Sonja Ilić

Morphological and morphometric study of protective effect of green tea in gentamicin-induced nephrotoxicity in rats.

AIMS One of the most popular beverages worldwide, green tea, was investigated for its potential protective effect in a rat model of gentamicin-induced nephrotoxicity by monitoring functional and morphological changes in kidneys. MAIN METHODS The study was conducted on four groups of rats: control group (C), treated with only gentamicin (GM), treated with only green tea (GT) and treated with both gentamicin and green tea (GT+GM). Kidney function, oxidant and antioxidant parameters of renal tissue, as well as histopathological studies were assessed. Morphometric analysis was used to quantify these histopathological changes. KEY FINDINGS Gentamicin caused significant elevations in serum creatinine and urea and oxidative stress parameter (AOPP), while antioxidative enzyme catalase was significantly decreased. Histological sections of kidneys in GM group revealed necrosis of proximal tubules, vacuolation of cytoplasm and massive mononuclear inflammatory infiltrates in interstitium. Coadministration of green tea with gentamicin histologically showed renoprotective effect. Histological results were confirmed and quantified by morphometric analysis. Also in this group we measured ameliorated parameters of renal functions and antioxidative defense. SIGNIFICANCE Regenerative potential of green tea after renal injury induced by gentamicin could be explained through the decrease of oxidative stress and lipid peroxidation. Green tea is a natural antioxidant, with many health promoting effects, widely available and in accordance to that affordable. Because of the established habits, people largely consume it as a beverage. It could be beneficial in the reduction of oxidative stress and changes caused by it primarily in renal tubules and interstitium.

Beneficial effects of calcium oral coadministration in gentamicin-induced nephrotoxicity in rats.

Abstract Frequent therapeutical use of an aminoglycoside antibiotic gentamicin (GM) is limited by its nephrotoxic effects often characterized by both morphological and functional alterations of kidney leading to acute renal failure. The aim of this study was to examine the effect of dietary calcium supplementation on GM-induced nephrotoxicity in rats. Experiments were performed on 30 adult male Wistar rats divided into three groups of 10 animals each. G-group received GM intraperitoneally at a dose of 100 mg/kg; GCa-group received the same dose of GM concomitantly with 1 g/kg calcium carbonate given orally; and C-group, serving as control, received 1 mL/day of normal saline. All groups were treated during 8 consecutive days. Quantitative evaluation of GM-induced structural and functional changes of kidney was performed by histopathological, morphometrical, and biochemical analyses. Compared with control, G-group of rats were found to have diffusely and unequally thickened glomerular basement membrane with neutrophil cells infiltration. In addition, vacuolization of cytoplasm of proximal tubule cells with coagulation-type necrosis was observed. These GM-induced pathological lesions were significantly reduced in the rats of GCa-group. Morphometric analysis revealed statistically significant differences in the size of glomeruli (area, major and minor axes, perimeter), optical density, and roundness of glomeruli (p < 0.05) between G and GCa groups. Biochemical analysis showed significant elevation in blood urea and serum creatinine concentrations, whereas potassium concentration was lowered in G-group compared with the other groups (p < 0.01). It is concluded that oral supplementation of calcium during treatment with GM resulted in significant reduction of morphological and functional kidney alterations.

Bilberry: Chemical Profiling, in Vitro and in Vivo Antioxidant Activity and Nephroprotective Effect against Gentamicin Toxicity in Rats

We assessed possible protective effect of bilberry diet in rat model of nephrotoxicity. In vivo and in vitro antioxidant activity and chemical profiling of this functional food was performed. With aid of HPLC‐DAD and spectrophotometric method, 15 individual anthocyanins were quantified alongside total tannin, phenylpropanoid, and anthocyanin content. The study was conducted on four groups of rats: control, treated with only gentamicin, treated with only bilberry, and treated with both gentamicin and bilberry. Kidney function was evaluated by tracking urea and creatinine. Morphology of renal tissue and its changes were recorded pathohistologically and quantified morphometrically. Bilberry (100 mg/kg daily) showed strong nephroprotective effect against gentamicin toxicity in rats (as shown through MDA, AOPP, and catalase levels). In conclusion, the demonstrated protective activity of bilberry extract matched well with the assessed in vivo and in vitro antioxidant activity as well as with its polyphenolic content, particularly with high anthocyanin levels. Copyright

The Encapsulation of Lycopene in Nanoliposomes Enhances Its Protective Potential in Methotrexate-Induced Kidney Injury Model

Methotrexate is an antimetabolic drug with a myriad of serious side effects including nephrotoxicity, which presumably occurs due to oxidative tissue damage. Here, we evaluated the potential protective effect of lycopene, a potent antioxidant carotenoid, given in two different pharmaceutical forms in methotrexate-induced kidney damage in rats. Serum biochemical (urea and creatinine) and tissue oxidative damage markers and histopathological kidney changes were evaluated after systemic administration of both lycopene dissolved in corn oil and lycopene encapsulated in nanoliposomes. Similar to previous studies, single dose of methotrexate induced severe functional and morphological alterations of kidneys with cell desquamation, tubular vacuolation, and focal necrosis, which were followed by serum urea and creatinine increase and disturbances of tissue antioxidant status. Application of both forms of lycopene concomitantly with methotrexate ameliorated changes in serum urea and creatinine and oxidative damage markers and markedly reversed structural changes of kidney tissue. Moreover, animals that received lycopene in nanoliposome-encapsulated form showed higher degree of recovery than those treated with free lycopene form. The findings of this study indicate that treatment with nanoliposome-encapsulated lycopene comparing to lycopene in standard vehicle has an advantage as it more efficiently reduces methotrexate-induced kidney dysfunction.

