possible protective role of curcumin versus garlic in amiodarone-induced keratopathy in rats: light and electron microscopic study

Amiodarone is a highly effective antiarrhythmic drug. However, amiodarone-induced corneal keratopathy is one of the most common side effects in humans. Amiodarone toxicity is attributed to its metabolites, which induce a significant increase in inflammatory mediators and cytokine release as well as free-radical formation. To clarify the possible protective effect of the natural antioxidants curcumin versus garlic on amiodarone-induced keratopathy. This study was carried out on 40 male albino rats weighing 180-200 g. The rats were divided randomly into four main groups [10 rats each]: group I included rats that were used as controls. The rats in group II received amiodarone [30 mg/kg/day] daily by a gavage for 6 weeks. The rats in groups III and IV received curcumin [100 mg/kg/day] and garlic [300 mg/kg/day], respectively, plus amiodarone. After 6 weeks, blood samples were collected for the determination of malondialdehyde and superoxide dismutase serum levels. Then, corneal specimens were rapidly taken from all rats and processed for both light and electron microscopic examination. Light microscopic examination of group II corneal sections showed that the majority of the basal and intermediate epithelial cell layers of the corneal epithelium showed a vacuolated cytoplasm with pyknotic nuclei. The substantia propria became thick and showed abundant collagen bundles, focal masses of disorganized irregularly arranged collagen, and neovascularization. The Descemet's endothelial cell layer appeared thick with focal areas of stratification. In addition, the mean corneal thickness in group II was significantly increased [P<0.05]. Ultrastructural examination showed shrunken irregular basal and intermediate epithelial cell layers with multiple cytoplasmic vacuoles, wide intercellular spaces, and partial loss of the desmosomal junction. The keratocytes and stratified Descemet's endothelial cells showed numerous cytoplasmic vacuoles, lysosomes, and lamellar bodies. Moreover, the mean serum level of malondialdehyde was significantly increased [P<0.05] and the mean serum level of superoxide dismutase was significantly decreased [P<0.05]. In the rats of group IV, garlic significantly attenuated the amiodarone-induced corneal changes and the biochemical alterations compared with curcumin [group III]. Garlic exerts a greater ameliorative effect on amiodarone-induced keratopathy over curcumin and it can be recommended as an adjuvant therapy with amiodarone in patients treated with this drug for a long time

Effect of fenofibrate on the experimentally induced hepatic ischemia/reperfusion injury in rats: biochemical, light, and electron microscopic studies

Liver ischemia/reperfusion [I/R] injury is a serious clinical problem. It is one of the main causes of hepatic failure after liver surgery. It was proved that reactive oxygen species and tumor necrosis factor-alpha [TNF-alpha] are important mediators in liver I/R injury. This study was designed to investigate the effect of preischemic treatment with fenofibrate [peroxisome proliferator-activated receptor-alpha activator] on the oxidative stress and inflammatory response to hepatic I/R injury in rats. Forty-eight male rats were equally divided into four groups: group 1 [sham group], group 2 [fenofibrate-treated sham group], group 3 [hepatic I/R group; hepatic I/R was induced by clamping the blood supply of the left lateral and median lobes of the liver for 60 min, followed by reperfusion for 4 h], and group 4 [fenofibrate-treated hepatic I/R group; the animals were pretreated with a single dose of fenofibrate [50mg/kg body weight, intraperitoneally] 1 h before ischemia]. After 4 h of reperfusion, blood samples were obtained to assess serum alanine aminotransferase and TNF-alpha. Then liver tissues were obtained to assess hepatic malondialdehyde and superoxide dismutase activity. In addition, liver specimens from each group were obtained and processed for light and electron microscopic studies. Hepatic I/R induced a significant elevation of serum alanine aminotransferase, TNF-alpha, and malondialdehyde. However, superoxide dismutase activity in the hepatic tissues showed significant reduction. Light microscopic examination of group 3 showed a disorganized hepatic architecture with congestion, multiple areas of hemorrhage, and focal necrosis. In addition, mononuclear cellular infiltrate was observed in the portal tract. The hepatocytes showed necrosis, apoptosis, and vacuolated cytoplasm. Moreover, there was a significant increase in the mean diameter of the central veins, blood sinusoids, portal vessels, and bile ducts [P<0.001]. Scanning electron micrographs showed dilated blood sinusoids packed with red blood cells and leukocytes. Ultrastructural study showed hepatocytes containing multiple cytoplasmic vacuoles and lysosomes. The mitochondria appeared swollen with cristolysis or with an electron-dense matrix. Moreover, Kupffer cells showed apoptotic bodies and multiple lysosomes in their cytoplasm. In addition, the hepatic stellate cells appeared surrounded by wide areas containing collagen fibers. In group 4, preischemic treatment with fenofibrate significantly attenuated the biochemical and histological alterations of I/R-induced liver injury. Fenofibrate could be promising as an adjuvant therapy before hepatic surgery for rescuing the liver from I/R injury

