Mohammed S. Al-Ayed

Effects of naked gold nanoparticles on proinflammatory cytokines mRNA expression in rat liver and kidney.

The data on the biocompatibility of naked gold nanoparticles (GNPs) are scarce, and their interpretation is controversial. We studied the acute (1 day) and subchronic (5 days) effects of GNPs (10 and 50 nm diameter) on expression of interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) in the liver and kidneys of rats. In the liver, the GNPs of both sizes (10 and 50 nm) significantly increased the cytokines gene expression on day 1 which was subsided on day 5; the GNPs of 50 nm size produced more severe inflammatory response as compared to smaller sized GNPs. In the kidney, the GNPs did not produce any significant change in the expression of IL-1β. Although the gene expression of IL-6 and TNF-α was not affected by GNPs of 10 nm size, 50 nm GNPs significantly increased the expression of IL-6 and TNF-α in the kidneys of rats on day 1 after treatment which returned to normalcy on day 5. These findings indicate the possible immunocompatibility of medium sized GNPs as they caused only a transient acute phase increase in proinflammatory cytokines expression followed by their normalcy during the repeated exposure.

The changes in various hydroxyproline fractions in aortic tissue of rabbits are closely related to the progression of atherosclerosis

BackgroundThe most important function of collagen and elastin is to induce several mechanical parameters which are known to play a dominant role in governing mechanical properties of the blood vessels. The aortic tissue of rabbit is one of the important sources of collagen and elastin. The effects of high fat diet (HFD) on the hydroxyproline (Hyp) fractions in serum and aortic tissues of rabbits and collagen content in the aortic tissues of rabbits have not been documented before. The present study was undertaken to investigate the changes in Hyp fractions in serum and aortic tissues of rabbits and collagen content in the aortic tissues of rabbits during the progression of atherosclerosis. The atherosclerotic model used in this study was the New Zealand white rabbit (male; 12 weeks old). Twenty five rabbits were individually caged, and divided into control group (NOR; n = 10) and HFD group (CHO; n = 15). The control group was fed (100 g/day) of normal (NOR) diet for a period of 15 weeks. The HFD group was fed normal diet supplemented with 1.0% cholesterol plus 1.0% olive oil (100 g/day) for the same period of time.ResultsWe found that the TC, LDLC, and TG (mg/dl) were significantly (p < 0.001) increased in HFD rabbits compared with control rabbits with percentage normalized changes of 1198%, 1591%, and 710%, respectively. The peptide-bound Hyp in the serum was significantly (P < 0.05) increased in HFD rabbits compared with control rabbits with percentage normalized change of 517% while it significantly (P < 0.01) decreased in aortic tissues of HFD rabbits compared with control rabbits with percentage normalized change of 65%. The protein-bound Hyp in the serum was significantly (P < 0.01) increased in HFD rabbits compared with control rabbits with percentage normalized change of 100%; the protein-bound Hyp in the aortic tissues of control rabbits was 235.30 ± 55.14 (Mean ± SD) while it was not detectable (ND) in HFD rabbits. Total serum Hyp showed no significant (P < 0.05) change in HFD rabbits compared with control rabbits while it was significantly (P < 0.05) decreased in aortic tissues of HFD rabbits compared with control rabbits with percentage normalized change of 73%. The total collagen was significantly (p < 0.01) decreased in aortic tissues of HFD rabbits compared with control rabbits with percentage normalized change of 73% which was supported by histological study.ConclusionsThese results suggest that percentage decrease in various Hyp fractions in aortic tissue of HFD rabbits are closely related to percentage decrease of collagen content in aortic tissues of HFD rabbits. These results also suggest that it may be possible to use the changes in various Hyp fractions in aortic tissues of rabbits as an important risk factor during the progression of atherosclerosis.

Absorption optical density as a diagnostic tool for indicating the toxicity of gold nanoparticles

Nanotechnology has recently emerged as a promising approach for treatment and diagnosis of a variety of diseases. The aim of this study was to evaluate the blood absorption spectra to assess bioaccumulation and toxic effects of 100 µl of 10 and 50 nm gold nanoparticles (GNPs) upon intraperitoneal administration in rats for periods of three and seven days. Healthy 30 male Wistar-Kyoto rats were individually caged and divided into control group (NG: n = 10), group 1 (A: infusion of 10 nm GNPs for three days; n = 5; B: infusion of 10 nm GNPs for seven days; n = 5) and group 2 (A: infusion of 50 nm GNPs for three days; n = 5; B: infusion of 50 nm GNPs for seven days; n = 5). Dose of 100 µl of 10 and 50 nm GNPs were administered intraperitonealy to the animals. The blood absorbance peaks for G1A, G1B, G2A and G2B significantly decreased compared with the control. The blood absorbance peaks for G1A significantly decreased compared with G1B; and G2A significantly decreased compared with G2B. This implies that G1A is highly reactive than G1B, and G2A is highly reactive than G2B. A significant decrease (p<0.05) in all blood absorbance peaks observed by the administration of 10 and 50 nm GNPs for periods of three and seven days compared with the control. For the same GNPs size, the accumulation of GNPs in the blood after the administration of GNPs for three days was greater than that for seven days. In addition to non-significant blood absorbance peak differences were observed with the different GNP sizes for the same period of administration of GNPs. This study suggests that the 10 nm GNPs are mostly up taken and accumulated by tissues which support the toxic effects of the smaller GNPs by tissues. However, the 50 nm GNPs are and highly accumulated in blood, suggesting the toxic effects of the larger GNPs by blood. Thus, the absorption optical density can be considered as a diagnostic tool indicating the bioaccumulation and toxicity effects of GNPs in the tissues of rats.

