A review of bioanalytical techniques for evaluation of cannabis (Marijuana, weed, Hashish) in human hair

Cannabis products (marijuana, weed, hashish) are among the most widely abused psychoactive drugs in the world, due to their euphorigenic and anxiolytic properties. Recently, hair analysis is of great interest in analytical, clinical, and forensic sciences due to its non-invasiveness, negligible risk of infection and tampering, facile storage, and a wider window of detection. Hair analysis is now widely accepted as evidence in courts around the world. Hair analysis is very feasible to complement saliva, blood tests, and urinalysis. In this review, we have focused on state of the art in hair analysis of cannabis with particular attention to hair sample preparation for cannabis analysis involving pulverization, extraction and screening techniques followed by confirmatory tests (e.g., GC–MS and LC–MS/MS). We have reviewed the literature for the past 10 years’ period with special emphasis on cannabis quantification using mass spectrometry. The pros and cons of all the published methods have also been discussed along with the prospective future of cannabis analysis.

Antioxidant and anticancer activities of chamomile (Matricaria recutita L.)

Objectives

The present study aimed at determining the antioxidant activity, total phenols and flavonoids and to evaluate the antiproliferative activity of ethanolic extract of Matricaria recutita L. (chamomile). The antioxidant activities were measured using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay. The total phenolic content was measured by the Folin–Ciocalteu assay. The flavonoid content was determined using the aluminum chloride method. The MTT assay was used to estimate the antiproliferative activities against human hepatoma (HepG2) cancer cell line. We assessed the mode of action of the extract as a cancer preventive agent and reported its ability to regulate tumor angiogenesis by down regulating in a dose dependent manner the expression of some proteins involved in the process.

Results

The percentage inhibition of DPPH scavenging activity was dose-dependent ranging between (94.8% ± 0.03) at 1.50 mg/mL and (84.2% ± 0.86) at 0.15 mg/mL. It showed high polyphenols (21.4 ± 0.327 mg GAE/g) and high flavonoids content (157.9 ± 2.22 mg QE/g). Effect of extract was investigated against HepG2 cells. A dose-dependent reduction in cell viability was recorded in cells treated with the extract. The IC₅₀ was ~ 300 µg/mL. It significantly inhibited the level of important prerequisite angiogenesis markers both in HepG2 cells and ex vivo.

Electronic supplementary material

The online version of this article (10.1186/s13104-018-3960-y) contains supplementary material, which is available to authorized users.

Antioxidant and anticancer activities of Trigonella foenum-graecum, Cassia acutifolia and Rhazya stricta

BACKGROUND

Here, we determined in vitro antioxidant activity, total phenols and flavonoids and evaluated antiproliferative activity of three medicinal plant extracts: Trigonella foenum-graecum (Fenugreek), Cassia acutifolia (Senna) and Rhazya stricta (Harmal).

METHODS

The leaves of the three medicinal plants were extracted with 70% ethanol. Antioxidant activities of the extracts were determined by using DPPH (1,1-diphenyl-2-picrylhydrazyl) assay. Total flavonoid and phenolic contents were determined using colorimetric assays. MTT assay was used to estimate the antiproliferative activities of the extracts against human hepatoma (HepG2) cancer cell line. In addition, the effects of R. stricta extract on cell cycle, colony formation, and wound healing of HepG2 cells and tube formation of HUVEC cells were assessed.

RESULTS

Percentage inhibition of DPPH scavenging activity were dose-dependent and ranged between (89.9% ± 0.51) and (28.6% ± 2.07). Phenolic contents ranged between (11.5 ± 0.013) and (9.7 ± 0.008) mg GAE/g while flavonoid content ranged between (20.8 ± 0.40) and (0.12 ± 0.0.01) mg QE/g. Antiproliferative results of the extracts were found to be consistent with their antioxidant activity. Among the extracts evaluated, that of R. stricta showed the best antioxidant, antiproliferative and antimetastatic activities at low concentration. It also inhibited the colony-formation capacity of HepG2 cells and exhibited antiangiogenic activity. Cell cycle analysis showed significant arrest of cells at G2/M phase 12 and 48 h after treatment and significant arrest at G1/S phase after 24 h of treatment. Consistent data were observed in western blot analysis of protein levels of Cdc2 and its cyclin partners.

