Instruct: Given a question, retrieve relevant documents that answer the question.
Query: nitroglycerin
Evidence suggests that endothelial dysfunction is on the causal pathway for both atherogenesis and destabilization of established plaques. In this review, the role of flow-mediated dilatation (FMD) as a non-invasive method to assess endothelial function is discussed. Technical modifications and development of analysis software have significantly improved the variability of the method. Following a strict standardized protocol enables reproducible measurements to be achieved and export of the technique from specialized laboratories to population studies and multicentre settings. Endothelial function assessed by FMD has been shown to be affected by cardiovascular risk factors, to be related to structural arterial disease and to cardiovascular outcome, validating its use for studying the pathophysiology of arterial disease. Numerous studies have also demonstrated that it is responsive to physiological and pharmacological interventions. Flow-mediated dilatation provides unique opportunities in drug development programmes to assess an early rapidly responsive signal of risk or benefit, complementing endpoints of structural arterial disease and cardiovascular outcomes that take much longer and are more expensive.
Tritiated naloxone, a powerful opiate antagonist, specifically binds to an opiate receptor of mammalian brain and guinea pig intestine. Competition for the opiate receptor by various opiates and their antagonists closely parallels their pharmacological potency. The opiate receptor is confined to nervous tissue.
Total N-nitroso compounds (NOC) and NOC precursors (NOCP) were determined in extracts of food and tobacco products. Following Walters' method, NOC were decomposed to NO with refluxing HBr/HCl/HOAc/EtOAc and NO was measured by chemiluminescence. NOC were determined after sulfamic acid treatment to destroy nitrite, and NOCP were determined after treatment with 110 mM nitrite and then sulfamic acid. Analysis without HBr gave results < or =20% of those with HBr. This NOC method was efficient for nitrosamines but not nitrosoureas. The standard nitrosation for determining NOCP gave high yields for readily nitrosated amines, including 1-deoxy-1-fructosylvaline, but not for simple amines, dipeptides, and alkylureas. Mean NOC and NOCP results were (respectively, in micromol/kg of product) 5.5 and 2700 for frankfurters, 0.5 and 660 for fresh meat, 5.8 and 5800 for salted, dried fish, and 660 and 2900 for chewing tobacco (all for aqueous extracts) and 220 and 20000 nmol/cigarette for MeCN extracts of cigarette smoke filter pads.
The triptans, selective serotonin 5-HT1B/1D agonists, are very effective acute migraine drugs. Soon, seven different triptans will be clinically available at 13 different oral doses, making evidence-based selection guidelines necessary. Triptan trials have similar designs, facilitating meta-analysis. We wished to provide an evidence-based foundation for using triptans in clinical practice, and to review the methodological issues surrounding triptan trials. We asked pharmaceutical companies and the principal investigators of company-independent trials for the 'raw patient data' of all double-blind, randomized, controlled, clinical trials with oral triptans in migraine. All data were cross-checked with published or presented data. We calculated summary estimates across studies for important efficacy and tolerability parameters, and compared these with those from direct, head-to-head, comparator trials. Out of 76 eligible clinical trials, 53 (12 not yet published) involving 24089 patients met the criteria for inclusion. Mean results (and 95% confidence intervals) for sumatriptan 100 mg, the first available and most widely prescribed oral triptan, are 59% (57-60) for 2 h headache response (improvement from moderate or severe to mild or no pain); 29% (27-30) for 2 h pain free (improvement to no pain); 20% (18-21) for sustained pain free (pain free by 2 h and no headache recurrence or use of rescue medication 2-24 h post-dose), and 67% (63-70) for consistency (response in at least two out of three treated attacks); placebo-subtracted proportions for patients with at least one adverse event (AE) are 13% (8-18), for at least one central nervous system AE 6% (3-9), and for at least one chest AE 1.9% (1.0-2.7). Compared with these data: rizatriptan 10 mg shows better efficacy and consistency, and similar tolerability; eletriptan 80 mg shows better efficacy, similar consistency, but lower tolerability; almotriptan 12.5 mg shows similar efficacy at 2 h but better sustained pain-free response, consistency, and tolerability; sumatriptan 25 mg, naratriptan 2.5 mg and eletriptan 20 mg show lower efficacy and better tolerability; zolmitriptan 2.5 mg and 5 mg, eletriptan 40 mg, and rizatriptan 5 mg show very similar results. The results of the 22 trials that directly compared triptans show the same overall pattern. We received no data on frovatriptan, but publicly available data suggest substantially lower efficacy. The major methodological issues involve the choice of the primary endpoint, consistency over multiple attacks, how to evaluate headache recurrence, use of placebo-subtracted proportions to control for across-study differences, and the difference between tolerability and safety. In addition, there are a number of methodological issues specific for direct comparator trials, including encapsulation and patient selection. At marketed doses, all oral triptans are effective and well tolerated. Differences among them are in general relatively small, but clinically relevant for individual patients. Rizatriptan 10 mg, eletriptan 80 mg and almotriptan 12.5 mg provide the highest likelihood of consistent success. Sumatriptan features the longest clinical experience and the widest range of formulations. All triptans are contra-indicated in the presence of cardiovascular disease.
