Amylase and glucosidase enzyme inhibitory activity of ginger (Zingiber officinale Roscoe) an in vitro study

The prevalence of type 2 diabetes has reached to an epidemic proportion in Sri Lanka. The need for achieving better control of blood glucose level has been evident in diabetes management. However it is not easy to achieve this goal in a large proportion of patients. This is partly due to limitations of currently available pharmacological agents which stimulate research on novel anti-diabetic agents with different mechanisms. Digestive enzymes have been targeted as potential avenues for modulation of blood glucose concentration through inhibition of the enzymatic breakdown of complex carbohydrates to meal derived glucose absorption. Acarbose is a widely used oral anti-diabetic drug which inhibits the α-glucosidase, enzyme responsible for breaking down of disaccharides and polysaccharides into glucose. Many herbal extracts have been found to posses similar inhibitory effects. Ginger (Zingiber officinale Roscoe) has developed a reputation in treatment of several diseases. In vitro enzymic inhibitory effect of ginger was investigated in this study. Enzymes α -amylase and α -glucosidase treated with either Acarbose or ginger extract were allowed to react with cooked rice and percentages of glucose content were measured. The glucosidase and amylase activities on the rice were inhibited by addition of ginger cause significant reduction in glucose percentages (36.86± 1.05 to 26.87± 2.17, P<0.05 and 49.04±0.65 to 35.35±2.22, P<0.05) which showed comparable results with Acarbose on glucosidase activity (36.86± 1.05 to, 27.8±1.32 P<0.05). Results of the study indicates ginger as a potential plant based amylase and glucosidase inhibitor in carbohydrate digestion but usage in glycaemic control in human has to be investigated further.

Physiological responses to psychological stress: importance of adiposity in men aged 50-70 years

We tested the hypothesis that overweight/obese men aged 50–70 years will have a greater salivary cortisol, salivary alpha amylase and heart rate (HR) responses to psychological stress compared with age matched lean men. Lean (BMIZ20–25 kg/m2; nZ19) and overweight/obese (BMIZ27–35 kg/m2; nZ17) men (50–70 years) were subjected to a well-characterised psychological stress (Trier Social Stress Test, TSST) at 1500 h. Concentrations of cortisol and alpha amylase were measured in saliva samples collected every 7–15 min from 1400 to 1700 h. HR was recorded using electrocardiogram. Body weight, BMI, percentage body fat, resting systolic and diastolic blood pressure and mean arterial pressure were significantly higher (P!0.05) in overweight/obese men compared with lean men. Both groups responded to the TSST with a substantial elevation in salivary cortisol (372%), salivary alpha amylase (123%) and HR (22%). These responses did not differ significantly between the groups (time!treatment interaction for salivary cortisol, salivary alpha amylase and HR; PZ0.187, PZ0.288, PZ0.550, respectively). There were no significant differences between the groups for pretreatment values, peak height, difference between pretreatment values and peak height (reactivity) or area under the curve for salivary cortisol, salivary alpha amylase or HR (PO0.05 for all). The results showed that, for men with a moderate level of overweight/obesity who were otherwise healthy, the response of salivary cortisol, salivary alpha amylase and HR to acute psychological stress was not impaired.

The effect of working on-call on stress physiology and sleep: a systematic review

On-call work is becoming an increasingly common work pattern, yet the human impacts of this type of work are not well established. Given the likelihood of calls to occur outside regular work hours, it is important to consider the potential impact of working on-call on stress physiology and sleep. The aims of this review were to collate and evaluate evidence on the effects of working on-call from home on stress physiology and sleep. A systematic search of Ebsco Host, Embase, Web of Science, Scopus and ScienceDirect was conducted. Search terms included: on-call, on call, standby, sleep, cortisol, heart rate, adrenaline, noradrenaline, nor-adrenaline, epinephrine, norepinephrine, nor-epinephrine, salivary alpha amylase and alpha amylase. Eight studies met the inclusion criteria, with only one study investigating the effect of working on-call from home on stress physiology. All eight studies investigated the effect of working on-call from home on sleep. Working on-call from home appears to adversely affect sleep quantity, and in most cases, sleep quality. However, studies did not differentiate between night's on-call from home with and without calls. Data examining the effect of working on-call from home on stress physiology were not sufficient to draw meaningful conclusions.

