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

Abstract

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/kg1/day); G3-ZnO-NPs-exposed rats co-administrated L-arg (200 mg/kg1/day); G4-ZnO-NPs-exposed rats co-administrated vit E (200 mg/kg1/day). 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.

<p>Oral Exposure to ZnO Nanoparticles Disrupt the Structure of Bone in Young Rats via the OPG/RANK/RANKL/IGF-1 Pathway</p>

“…However, Abdelkarem et al reported that serum levels of Ca and P did not significantly differ when rats were dosed with 600 mg/kg ZnO NPs for 5 days by oral administration. 10 Herein, we found that increasing the duration of administration may increase the possibility of damage to the bone tissue. Thus, we believe that ZnO NPs disrupt the balance of bone metabolism and promote osteoclast activity.…”

“…In China, each child whose height is two standard deviations less than the mean height of children of the same sex, age, and race are considered to have a short stature. 10 The age-standardized prevalence of short stature is 3.70% in China. 11 A number of studies have found that short stature may affect the physical and mental health of children, especially boys.…”

<p>Enhancing ZnO-NP Antibacterial and Osteogenesis Properties in Orthopedic Applications: A Review</p>

“…13,14 NPs are widely applied in industry, cosmetics, and food products. 15,16 As a trace element, zinc participates in various metabolic processes. A substantial proportion of zinc (~30%) is stored in bone, and the pathological reduction of zinc levels impairs bone growth.…”

Osteoporosis: Current and Emerging Therapies Targeted to Immunological Checkpoints

“…The bone protecting effects of vitamin D are well known, but also other compounds, such as vitamin C, B12 and folates seem to exert beneficial anti-inflammatory and metabolic effects on bone health. Both L-arginine and vitamin E coadministration reduces TNF-α and IL-6 levels induced by zinc oxide nanoparticle administration in rats, counteract its deleterious effects on bone turn over [ 84 ]. Tart cherry (Prunus cerasus), a fruit rich in polyphenols, such as flavonols, hydroxycinnamic acids, proanthocyanidins and anthocyanidins, has been reported to display antioxidant and anti-inflammatory properties and could be used as a supplement to prevent inflammation-mediated bone loss in TNF-overexpressing transgenic mice [ 85 ].…”