Light and electron microscopic study of thoracic aorta in premature menopause-induced rats and the possible protective role of ginger

Premature menopausal age increases the risk of atherosclerosis, hypertension, coronary heart disease and mortality. On the other hand, estrogen replacement therapy in menopausal women may increase the risk of breast cancer. To study the histological changes in thoracic aorta in premature menopause-induced rats and the possible protective role of Ginger. Thirty six adult female rats aged three months were used in this study Rats were divided into two groups: group A [control group, n=12 rats] and group B [experimental group, n=24 rats]. Bilateral ovariectomy was performed to the experimental group, which was then divided into two equal groups: group B I rats fed normal diet and group 132 rats fed ginger [500 mg/kg/body weight] enriched diet. Six-months after ovariectomy, specimens from the thoracic aorta were taken, processed and examined by light microscope and scanning and transmission electron microscope. Light microscopic study of thoracic aorta of group B1 showed a sub-endothelial mass of aggregated foamy cells was seen projecting into the lumen with focal degeneration in the elastic laminae below this mass. The tunica media showed large number of smooth muscles [SMCs] with vacuolated cytoplasm. Moreover, aortic aneurysm was also noticed. The mean intima-media thickness was significantly increased [103.84 +/- 7.5 micro m] [P<0.001]. Scanning electron microscopic study showed irregular luminal surface of the aorta with multiple elevated streaks. endothelial projections, erosions and a large thrombus attached to the endothelium. The ultrastructure study showed Lipid-loaded monocyts attached to the endothelium and Lipid-loaded SMCs in the media. Moreover the Lipid-loaded endotheial cells showed small condensed nucleus and discontinuous cell membrane with absence of the electron dense bodies. The internal elastic lamina appeared thin and electron dense. Meanwhile light and electron microscopic study of group B2 aorta showed attenuated histopathological changes and the mean intima-media thickness was significantly decreased [83.6 + 7.4 micro m micro m] [P<0.001]. Ginger significantly attenuated the premature menopause-induced morphological changes in the rat thoracic aorta. Therefore Ginger enriched diet could be recommended for early menopausal women as well as individuals with high risk of atherosclerosis, hypertension and coronary heart disease

Effect of postnatal exposure to cigarette smoke on the tracheal epithelium of albino rat

Environmental tobacco smoke [ETS] is one of the most common indoor pollutants to which many children are exposed. The present work was carried out to investigate the his-ological changes of rat tracheal epithelium after postnatal exposure to cigarette smoke. Fifteen newborn albino rats were daily exposed to side-stream cigarette smoke [10 cigarettes a day, 6 days a week] for 12 weeks. From the trachea, paraffin sections were prepared and stained with Haematoxylin and eosin [H and E] stain and alcian blue-periodic acid-Schiff's stain [AB/PAS]. Toluidine blue stained semithin sections were also prepared and examined by light microscope. Ultrathin sections were processed for electron microscopic [EM] examination. In H and E stained sections the tracheal mucosa of the experimental animals showed erosion in the epithilium, oedema, and heavy mono-nuclear cellular infiltrate in the corium which resulted in polyp formation and decreased number of ciliated cells. Preneoplastic variants in the form of squamous metaplasia and dysplasia were also seen. AB/PAS stained sections revealed progressive increase in the number of goblet cells. Semithin sections showed increased number of globule leucocytes, basal cell hyperplasia and dysplasia. Electron microscope revealed swollen cilia, intracytoplasrmic cilia and loss of some basal bodies. Goblet cells were packed with numerous confluent mucus granules. Moreover, degenerated and apoptotic cells were also observed Therefore, it is strongly recommended to protect children from exposure to ETS and to warn parents about the hazards of continuous exposure of their children to cigarette smoke