Numerous studies have shown that acute particulate air pollution exposure is linked with pulmonary adverse effects, including alterations of pulmonary function, inflammation, and oxidative stress. Nootkatone, a constituent of grapefruit, has antioxidant and anti-inflammatory effects. However, the effect of nootkatone on lung toxicity has not been reported so far. In this study we evaluated the possible protective effects of nootkatone on diesel exhaust particles (DEP)-induced lung toxicity, and the possible mechanisms underlying these effects. Mice were intratracheally (i.t.) instilled with either DEP (30 µg/mouse) or saline (control). Nootkatone was given to mice by gavage, 1 h before i.t. instillation, with either DEP or saline. Twenty-four hours following DEP exposure, several physiological and biochemical endpoints were assessed. Nootkatone pretreatment significantly prevented the DEP-induced increase in airway resistance in vivo, decreased neutrophil infiltration in bronchoalveolar lavage fluid, and abated macrophage and neutrophil infiltration in the lung interstitium, assessed by histolopathology. Moreover, DEP caused a significant increase in lung concentrations of 8-isoprostane and tumor necrosis factor α, and decreased the reduced glutathione concentration and total nitric oxide activity. These actions were all significantly alleviated by nootkatone pretreatment. Similarly, nootkatone prevented DEP-induced DNA damage and prevented the proteolytic cleavage of caspase-3. Moreover, nootkatone inhibited nuclear factor-kappaB (NF-κB) induced by DEP. We conclude that nootkatone prevented the DEP-induced increase in airway resistance, lung inflammation, oxidative stress, and the subsequent DNA damage and apoptosis through a mechanism involving inhibition of NF-κB activation. Nootkatone could possibly be considered a beneficial protective agent against air pollution-induced respiratory adverse effects.

Synthetic bone graft substitutes have attracted increasing attention in tissue engineering. This study aimed to fabricate a novel, bioactive, porous scaffold that can be used as a bone substitute. Strontium and zinc doped nano-hydroxyapatite (Sr/Zn n-HAp) were synthesized by a water-based sol-gel technique. Sr/Zn n-HAp and poly (lactide-co-glycolide) (PLGA) were used to fabricate composite scaffolds by supercritical carbon dioxide technique. FTIR, XRD, TEM, SEM, and TGA were used to characterize Sr/Zn n-HAp and the composite scaffolds. The synthesized scaffolds were adequately porous with an average pore size range between 189 to 406 µm. The scaffolds demonstrated bioactive behavior by forming crystals when immersed in the simulated body fluid. The scaffolds after immersing in Tris/HCl buffer increased the pH value of the medium, establishing their favorable biodegradable behavior. ICP-MS study for the scaffolds detected the presence of Sr, Ca, and Zn ions in the SBF within the first week, which would augment osseointegration if implanted in the body. nHAp and their composites (PLGA-nHAp) showed ultimate compressive strength ranging between 0.4–19.8 MPa. A 2.5% Sr/Zn substituted nHAp-PLGA composite showed a compressive behavior resembling that of cancellous bone indicating it as a good candidate for cancellous bone substitute.

Pulmonary exposure to cerium oxide nanoparticles (CeO₂ NPs) can occur either at the workplace, or due to their release in the environment. Inhaled CeO₂ NPs are known to cross the alveolar–capillary barrier and reach various parts of the body, including the vasculature. The anticancer drug cisplatin (CP) causes vascular damage. However, the effects CeO₂ NPs on vascular homeostasis in a rat model of CP-induced vascular injury remain unclear. Here, we assessed the impact and underlying mechanism of pulmonary exposure to CeO₂ NPs on aorta in rats given a single intraperitoneal injection of cisplatin (CP, 6 mg/kg) to induce vascular damage. Six days later, the rats were intratracheally instilled with either CeO₂ NPs (1 mg/kg) or saline (control), and various variables were studied 24 h thereafter in the aortic tissue. The concentration of reduced glutathione and the activity of catalase were significantly increased in the CP + CeO₂ NPs group compared with both the CP + saline and the CeO₂ NPs groups. The activity of superoxide dismutase was significantly decreased in the CP + CeO₂ NPs group compared with both the CP + saline and CeO₂ NPs groups. The expression of nuclear factor erythroid-derived 2-like 2 (Nrf2) by the nuclei of smooth muscles and endocardial cells assessed by immunohistochemistry was significantly augmented in CeO₂ NPs versus saline, in CP + saline versus saline, and in CP + CeO₂ NPs versus CeO₂ NPs. Moreover, the concentrations of total nitric oxide, lipid peroxidation and 8-hydroxy-2-deoxyguanosine were significantly elevated in the CP + CeO₂ NPs group compared with both the CP + saline and the CeO₂ NPs groups. Similarly, compared with both the CP + saline and CeO₂ NPs groups, the combination of CP and CeO₂ NPs significantly elevated the concentrations of interleukin-6 and tumour necrosis factor-α. Additionally, aortic DNA damage assessed by Comet assay was significantly increased in CeO₂ NPs compared with saline, and in CP + saline versus saline, and all these effects were significantly aggravated by the combination of CP and CeO₂ NPs. We conclude that pulmonary exposure to CeO₂ NPs aggravates vascular toxicity in animal model of vascular injury through mechanisms involving oxidative stress, Nrf2 expression, inflammation and DNA damage.