CONCLUSIONS

These findings introduce R. stricta as a potentially useful anti-metastatic agent and a novel potential anti-tumour agent for hepatocellular carcinoma (HCC) treatment.

Application of a new vitamin D blood test on the Emirati population

Research shows that immunoassay techniques are not the best choice for the estimation of vitamin D in human blood samples. The main reasons are that some immunoassays are not able to distinguish between 25-OHD3 and 25-OHD2 vitamin D metabolites. Furthermore, immunoassays cannot differentiate between 25OHD and inactive epimers of vitamin D. Vitamin D epimers and isobars have been known to overlap with the 25OHD signals and give false positives when tested. Liquid chromatography tandem-mass spectrometry (LC-MS/MS) can differentiate between 25OHD3 and 25OHD2. Separating epimers and isobars (which have the same molecular weight) from vitamin D is achieved through chromatographic separation from actual 25OHD peaks, although this could also cause inaccuracies in vitamin D measurements. The main aim of this study was to develop and validate an improved LC-MS/MS method (using a Shimadzu 8060 system) that could accurately detect and quantitate up to 10 different metabolites of vitamin D, as well as differentiate the epimers and isobars. The secondary aim was to apply the developed LC-MS/MS method for the accurate measurement of blood vitamin D levels in the Emirati population. The Shimadzu 8060 system was run using positive ion electrospray ionization (ESI) in Dynamic Multiple Reaction Monitoring (DMRM) mode for quantification. The method involved blood sample collection from 80 Emirati volunteers, followed by serum extraction and liquid-liquid extraction. The chromatography column used for the analysis was an Ascentis Express F5. Precursor and product ions were detected using a Shimadzu 8060 LC-MS/MS system, and 10 metabolites of vitamin D were detected and quantified, including epimers and isobars. The method validation showed good sensitivity, recovery, linearity, precision, specificity, and accuracy. Furthermore, the data showed that vitamin D epimer 3-epi-25OHD and isobar 7-α-hydroxy-4-cholesten-3-one (7αC4) accounted for a significant portion of vitamin D results in the Emirati population. We report a more reliable, reproducible, and robust LC-MS/MS method for the accurate detection of 25OHD (vitamin D) in the Emirati population. The method has the capacity to detect and separate 10 metabolites of vitamin D as well as separate 25OHD from co-eluting epimers and isobars. The method has also been successfully implemented in gauging vitamin D deficiency in the Emirati population. Thus, this improved LC-MS/MS method could prove very useful in accurately estimating the levels of vitamin D in the Emirati population and in further clinical studies.

Profiling cellular bioenergetics, glutathione levels, and caspase activities in stomach biopsies of patients with upper gastrointestinal symptoms

AIM: To measure biochemical parameters in stomach biopsies and test their suitability as diagnostic biomarkers for gastritis and precancerous lesions.

METHODS: Biopsies were obtained from the stomachs of two groups of patients (n = 40) undergoing fiber-optic endoscopy due to upper gastrointestinal symptoms. In the first group (n = 17), only the corpus region was examined. Biopsies were processed for microscopic examination and measurement of mitochondrial O₂ consumption (cellular respiration), cellular adenosine triphosphate (ATP), glutathione (GSH), and caspase activity. In the second group of patients (n = 23), both corpus and antral regions were studied. Some biopsies were processed for microscopic examination, while the others were used for measurements of cellular respiration and GSH level.

RESULTS: Microscopic examinations of gastric corpus biopsies from 17 patients revealed normal mucosae in 8 patients, superficial gastritis in 7 patients, and chronic atrophic gastritis in 1 patient. In patients with normal histology, the rate (mean ± SD) of cellular respiration was 0.17 ± 0.02 μmol/L O₂ min^-1 mg^-1, ATP content was 487 ± 493 pmol/mg, and GSH was 469 ± 98 pmol/mg. Caspase activity was detected in 3 out of 8 specimens. The values of ATP and caspase activity were highly variable. The presence of superficial gastritis had insignificant effects on the measured biomarkers. In the patient with atrophic gastritis, cellular respiration was high and ATP was relatively low, suggesting uncoupling oxidative phosphorylation. In the second cohort of patients, the examined biopsies showed either normal or superficial gastritis. The rate of cellular respiration (O_2.μmol/L min^-1 mg^-1) was slightly higher in the corpus than the antrum (0.18 ± 0.05 vs 0.15 ± 0.04, P = 0.019). The value of GSH was about the same in both tissues (310 ± 135 vs 322 ± 155, P = 0.692).

