Comparison in bioactivity and characteristics of Ginkgo biloba seed polysaccharides from four extract pathways.

The effects of hot-water extraction (HWE), ultrasound-treated extraction (UTE), enzyme-treated extraction (ETE) and ultrasound-enzyme treated extraction (UETE) on the α-glucosidase inhibitory activity, antioxidant activities and characteristics of Ginkgo biloba seed polysaccharides were investigated and compared in this study. Among the four extracted polysaccharides, the UETE-polysaccharide initially exhibited the highest α-glucosidase inhibitory activity and antioxidant activities. The HWE-polysaccharide showed a large number of small compact spherical structures, and the UTE-polysaccharide exhibited an irregular pleated porous shape; meanwhile, the ETE-polysaccharide and UETE-polysaccharide were spongy with smooth surface topography, as observed by scanning electron microscopy (SEM). The four polysaccharides varied in monosaccharide composition. The HWE-polysaccharide mainly consisted of homogeneous mannose; the UETE-polysaccharide was primarily composed of mannose, rhamnose, and glucose in a molar ratio of 8.25:1.00:1.53. The HWE-polysaccharide had the largest molecular weight (4.2 × 105 Da), reduced by the order of the UETE-polysaccharide (2.02 × 104 Da), ETE-polysaccharide (1.72 × 104 Da), and UTE-polysaccharide (1.34 × 104 Da). Thus, the four extract methods exerted significant effects on the bioactivity and characteristics of the polysaccharides. The UETE-polysaccharide from G. biloba seeds showed the highest bioactive activities and distinctive structural characteristics.

N-Acetylcysteine (NAC) for the Prevention of Liver Failure in Heat Injury-Mediated Ischemic Hepatitis.

Exertional Heat Illness with associated ischemic hepatitis (IH) is a common occurrence among military trainees; however, few specific therapies exist if unresponsive to appropriate supportive measures. A 27-year-old basic combat trainee presented with altered mental status, renal insufficiency, rhabdomyolysis, and a core temp of 107.9 °F after collapsing during a run, leading to the diagnosis of heat stroke. While the patient's azotemia and creatinine kinase levels rapidly improved with aggressive intravenous hydration, transaminases continued to increase to nearly 155 times the upper limit of normal. Further laboratory evaluation revealed coagulopathy and thrombocytopenia suggestive of acute liver failure (ALF). On hospital day three, the patient was started on N-acetylcysteine (NAC). Evaluation for infectious and autoimmune etiologies of ALF was unremarkable; thus, the patient's symptomatology was attributed to IH resulting from heat stroke. Liver function normalized on NAC. Heat Injury is common among US Army recruits and results in thousands of hospitalizations in recent years. IH is characterized by diffuse hepatocyte necrosis following an episode of hemodynamic instability, and is an established sequela of Heat Injury. The mortality of IH among critically ill patients has been estimated to be as high as 60%, with those demonstrating coagulopathy especially at risk. NAC is shown to improve the transplant-free survival rate in non-acetaminophen related ALF, consistent with its proposed mechanisms of improving hepatic blood flow and conjugating toxic metabolites. NAC therapy should be considered early in the course of heat injury-mediated IH to reduce reperfusion injury, improving transplant free outcomes.

Gastroprotective effect of standardized leaf extract from Argyreia speciosa on experimental gastric ulcers in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Argyreia speciosa (L.f), Sweet (Family Convolvulaceae) is used traditionally in Indian System of Medicine as aphrodisiac, rejuvenating agent, intellect promoting agent, brain tonic and in the therapy of hepatomegaly, diabetes and chronic ulcer. AIM OF THE STUDY: To study the gastroprotective effect of standardized butanol fraction of Argyreia speciosa leaf (ASE). MATERIALS AND METHODS: The butanol fraction of Argyreia speciosa leaf (ASE; 50, 100 and 200mg/kg body weight) was administered orally, twice daily for 5 days for prevention from Aspirin (ASP)-, ethanol (EtOH)-, cold-restraint stress (CRS) - and pylorus ligation (PL)-induced ulcers. Estimation of antioxidant enzymes activity was carried out in CRS-induced ulcer model, and various gastric secretion parameters like volume of gastric juice, acid output, and pH value were estimated in PL-induced ulcer model. RESULT: ASE showed dose-dependent ulcer protective effect in ASP 23.64-58.76% (p<0.01 to p<0.001), EtOH 15.45-58.45% (p<0.001), CRS 19.39-78.36% (p<0.001) and PL 19.67-69.04% (p<0.05 to p<0.01), respectively. The percentage of protection by standard drug ranitidine was 77.77-84.32% (p<0.01 to p<0.001) in various gastric ulcer models. The gastric wall mucus was significantly (p<0.001) enhanced by ASE and is regarded as the first line of defence against EtOH-induced gastric ulcers showing cytoprotective property. ASE showed a marginal decrease in volume, acid pepsin concentration and acid pepsin output. However, ASE reduced the ulcer index with significant decrease in LPO level (p<0.001), and SOD level (p<0.01 to p<0.001) as compared with CRS-induced group. A gradual and significant increase in CAT values were observed at 100 and 200mg/kg dose levels (p<0.01 to p<0.001). CONCLUSIONS: The results of our study revealed that Argyreia speciosa possess significant dose dependent gastroprotective activity, probably due to its free radical scavenging activity.

Nitrite and nitrate measurement by Griess reagent in human plasma: evaluation of interferences and standardization.

Nitrite and nitrate represent the final products of nitric oxide (NO) oxidation pathways, and their hematic concentrations are frequently assessed as an index of systemic NO production. However, their intake with food can influence their levels. Nitrite and nitrate could have a role by producing NO, because nitrite can release NO after reaction with deoxyhemoglobin and dietary nitrate can be reduced substantially to nitrite by commensal bacteria in the oral cavity. Different methods have been applied for nitrite/nitrate detection, with the most commonly used being the spectrophotometric assay based on the Griess reagent. However, a reference methodology for these determinations is still missing and many possible interferences have been reported. This chapter assesses how different experimental conditions can influence the results when detecting nitrite and nitrate in human plasma by the Griess assay and provides a simple method characterized by high reproducibility and minimized interferences by plasma constituents.