Lycopodium Mitigates Oxidative Stress and Inflammation in the Colonic Mucosa of Acetic Acid-Induced Colitis in Rats.

Inflammatory bowel diseases (IBDs) such as ulcerative colitis (UC) and Crohn's disease (CD) are diseases of the gastrointestinal system involving genetic and environmental factors attributed to oxidative stress and inflammation. Targeting oxidative stress and inflammation by novel dietary compounds of natural origin convincingly appears to be one of the important therapeutic strategies to keep the disease in remission. As there is no permanent cure for IBD except for chronic long-term treatment or surgery, it is therefore imperative to investigate plant-based agents that are receiving attention for their therapeutic benefits to overcome the debilitating clinical conditions of IBD. Lycopodium (LYCO), a plant of tropical and subtropical origin and known by numerous names such as ground pine, club moss, or devil's claw, has been popularly used for centuries in traditional medicine including Chinese and Indian medicines. In the present study, the effect of LYCO has been investigated in an acetic acid (AA)-induced colitis model in Wistar rats. LYCO was orally administered at the dose of 50 mg/kg/day either 3 days before or 30 min after the induction of IBD and continued for 7 days by intrarectal administration of AA. The changes in body weight and macroscopic and microscopic analysis of the colon of rats of different experimental groups were observed on days 0, 2, 4, and 7. The levels of myeloperoxidase (MPO), reduced glutathione (GSH), and malondialdehyde (MDA) were measured. AA caused a significant reduction in body weight and increased macroscopic and microscopic ulcer scores along with a significant decline in antioxidant enzymes, superoxide dismutase (SOD), and catalase and antioxidant substrate, glutathione (GSH). There was a concomitant increased formation of malondialdehyde (MDA), a marker of lipid peroxidation, and raised myeloperoxidase (MPO) activity, a marker of neutrophil activation. Treatment with LYCO significantly improved IBD-induced reduction in body weight, improved histology, inhibited MDA formation, and restored antioxidants along with reduced MPO activity. AA also caused the release of proinflammatory cytokines such as interleukin-1ß (IL-1ß) and interleukin-23 (IL-23). Furthermore, AA also increased the levels of calprotectin, a protein released by neutrophils under inflammatory conditions of the gastrointestinal tract. LYCO treatment significantly reduced the release of calprotectin and proinflammatory cytokines. The results demonstrate that LYCO treatment has the potential to improve disease activity by inhibiting oxidative stress, lipid peroxidation, and inflammation along with histological preservation of colonic tissues.

Histamine H3 receptor antagonists - Roles in neurological and endocrine diseases and diabetes mellitus.

Human histamine H3 receptor (H3R) was initially described in the brain of rat in 1983 and cloned in 1999. It can be found in the human brain and functions as a regulator of histamine synthesis and release. H3 receptors are predominantly resident in the presynaptic region of neurons containing histamine, where they modulate the synthesis and release of histamine (autoreceptor) or other neurotransmitters such as dopamine, norepinephrine, gamma-aminobutyric acid (GABA), glutamate, acetylcholine and serotonin (all heteroreceptors). The human histamine H3 receptor has twenty isoforms of which eight are functional. H3 receptor expression is seen in the cerebral cortex, neurons of the basal ganglia and hippocampus, which are important for process of cognition, sleep and homoeostatic regulation. In addition, histamine H3R antagonists stimulate insulin release, through inducing the release of acetylcholine and cause significant reduction in total body weight and triglycerides in obese subjects by causing a feeling of satiety in the hypothalamus. The ability of histamine H3R antagonist to reduce diabetes-induced hyperglycaemia is comparable to that of metformin. It is reasonable therefore, to claim that H3 receptor antagonists may play an important role in the therapy of disorders of cognition, the ability to sleep, oxidative stress, inflammation and anomaly of glucose homoeostasis. A large number of H3R antagonists are being developed by pharmaceutical companies and university research centres. As examples of these new drugs, this review will discuss a number of drugs, including the first histamine H3R receptor antagonist produced.

Health Benefits, Pharmacological Effects, Molecular Mechanisms, and Therapeutic Potential of α-Bisabolol.