The association of smartphone usage with subjective sleep quality and daytime sleepiness among medical students

ABSTRACT About a third of adults have sleep problems, while in the student population this number is much higher due to a specific lifestyle. It has been shown that the use of devices with light-emitting diode screens before sleep adversely affects sleep, sleeping and circadian rhythm in respondents. The aim of this study was to assess subjective sleep quality and level of daytime sleepiness among medical students, as well as the correlation of these parameters with the smartphone usage time. Smartphone usage time was determined using the Android Application Quality Time. A statistically significant and strong positive (r = 0.613) correlation between subjective sleep quality and the use of mobile phones has been determined. By correlation analysis of daytime sleepiness and the use of mobile phones, it was found that there was a medium strong negative (r = -0.23) correlation between these parameters, which was not statistically significant. The results of this study have shown that the subjective quality of sleep is significantly impaired and of poor quality; and a significant correlation between the use of mobile phones and the quality of sleep has been demonstrated.

Effects of coenzyme Q 10 encapsulated in nanoliposomes on wound healing processes after tooth extraction

Background/purpose Tooth extraction is often followed by a number of different complications that demand additional treatment. In order to accelerate healing processes and decrease the complication occurrence various agents, growth factors, natural and synthetic antioxidants (e.g coenzyme Q10-CoQ10), are applied. Due to the partially known health-promoting effects of CoQ10 we decided to assess potential of its encapsulated in nanoliposomes form on wound healing process following tooth extraction. Materials and methods Effects of free and encapsulated form of CoQ10 on wound healing processes after tooth extraction in rats, 3 and 7 days following surgical procedure, was studied by means of tissue biochemical (myeloperoxidase activity and nitric oxide (NO) concentrations) and pathohistological analysis. Results The obtained results indicate that the encapsulated form of CoQ10 compared to control and CoQ10 treated animals statistically significantly decreases inflammatory process estimated through myeloperoxidase activity and NO concentrations, as well as based on histopathological analysis 3 and 7 days following surgery. Conclusion The results of this study unequivocally prove that the encapsulation of CoQ10 in nanoliposomes enhances CoQ10 activity by accelerating wound healing process after tooth extraction.

Beneficial Effects of Green Tea Extract in Gentamicin-Induced Acute Renal Failure in Rats / Povoljni efekti ekstrakta zelenog čaja na akutnu bubrežnu insuficijenciju uzrokovanu gentamicinom kod pacova

Summary The aim of this study was to investigate whether green tea extract has beneficial effect on gentamicin-induced acute renal failure. The investigation was conducted on thirty-two Wistar rats divided into four groups of 8 animals each. Control (C) group received normal saline. GT group received green tea extract orally, 300mg/kg. GM group received gentamicin intraperitoneally, 100mg/kg and GT+GM group received both gentamicin and green tea extract. Histological sections of kidney in GM group revealed necrosis of proximal tubules, vacuolization of cytoplasm and massive mononuclear inflammatory infiltrates in interstitium. Coadministration of green tea with gentamicin had renoprotective effect and showed only mild infiltrations, normal glomeruli and alleviated tubular degeneration. Analysis of biochemical parameters showed significantly higher urea and creatinine serum concentrations in GM group in comparison with C group and GT+GM group (p<0.001). Plasma lipid peroxidation biomarker MDA was significantly higher in GM group than those in C group (p<0.001), whereas the values for GT+GM group were significantly lower than MDA recorded for GM group (p<0.001). Beneficial effects of green tea on gentamicin-induced nephrotoxicity is explained through decrease of oxidative stress and lipid peroxidation.Our results indicate that green tea administration has nephroprotective effect on oxidative stress and acute renal failure caused by gentamicin. Sažetak Cilj našeg istraživanja bio je da ispitamo efekat zelenog čaja na akutnu bubrežnu insuficijenciju uzrokovanu gentamicinom. Istraživanje smo sproveli na trideset dva pacova Wistar soja koje smo podelili u četiri grupe od po 8 životinja. Kontrolna (C) grupa primala je fiziološki rastvor. GT grupa je primala oralno ekstrakt zelenog čaja u dozi od 300 mg/kg. GM grupa primala je gentamicin intraperitonealno u dozi od 100 mg/kg, a GT+GM grupa primala je zajedno gentamicin i ekstrakt zelenog čaja. Histološki preparati bubrega pacova GM grupe pokazali su nekrozu proksimalnih tubula, vakuolizaciju citoplazme i masivni mononuklearni zapaljenski infiltrat u intersticijumu. Istovremena primena zelenog čaja sa gentamicinom imala je renoprotektivni efekat i pokazala samo blage infiltrate, normalne glomerule i smanjenu degeneraciju tubula. Analiza biohemijskih parametara pokazala je statistički značajno povećanje koncentracije uree i kreatinina u GM grupi, u poređenju sa C grupom i GT+GM grupom (p<0,001). Biomarker lipidne peroksidacije u plazmi MDA bio je značajno viši u GM grupi u odnosu na C grupu (p<0,001), dok su njegove vrednosti u GT+GM grupi bile značajno niže u poređenju sa GM grupom (p<0,001). Korisni efekti zelenog čaja na gentamicinom uzrokovanu nefrotoksičnost mogu se objasniti smanjenjem oksidativnog stresa i lipidne peroksidacije. Naši rezultati ukazuju da primena zelenog čaja ima protektivni efekat na oksidativni stres i akutnu bubrežnu insuficijenciju uzrokovanu gentamicinom.