Stimulation of cytokine production in human peripheral blood mononuclear cells by an aqueous Chlorella extract

CPE is an aqueous extract of the edible micro alga Chlorella pyrenoidosa, which has been shown to have immunostimulatory effects in vivo. In the present study, CPE was evaluated for an ability to stimulate cytokine production by human peripheral blood mononuclear cells (PBMC). PBMC from healthy individuals were treated ex vivo for 24 hours with 1, 10 and 100 μg/mL CPE. This resulted in a marked increase in the level of IL-10, a regulatory cytokine, and strong stimulation of the T-helper-1 (Th1) cell cytokines, IFN-γ and TNF-α. In contrast, stimulation of representative T-helper-2 (Th2) cell cytokines, IL-4 and IL-13, was minor. CPE (1, 10 or 100 μg/mL) did not cause a proliferation of human PBMC suggesting that enhanced secretion of cytokines was not secondary to an increase in cell number. We conclude that CPE stimulation of human PBMC induces a Th1-patterned cytokine response and a strong anti-inflammatory regulatory cytokine response, observations that await confirmation in vivo.

Process for the production of ultrafine plate-like alumina particles

A process for producing plate-like alumina particles with a high aspect ratio is described. Nano-sized particles of an aluminium precursor compound, optionally formed by milling, are mixed with a sufficient volume fraction of a diluent and heat treated to form substantially discrete plate-like alpha alumina particles dispersed in the diluent. A mineraliser may be added to lower the effective melting point of the system. Substantially discrete plate-like particles may be formed without agitation when the heat treatment is conducted below the melting point of the diluent.

Process for the production of ultrafine plate-like alumina particles

A process for producing plate-like alumina particles with a high aspect ratio is described. Nano-sized particles of an aluminium precursor compound, optionally formed by milling, are mixed with a sufficient volume fraction of a diluent and heat treated to form substantially discrete plate-like alpha alumina particles dispersed in the diluent. A mineraliser may be added to lower the effective melting point of the system. Substantially discrete plate-like particles may be formed without agitation when the heat treatment is conducted below the melting point of the diluent.

Impact of training on changes in perceived stress and cytokine production

Data on training of competitive athletes and the inflammatory response, and, more specifically, the utility of psychological inventories to monitor this response in regards to overreaching is limited. The aim of the present study was to investigate the association of the Perceived Stress Scale (PSS) and inflammatory markers in elite rowers. Eight rowers (males n = 4; females n = 4) were monitored over an 8-week training period, comprising 12 sessions each week and training an average 3.11 h·d-1. Training volume was periodized weekly while intensity was maintained throughout the study. Perceived stress was measured weekly pretraining, and capillary blood samples (500 μL) were taken post-training. Significant associations between perceived stress and cytokines interleukin-6 (p < .05) and tumor necrosis factor alpha (p < .05) were observed. While further investigation of the role of cytokines in the overtraining process is required, these data provide preliminary support for an association between perceived stress and the inflammatory responses to training.

Fermentative production of rhamnosidase from Staphylococcus xylosus MAK 2 in a bioreactor for bio-energy generation

Increasing concern about the environment, food and feed shortages and hike in the price of petroleum have stimulated interest in new ways of producing biofuels. The interest is rapidly increasing towards converting agricultural wastes to commercially valuable products. Biofuels made from waste biomass can offer immediate and sustained greenhouse gas advantages. In this direction, we are focusing on Citrus processing waste, a byproduct of juice manufacture, which contains high amount of flavonoids and polysaccharides. There is a considerable industrial interest in the enzymatic transformation of flavonoids to hydrolysis products; that offers a pathway to bio-energy generation. Rhamnosidase of bacterial origin are very few and thus are potentially subject for research.

Staphylococcus xylosus, Gram positive cocci, a nonpathogenic member of CNS family, isolated from soil was used to produce α-L-rhamnosidase. This new strain, so far unknown for the production of α-L-Rhamnosidase, was identified and characterized as Staphyloccocus sp. through biochemical tests and 16S DNA sequence analysis. Effect of various medium and process parameters like pH, temperature, aeration and agitation rates and inducer concentration were studied. Further, the enzyme activity was enhanced by adding the inducer and divalent metal ion to the optimised fermentation medium. We have recovered important sugars “rhamnose” and “galacturonic acid” from the processed waste which would be utilized for ethanol production. This presentation will summarize current efforts to develop an enzymatic treatment which would facilitate the economical processing of citrus waste for bioenergy generation.