BACKGROUND: Ginger has been used throughout the world as a therapeutic agent for centuries. The herb is increasingly used in Western society also, with one of the most common indications being pregnancy-induced nausea and vomiting (PNV). OBJECTIVES: To examine the evidence for the safety and effectiveness of ginger for PNV. METHODS: Randomised controlled trials (RCTs) of ginger and PNV were sourced from CINAHL, the Cochrane library, MEDLINE and TRIP. The methodological quality of RCTs was assessed using the Critical Appraisal Skills Programme (CASP) tool. RESULTS: Four RCTs met the inclusion criteria. All trials found orally administered ginger to be significantly more effective than placebo in reducing the frequency of vomiting and intensity of nausea. Adverse events were generally mild and infrequent. CONCLUSION: The best available evidence suggests that ginger is a safe and effective treatment for PNV. However, there remains uncertainty regarding the maximum safe dosage of ginger, appropriate duration of treatment, consequences of over-dosage, and potential drug-herb interactions; all of which are important areas for future research. Copyright © 2012 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.
Glyphosate surfactant herbicide (GlySH) toxicity is an uncommon poisoning. We report two fatalities involving suicidal ingestion of this herbicide. Both deaths occurred despite early recognition of the serious nature of the poisoning and aggressive treatment. The deaths in this series are analysed in the context of a review of existing literature. Although traditionally regarded as minimally toxic, many deaths have been reported following suicidal ingestion. Severe GlySH toxicity may be refractory even to the most intensive supportive care. The triad of pulmonary oedema, metabolic acidosis and hyperkalaemia portends poor outcome. While containing a carbon phosphorus moiety, GlySH does not exhibit organophosphate toxicity. A clinical guide to assessing severity of GlySH toxicity is proposed and treatment modalities discussed.
PURPOSE: Dietary nitrate supplementation has been shown to reduce the O2 cost of submaximal exercise and to improve high-intensity exercise tolerance. However, it is presently unknown whether it may enhance performance during simulated competition. The present study investigated the effects of acute dietary nitrate supplementation on power output (PO), VO2, and performance during 4- and 16.1-km cycling time trials (TT). METHODS: After familiarization, nine club-level competitive male cyclists were assigned in a randomized, crossover design to consume 0.5 L of beetroot juice (BR; containing ∼ 6.2 mmol of nitrate) or 0.5 L of nitrate-depleted BR (placebo, PL; containing ∼ 0.0047 mmol of nitrate), ∼ 2.5 h before the completion of a 4- and a 16.1-km TT. RESULTS: BR supplementation elevated plasma [nitrite] (PL = 241 ± 125 vs BR = 575 ± 199 nM, P < 0.05). The VO2 values during the TT were not significantly different between the BR and PL conditions at any elapsed distance (P > 0.05), but BR significantly increased mean PO during the 4-km (PL = 279 ± 51 vs BR = 292 ± 44 W, P < 0.05) and 16.1-km TT (PL = 233 ± 43 vs BR = 247 ± 44 W, P < 0.01). Consequently, BR improved 4-km performance by 2.8% (PL = 6.45 ± 0.42 vs BR = 6.27 ± 0.35 min, P < 0.05) and 16.1-km performance by 2.7% (PL = 27.7 ± 2.1 vs BR = 26.9 ± 1.8 min, P < 0.01). CONCLUSIONS: These results suggest that acute dietary nitrate supplementation with 0.5 L of BR improves cycling economy, as demonstrated by a higher PO for the same VO2 and enhances both 4- and 16.1-km cycling TT performance.