Background/Aims: It has been shown, both experimentally and clinically, that water-pipe smoke (WPS) exposure adversely affects the cardiovascular system (CVS) through the generation of oxidative stress and inflammation. Betaine, a naturally occurring compound in common foods, has antioxidant and anti-inflammatory actions. However, its potential to mitigate the adverse effect of WPS on the CVS has never been reported before. This is the subject of this study in mice. Methods: Mice were exposed daily for 30 min to either normal air (control), or to WPS for two consecutive weeks. Betaine was administered daily by gavage at a dose of 10mg/kg, 1h before either air or WPS exposure. Results: Betaine mitigated the in vivo prothrombotic effect of WPS in pial arterioles and venules. Moreover, it reversed the WPS-induced decrease in circulating platelets. Likewise, betaine alleviated platelet aggregation in vitro, and the shortening of activated partial thromboplastin time and prothrombin time induced by WPS. Betaine reduced the increase of plasminogen activator inhibitor-1 and fibrinogen concentrations in plasma induced by WPS. Betaine also diminished the WPS-induced increase of plasma concentrations of interleukin 6 and tumor necrosis factor α, and attenuated the increase of lipid peroxidation and superoxide dismutase. Immunohistochemical analysis of the heart revealed an increase in the expression of inducible nitric oxide synthase and cytochrome C by cardiomyocytes of the WPS-exposed mice. These effects were averted by betaine. Conclusion: Our findings suggest that betaine treatment significantly mitigated WPS-induced hypercoagulability, and inflammation, as well as systemic and cardiac oxidative stress.

Background/Aims: Epidemiologically, diabetics are more prone to the adverse health effects of particulate air pollution than healthy individuals. We recently demonstrated an increased cardiovascular and respiratory susceptibility to diesel exhaust particles (DEP) in mice with type 1 diabetes. However, the pancreatic effects of DEP in healthy and diabetic mice are unknown. Methods: Presently, we evaluated the pancreatic impact of DEP in healthy mice, and mice with streptozotocin-induced type 1 diabetes. Four weeks following induction of diabetes, mice were intratracheally instilled (i.t.) with either DEP (0.4 mg/kg) or saline, and several histological and biochemical endpoints were measured 24 h thereafter. Results: Neither the histology nor the stain for apoptosis in the pancreatic islets and exocrine glands were affected by DEP. In diabetic mice exposed to saline, the islet cells showed cellular vacuolation and apoptotic islet cells (71.6 ± 2.6%). In diabetic mice exposed to DEP, a more marked decrease in the size and number of islet cells with cellular vacuolation along with a significant increase of apoptotic islet cells (79.1 ± 1.7 %, P<0.05) were observed. In diabetic mice, DEP increased significantly pancreatic amylase activity and markers of oxidative stress including 8-isoprostane, superoxide dismutase and reduced glutathione compared with either diabetic mice exposed to saline or non-diabetic mice exposed to DEP. Staining for inducible nitric oxide synthase (iNOS) in healthy mice exposed to either saline or DEP showed no staining in either pancreatic islets cells or acini. In saline-treated diabetic mice, a mild cytoplasmic staining for iNOS in some pancreatic islet cells was observed. Notably, in diabetic mice exposed to DEP, a marked cytoplasmic staining for iNOS in most pancreatic islet cells and some acinar cells was seen. Conclusion: We conclude that DEP caused detrimental effects on the pancreas of diabetic mice, and that oxidative stress is responsible, at least partially, for the observed effects

The consumption of water-pipe smoking (WPS) has been promoted by the use of flavoured tobacco. However, little is known about the impact of flavouring on the cardiovascular toxicity induced by WPS inhalation. Here, we compared the cardiovascular effects and underlying mechanism of actions of plain (P) (unflavoured) versus apple-flavoured (AF) WPS (30 minutes/day, 5 days/week for 1 month) in mice. Control mice were exposed to air. Both P- and AF-WPS inhalation induced an increase in systolic blood pressure, thrombogenicity and plasma concentration of fibrinogen and von Willebrand factor. In heart homogenates, AF-WPS inhalation caused an increase of 8-isoprostane and a decrease in the levels of reduced glutathione (GSH) and superoxide dismutase (SOD). Nevertheless, P-WPS decreased only the activity of SOD. The concentrations of tumour necrosis factor α and interleukin 1β were increased only in heart homogenates of mice exposed to AF-WPS. Although both P- and AF-WPS increased the concentration of troponin I in heart homogenates and induced DNA damage, the concentration of cleaved caspase 3 was only increased in mice exposed to AF-WPS. Immunohistochemical analysis of the hearts showed that both P- and AF- WPS inhalation decreased the expression of SOD. Moreover, the expression of nuclear factor erythroid-derived 2-like 2 at nuclear level in the heart was higher in both AF-WPS and P-WPS compared with control group, and the effect observed in AF-WPS group was more significant than that seen in P-WPS group. Likewise, the concentration of heme oxygenase-1 was significantly increased in both P-WPS and AF-WPS groups compared with control group, and the effect seen in AF-group was higher than that observed in P-WPS group. In conclusion, our findings showed that both P- and AF-WPS induce thrombogenicity and cardiac injury, and that this toxicity is potentiated by the presence of flavouring.