Plant extract assisted extracellular tannase production by Aspergillus sp MIK 23

An extracellular tannase (E.C. 3.1.1.20) producing fungal strain was isolated from soil and identified as Aspergillus sp MIK23. Out of various plant extracts, Terminalia chebula powder (TCP) in the optimized medium enhanced enzyme production. Maximum yield of tannase (3 IU ml-1) was obtained with glucose (10 g/L), urea (2 g/L), and yeast extract (2.5 g/L) when inoculated with 10% inoculum in 48 h. An initial medium at pH 6.0 and a cultivation temperature of 37 0C was found to be optimum for enzyme production. Metal ions Mg2+, Zn2+, Ca2+, Cu2+ and Cd2+ did not improve enzyme activity, whereas, Ca2+, Fe2+ and Hg2+ repressed enzyme activity. The enzyme was purified using ammonium sulfate precipitation followed by Q-sepharose ion-exchange chromatography. The enzyme was purified to 42-fold with an overall recovery of 20. The pH and temperature optima of the purified tannase were found to be 7.0 and 37°C, respectively.

Effect of cell-surface components and metabolites of lactic acid bacteria and probiotic organisms on cytokine production and induction of CD25 expression in human peripheral mononuclear cells

In the current study, the relative contribution of cell-surface components (CSC) and cell-free supernatants (CFS) in the immuno-modulatory properties of 17 strains of probiotic and lactic acid bacteria (LAB) was assessed. The production of pro- and antiinflammatory cytokines including IL-2, IL-4, IL-10, IL-12 p70, IFN-γ, tumor necrosis factor-α (TNF-α), and transforming growth factor-β was measured at different time points after stimulation of buffy coat derived-peripheral blood mononuclear cells (PBMC) from healthy donors with CSC and CFS of probiotic and LAB. Results showed that CSC of probiotic and LAB strains induced production of T helper 1 and 2 type cytokines. Transforming growth factor-β was stimulated at highest concentrations, followed by IL-10 and TNF-α. The CFS of all tested bacterial strains induced PBMC for significantly high levels of IL-10 secretion compared with unstimulated cells, but the values were less than lipopolysaccharide-stimulated cells. Cytokines due to CFS stimulation showed declined concentration for IL-2, TNF-α, and IL-4, and complete disappearance of IL-12, IFN-γ, and transforming growth factor-β in the cultured medium at 96 h of incubation. Results of cytokine data demonstrate proinflammatory TNF-α immune responses are mainly directed through cell-surface structures of probiotic and LAB, but antiinflammatory immune responses are mediated both by metabolites and cell-surfaces of these bacteria. The induction of CD4(+)CD25(+) regulatory T cells after stimulation of PBMC with CSC and CFS of probiotic and LAB showed regulatory T cell activity appeared to be influenced both by the CSC and metabolites, but was principally triggered by cell surfaces of probiotic and LAB strains.

Clinical MRSA isolates from skin and soft tissue infections show increased in vitro production of phenol soluble modulins

BACKGROUND: Phenol-soluble modulins (PSMs) are amphipathic, pro-inflammatory proteins secreted by most Staphylococcus aureus isolates. This study tested the hypothesis that in vitro PSM production levels are associated with specific clinical phenotypes. METHODS: 177 methicillin-resistant S. aureus (MRSA) isolates from infective endocarditis (IE), skin and soft tissue infection (SSTI), and hospital-acquired/ventilator-associated pneumonia (HAP) were matched by geographic origin, then genotyped using spa-typing. In vitro PSM production was measured by high performance liquid chromatography/mass spectrometry. Statistical analysis was performed using Chi-squared or Kruskal-Wallis tests as appropriate. RESULTS: Spa type 1 was significantly more common in SSTI isolates (62.7% SSTI; 1.7% IE; 16.9% HAP; p < 0.0001) while HAP and IE isolates were more commonly spa type 2 (0% SSTI; 37.3% IE; 40.7% HAP; p < 0.0001). USA300 isolates produced the highest levels of PSMs in vitro. SSTI isolates produced significantly higher quantities of PSMα1-4, PSMβ1, and δ-toxin than other isolates (p < 0.001). These findings persisted when USA300 isolates were excluded from analysis. CONCLUSIONS: Increased in vitro production of PSMs is associated with an SSTI clinical source. This significant association persisted after exclusion of USA300 genotype isolates from analysis, suggesting that PSMs play a particularly important role in the pathogenesis of SSTI as compared to other infection types.