Linaclotide (Linzess) for irritable bowel syndrome with constipation and for chronic idiopathic constipation.
Peppermint oil is easily available as a constituent of medicines. A near fatal case due to ingestion of toxic dose of oral peppermint oil is being reported. The patient came in a comatosed state and was in shock. She was managed with mechanical ventilation and ionotropes. Her vital parameters reached normal within 8 hours and became conscious by 24 hours. The side effects of peppermint oil are considered to be mild but this case report warns that ingestion of oral toxic doses of peppermint oil could be dangerous.
Intestinal permeability was estimated in healthy subjects after ingestion of aspirin (1.2+1.2 g), ibuprofen (400+400 mg) and indomethacin (75+50 mg) at midnight and an hour before starting a 51chromium labelled ethylenediaminetetraacetate absorption test. Intestinal permeability increased significantly from control levels following each drug and the effect was related to drug potency to inhibit cyclooxygenase. Intestinal permeability increased to a similar extent after oral and rectal administration of indomethacin showing that the effect is systemically mediated. Prostaglandin E2 decreased intestinal permeability significantly but failed to prevent the indomethacin induced increased intestinal permeability. These studies show that non-steroidal anti-inflammatory drugs disrupt the intestinal barrier function in man and suggest that the morphological correlates of the damage may reside at the level of the intercellular junctions.
Frequently, patients identified as high risk for postoperative nausea and vomiting (PONV) are treated prophylactically with intravenous (IV) ondansetron and postoperatively with IV promethazine. The purpose of this study was to determine if using an aromatic therapy of 70% isopropyl alcohol (IPA) would be more effective than promethazine in resolution of breakthrough PONV symptoms in groups of high-risk patients administered prophylactic ondansetron. All subjects enrolled were identified as high risk for PONV, administered general anesthesia and a prophylactic antiemetic of 4 mg of IV ondansetron, and randomized to receive IPA or promethazine for treatment of breakthrough PONV Demographics, verbal numeric rating scale (VNRS) scores for nausea, time to 50% reduction in VNRS scores, and overall antiemetic and incidence of PONV were measured. The data for 85 subjects were included in analysis; no differences in demographic variables or baseline measurements were noted between groups. The IPA group reported a faster time to 50% reduction in VNRS scores and decreased overall antiemetic requirements. A similar incidence in PONV was noted between groups. Based on these findings, we recommend that inhalation of 70% IPA is an option for treatment of PONV in high-risk patients who have received prophylactic ondansetron.
The Family Smoking Prevention and Tobacco Control Act gives the Food and Drug Administration power to regulate tobacco products. This commentary calls for immediate regulation of the carcinogenic tobacco-specific nitrosamines 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and N’-nitrosonornicotine (NNN) in cigarette tobacco as a logical path to cancer prevention. NNK and NNN, powerful carcinogens in laboratory animals, have been evaluated as “carcinogenic to humans” by the International Agency for Research on Cancer. NNK and NNN are present in the tobacco of virtually all marketed cigarettes; levels in cigarette smoke are directly proportional to the amounts in tobacco. The NNK metabolite NNAL, itself a strong carcinogen, is present in the urine of smokers and non-smokers exposed to secondhand smoke. Some of the highest levels of NNK and NNN are found in U.S. products. It is well established that factors such as choice of tobacco blend, agricultural conditions, and processing methods influence levels of NNK and NNN in cigarette tobacco and cigarette smoke. Therefore, it is time to control these factors and produce cigarettes with 100 ppb or less each of NNK and NNN in tobacco, which would result in an approximate 15-20 fold reduction of these carcinogens in the mainstream smoke of popular cigarettes sold in the United States.
