Potential Role of L-Arginine and Vitamin E Against Bone Loss Induced by Nano-Zinc Oxide in Rats.

The purpose of this study was to illustrate the effects of zinc oxide nanoparticles (ZnO-NPs) administration on bone turnover and bone resorbing agents in rats and how L-arginine (L-arg) or vitamin E (vit E) co-administrations might affect them. Fasting rats were randomly divided into four groups (n = 10): G1-normal healthy animals; G2-ZnO-NPs-exposed rats (600 mg/kg-1/day-1); G3-ZnO-NPs-exposed rats co-administrated L-arg (200 mg/kg-1/day-1); G4-ZnO-NPs-exposed rats co-administrated vit E (200 mg/kg-1/day-1). The ingredients were orally administered daily. The body weight and food consumption of rats were recorded during the administration period and the experiment continued for three consecutive weeks. The results demonstrated that ZnO-NPs administration induced bone loss in rats as manifested by reduced activity of bone alkaline phosphatase (B-ALP) and increased level of C-terminal peptide type I collagen (CTx). The increase of inflammatory markers, tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) by ZnO-NPs suggests that deleterious effects of ZnO-NPs on bone turnover were, in part, due to inflammation. Confirming to this suggestion, both L-arg and vit E reduced TNF-α and IL-6 levels and consequently decreased bone resorption as indicated by reduced serum CTx level. This study proved that ZnO-NPs can induce bone turnover, which may be reduced by L-arg or vit.E co-administration, partly by anti-inflammatory mechanism.

[Changes in the plasma concentration of vitamin A, vitamin E and beta-carotene in polytrauma patients and in patients with osteitis in relation to course of illness]. / Veränderungen in der Plasmakonzentration von Vitamin A, Vitamin E und beta-Karotin bei Polytraumatisierten und Patienten mit Osteitis in Abhängigkeit vom Krankheitsverlauf.

In 17 patients with osteitis and 16 polytraumatized patients changes in the plasma levels of vitamin A, vitamin E and beta-carotene were investigated. Plasma samples taken preoperatively, daily during the first three days and then twice a week postoperatively were analysed for fat-soluble vitamins by high performance liquid chromatography (HPLC). Significant changes in plasma levels of all three components depending on the outcome of injury were found in all patients. Increased levels were observed in patients that survived the injury, while in those who died a significant decrease was observed. Recommendations regarding the supplementation with these vitamins in clinical practice can not be made based on these results, but substitute might prove beneficial for vitamin E in certain types of injury.

[Resorbable antibiotic delivery systems in local treatment of chronic osteitis--polyglycolic acid/poly-L-lactide as drug carrier. Experimental studies in vitro]. / Resorbierbare Antibiotikumträger zur lokalen Behandlung der chronischen Osteitis--Polyglykolsäure/Poly-L-Laktid als Träger. Experimentelle Untersuchungen in vitro.

Resorbable polyglycolic acid (PGA)- and poly-L-lactic acid (PLLA) cylinders were investigated in vitro to explore their properties as an antibiotic deposit (Ciprobay, Bayer Leverkusen) with prolonged release. PGA cylinders sized 3.2 x 5 mm, 4.5 x 5 mm and 4.5 x 7 mm respectively were shaped in monofil and polyfil technique. The Ciprofloxacin concentration varied from 0.5 mg to 5.0 mg of each cylinder. The cylinders were eluated in phosphate buffer, pH-value of 7.4, at 37 degrees C. The daily antibiotic release was measured by high performance liquid chromatography. Best combinations we could find demonstrated an initial delivery of Ciprofloxacin in vitro of 67 mg/l. The average daily release was about 16 mg/l during the first 36 days. After complete hydrolysis of the PGA carriers the recovery of Ciprofloxacin reached up to 6.5% and 11.6% respectively. For 40 bioactive cylinders (size phi 3.5 mm x 5 mm, containing 4 mg Ciprofloxacin) were eluated with phosphate buffer (pH 7.4 at 37 degrees C) respectively fresh human blood plasma and tested under various conditions. A gentamicin-polymethylmetacrylate (PMMA) chain (Septopal, E. Merck, Darmstadt) was exposed to equal test conditions for comparison. The quantities of released Ciprofloxacin and Gentamicin were analysed by a microbiological method (bioassay). Initially released rates of Ciprofloxacin were measured very high (up to 180 mg/l) but decreased rapidly within the first 5 days (4.2-22.5 mg/l). The release of Gentamicin produces an initial sharp decrease in concentration during the first 3 days (from 227.5 mg/l to 77.5 mg/l); this is then followed by an almost constant release over a long period of time (about 20 mg/l).(ABSTRACT TRUNCATED AT 250 WORDS)