Effects of caffeic acid phenethyl ester on cerebral cortex: structural changes resulting from middle cerebral artery ischemia reperfusion.

Overproduction of free radicals is important in the pathogenesis of the cerebral damage induced by ischemia reperfusion. Caffeic acid phenethyl ester, an active component of propolis extract, exhibits antioxidant properties. The study was carried out in 16 male Wistar albino rats, divided into two groups: ischemia reperfusion and ischemia reperfusion with caffeic acid phenethyl ester. The middle cerebral artery was occluded for 60 min with an intraluminal suture, followed by 24-h reperfusion. In this study, widespread infarcted areas, red neurons (eosinophilic degeneration), pyknotic cells, vacuolization and neuroglial cell infiltration were observed in the cerebral cortex in the ischemia reperfusion group. In the caffeic acid phenethyl ester group, slightly infarcted areas were observed and neuroglial cell infiltration was not determined. Congestion of choroid plexus and pia mater was found more severe in the ischemia reperfusion group than in the caffeic acid phenethyl ester group. In the caffeic acid group, neuroglial cell activation was rare. Vacuolization, an indication of brain edema, was prevented by caffeic acid phenethyl ester. In the present study, we showed that pre-treatment with a single i.p. injection of caffeic acid phenethyl ester at 50 microM/kg dose reduced the structural changes.

Effects of testosterone on leptin production in anterior pituitary cells of rats: an immunohistochemical study.

The aim of this study was to immunohistochemically examine the effects of orchidectomy and administration of testosterone hormone on leptin production in the rat anterior pituitary. Twenty-one male Wistar rats were divided into three groups. Group I and group II were designated as control (sham-orchidectomized) and orchidectomized rats, respectively. Rats in group III were orchidectomized and injected daily with testosterone propionate for 1 month. At the end of the experimental period, all animals were sacrificed by decapitation. The pituitary glands of all rats were removed and processed for semi-quantitative evaluation of immunohistochemical leptin staining. Intensity of immunostaining was determined on a scale between 0 (no staining) and 5 (heavy staining). Immunostaining of leptin was moderate (3+) in control rats, heavy (5+) in orchidectomized rats, and low (1+) in testosterone-treated orchidectomized rats, respectively. These findings indicate that orchidectomy increases leptin secretion in anterior pituitary cells, and this increase of leptin synthesis can be prevented by administration of testosterone propionate. Thus, testosterone seems to affect leptin production in the anterior pituitary of male rats.

A polyethylene-high proportion hydroxyapatite implant and its investigation in vivo.

An implant from hydroxyapatite and polyethylene (HA+PE) composite was investigated for the usability in large bone defects. With this aim, the implants were manufactured in blocks by hot compacting the mixture of 80% HA and 20% PE weight ratio. Powders were machined in a lathe in the dimensions of diaphysis of the radius of the mongrel dogs. Then a defect, 1.5 cm in length, was made in the diaphysis of the radius with an operation performed under general anaesthesia in 16 healthy mongrel dogs. The defects were filled with implant as a block. The dogs were observed radiologically in 15-day intervals and examined clinically in certain intervals. The bone samples were taken out from four dogs for the histopatological examinations at the end of the 2nd, 4th, 6th and 12th months, respectively. Clinical examinations indicated the occurrence of slight lameness in all cases at the first month of experiment, but lameness completely disappeared in a further examination. Progressive resorption and new bone formation began in the implants from the first month, but complete resorption was not observed in any case at the end of 12-month period. SEM and optical microscope examinations revealed fibroblast cell with its clear cytoplasmic extensions and osteoblast cells in endosteum in the inner region. Bone formation increasing and extending to the pores of implant in time and blood vessels with lamellar structure and Haversian system were observed. As a result, it was indicated that HA+PE composite implants could be applied with confidence and are useful in treatment of large bone defects in long bone of dogs.

Effects of melatonin and vitamin C on cigarette smoke-induced damage in the kidney.

This study was carried out to investigate smoke-induced structural and biochemical changes and protective effects of co-administered melatonin and vitamin C in the kidney. Twenty-four Wistar adult female rats were used in this study. Animals were divided into four groups. The first group rats were used as control. The second group of rats inhaled cigarette smoke. Smile smoke inhaling third and fourth group rats received melatonin and vitamin C, respectively. At the end of experimental study, kidney tissues and blood samples were taken under ether anesthesia. Tissues were prepared and examined by light microscopy. Malondialdehyde and glutathione levels and catalase activity were determined. By light microscopic observation, a decrease of Bowman space of some renal corpuscles, foamy-like tubules, dilatation and congestion of the peritubuler vessels, and atrophy of the some renal corpuscles were observed in group II. In groups III and IV melatonin and vitamin C relatively protected the kidney tissue against smoke intoxication. Biochemical examination showed that malondialdehyde and glutathione levels and catalase activity in group II were higher than in group I. Melatonin and vitamin C injection to group III and IV caused a decrease in malondialdehyde and glutathione levels. Catalase activity did not change in these groups. We have shown that cigarette smoke inhalation caused structural changes in the kidney. However, melatonin and vitamin C administration produced in some degree protection against smoke-induced damage.