In the early 1930s, the industrial chemical dinitrophenol found widespread favor as a weight-loss drug, due principally to the work of Maurice Tainter, a clinical pharmacologist from Stanford University. Unfortunately the compound's therapeutic index was razor thin and it was not until thousands of people suffered irreversible harm that mainstream physicians realized that dinitrophenol's risks outweighed its benefits and abandoned its use. Yet, it took passage of the Food, Drug, and Cosmetic Act in 1938 before federal regulators had the ability to stop patent medicine men from selling dinitrophenol to Americans lured by the promise of a drug that would safely melt one's fat away.
Postoperative nausea and vomiting (PONV) continues to be one of the most common complaints following surgery, occurring in more than 30% of surgeries, or as high as 70% to 80% in certain high-risk populations without prophylaxis. The 5-hydroxytryptamine type 3 (5-HT(3)) receptor antagonists continue to be the mainstay of antiemetic therapy, but newer approaches, such as neurokinin-1 antagonists, a longer-acting serotonin receptor antagonist, multimodal management, and novel techniques for managing high-risk patients are gaining prominence. The related problem of postdischarge nausea and vomiting (PDNV) has received increasing attention from health care providers. The issues of PONV and PDNV are especially significant in the context of ambulatory surgeries, which comprise more than 60% of the combined 56.4 million ambulatory and inpatient surgery visits in the United States. Because of the relatively brief period that ambulatory patients spend in health care facilities, it is particularly important to prevent and treat PONV and PDNV swiftly and effectively. Copyright (c) 2010. Published by Elsevier Inc.
1. The effects of grapefruit juice and naringenin on the activity of the human cytochrome P450 isoform CYP1A2 were evaluated using caffeine as a probe substrate. 2. In vitro naringin was a potent competitive inhibitor of caffeine 3-demethylation by human liver microsomes (Ki = 7-29 microM). 3. In vivo grapefruit juice (1.2 l day-1 containing 0.5 g l-1 naringin, the glycone form of naringenin) decreased the oral clearance of caffeine by 23% (95% CI: 7%-30%) and prolonged its half-life by 31% (95% CI: 20%-44%) (n = 12). 4. We conclude that grapefruit juice and naringenin inhibit CYP1A2 activity in man. However, the small effect on caffeine clearance in vivo suggests that in general the ingestion of grapefruit juice should not cause clinically significant inhibition of the metabolism of other drugs that are substrates of CYPIA2.
Effect of aqueous extract of several herbs on human platelet aggregation in vitro was investigated. Out of 28 herbs/nutriceuticals investigated, camomile, nettle alfalfa, garlic and onion exhibited most significant anti-platelet activity (>or=45% inhibition). Aqueous extracts of alfalfa, fresh nettle, and camomile inhibited ADP induced-platelet aggregation by 73, 65 and 60%, respectively, compared with control (P < 0.05). Camomile and alfalfa inhibited collagen-induced platelet aggregation by 84 and 65%, respectively, but nettle could not inhibit collagen-induced aggregation. In contrast, nettle was the most potent inhibitor (66%) of whole blood aggregation induced by collagen, followed by alfalfa (52%), and camomile (30%) compared with control (P < 0.05). None of these three herbs however could inhibit arachidonic acid or thrombin induced platelet aggregation. Camomile and alfalfa strongly inhibited thromboxane B2 synthesis induced by ADP or collagen, but nettle had no effect. Alfalfa and nettle increased cGMP levels in platelets by 50 and 35%, respectively, compared with the control (1.85 +/- 0.23 nM) (P < 0.005). All these data indicate that camomile, nettle and alfalfa have potent anti-platelet properties, and their inhibitory actions are mediated via different mechanisms.
