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Previous studies demonstrated methane generation in aerobic cells. Our aims were to investigate the methanogenic features of sodium azide (NaN(3))-induced chemical hypoxia in the whole animal and to study the effects of l-α-glycerylphosphorylcholine (GPC) on endogenous methane production and inflammatory events as indicators of a NaN(3)-elicited mitochondrial dysfunction. Group 1 of Sprague-Dawley rats served as the sham-operated control; in group 2, the animals were treated with NaN(3) (14 mg·kg(-1)·day(-1) sc) for 8 days. In group 3, the chronic NaN(3) administration was supplemented with daily oral GPC treatment. Group 4 served as an oral antibiotic-treated control (rifaximin, 10 mg·kg(-1)·day(-1)) targeting the intestinal bacterial flora, while group 5 received this antibiotic in parallel with NaN(3) treatment. The whole body methane production of the rats was measured by means of a newly developed method based on photoacoustic spectroscopy, the microcirculation of the liver was observed by intravital videomicroscopy, and structural changes were assessed via in vivo fluorescent confocal laser-scanning microscopy. NaN(3) administration induced a significant inflammatory reaction and methane generation independently of the methanogenic flora. After 8 days, the hepatic microcirculation was disturbed and the ATP content was decreased, without major structural damage. Methane generation, the hepatic microcirculatory changes, and the increased tissue myeloperoxidase and xanthine oxidoreductase activities were reduced by GPC treatment. In conclusion, the results suggest that methane production in mammals is connected with hypoxic events associated with a mitochondrial dysfunction. GPC is protective against the inflammatory consequences of a hypoxic reaction that might involve cellular or mitochondrial methane generation.

This study was designed to follow the time course of inflammatory activation in a rodent model of 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis. We hypothesized that oral phosphatidylcholine (PC) pretreatment regimens may influence leukocyte-mediated microcirculatory reactions in this condition. In series I, Wistar rats were monitored 1 day after colitis induction (n = 24), and in series II (n = 24) on day 6 following a TNBS enema. The PC-pretreated animals received a 2% PC-enriched diet for 6 days before the TNBS enema (series I), or for 3 days before and 3 days after TNBS treatment (series II). The macrohemodynamics, serosal microcirculation (visualized by intravital videomicroscopy), colonic xanthine oxidoreductase, myeloperoxidase and nitric oxide end products, and changes in proinflammatory cytokine levels in plasma were measured. The mucosal structural injury was monitored in vivo by means of confocal laser scanning endomicroscopy. The TNBS enema induced a systemic hyperdynamic circulatory reaction with increased serosal capillary blood flow and significantly elevated colonic inflammatory enzyme activities, levels of nitric oxide production, and cytokine concentrations. Acute colitis caused disruption of the capillary network, whereas the morphologic damage was less severe in series II. The PC pretreatment protocols led to significant decreases in the serosal hyperemic reaction, the cytokine levels, and the inflammatory enzyme activities. The objective signs of tissue damage were reduced in both series, and the number of mucus-producing goblet cells in the resolving phase of colitis was increased. Dietary PC efficiently decreases the cytokine-mediated progression of inflammatory events and preserves the microvascular structure in the large intestine.

Our goal was to characterize the neuroprotective properties of orally administered phosphatidylcholine (PC) in a rodent model of systemic inflammation. Sprague-Dawley rats were killed at 3 h, 1 day, 3 days, or 7 days after i.p. administration of lipopolysaccharide (LPS) to determine the plasma levels of tumor necrosis factor α (TNF-α) and interleukin 6 cytokines. The control group and one group of LPS-treated animals were nourished with standard laboratory chow, whereas another LPS-treated group received a special diet enriched with 1% PC for 5 days before the administration of LPS and thereafter during the 7-day observation period. Immunohistochemistry was performed to visualize the bromodeoxyuridine and doublecortin-positive neuroprogenitor cells and Iba1-positive microglia in the hippocampus, whereas the degree of mucosal damage was evaluated on ileal and colon biopsy samples after hematoxylin-eosin staining. The activities of proinflammatory myeloperoxidase and xanthine-oxidoreductase and the tissue nitrite/nitrate (NOx) level were additionally determined, and the cognitive functions were monitored via Morris water maze testing. The inflammatory challenge transiently increased the hippocampal NOx level and led to microglia accumulation and decreased neurogenesis. The intestinal damage, mucosal myeloperoxidase, xanthine-oxidoreductase, and NOx changes were less pronounced, and long-lasting behavioral alterations were not observed. Phosphatidylcholine pretreatment reduced the plasma TNF-α and hippocampal NOx changes and prevented the decreased neurogenesis. These data demonstrated the relative susceptibility of the brain to the consequences of transient peripheral inflammatory stimuli. Phosphatidylcholine supplementation did not reduce the overall extent of peripheral inflammatory activation, but efficiently counteracted the disturbed hippocampal neurogenesis by lowering circulating TNF-α concentrations.

We have shown that phosphatidylcholine (PC) metabolites may have a function in counteracting the production of reactive oxygen species (ROS), and that this mechanism can lead to the generation of methane from choline. The aims were to establish whether the dietary administration of PC can protect the reperfused small bowel mucosa by its acting as an anti-inflammatory agent and to investigate this possibility in association with in vivo methane generation. Group 1 (n = 5) of anesthetized dogs served as sham-operated controls, whereas in groups 2 (n = 6) and 3 (n = 6), complete small intestinal ischemia was induced by occluding the superior mesenteric artery for 60 min. Groups 1 and 2 were fed with normal laboratory chow for 1 week before the experiments, whereas the animals in group 3 received a special diet containing 1% soybean PC. The intramucosal pH and the difference of the arterial and local PCO2 (PCO2 gap) were detected by indirect tonometry. Intestinal superoxide production and myeloperoxidase (MPO) activity (a marker of tissue leukocyte infiltration) were ascertained on ileal biopsy samples 180 min after reperfusion. The content of methane in the exhaled air was determined by gas chromatography. I/R was characterized by significant tissue acidosis with ROS generation and elevated MPO activity. These changes were accompanied by increased methane production in the exhaled air during reoxygenation. The PC-enriched diet prevented the decrease in intramucosal pH, diminished the intestinal superoxide generation and the MPO activity, and significantly decreased the exhaled methane concentration. The increased dietary uptake of PC exerts an anti-inflammatory influence in the gastrointestinal tract. Exhaled methane is linked to abnormal ROS generation; a decreased methane production is associated with significantly reduced inflammatory activation during I/R.

Stimulation of lignin peroxidase production by exogenous phospholipids depends on the composition of the phospholipid fraction prepared by using the Nattermann process. The fraction composed mainly of negatively charged phospholipids (NAT 89) was the most efficient source for exoprotein secretion by Phanerochaete chrysosporium INA-12. The results of biochemical marker assays and ultrastructural morphology determination by electron microscopy were correlated. Activities of succinate dehydrogenase, a mitochondrial marker, and cytochrome c oxidoreductase, an endoplasmic reticulum (ER) marker, were increased 1.3- and 2.2-fold, respectively, in the presence of NAT 89. Electron microscopy observations suggested that the amount of mitochondria and ER in culture containing phospholipids was increased at the optimum day of lignin peroxidase production. Therefore, phospholipids enhanced energetic metabolism of strain INA-12 and markedly modified fungus physiology. Since ER is involved in enzyme synthesis, we suggest that its increased amount in mycelium cultured with NAT 89 is directly associated with the higher production of lignin peroxidase.