Effect of lipopolysaccharide on alteration of phospholipids and their fatty acid composition in spleen and thymus byin vitrometabolic labeling

Alteration of mitochondrial phospholipid due to the PLA2 activation in rat brains under cadmium toxicity

Cadmium (Cd) is a heavy metal that has received considerable environmental and occupational concern. Cd causes toxic effects due to its accumulation in a variety of tissues, including the kidney, liver and the nervous system (CNS); however, the exact mechanism is poorly understood. In the present study, we tried to explore the impact of acute cadmium exposure on rat brain phospholipids (PLs). Cd exposure significantly reduced PLs in a time dependent manner and the reduction was due to the activation of the Phospholipase A2 enzymes (sPLA2, cPLA2). The release of arachidonic acid from PLs increased during inflammatory conditions by PLA2s. The mRNA expression of cyclooxygenase2 (COX2) and subsequently the pro-inflammatory cytokines, namely, Interleukin 1 (IL-1) and IL-6, were up regulated; however, the expression of anti-inflammatory cytokine IL-10 was reduced in a time dependent manner. The expression of the Tumor necrosis factor alpha (TNF-α), Inducible nitric oxide synthase (iNOS) and Interferon gamma (INF-γ) also experienced increases in the expression. Likewise the mRNA expression of the pro-apoptotic factor, Bcl-2-associated X protein (Bax), was elevated, whereas anti-apoptosis B-cell lymphoma 2 (Bcl2) was down regulated. This present study might help to decipher the effects of cadmium toxicity on rat brain.

Modulatory effect of cadmium on the expression of phospholipase A2 and proinflammatory genes in rat testis

Cadmium (Cd) is a toxic metal that is hazardous to health, and its exposure showed a significant reduction in mitochondrial phospholipid function in the rat testes. Cd induction enhanced phospholipases (PLA2 s) activities, specifically the secretory PLA2 and cytosolic PLA2 . There was a reduction in mitochondrial membrane potential and significant decline in the respiratory complexes, which was confirmed by 2D blue native gel. The mRNA expression of cyclooxygenase and proinflammatory cytokine genes interleukin (IL)-1, IL-6, tumor necrosis factor-α, inducible nitric oxide synthase, and interferon-γ increased and that of anti-inflammatory cytokine IL-10 reduced with Cd exposure in a time-dependent manner. The gene expression of the proapoptotic factor Bax was elevated, and in parallel, the antiapoptotic factor Bcl2 was down-regulated. Hence, this study explored the testes under Cd toxicity and observed alterations in PLA2 s and mitochondrial membrane composition/function and further explored the impact of these alterations on proinflammation and apoptosis. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1176-1184, 2016.

Prophylactic treatment of asthma by an ozone scavenger in a mouse model

Our hypothesis that inflammation in asthma involves production of ozone by white blood cells and that ozone could be an inflammatory mediator suggests that scavengers of reactive oxygen species (ROS), for example, electron-rich olefins, could serve for prophylactic treatment of asthma. Olefins could provide chemical protection against either exogenous or endogenous ozone and other ROS. BALB/c mice pretreated by inhalation of d-limonene before an ovalbumin challenge exhibited significant attenuation of the allergic asthma symptoms. Diminution of the inflammatory process was evident by reduced levels of aldehydes, reduced counts of neutrophils in the BAL fluid and by histological tests. A surprising systemic effect was observed by decreased levels of aldehydes in the spleen, suggesting that the examination of tissues and organs that are remote from the inflammation foci could provide valuable information on the distribution of the oxidative stress and may serve as guide for targeted treatment.

In vitro exposure of tobacco specific nitrosamines decreases the rat lung phospholipids by enhanced phospholipase A2 activity

Tobacco-specific nitrosamines (TSNA) have implications in the pathogenesis of various lung diseases and conditions are prevalent even in non-smokers. N-nitrosonornicotine (NNN) and 4-(methyl nitrosamino)-1-(3-pyridyl)-1-butanone (NNK) are potent pulmonary carcinogens present in tobacco product and are mainly responsible for lung cancer. TSNA reacts with pulmonary surfactants, and alters the surfactant phospholipid. The present study was undertaken to investigate the in vitro exposure of rat lung tissue slices to NNK or NNN and to monitor the phospholipid alteration by [(32)P]orthophosphate labeling. Phospholipid content decreased significantly in the presence of either NNK or NNN with concentration and time dependent manner. Phosphatidylcholine (PC) is the main phospholipid of lung and significant reduction was observed in PC ∼61%, followed by phosphatidylglycerol (PG) with 100μM of NNK, whereas NNN treated tissues showed a reduction in phosphatidylserine (PS) ∼60% and PC at 250μM concentration. The phospholipase A2 assays and expression studies reveal that both compounds enhanced phospholipid hydrolysis, thereby reducing the phospholipid content. Collectively, our data demonstrated that both NNK and NNN significantly influenced the surfactant phospholipid level by enhanced phospholipase A2 activity.