Influence of caffeine administered at 45 °C on bone tissue development.

INTRODUCTION AND OBJECTIVE: Caffeine is one of the world's most commonly ingested alkaloids which easily permeates the placenta. The teratogenic and embryotoxic influence of large doses of caffeine has been established in many experimental studies on animals. The objective of this work was to assess the influence of caffeine, administered at 45 °C, on the development of the bone tissue of rats, with particular reference to elemental bone composition using an X-ray microprobe. MATERIALS AND METHODS: The research was conducted on white rats of the Wistar strain. The fertilized females were divided into two groups: an Experimental Group (Group E) and a Control Group (Group C). The females in Group E were given caffeine orally (at 45 °C) in 30 mg/day doses from the 8th to the 21st day of pregnancy. The females in Group C were given water at the same temperature. The fetuses were used to assess the growth and mineralization of the skeleton. A qualitative analysis of the morphology and mineralization of bones was conducted using the alcian-alizarin method. For calcium and potassium analysis, an X-ray microprobe was used. RESULTS: By staining the skeleton using the alcian-alizarin method, changes in 52 of Group E fetuses were observed. The frequency of the development variants in the Group E rats was statistically higher, compared with Group C. CONCLUSIONS: Receiving caffeine at a higher temperature may result in different pharmacodynamics and significantly change tolerance to it. In Group E, a significant decrease in the calcium level, as well as an increase in the potassium level, was observed. The X-ray microprobe can be a perfect complement to the methods which enable determination of the mineralization of osseous tissue.

The influence of a thyroxine supplemented diet on selected hepatic redox equilibrium markers, liver morphology and the serum lipid profile in rats treated with doxorubicin.

INTRODUCTION: Cytotoxicity of doxorubicin (DOX) - an anticancer drug, mostly results from reactive oxygen species (ROS) generation. Some enzymes catalyzing this process and enzymes of antioxidant defense are regulated by iodothyronine hormones. Thus, disorders in iodothyronine hormone status may affect doxorubicin-induced redox imbalance and anabolic/catabolic disorders. The aim of this study was to evaluate the influence of doxorubicin and thyroxine (T4) associated treatment on liver morphology, markers of oxidative stress and plasma lipid parameters. MATERIALS AND METHODS: Rats were intraperitoneally treated with doxorubicin (1.5 mg/kg) once a week for ten weeks. Thyroxine was simultaneously given in drinking water (0.2 or 2.0 mg/l) for 14 weeks. RESULTS: There were higher hepatic level of malonyldialdehyde (MDA) of all tested groups and at the same time in rats treated with DOX plus T4 lower concentrations of total glutathione compared to controls were observed. Morphology of liver did not show any features of necrosis or steatosis but a decrease of glycogen content in T4+DOX groups compared to DOX treatment was observed. The concomitant administration of a lower dose of thyroxine and doxorubicin decreased triglycerides (TG) and increased LDL level compared to the DOX group. DISCUSSION: Thyroxin supplementation caused redox equilibrium disorders and oxidative stress in liver of rats receiving DOX. The study revealed the normalizing influence of thyroxin on glycogen deposits that were observed after doxorubicin treatment. Apart from an adverse impact of thyroxine administration on LDL in rats treated with doxorubicin, a beneficial effect of lower dose of thyroxine on serum TG level was revealed.

Different effects of resveratrol on dose-related Doxorubicin-induced heart and liver toxicity.

The aim of the study was to evaluate the effect of resveratrol in doxorubicin-induced cardiac and hepatic toxicity. Doxorubicin was administered once a week throughout the period of 7 weeks with 1.0 or 2.0 mg/kg body weight or concomitantly with resveratrol (20 mg/kg of feed). Heart and liver toxicity was histologically and biochemically evaluated. Resveratrol protected from the heart lipid peroxidation caused by 1 mg doxorubicin and it sharply diminished superoxide dismutase activity. An insignificant effect of resveratrol on the lipid peroxidation level and the superoxide dismutase activity was observed in the hearts of rats administered a higher dose of doxorubicin. However, resveratrol attenuate necrosis and other cardiac histopathological changes were induced by a high dose of doxorubicin. Interestingly, it slightly intensified adverse cardiac histological changes in rats receiving a lower dose of doxorubicin. Resveratrol did not have any protective effect on the hepatic oxidative stress, while exerting a mild beneficial effect on the morphological changes caused by doxorubicin. All in all, this study has shown different effects of resveratrol on dose-related doxorubicin-induced heart and liver toxicity. Resveratrol may modulate the hepatic and cardiac effect of doxorubicin, depending on the drug dose.