CONCLUSION: The corpus mucosa was metabolically more active than the antrum tissue. The data in this study will help in understanding the pathophysiology of gastric mucosa.

Effect of traditional Arabic coffee consumption on the glycemic index of Khalas dates tested in healthy and diabetic subjects

The consumption of dates with coffee is common among Arabs and may affect postprandial hyperglycemia ex-cursion. The study aimed to determine the effect of coffee on the glycemic index of a common variety of dates (Khalas) tested in healthy and type 2 diabetes mellitus individuals. Study subjects were thirteen healthy volunteers (mean age: 40.2±6.7 years) and ten diabetic participants with a mean HbA1c of 6.6±(0.7%) and a mean age of 40.8±5.7 years. Each subject participated in five days of tests with 50 g of glucose and 50 g equivalent of available carbohydrates from the dates (with/without coffee). Capillary glucose was measured in the healthy subjects at 0, 15, 30, 45, 60, 90 and 120 min, and for the diabetics at 0, 30, 60, 90, 120, 150 and 180 min. Glycemic indices were determined as ratios of the incremental areas under the response curves for the interventions. Statistical analyses were performed using the independent samples and paired t-tests. Mean±SE glycemic indices of the Khalas dates for the healthy individuals were 55.1±7.7 and 52.7±6.2 without and with coffee consumption, respectively. Similar values were observed for those with diabetes (53.0±6.0 and 41.5±5.4). Differences between glycemic indices of Khalas with or without coffee were not significant (p=0.124). There were no significant differences in glycemic index between the diabetic and healthy subjects (p=0.834 and p=0.202 without and with coffee respectively). In conclusion, at least in the short term, coffee does not adversely affect capillary glucose levels following Khalas dates consumption in healthy and diabetic volunteers.

Half of the Emirati population has abnormal red cell parameters: challenges for standards and screening guidelines

In populations with high prevalences of iron deficiency and thalassemia trait, many apparently healthy individuals have abnormal erythroid parameters, which may cause diagnostic problems in clinical practice. We studied the prevalence and causes of red cell parameter values outside their reference ranges in 394 healthy individuals of Bedouin Arab origin, who had complete blood counts (CBCs), hemoglobin (Hb) analyses and serum ferritin tests done. Their mean age ± standard deviation (SD) was 24.8 ± 4.9 years and 51.8% were females. Overall, 53.0% (209/394) had low Hb, MCV or MCH or high RDW. Anemia was present in 27.0% (55/204) of the women and 3.0% (6/190) of the men. Overall prevalence of MCV < 80.0 fL was 45.0% (176/394) and MCH < 27.0 pg was 48.0% (190/394); RDW > 14.0% was found in 21.0% (43/204) of women and 7.0% (14/190) of men. Of the women, 16.0% had iron deficiency anemia (33/204) and 65.0% had ferritin values of < 30.0 μg/L (133/204). The estimated prevalence of α-thalassemia (α-thal) trait in men was 32.0% (60/190) and that of β-thalassemia (β-thal) trait in both sexes was 3.0% (12/394). In conclusion, half of the healthy Emirati population have abnormal CBC values. For clinical purposes, they require reference standards for red cells that are derived from their own population. Screening of women for iron deficiency is justified due to a high prevalence of iron deficiency.

The obesity paradox in patients with acute coronary syndrome: results from the Gulf RACE-2 study

We investigated the association between in-hospital and peri-hospital mortality and body mass index (BMI)/waist circumference (WC) in a prospective acute coronary syndrome (ACS) registry in the Arabian Gulf. No significant associations with in-hospital mortality were found. Normal BMI had highest peri-hospital mortality, notably those with high WC. In logistic regression of mortality on obesity measures and potential confounders, the effects of obesity measures were no longer significant. In-hospital death increased by 5% with age and decreased by 42% in males. Mortality increased 3.7-fold with ST-elevation myocardial infarction (STEMI) and 3.0-fold with heart failure (HF) but decreased by 33% with dyslipidemia. Peri-hospital death increased by 4% with age and decreased by 30% in males. Mortality increased 2.8-fold with STEMI and 2.4-fold with HF. In- and peri-hospital mortality in ACS is significantly associated with age, gender, STEMI, HF, and dyslipidemia but not obesity measures.

