/TT co-supplementation plays a potential role in preventing APAP-induced glycogen depletion by increasing detoxification and scavenging the reactive metabolites. Selenium/TT extract oral co-administration possesses a significant hepatoprotective property and mitigates APAP-induced hepatotoxicity by enhancing its antioxidant role and improving tissue integrity. Selenium/TT supplementation could represent an effective treatment against APAP-induced hepatotoxicity. Further studies are needed to elucidate the exact mechanism underlying the protective role of TT extract.

RESUMEN: La dosis excesiva o el uso clínico a largo plazo de dosis terapéuticas de acetaminofeno (APAP) causa hepatotoxicidad. Se ha descubierto que varias estrategias que intentaron mejorar la hepatotoxicidad por APAP no son adecuadas para la práctica clínica. Este estudio tuvo como objetivo ilustrar los cambios histopatológicos inducidos por la dosis terapéutica de APAP e investigar el papel hepatoprotector de la administración conjunta de extracto de selenio / Tribulus terrestris (TT) simultá- neamente contra la hepatotoxicidad inducida por APAP en ratas. Cincuenta y cuatro ratas Wistar albino machos sanas se aleatorizaron en nueve grupos (G1 - G9) de seis ratas cada una, y se administraron con APAP y TT por vía oral durante 30 días de la siguiente manera: Control (2 ml de solución salina normal), APAP (470 mg / kg), APAP (470 mg / kg) + selenio (2 mg / kg), APAP (470 mg / kg) + TT (98 mg / kg), APAP (470 mg / kg) + selenio (2 mg / kg) + TT (98 mg / kg), APAP (470 mg / kg) + silimarina (200 mg / kg), selenio (2 mg / kg), TT (98 mg / kg) y silimarina (200 mg / kg). Los resultados demostraron que la exposición de las ratas a la dosis terapéutica de APAP durante 30 días causó cambios histopatológicos significativos paralelos a parámetros elevados de química sanguínea. La administración conjunta de extracto de selenio / TT mostró lesiones histopatológicas significativamente reducidas y niveles restaurados o disminuidos de los parámetros de química sanguínea. La histología hepática en el extracto de selenio / TT mostró una arquitectura hepática normal con cambios leves y las ratas tratadas con silimarina no mostraron cambios histopatológicos. La tinción histoquímica de PAS mostró que la hepatotoxicidad inducida por APAP se caracterizó por la pérdida de glucógeno de los hepatocitos. La suplementación con selenio / TT juega un papel potencial en la prevención de la pérdida de glucógeno inducido por APAP al aumentar la desintoxicación y eliminar los metabolitos reactivos. La administración conjunta de extracto de selenio / TT posee una propiedad hepatoprotectora significativa y mitiga la hepatotoxicidad inducida por APAP al mejorar su papel antioxidante y la integridad del tejido. La suplementación con selenio / TT podría representar un tratamiento efectivo contra la hepatotoxicidad inducida por APAP. Se necesitan más estudios para dilucidar el mecanismo exacto que subyace a la función protectora del extracto TT.

Renal histological alterations induced by acute exposure of titanium dioxide nanoparticles / Alteraciones histológicas renales inducidas por la exposición aguda de nanopartículas de dióxido de titanio

SUMMARY: Titanium dioxide nanoparticles (TiO2 NPs) are widely used in many commercial products, nanomedicine, agriculture, personal care products, different industries and pharmaceutical preparations with potential risk in human health and the environment. The current work was conducted to investigate the renal damage that might be induced by the acute toxicity TiO2 NPs. A total of 40 healthy male adult Wistar albino rats (Rattus norvegicus) were exposed to TiO2 NPs (126, 252, 378 mg/kg bw) for 24 and 48 h. Fresh portions of the kidneys from each rat were processed for histological and histochemical alterations. In comparison with respective control rats, exposure to TiO2 NPs has marked the following glomerular, tubular and interstitial alterations including the followings: glomerular congestion, Bowman's capsule swelling and dilatation, inflamed glomeruli, renal tubules cloudy swelling, karyorrhexis, karyolysis, infiltration of inflammatory cells, congestion, necrosis, hydropic degeneration, dilatation and congestion of blood vessels, hyaline droplets and hyaline casts precipitation, interstitial edema and fibrosis. From the findings of the current work one may conclude that TiO2 NPs are capable of inducing kidney damage with more insulation in the cortex and the proximal convoluted tubules than the medulla and the distal ones respectively. In addition, it might be concluded that renal damage induced by these nanomaterials is dose and duration of exposure dependent. Further hematological, biochemical, immunohistochemical, and ultra-structural studies are recommended.

RESUMEN: Las nanopartículas de dióxido de titanio (TiO2 NP) se usan ampliamente en muchos productos comerciales, nanomedicina, agricultura, productos para el cuidado personal, diferentes industrias y preparaciones farmacéuticas con riesgo potencial para la salud humana y el medio ambiente. El trabajo actual se realizó para investigar el daño renal que podría ser inducido por la toxicidad aguda NP de TiO2. Un total de 40 ratas Wistar albinas adultas sanas (Rattus norvegicus) fueron expuestas a TiO2 NP (126, 252, 378 mg / kg de peso corporal) durante 24 y 48 h. Las muestras de los riñones de las ratas se procesaron para estudios histológicos e histoquímicos. En comparación con las ratas control, la exposición de las ratas a TiO2 NP presentaron las siguientes alteraciones glomerulares, tubulares e intersticiales: congestión glomerular, dilatación de la cápsula de Bowman, inflamación glomerular, túbulos renales aumentados, cariorrexis, cariólisis, infiltración de células inflamatorias, congestión, necrosis, degeneración hidrópica, dilatación y congestión de vasos sanguíneos, gotas y precipitaciones hialina, edema intersticial y fibrosis. A partir de los hallazgos del trabajo actual, se puede concluir que las NP de TiO 2 son capaces de inducir daño renal con más aislamiento en la corteza y en los túbulos contorneados proximales que en la médula y los túbulos contorneados distales, respectivamente. Además, se podría concluir que el daño renal inducido por estos nanomateriales depende de la dosis y la duración de la exposición. Se recomiendan estudios adicionales hematológicos, bioquímicos, inmunohistoquímicos y ultraestructurales.