Caffeine is the most widely used pharmacologic substance in the world. It is found in common nonessential grocery items (e.g., coffee, tea, cocoa, and chocolate). The effects of caffeine on cardiovascular diseases, including hypertension, remain controversial, and there is little information on its direct effect on vascular function. The purpose of this study was to determine the effect of caffeine on endothelial function in humans. This study was a double-blind, randomized placebo and active drug study. Forearm blood flow (FBF) responses to acetylcholine (ACh), an endothelium-dependent vasodilator, and to sodium nitroprusside, an endothelium-independent vasodilator, were evaluated in healthy young men before and after the oral administration of caffeine 300 mg (n = 10) or placebo (n = 10). FBF was measured by using a strain-gauge plethysmograph. Caffeine significantly increased systolic and diastolic blood pressures by 6.0 +/- 6.0 and 2.6 +/- 3.1 mm Hg (p <0.05), respectively, but did not alter heart rate or baseline FBF. Caffeine augmented the FBF responses to ACh from 21.2 +/- 7.1 to 26.6 +/- 8.1 ml/min/100 ml tissue (p <0.05), whereas sodium nitroprusside-stimulated vasodilation was not altered by caffeine administration. The intra-arterial infusion of N(G)-monomethyl-L-arginine, a nitric oxide synthase inhibitor, abolished the caffeine-induced augmentation of FBF response to ACh. In the placebo group, the ACh- and sodium nitroprusside-stimulated vasodilation was similar before and after the follow-up period. In conclusion, these findings suggest that the acute administration of caffeine augments endothelium-dependent vasodilation in healthy young men through an increase in nitric oxide production.
PURPOSE OF REVIEW: This review provides a comprehensive selection of the latest clinical trial results in antimigraine treatment. RECENT FINDINGS: The oral calcitonine gene-related peptide antagonist telcagepant is efficacious in acute treatment. Compared to triptans, its efficacy is almost comparable but its tolerance is superior. The same is true for the 5HT-1F agonist lasmiditan, another agent devoid of vascular effects. Triptans, as other drugs, are more efficient if taken early but nonsteroidal anti-inflammatory drugs and analgesics remain useful for acute treatment, according to several meta-analyses. Single-pulse transcranial magnetic stimulation during the aura rendered more patients pain-free (39%) than sham stimulation (22%) in one study. Topiramate could be effective for migrainous vertigo, but it did not prevent transformation to chronic migraine in patients with high attack frequency. Onabotulinumtoxin A was effective for chronic migraine and well tolerated, but the therapeutic gain over placebo was modest; the clinical profile of responders remains to be determined before widespread use. Occipital nerve stimulation was effective in intractable chronic migraine with 39% of responders compared to 6% after sham stimulation. This and other neuromodulation techniques, such as sphenopalatine ganglion stimulation, are promising treatments for medically refractory patients but large controlled trials are necessary. One study suggests that outcome of patent foramen ovale closure in migraine might depend on anatomic and functional characteristics. SUMMARY: Drugs with a better efficacy or side-effect profile than triptans may soon become available for acute treatment. The future may also look brighter for some of the very disabled chronic migraineurs thanks to novel drug and neuromodulation therapies.
Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used. It is well recognised that they may adversely cause damage throughout the gastrointestinal tract and aggravate pre-existing disease. Their side effects on the upper gastrointestinal tract can be assessed by various means; each study type has different clinical connotations. Short-term use (less than 14 days) demonstrates dose-dependent damage of prescribed NSAIDs; the damage is proportional to the acidity of the drugs and not seen with Cyclooxygenase-2 (COX-2) selective inhibitors that have a pKa over 7.0. There have not been any serious outcomes, such as bleeding or perforation in these studies, and Helicobacter pylori (HP) plays no role in this damage. Long-term (3 months or more) endoscopy studies in patients show ulcer rates from 15%-35% with the various NSAIDs, but serious outcomes are exceedingly rare. Epidemiological studies show an association between NSAID intake and serious events. Ibuprofen is consistently at the lower end of toxicity rankings, whereas ketorolac and azapropazone are the worst. The risk of bleeding is increased with advancing age, presence of HP, previous history of bleeding, anticoagulant use, etc. The mega-trials show that COX-2 selective agents halve the bleeding episodes, but NSAID-induced gastric bleeding is very rare usually, less than 1 in 200 subjects taking them for a year. Seventy percent of patients develop NSAID-enteropathy, which is associated with intestinal blood and protein loss and rarely strictures. Over-the-counter (OTC) use of ibuprofen and diclofenac is associated with symptomatic gastrointestinal side effects comparable with placebo. Ibuprofen is shown to be remarkably well tolerated at OTC doses in a number of studies. There are recent studies to suggest that OTC NSAIDs should be taken on a fasting stomach, not with food as commonly advocated. © 2012 Blackwell Publishing Ltd.