Bioenergetic study of murine hepatic tissue treated in vitro with atorvastatin

Atorvastatin (a 3-hydroxy-3-methylglutaryl coenzyme-A reductase inhibitor) is a widely used cholesterol-lowering drug, which is recognized for its potential hepatotoxicity. This study investigated in vitro effects of this agent on hepatic tissue respiration, ATP content, caspase activity, urea synthesis and histology. Liver fragments from Taylor Outbred and C57Bl/6 mice were incubated at 37°C in Krebs-Henseleit buffer continuously gassed with 95% O₂: 5% CO₂ in the presence and absence of atorvastatin. Phosphorescence O₂ analyzer that measured dissolved [O₂] as a function of time was used to monitor cellular mitochondrial O₂ consumption. The caspase-3 substrate N-acetyl-asp-glu-val-asp-7-amino-4-methylcoumarin was used to monitor caspase activity. The rates of hepatocyte respiration (μM O₂ min^-1 mg^-1) in untreated samples were 0.15 ± 0.07 (n = 31). The corresponding rates for samples treated with 50 nM (therapeutic concentration), 150 nM or 1.0 μM atorvastatin for ≤13 h were 0.13 ± 0.05 (n = 19), p = 0.521. The contents of hepatocyte ATP (pmol^-1 mg^-1) in untreated samples were 40.3 ± 14.0 and in samples treated with 1.0 μM atorvastatin for ≤4.5 h were 48.7 ± 23.9 (p = 0.7754). The concentrations of urea (mg/dL mg^-1, produced over 50 min) for untreated samples were 0.061 ± 0.020 (n = 6) and for samples treated with 1.0 μM atorvastatin for ≤6 h were 0.072 ± 0.022 (n = 6), p = 0.3866. Steadily, hepatocyte caspase activity and histology were unaffected by treatments with up to 1.0 μM atorvastatin for ≤6 h. Thus, the studied murine model showed preserved hepatocyte function and structure in the presence of high concentrations of atorvastatin.

A preparation of murine liver fragments for in vitro studies: liver preparation for toxicological studies

Background

The aim of this study was to develop liver tissue preparation suitable for investigating toxins. Hepatocyte respiration, ATP content, urea synthesis, caspase activity and morphology were measured as a function of in vitro incubation time. Mice were anesthetized by sevoflurane inhalation. Small liver fragments were then rapidly excised and incubated at 37°C in Krebs-Henseleit buffer (continuously gassed with 95% O₂: 5% CO₂) for up to 6 h. Phosphorescence O₂ analyzer was used to determine the rate of cellular mitochondrial O₂ consumption (k_c, μM O₂ min^-1 mg^-1). Cellular ATP was measured using the luciferin/luciferase system. The caspase-3 substrate N-acetyl-asp-glu-val-asp-7-amino-4-methylcoumarin (Ac-DEVD-AMC) was used to monitor intracellular caspase activity; cleaved AMC moieties (reflecting caspase activity) were separated on HPLC and detected by fluorescence.

Findings

Respiration was inhibited by cyanide, confirming the oxidation occurred in the respiratory chain. The values of k_c (mean ± SD) for 0≤ t ≤6 h were 0.15 ± 0.02 μM O₂ min^-1 mg^-1 (n = 18, coefficient of variation, CV = 13%), ATP content 131 ± 69 pmol mg^-1 (1≤ t ≤6 h, n = 16, CV = 53%), synthesized urea 0.134 ± 0.017 mg/dL mg^-1 in 50 min (0≤ t ≤6 h, n = 14, CV = 13%), and AMC peak area 62,540 ± 26,227 arbitrary units mg^-1 (1≤ t ≤6 h, n = 3, CV = 42%). Hepatocyte morphology and organelles were reasonably persevered.

