From nitrate to NO: potential effects of nitrate-reducing bacteria on systemic health and disease.

Current research has described improving multisystem disease and organ function through dietary nitrate (DN) supplementation. They have provided some evidence that these floras with nitrate (NO3-) reductase are mediators of the underlying mechanism. Symbiotic bacteria with nitrate reductase activity (NRA) are found in the human digestive tract, including the mouth, esophagus and gastrointestinal tract (GT). Nitrate in food can be converted to nitrite under the tongue or in the stomach by these symbiotic bacteria. Then, nitrite is transformed to nitric oxide (NO) by non-enzymatic synthesis. NO is currently recognized as a potent bioactive agent with biological activities, such as vasodilation, regulation of cardiomyocyte function, neurotransmission, suppression of platelet agglutination, and prevention of vascular smooth muscle cell proliferation. NO also can be produced through the conventional L-arginine-NO synthase (L-NOS) pathway, whereas endogenous NO production by L-arginine is inhibited under hypoxia-ischemia or disease conditions. In contrast, exogenous NO3-/NO2-/NO activity is enhanced and becomes a practical supplemental pathway for NO in the body, playing an essential role in various physiological activities. Moreover, many diseases (such as metabolic or geriatric diseases) are primarily associated with disorders of endogenous NO synthesis, and NO generation from the exogenous NO3-/NO2-/NO route can partially alleviate the disease progression. The imbalance of NO in the body may be one of the potential mechanisms of disease development. Therefore, the impact of these floras with nitrate reductase on host systemic health through exogenous NO3-/NO2-/NO pathway production of NO or direct regulation of floras ecological balance is essential (e.g., regulation of body homeostasis, amelioration of diseases, etc.). This review summarizes the bacteria with nitrate reductase in humans, emphasizing the relationship between the metabolic processes of this microflora and host systemic health and disease. The potential effects of nitrate reduction bacteria on human health and disease were also highlighted in disease models from different human systems, including digestive, cardiovascular, endocrine, nervous, respiratory, and urinary systems, providing innovative ideas for future disease diagnosis and treatment based on nitrate reduction bacteria.

Effect of notoginsenoside R1 on hepatic microcirculation disturbance induced by gut ischemia and reperfusion.

AIM: To assess the effect of notoginsenoside R1 on hepatic microcirculatory disturbance induced by gut ischemia/reperfusion (I/R) in mice. METHODS: The superior mesenteric artery (SMA) of C57/BL mice was ligated for 15 min to induce gut ischemia followed by 30-min reperfusion. In another set of experiments, R1 was continuously infused (10 mg/kg per hour) from 10 min before I/R until the end of the investigation to study the influence of R1 on hepatic microcirculatory disturbance induced by gut I/R. Hepatic microcirculation was observed by inverted microscopy, and the vascular diameter, red blood cell (RBC) velocity and sinusoid perfusion were estimated. Leukocyte rolling and adhesion were observed under a laser confocal microscope. Thirty and 60 min after reperfusion, lactate dehydrogenase (LDH), alanine aminotransferase (ALT) and aspartate transaminase (AST) in peripheral blood were determined. The expression of adhesion molecules CD11b/CD18 in neutrophils and tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and monocyte chemotactic protein-1 (MCP-1) in plasma were evaluated by flow cytometry. E-selectin and intercellular adhesion molecule-1 (ICAM-1) in hepatic tissue were examined by immunofluorescence. RESULTS: After gut I/R, the diameters of terminal portal venules and central veins, RBC velocity and the number of perfused sinusoids were decreased, while the leukocyte rolling and adhesion, the expression of E-selectin in hepatic vessels and CD18 in neutrophils, IL-6, MCP-1, LDH, ALT and AST were increased. R1 treatment attenuated these alterations except for IL-6 and MCP-1. CONCLUSION: R1 prevents I/R-induced hepatic microcirculation disturbance and hepatocyte injury. The effect of R1 is related to its inhibition of leukocyte rolling and adhesion by inhibiting the expression of E-selectin in endothelium and CD18 in neutrophils.

Evaluation of prognostic markers in severe drug-induced liver disease.

AIM: To analyze the outcome of patients with severe drug-induced liver disease (DILD) associated with jaundice classified as hepatocellular, cholestatic or mixed liver injury and to evaluate the validity of Hyos rule and the most important predictors for outcome. METHODS: The Adverse Drug Reaction Advisory Committee was set up in 1997 in our hospital to identify all suspicions of DILD following a structured prospective report form. Liver damage was divided into hepatocellular, cholestatic, and mixed types according to laboratory and histologic criteria when available. Further evaluation of causality assessment was performed. RESULTS: From January 1997 to December 2004, 265 patients were diagnosed with DILD, and 140 (52.8%) of them were female. hepatocellular damage was the most common (72.1%), the incidence of death was 9.9% in patients with hepatocellular damage and 9.5% in patients with cholestatic/mixed damage (P < 0.05). There was no difference in age of dead and recovered patients. The proportion of females and males was similar in recovered and dead patients, no difference was observed in duration of treatment between the two groups. The serum total bilirubin (P < 0.001), direct bilirubin (P < 0.001) and aspartate transaminase (AST) (P = 0.013) values were higher in dead patients than in recovered patients. Chinese herbal medicine was the most frequently prescribed, accounting for 24.2% of the whole series. However, antitubercular drugs (3.4%) were found to be the primary etiological factor for fetal DILD. Factors associated with the development of fulminant hepatic failure were hepatic encephalopathy (OR = 43.66, 95% CI = 8.47-224.95, P < 0.0001), ascite (OR = 28.48, 95% CI = 9.26-87.58, P < 0.0001), jaundice (OR = 11.43, 95% CI = 1.52-85.96, P = 0.003), alcohol abuse (OR = 3.83, 95% CI = 1.26-11.67, P = 0.035) and direct bilirubin (OR = 1.93, 95% CI = 1.25-2.58, P = 0.012). CONCLUSION: Death occurs in 9.8% of patients with DILD. Chinese herbal medicine stands out as the most common drug for DILD. While antitubercular drugs are found to be the primary etiological factor for fetal DILD, hepatic encephalopathy, ascites, jaundice, alcohol abuse and direct bilirubin levels are associated with the death of DILD patients.

Hepatic veno-occlusive disease induced by Gymura segetum: report of two cases.

BACKGROUND: Hepatic veno-occlusive disease (VOD) or sinusoidal obstruction syndrome is associated with a high mortality because of its severity. Gymura segetum, a Chinese herbal medicine, is always used to cure injury and bleeding in rural areas in China. This study was undertaken to better understand VOD and its relations to the effect of Gymura segetum. METHODS: Between 2000 and 2002, two patients were admitted to our department because of VOD. Before admission, both of them had been injured and taken oral decoction of patent drug Gymura segetum. We analyzed the clinical manifestations, diagnosis and therapy of the two patients. RESULTS: Pyrrolizidine in Panax notginseng was proved to induce VOD. The diagnosis of VOD depended on hepatic biopsy. CONCLUSION: Gymura segetum can induce VOD. More attention should be paid to its unsuscepted side effects.