Use of X-ray microprobe to diagnose bone tissue demineralization after caffeine administration.

Caffeine is a methylxanthine which permeates the placenta. In studies on animals, it has been shown to produce teratogenic and embryotoxic effects in large doses. The objective of this study was to assess the influence of caffeine on the development of bone tissue, with particular reference to elemental bone composition using an X-ray microprobe. The research was conducted on rats. The fertilized females were randomly divided into an experimental and a control group. The experimental group was given caffeine orally in 30 mg/day doses from the 8th to the 21st day of pregnancy, while the control group was given water. The fetuses were used to assess the growth and mineralization of the skeleton. On the basis of double dyeing, a qualitative analysis of the bone morphology and mineralization was conducted. For calcium and potassium analysis, an X-ray microprobe was used. In 67 fetuses from the experimental group, changes in skeleton staining with the alcian-alizarin method were noticed. The frequency of the development of variants in the experimental group was statistically higher. In the experimental group,a significant decrease in the calcium level, as well as an increase in the potassium level, was observed. The X-ray microprobe's undoubted advantage is that is offers a quick qualitative and quantitative analysis of the elemental composition of the examined samples. Employing this new technique may furnish us with new capabilities when investigating the essence of the pathology process.

Tirapazamine-doxorubicin interaction referring to heart oxidative stress and Ca²âº balance protein levels.

Doxorubicin (DOX) causes long-term cardiomyopathy that is dependent on oxidative stress and contractility disorders. Tirapazamine (TP), an experimental adjuvant drug, passes the same red-ox transformation as DOX. The aim of the study was to evaluate an effect of tirapazamine on oxidative stress, contractile protein level, and cardiomyocyte necrosis in rats administered doxorubicin. Rats were intraperitoneally injected six times once a week with tirapazamine in two doses, 5 (5TP) and 10 mg/kg (10TP), while doxorubicin was administered in dose 1.8 mg/kg (DOX). Subsequent two groups received both drugs simultaneously (5TP+DOX and 10TP+DOX). Tirapazamine reduced heart lipid peroxidation and normalised RyR2 protein level altered by doxorubicin. There were no significant changes in GSH/GSSG ratio, total glutathione, cTnI, AST, and SERCA2 level between DOX and TP+DOX groups. Cardiomyocyte necrosis was observed in groups 10TP and 10TP+DOX.

[Chemoprevention of oral cancer--clinical and experimental studies]. / Chemoprewencja nowotworów plaskonablonkowych jamy ustnej--badania kliniczne i doswiadczalne.

Chemoprevention is one of the cancer prevention methods, applied for the oral squamous cell carcinoma and its main precursor lesions--leukoplakia and erythroplakia. Presently, the most extensive clinically studied group used in such cases are retinoids: vitamin A (retinol), 13-cis-retinic acid (isotretinoin), N-(4-hydroxyphenyl)retinamide (fenretinide) and precursor of vitamin A--beta-carotene. However, despite good short-time effectiveness, retinoids do not prevent recurrences of the lesions and insignificantly increase cancer-free survival. Moreover, they are also characterized by relatively high toxicity. Vitamin E, Bowman-Birkprotease inhibitor, Spirulina fusiformis and green tee extracts as well as traditional Chinese herbs known as ZengShengPing were also found as effective agents. Lack of activity was reported for cyclooxygenase inhibitors--ketorolac and celecoxib. More promising data was collected from animal experimental studies with chemically induced oral squamous cell carcinoma. Chemopreventive activity was revealed for various agents including plant-derived compounds like resveratrol, green and black tee polyphenols, as well as protocatechuic, ellagic and caffeic acids.

[Coffee and caffeine - enemies or alliantes of a cardiologist?]. / Kawa i kofeina ­ wrogowie czy sprzymierzency kardiologa?