Conclusions

The described liver tissue preparation demonstrates stable hepatocyte structure, ultrastructure and biomarkers for up to 6 h, permitting in vitro studies.

Gender disparities in the presentation, management and outcomes of acute coronary syndrome patients: data from the 2nd Gulf Registry of Acute Coronary Events (Gulf RACE-2)

Background

Gender-related differences in mortality of acute coronary syndrome (ACS) have been reported. The extent and causes of these differences in the Middle-East are poorly understood. We studied to what extent difference in outcome, specifically 1-year mortality are attributable to demographic, baseline clinical differences at presentation, and management differences between female and male patients.

Methodology/Principal Findings

Baseline characteristics, treatment patterns, and 1-year mortality of 7390 ACS patients in 65 hospitals in 6 Arabian Gulf countries were evaluated during 2008–2009, as part of the 2nd Gulf Registry of Acute Coronary Events (Gulf RACE-2). Women were older (61.3±11.8 vs. 55.6±12.4; P<0.001), more overweight (BMI: 28.1±6.6 vs. 26.7±5.1; P<0.001), and more likely to have a history of hypertension, hyperlipidemia or diabetes. Fewer women than men received angiotensin-converting enzyme inhibitors (ACE), aspirin, clopidogrel, beta blockers or statins at discharge. They also underwent fewer invasive procedures including angiography (27.0% vs. 34.0%; P<0.001), percutaneous coronary intervention (PCI) (10.5% vs. 15.6%; P<0.001) and reperfusion therapy (6.9% vs. 20.2%; P<0.001) than men. Women were at higher unadjusted risk for in-hospital death (6.8% vs. 4.0%, P<0.001) and heart failure (HF) (18% vs. 11.8%, P<0.001). Both 1-month and 1-year mortality rates were higher in women than men (11% vs. 7.4% and 17.3% vs. 11.4%, respectively, P<0.001). Both baseline and management differences contributed to a worse outcome in women. Together these variables explained almost all mortality disparities.

Conclusions/Significance

Differences between genders in mortality appeared to be largely explained by differences in prognostic variables and management patterns. However, the origin of the latter differences need further study.

Characteristics and in-hospital outcomes of patients with acute coronary syndromes and heart failure in the United Arab Emirates

Background

Heart failure (HF) is a serious complication of acute coronary syndromes (ACS), and is associated with high in-hospital mortality and poor long-term survival. The aims of this study were to describe the clinical characteristics, management and in-hospital outcomes of coronary syndrome (ACS) patients with HF in the United Arab Emirates.

Findings

The study was selected from the Gulf Registry of Acute Coronary Events (Gulf RACE), a prospective multi-national, multicenter registry of patients hospitalized with ACS in six Middle East countries. The present analysis was focused on participants admitted to various hospitals in the UAE with a diagnosis of ACS in 2007 and were analyzed in terms of HF (Killip class II/III and IV) on admission. Of 1691 patients (mean age: 52.6 ± 11.7 years; 210 Females, 1481 Males) with ACS, 356 (21%) had an admission diagnosis of HF (Killip class II/III and IV). HF patients were less frequently males (19.2% vs. 34.3%; P < 0.001). HF was more frequently associated with hypertension (64.3% vs. 43.9%; P < 0.001), hyperlipidemia (49.4% vs. 31.8%; P < 0.001) and diabetes mellitus (DM) (51.1% vs. 36.2%; P < 0.001). HF was significantly associated with in-hospital mortality (OR = 11.821; 95% CI: 5.385-25.948; P < 0.001). In multivariate logistic regression, age, hyperlipidemia, heart rate and DM were associated with higher in-hospital HF.

Conclusions

HF is observed in about 1 in 5 patients with ACS in the UAE and is associated with a significant increase in in-hospital mortality and other adverse outcomes.

Prevalence, Characteristics, and In-Hospital Outcomes of Metabolic Syndrome among Patients with Acute Coronary Syndrome in the United Arab Emirates

Objective:

To evaluate clinical profiles, management and in-hospital outcomes of acute coronary syndrome (ACS) patients with metabolic syndrome (MetS) in the United Arab Emirates (UAE).