Effects of feeding periods of high cholesterol and saturated fat diet on blood biochemistry and hydroxyproline fractions in rabbits.

Hypercholesterolemia and hypertriglyceridemia are considered as important risk factors during the atherosclerotic process. The aim of the present investigation was to study the total cholesterol (TC), low-density lipoprotein cholesterol (LDLC), high density lipoprotein (HDL), triglyceride (TG), platelet levels and hydroxyproline fractions during the pathogenesis of atherosclerosis. For this purpose, twenty five 12-weeks, New Zealand white male rabbits, were purchased, individually caged, and divided into either control group or cholesterol-fed group. The control group (n = 10) was fed 100 g/day of normal diet, ORC-4 (Oriental Yeast Co. Ltd., Tokyo, Japan) for a period of 15 weeks. The cholesterol-fed group (n = 15) was fed a high cholesterol and saturated fat diet of ORC-4 containing 1% cholesterol plus 1% olive oil (100 g/day) for periods of 5 (group 1), 10 (group 2) and 15 (group 3) weeks. Blood sample from each animal was taken at the end of the experimental period for the biochemical analysis. The results of the present study showed that TC, LDLC, TG, HDLC and platelets were significantly (P < 0.01) increased in cholesterol-fed rabbits as compared with control rabbits. The serum hydroxyproline (Hyp) in rabbits belonging to group 1 showed no significant alteration when compared to control group. Group 2 rabbits showed a significant increase of 103% (P < 0.01) and 100% (P < 0.001) in free and protein—bound hydroxyproline fractions respectively when compared to control rabbits. However, there was no significant change in peptide—bound and total serum hydroxyproline levels as compared to the control group (P > 0.05). There was no significant (P > 0.05) decrease of free serum hydroxyproline in group 3 rabbits when compared to control rabbits. On the other hand, group 3 rabbits showed a significant increase in peptide-bound and protein- bound Hyp by 517% (P < 0.05) and 100% (P < 0.01) respectively when compared to control rabbits. However, total serum Hyp in group 3 rabbits showed no significant (P > 0.05) change when compared to control rabbits. These results suggest that feeding rabbits high cholesterol and saturated fat diet for feeding periods of 5, 10 and 15 weeks induced significant change in TC, LDLC, HDL, TG, platelet levels and various Hyp fractions in serum without any significant change in the total Hyp content.

Effect of melanin on gold nanoparticle-induced hepatotoxicity and lipid peroxidation in rats

Introduction Melanin pigments are produced by melanocytes and are believed to act as antioxidants based on the belief that melanin can suppress electronically stirred states and scavenge the free radicals. Materials and methods The study was aimed to verify and prove the toxicity induced by administration of gold nanoparticles (GNPs) and to characterize the role of melanin as an antioxidant against inflammatory liver damage, oxidative stress, and lipid peroxidation induced intraperitoneally by GNPs in vivo. Results The findings from this study confirmed that administration of GNPs intraperitoneally caused liver damage in addition to producing oxidative stress and fatty acid peroxidation. The treatment of rats with melanin along with GNPs induced dramatic changes in all the measured biochemical parameters. Our data demonstrated that melanin completely inhibited inflammatory liver damage, oxidative stress, and lipid peroxidation, which was confirmed by the histological investigation of different liver sections stained by H&E. Conclusion These results suggest the beneficial use of melanin together with GNPs for alleviating its toxicity. Other studies should be implemented taking into consideration the role of melanin in comparison with other natural antioxidants.

Synthesizing new glass 40P2O5 – 50BaO - 2.5Na2O – 2.5MgO - 5TiO2 for the application in high radiation environmental dosimetry

This paper aimed to present the thermoluminescence (TL) characteristics of phosphorus pentoxide (P2O5) nanopowders as a glass former, modified with barium oxide (BaO) glass, the mixture was activated with titanium oxide (TiO2), and then co-activated with magnesium oxide (MgO) and sodium oxide (NaO). The glass was arranged into five different samples depending on the activator concentration and co-activator with the glass matrix 40 P2O5 - 50 BaO. The sample glass 40P2O5 – 50BaO - 2.5Na2O – 2.5MgO - 5TiO2 confirmed and proved the following properties: simple, reasonable, modest way of synthesis, losing nearly about 18.57% from its TL information in 10 days, apparent glow curve shape, linear response, less fading, and high Zeff value. Thus, this new formed kind of glass might play a crucial role especially in the field of high radiation environmental dosimetry.This paper aimed to present the thermoluminescence (TL) characteristics of phosphorus pentoxide (P2O5) nanopowders as a glass former, modified with barium oxide (BaO) glass, the mixture was activated with titanium oxide (TiO2), and then co-activated with magnesium oxide (MgO) and sodium oxide (NaO). The glass was arranged into five different samples depending on the activator concentration and co-activator with the glass matrix 40 P2O5 - 50 BaO. The sample glass 40P2O5 – 50BaO - 2.5Na2O – 2.5MgO - 5TiO2 confirmed and proved the following properties: simple, reasonable, modest way of synthesis, losing nearly about 18.57% from its TL information in 10 days, apparent glow curve shape, linear response, less fading, and high Zeff value. Thus, this new formed kind of glass might play a crucial role especially in the field of high radiation environmental dosimetry.