New antiemetic drug developments, formulations, guidelines, risk evaluation, and controversies have occurred in the area of postoperative nausea and vomiting (PONV). These developments have helped improve our understanding of the prevention and treatment of PONV in the postanesthesia care unit and after discharge home or to the hospital ward. Antiemetic drug research has resulted in the introduction of the second-generation 5-hydroxytryptamine-3 (5-HT3) receptor antagonist palonosetron and the neurokinin-1 (NK-1) receptor antagonist aprepitant, as well as new data on existing antiemetics. The next frontier and need for further nausea and vomiting research and therapy is the area of postdischarge nausea and vomiting after the patient is discharged home from phase II of the ambulatory stepdown unit or to the hospital ward. Antiemetic drug selection depends on efficacy, cost, safety, and ease of dosing. Safety concerns have arisen regarding the side effects of antiemetics, specifically their effect on the ECG with prolongation of the QTc interval by the butyrophenones and the first-generation 5-HT3 receptor antagonist class of antiemetics. The impact of pharmocogenetics on antiemetic drug metabolism and their resulting efficacy has been correlated with genetic makeup affecting drug response. A discussion of ethics in PONV research has been initiated by the meta-analysis of PONV studies. To help guide antiemetic selection and PONV therapy for clinical practitioners, the Society of Ambulatory Anesthesia (SAMBA) PONV consensus guidelines have been introduced and updated.
Many constituents present in the human diet may inhibit endogenous formation of N-nitroso compounds (NOC). Studies with human volunteers showed inhibiting effects of intake of ascorbic acid and green tea consumption on nitrosation using the N-nitrosoproline test. The aim of the present study was to evaluate the effects of ascorbic acid and green tea on urinary excretion of carcinogenic N-nitrosodimethylamine (NDMA) and N-nitrosopiperidine (NPIP) in humans. Twenty-five healthy female volunteers consumed a fish meal rich in amines as nitrosatable precursors in combination with intake of nitrate-containing drinking water at the Acceptable Daily Intake level during 7 consecutive days. During 1 week before and after nitrate intake a diet low in nitrate was consumed. Using the same protocol, the effect of two different doses of ascorbic acid (250 mg and 1 g/day) and two different doses of green tea (2 g and 4 g/day) on formation of NDMA and NPIP was studied. Mean nitrate excretion in urine significantly increased from control (76+/-24) to 167+/-25 mg/24 h. Intake of nitrate and fish resulted in a significant increase in mean urinary excretion of NDMA compared with the control weeks: 871+/-430 and 640+/-277 ng/24 h during days 1-3 and 4-7, respectively, compared with 385+/-196 ng/24 h (p<0.0002). Excretion of NPIP in urine was not related to nitrate intake and composition of the diet. Intake of 250 mg and 1 g of ascorbic acid per day resulted in a significant decrease in urinary NDMA excretion during days 4-7 (p=0.0001), but not during days 1-3. Also, consumption of four cups of green tea per day (2 g) significantly decreased excretion of NDMA during days 4-7 (p=0.0035), but not during days 1-3. Surprisingly, consumption of eight cups of green tea per day (4 g) significantly increased NDMA excretion during days 4-7 (p=0.0001), again not during days 1-3. This increase is probably a result of catalytic effects of tea polyphenols on nitrosation, or of another, yet unknown, mechanism. These results suggest that intake of ascorbic acid and moderate consumption of green tea can reduce endogenous NDMA formation.
Ginger has long been used as an alternative medication to prevent motion sickness. The mechanism of its action, however, is unknown. We hypothesize that ginger ameliorates the nausea associated with motion sickness by preventing the development of gastric dysrhythmias and the elevation of plasma vasopressin. Thirteen volunteers with a history of motion sickness underwent circular vection, during which nausea (scored 0-3, i.e., none to severe), electrogastrographic recordings, and plasma vasopressin levels were assessed with or without ginger pretreatment in a crossover-design, double-blind, randomized placebo-controlled study. Circular vection induced a maximal nausea score of 2.5 +/- 0.2 and increased tachygastric activity and plasma vasopressin. Pretreatment with ginger (1,000 and 2,000 mg) reduced the nausea, tachygastria, and plasma vasopressin. Ginger also prolonged the latency before nausea onset and shortened the recovery time after vection cessation. Intravenous vasopressin infusion at 0.1 and 0.2 U/min induced nausea and increased bradygastric activity; ginger pretreatment (2,000 mg) affected neither. Ginger effectively reduces nausea, tachygastric activity, and vasopressin release induced by circular vection. In this manner, ginger may act as a novel agent in the prevention and treatment of motion sickness.