Methods:

MetS was defined according to the criteria for its diagnosis by the International Diabetes Federation (IDF) and the American Heart Association/National Heart, Lung and Blood Institute (AHA/NHLBI). Participants were admitted to various hospitals in the UAE with a diagnosis of ACS in 2007 as part of the Gulf Registry of Acute Coronary Events (Gulf RACE) project. We compared baseline characteristics, treatment patterns, and in-hospital outcomes stratified by MetS status.

Results:

Of 1259 patients with ACS in the UAE (mean age: 52 ± 11 years, 88.8% males), the majority (n = 851, 67.6%) had MetS. MetS patients were more frequently males (86.4 vs 13.6%; P < 0.001). They were more obese (waist circumference and BMI, P < 0.001) as compared with non-MetS patients. MetS was more frequently associated with hypertension (51.1 vs 37.7%; P < 0.001) and diabetes mellitus (45.6 vs 24.3%; P < 0.001). After multivariate adjustment, certain MetS criteria rather than MetS itself were associated with higher in-hospital mortality and heart failure. Paradoxically, hypertension was associated with lower in-hospital mortality.

Conclusions:

Prevalence of MetS among patients with ACS in our study population was high. Certain MetS criteria were associated with higher in-hospital mortality and heart failure.

Characteristics, management, and in-hospital outcomes of diabetic patients with acute coronary syndrome in the United Arab Emirates

We describe the baseline characteristics, management, and in-hospital outcomes of patients in the United Arab Emirates (UAE) with DM admitted with an acute coronary syndrome (ACS) and assess the influence of DM on in-hospital mortality. Data was analyzed from 1697 patients admitted to various hospitals in the UAE with a diagnosis of ACS in 2007 as part of the 1st Gulf RACE (Registry of Acute Coronary Events). Of 1697 patients enrolled, 668 (39.4%) were diabetics. Compared to patients without DM, diabetic patients were more likely to have a past history of coronary artery disease (49.1% versus 30.1%, P < 0.001), hypertension (67.2% versus 36%, P < 0.001), and prior revascularization (21% versus 11.4%, P < 0.001). They experienced more in-hospital recurrent ischemia (8.5% versus 5.1%; P = 0.004) and heart failure (20% versus 10%; P < 0.001). The mortality rate was 2.7% for diabetics and 1.6% for nondiabetics (P = 0.105). After age adjustment, in-hospital mortality increased by 3.5% per year of age (P = 0.016). This mortality was significantly higher in females than in males (P = 0.04). ACS patients with DM have different clinical characteristics and appear to have poorer outcomes.

Gender differences in acute coronary syndrome in Arab Emirati women--implications for clinical management

Gender differences exist in many aspects of acute coronary syndrome (ACS), including presentation and delay in diagnosis and treatment. The aim of the study was to evaluate gender-related differences in ACS patients in the United Arab Emirates (UAE). We analyzed a subset (n = 1697) of the Gulf Registry of Acute Coronary Events (Gulf RACE) data collected in 2007 of patients with ACS from 18 UAE hospitals. Women were significantly older (mean age: 64.0 ± 12.4 years for females and 50.9 ± 10.6 years for males, P < .001), more often had cardiac risk factors and were significantly less treated with β-blockers and reperfusion therapy. The adjusted mortality rate of women was 4.6% versus 1.2% in men (P < .001). Heart failure was higher in females compared with men (24.6% vs 12.5%; P < .001). Reasons for the high in-hospital mortality in women need to be investigated further.

Synthesis and biological evaluation of potential new inhibitors of the bacterial transferase MraY with a β-ketophosphonate structure

Stable analogs of bacterial transferase MraY substrate or product with a pyrophosphate surrogate in their structure are described. β-ketophosphonates were designed as pyrophosphate bioisosteres and were investigated as UDP-GlcNAc mimics. The developed strategy allows introduction of structural diversity at a late stage of the synthesis. The biological activity of the synthesized compounds was evaluated on the MraY enzyme.

Glycemic indices of five varieties of dates in healthy and diabetic subjects

Background

This study was designed to determine the glycemic indices of five commonly used varieties of dates in healthy subjects and their effects on postprandial glucose excursions in individuals with type 2 diabetes mellitus.