Caffeine is a widespread known psychoactive substance that is present mainly in coffee, tea, soft and energy drinks. As a natural methylopxanthine it blocks A1 and A2 adenosine receptors and in high doses inhibits the phosphodiesterase activity. Caffeine also decreases calcium ion accumulation in the mitochondria of cardiomyocytes. A clinical and experimental data indicates that the caffeine and coffee increase the arterial wall stiffness, blood pressure and endothelium-dependent flow mediated dilatation. Caffeine also elevates cholesterol and homocysteine blood level. Moderate coffee consumption decreases the mortality of the cardiac infarct. However, acceleration of acute ischemic cardiac disease correlates with high coffee intake. The metyloxantine easily crosses the blood-placenta barrier, and may induce intrauterine growth retardation. Due to chronotropic and inotropic activity it may induce fetal tachycardia and/or extrasystolic beats.

Skeletal developmental effects of selective and nonselective cyclooxygenase-2 inhibitors administered through organogenesis and fetogenesis in Wistar CRL:(WI)WUBR rats.

Cyclooxygenase (COX) inhibitors are the most commonly ingested drugs. The aim of the study was to evaluate the prenatal skeletal effect of selective (DFU) and nonselective (tolmetin, ibuprofen, piroxicam) COX-2 inhibitors. All the tested compounds were administered intragastrically to pregnant Wistar rats from 7 to 21 gestation day. The initial dose was set at 8.5mg/kg/dose for tolmetin and ibuprofen, 0.3 and 0.2mg/kg/dose for piroxicam and DFU. The middle dose was increased 10-times. The highest dose, except for ibuprofen, was elevated 100-times. The highest dose for ibuprofen was set at 200mg/kg/dose. Tolmetin and ibuprofen were administered three times a day. Piroxicam and DFU were dosed once daily. After routine teratological examinations, extremities of randomly selected 21-day-old fetuses were taken for histological, immunohistochemical and molecular studies. The proximal femoral epiphyses were separated and their ultrastructure evaluated. The expression of genes coding cytokines (IL-1alpha, IL-1beta, IL-6, TNF-alpha, TNF-beta) and proteins (COX-1, COX-2, cathepsin K, collagen types I, II and X; osteocalcin, osteopontin) was evaluated in femoral epiphyses by RNase Protection Assay and/or immunohistochemically. The articulate development was checked histologically and found undisturbed in any of the experimental groups. The epiphysis of the 21-day-old fetuses, presented physiological expression of COX-1 and COX-2, as well as cathepsin K, collagen types I, II and X; osteopontin, osteocalcin and TNF-alpha. Increased developmental skeletal variation was noted in groups exposed to the highest dose of nonselective drugs. Unlike the increased number of skeletal variations observed in fetuses exposed to highest doses of nonselective compounds, both groups of COX inhibitors did not disturb joint formation and morphology of femoral epiphyses when administered even in high maternal toxic doses.

A new rapid radiological procedure for routine teratological use in bone ossification assessment: a supplement for staining methods.

BACKGROUND: Presently, bone ossification is assessed by the study of single-stained fetal bones (alizarin red-S) or double-stained bones and cartilaginous structures (alcian blue followed by alizarin red-S). Both methods, especially double-staining, are labor-intensive, time-consuming, and provide qualitative information regarding skeleton ossification. Quantitative evaluation of ossification is more difficult and is usually based on determination of calcium and other minerals in the bone by means of atomic absorption spectrometry. Here we introduce a simple new method that allows quantitative determination of skeleton ossification before routine staining examination. METHODS: Fetuses delivered by laparotomy on the 16th and 21st day of gestation as well as 1-day-old rat pups were examined. The fetuses and pups were prenatally subcutaneously exposed to sodium valproate or to physiological saline. Lateral, prone, and supine digital radiograms of each fetus were taken using the Digora-Soredex digital radiography system and the Planmeca Intra intraoral X-ray machine. According to the best visualization, the data concerning vertebra were analyzed. All the fetuses were then routinely double-stained using alcian blue and alizarin red-S. RESULTS: Malformations of axial skeleton (rib, sternum, and thoracic and sacral vertebra) were found in valproate-treated groups. Unlike cartilage malformations, the bone changes were detected in similar frequency in radiological and staining methods. Differences in densities according to the degree of ossification in the vertebral arches and bodies at different levels of the vertebral column, between drug-treated and negative control groups were noted. CONCLUSIONS: The preliminary results suggest that digital radiography examination is a useful method in determining delaying of skeleton ossification not detectable by other methods. It balances qualitative and quantitative aspects of the presently used methods and is also simple, objective, fast, and relatively inexpensive.