The raw form of garlic and some of its preparations are widely recognized as antiplatelet agents that may contribute to the prevention of cardiovascular disease. Herein, we examined the in-vitro antiaggregatory activity (IVAA) of human blood platelets induced by extracts of garlic samples that were previously heated (in the form of crushed versus uncrushed cloves) using different cooking methods and intensities. The concentrations of allicin and pyruvate, two predictors of antiplatelet strength, were also monitored. Oven-heating at 200 degrees C or immersing in boiling water for 3 min or less did not affect the ability of garlic to inhibit platelet aggregation (as compared to raw garlic), whereas heating for 6 min completely suppressed IVAA in uncrushed, but not in previously crushed, samples. The latter samples had reduced, yet significant, antiplatelet activity. Prolonged incubation (more than 10 min) at these temperatures completely suppressed IVAA. Microwaved garlic had no effect on platelet aggregation. However, increasing the concentration of garlic juice in the aggregation reaction had a positive IVAA dose response in crushed, but not in uncrushed, microwaved samples. The addition of raw garlic juice to microwaved uncrushed garlic restored a full complement of antiplatelet activity that was completely lost without the garlic addition. Garlic-induced IVAA was always associated with allicin and pyruvate levels. Our results suggest that (1) allicin and thiosulfinates are responsible for the IVAA response, (2) crushing garlic before moderate cooking can reduce the loss of activity, and (3) the partial loss of antithrombotic effect in crushed-cooked garlic may be compensated by increasing the amount consumed.
Nitrosamines mediate their mutagenic effects by causing DNA damage, oxidative stress, lipid peroxidation, and pro-inflammatory cytokine activation, which lead to increased cellular degeneration and death. However, the very same pathophysiological processes comprise the "unbuilding" blocks of aging and insulin-resistance diseases including, neurodegeneration, diabetes mellitus (DM), and non-alcoholic steatohepatitis (NASH). Previous studies demonstrated that experimental exposure to streptozotocin, a nitrosamine-related compound, causes NASH, and diabetes mellitus Types 1, 2 and 3 (Alzheimer (AD)-type neurodegeneration). Herein, we review evidence that the upwardly spiraling trends in mortality rates due to DM, AD, and Parkinson's disease typify exposure rather than genetic-based disease models, and parallel the progressive increases in human exposure to nitrates, nitrites, and nitrosamines via processed/preserved foods. We propose that such chronic exposures have critical roles in the pathogenesis of our insulin resistance disease pandemic. Potential solutions include: 1) eliminating the use of nitrites in food; 2) reducing nitrate levels in fertilizer and water used to irrigate crops; and 3) employing safe and effective measures to detoxify food and water prior to human consumption. Future research efforts should focus on refining our ability to detect and monitor human exposures to nitrosamines and assess early evidence of nitrosamine-mediated tissue injury and insulin resistance.
Summary γ-Hydroxybutanoic acid (GHB) is used as a date-rape drug, which renders the victims unconscious and defenceless. Intoxications are very difficult to detect for forensic scientists due to rapid metabolism to endogenous levels of GHB. We recently discovered a new major metabolite, 2, of GHB (1) that could potentially extend the analytical detection window for GHB intoxications. Herein we disclose synthetic procedures based on a Koenigs–Knorr glucuronidation approach that provides GHB glucuronide 2 and a deuterium-labelled analogue d 4-2 of high purity suitable for analytical chemistry. In addition, we have assessed the stability of GHB glucuronide 2 by mimicking the natural pH range for urine, which is of importance in the development of new analytical methods. Using NMR we show that GHB glucuronide 2 is highly stable towards aqueous hydrolysis within the pH range normally observed for urine even at elevated temperature.