Methods

Composition analysis was carried out for five types of dates (Tamer stage). The weights of the flesh of the dates equivalent to 50 g of available carbohydrates were calculated. The study subjects were thirteen healthy volunteers with a mean (± SD) age of 40.2 ± 6.7 years and ten participants with type 2 diabetes mellitus (controlled on lifestyle measures and/or metformin) with a mean HbA1c (± SD) of 6.6 ± (0.7%) and a mean age (± SD) of 40.8 ± 5.7 years. Each subject was tested on eight separate days with 50 g of glucose (on 3 occasions) and 50 g equivalent of available carbohydrates from the 5 varieties of date (each on one occasion). Capillary glucose was measured in the healthy subjects at 0, 15, 30, 45, 60, 90 and 120 min and for the diabetics at 0, 30, 60, 90, 120, 150 and 180 min. The glycemic indices were determined as ratios of the incremental areas under the response curves for the dates compared to glucose. Statistical analyses were performed using the Mann-Whitney U test and repeated measures analysis of variance.

Results

Mean glycemic indices ± SEM of the dates for the healthy individuals were 54.0 ± 6.1, 53.5 ± 8.6, 46.3 ± 7.1, 49.1 ± 3.6 and 55.1 ± 7.7 for Fara'd, Lulu, Bo ma'an, Dabbas and Khalas, respectively. Corresponding values for those with type 2 diabetes were very similar (46.1 ± 6.2, 43.8 ± 7.7, 51.8 ± 6.9, 50.2 ± 3.9 and 53.0 ± 6.0). There were no statistically significant differences in the GIs between the control and the diabetic groups for the five types of dates, nor were there statistically significant differences among the dates' GIs (df = 4, F = 0.365, p = 0.83).

Conclusion

The results show low glycemic indices for the five types of dates included in the study and that their consumption by diabetic individuals does not result in significant postprandial glucose excursions. These findings point to the potential benefits of dates for diabetic subjects when used in a healthy balanced diet.

Trial Registration Number

ClinicalTrials.gov NCT01307904

Prevalence of undiagnosed diabetes and quality of care in diabetic patients followed at primary and tertiary clinics in Abu Dhabi, United Arab Emirates

AIMS

To investigate the prevalence of undiagnosed type 2 diabetes (T2D) at primary health care (PHC) clinics, and to assess the quality of care of diabetic patients followed at a tertiary hospital diabetes center in Abu Dhabi, United Arab Emirates (UAE).

METHODS

Between May 2009 and October 2010, adult patients attending two PHC clinics, and adult diabetic patients attending the diabetes center, were invited to participate in the study. After overnight fast, participants returned for interview and laboratory tests. Undiagnosed T2D was defined by FPG ≥ 7.0 mmol/l or HbA1c ≥ 6.5%. Quality of care was assessed by reported care practices and achievement of internationally recognized targets.

RESULTS

Out of 239 patients at PHC clinics without history of T2D, 14.6% had undiagnosed T2D, and 31% had increased risk of diabetes (FPG 5.6-7.0 mmol/l or HbA1c 5.7-6.5%). The independent predictors of undiagnosed T2D were age (adjusted OR per year 1.07, 95% CI 1.04-1.11, p < 0.001) and BMI ≥ 25 (adjusted OR 4.2, 95% CI 0.91-19.7, p = 0.033). Amongst all 275 diagnosed T2D patients, including those attending PHC clinics and those followed at the diabetes center, it was found that 40.1% followed dietary recommendations, 12% reported visiting a diabetes educator, 28.2% walked for exercise, and 13.5% attained recognized targets of HbA1c < 7%, blood pressure < 130/80 mmHg, and LDL cholesterol < 2.6 mmol/l.

CONCLUSIONS

Almost half of the adult patients attending PHC clinics had undiagnosed T2D, or increased diabetes risk. Care practices, and achievement of treatment targets, were suboptimal.