Caffeic acid phenethyl ester protects kidneys against carbon tetrachloride toxicity in rats.

Caffeic acid phenethyl ester (CAPE), an active component of propolis produced by honeybees, exhibits antioxidant and anti-inflammatory properties. The aim of this study was to investigate possible protective effects of CAPE on carbon tetrachloride (CCl4)-induced renal damage in rats. A total of 24 animals were divided into three equal groups: the control rats received pure olive oil subcutaneously, rats in the second group were injected with CCl4 (0.5 ml/kg, s.c. in olive oil) and rats in the third group were injected with CCl4 (0.5 ml/kg) plus CAPE (10 micromol/kg, i.p.) every other day for one month. At the end of the experimental period, the animals were sacrificed and blood samples were collected. Serum urea and creatinine levels and renal malondialdehyde (MDA) contents were determined. Histopathological examination of the kidney was also performed using light microscopic methods. It was found that kidney MDA levels were increased significantly following CCl4 exposure and this increase was significantly inhibited by CAPE treatment, while no significant changes were observed in serum urea and creatinine levels. CCl4 administration alone also caused histopathologically prominent damage in the kidney compared to the control group. Glomerular and tubular degeneration, interstitial mononuclear cell infiltration and fibrosis, and vascular congestion in the peritubular blood vessels were observed in the renal cortex. With exception of rare vascular congestions, these histopathological changes were disappeared in rats treated with CCl4 plus CAPE. In view of the present findings, it is suggested that CAPE protects kidneys against CCl4 toxicity.

Pinealectomy increases and exogenous melatonin decreases leptin production in rat anterior pituitary cells: an immunohistochemical study.

Melatonin, the main hormone of the pineal gland, informs the body about the environmental light and darkness regimen, which in turn contributes to the photoperiodic adaptation of several physiological functions. Leptin, the hormone secreted mainly by adipocytes and some other tissues including the pituitary, informs the brain about the mass of adipose tissue, which plays an important role in energy homeostasis. Melatonin has been shown to decrease circulating leptin levels. It is currently not known whether melatonin has an effect on leptin synthesis in the pituitary. The aim of this study was to immunohistochemically examine the effects of pinealectomy and administration of melatonin on leptin production in the rat anterior pituitary. The pituitary samples obtained from 18 male Wistar rats including sham-pinealectomized, pinealectomized and melatonin-injected pinealectomized groups were immunohistochemically evaluated. Immunostaining of leptin was moderate (3+) in sham-pinealectomized rats, heavy (5+) in pinealectomized rats and low (1+) in melatonin-treated pinealectomized rats, respectively. The present results indicate that pinealectomy induces leptin secretion in anterior pituitary cells, and this increase of leptin synthesis can be prevented by administration of melatonin. Thus, melatonin seems to have both physiological and pharmacological effects on leptin production in the anterior pituitary of male rats.

Effects of systemic octreotide, local mytomycine-C and local corticosteroids on wound-healing reaction after glaucoma surgery.

PURPOSE: To determine and compare the effectiveness of octreotide, mitomycine-C and corticosteroids on wound-healing reaction after glaucoma surgery. METHODS: A full thickness scleral trephination was carried out by the same surgeon on tour groups of six rabbits. A sponge soaked in mytomicine-C was applied subconjunctivally in group 1 before trephination. Group 2 received corticosteroid drops tid topically for 14 days. Group 3 received subcutaneous octreotide injections tid for 14 days. The control group (group 4) was not given any drug that may interfere with wound healing. All groups received gentamycine drops tid for seven days. The rabbits were Sacrificed on the fourteenth day and the trephination area with overlying conjunctiva was excised. The samples were prefixed with glutaraldehyde, dehydrated and embedded in Araldite Cy 212. Ten semithin sections stained with toluidin blue were analysed for each group. Fibroblast and macrophage counts were performed on the surgical site and subconjunctival area. RESULTS: Intensive fibroblastic activity, increased number of vessels and active macrophages were observed only in group 4. The fibroblast and macrophage densities in this group were significantly higher than the other three groups in which wound healing was modulated (p < 0.001). Mean number of fibroblasts in group 1 was also significantly less than the ones of groups 2 and 3 (p < 0.01). Macrophage densities were similar in groups 1, 2 and 3. No statistical significance was found between groups 2 and 3 by means of fibroblast and macrophage densities. CONCLUSION: Octreotide reduced wound-healing reaction in a similar fashion to corticosteroids or mitomycine-C. These initial results seem promising.