Synthesis and Biological Evaluation of Muraymycin Analogues Active against Anti-Drug-Resistant Bacteria

Muraymycin analogues with a lipophilic substituent were synthesized using an Ugi four-component assemblage. This approach provides ready access to a range of analogues simply by altering the aldehyde component. The impact of the lipophilic substituent on the antibacterial activity was very large, and analogues 7b-e and 8b-e exhibited good activity against a range of Gram-positive bacterial pathogens including methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecium. This study also showed that the accessory urea-dipeptide motif contributes to MraY inhibitory and antibacterial activity. The knowledge obtained from our structure-activity relationship study of muraymycins provides further direction toward the design of potent MraY inhibitors. This study has set the stage for the generation of novel antibacterial "lead" compounds based on muraymycins.

Function-oriented synthesis of simplified caprazamycins: discovery of oxazolidine-containing uridine derivatives as antibacterial agents against drug-resistant bacteria

The rational simplification of the caprazamycin (CPZ) class of nucleoside natural products was carried out to address their molecular complexity. First, analogues 6-8, where the diazepanone ring of the CPZ was removed and a lipophilic side chain was attached to either the C-7' or N(6') atom, were used to investigate the conformation-activity relationship. On the basis of this relationship, we designed the oxazolidine-containing uridine derivatives 18-21 by restricting the conformation of 6-8. As a result, the (t)Bu ester derivatives 20 were found to be the most active against a range of bacterial strains containing VRE with a potency similar to that of the parent CPZs. This study provides a novel strategy for the development of a new type of antibacterial agent effective against drug-resistant bacteria.

Specific interactions of clausin, a new lantibiotic, with lipid precursors of the bacterial cell wall

We investigated the specificity of interaction of a new type A lantibiotic, clausin, isolated from Bacillus clausii, with lipid intermediates of bacterial envelope biosynthesis pathways. Isothermal calorimetry and steady-state fluorescence anisotropy (with dansylated derivatives) identified peptidoglycan lipids I and II, embedded in dodecylphosphocholine micelles, as potential targets. Complex formation with dissociation constants of approximately 0.3 muM and stoichiometry of approximately 2:1 peptides/lipid intermediate was observed. The interaction is enthalpy-driven. For the first time, to our knowledge, we evidenced the interaction between a lantibiotic and C(55)-PP-GlcNAc, a lipid intermediate in the biosynthesis of other bacterial cell wall polymers, including teichoic acids. The pyrophosphate moiety of these lipid intermediates was crucial for the interaction because a strong binding with undecaprenyl pyrophosphate, accounting for 80% of the free energy of binding, was observed. No binding occurred with the undecaprenyl phosphate derivative. The pentapeptide and the N-acetylated sugar moieties strengthened the interaction, but their contributions were weaker than that of the pyrophosphate group. The lantibiotic decreased the mobility of the pentapeptide. Clausin did not interact with the water-soluble UDP-MurNAc- and pyrophosphoryl-MurNAc-pentapeptides, pointing out the importance of the hydrocarbon chain of the lipid target.

Active site mapping of MraY, a member of the polyprenyl-phosphate N-acetylhexosamine 1-phosphate transferase superfamily, catalyzing the first membrane step of peptidoglycan biosynthesis

The MraY transferase is an integral membrane protein that catalyzes an essential step of peptidoglycan biosynthesis, namely the transfer of the phospho-N-acetylmuramoyl-pentapeptide motif onto the undecaprenyl phosphate carrier lipid. It belongs to a large superfamily of eukaryotic and prokaryotic prenyl sugar transferases. No 3D structure has been reported for any member of this superfamily, and to date MraY is the only protein that has been successfully purified to homogeneity. Nineteen polar residues located in the five cytoplasmic segments of MraY appeared as invariants in the sequences of MraY orthologues. A certain number of these invariant residues were found to be conserved in the whole superfamily. To assess the importance of these residues in the catalytic process, site-directed mutagenesis was performed using the Bacillus subtilis MraY as a model. Fourteen residues were shown to be essential for MraY activity by an in vivo functional complementation assay using a constructed conditional mraY mutant strain. The corresponding mutant proteins were purified and biochemically characterized. None of these mutations did significantly affect the binding of the nucleotidic and lipidic substrates, but the k cat was dramatically reduced in almost all cases. The important residues for activity therefore appeared to be distributed in all the cytoplasmic segments, indicating that these five regions contribute to the structure of the catalytic site. Our data show that the D98 residue that is invariant in the whole superfamily should be involved in the deprotonation of the lipid substrate during the catalytic process.