α-Bisabolol is one of the important monocyclic sesquiterpenes, derived naturally from essential oils of many edible and ornamental plants. It was first obtained from Matricaria chamomilla, commonly known as chamomile or German chamomile. The available literature indicates that this plant along with other α-Bisabolol containing plants is popularly used in traditional medicine for potential health benefits and general wellbeing. Nutritional studies are indicative of the health benefits of α-Bisabolol. Numerous experimental studies demonstrated pharmacological properties of α-Bisabolol including anticancer, antinociceptive, neuroprotective, cardioprotective, and antimicrobial. This review aims to collectively present different pharmacological activities based on both in vitro and in vivo studies. In the present review using synoptic tables and figures, we comprehensively present that α-Bisabolol possesses therapeutic and protective activities, therefore, it can be used for potential health benefits based on pharmacological effects, underlying molecular mechanism, and favorable pharmaceutical properties. Based on the studies mostly performed on cell lines or animal models, it is evident that α-Bisabolol may be a promising nutraceutical and phytomedicine to target aberrant biological mechanisms which result in altered physiological processes and various ailments. Given the polypharmacological effects and pleiotropic properties, along with favorable pharmacokinetics, and dietary availability and safety, α-Bisabolol can be used as a dietary agent, nutraceutical or phytopharmaceutical agent or as an adjuvant with currently available modern medicines. The regulatory approval of this molecule for use as food additives, and in cosmetics and fragrance industry is also supportive of its human usage. Moreover, further studies are necessary to address pharmaceutical, pharmacological, and toxicological aspects before clinical or nutritional usage in humans. The biological actions and health benefits open opportunities for pharmaceutical development with pharmacological basis of its use in future therapeutics.

Chemical constituents and medicinal properties of Allium species.

Allium species, belonging to Alliaceae family, are among the oldest cultivated vegetables used as food. Garlic, onions, leeks and chives, which belong to this family, have been reported to have medicinal properties. The Allium species constituents have been shown to have antibacterial and antioxidant activities, and, in addition, other biological properties. These activities are related to their rich organosulfur compounds. These organosulfur compounds are believed to prevent the development of cancer, cardiovascular, neurological, diabetes, liver diseases as well as allergy and arthritis. There have also been reports on toxicities of these compounds. The major active compounds of Allium species includes, diallyl disulfide, diallyl trisulfide, diallyl sulfide, dipropyl disulfide, dipropyl trisulfide, 1-propenylpropyl disulfide, allyl methyl disulfide and dimethyl disulfide. The aim of this review is to focus on a variety of experimental and clinical reports on the effectiveness, toxicities and possible mechanisms of actions of the active compounds of garlic, onions, leek and chives.

Lipocalin-2: Structure, function, distribution and role in metabolic disorders.

Lipocalin-2 (LCN-2) is a novel, 198 amino acid adipocytokine also referred to as neutrophil gelatinase-associated lipocalin (NGAL). LCN-2 is a circulatory protein responsible for the transportation of small and hydrophobic molecules (steroid, free fatty acids, prostaglandins and hormones) to target organs after binding to megalin/glycoprotein and GP330 SLC22A17 or 24p3R LCN-2 receptors. LCN-2 has been used as a biomarker for acute and chronic renal injury. It is present in a large variety of cells including neutrophil, hepatocytes, lung, bone marrow, adipose tissue, macrophages, thymus, non-neoplastic breast duct, prostate, and renal cells. Different functions have been associated with LCN-2. These functions include antibacterial, anti-inflammatory, and protection against cell and tissue stress. Moreover, LCN-2 can increase the pool of matrix metalloproteinase 9 in human neutrophil granulocytes. Other reported functions of LCN-2 include its ability to destroy the extracellular matrix, which could enable cancer progression and spread of metastasis. Recent reports show that the tissue level of LCN-2 is increased in metabolic disorders such as obesity and type 2 diabetes, suggesting an association between LCN-2 and insulin sensitivity and glucose homeostasis. The precise role of LCN-2 in the modulation of insulin sensitivity, glucose and lipid metabolism is still unclear. This review explores the structure of LCN-2, tissue distribution, and its interaction with important metabolic pathways.

Nerolidol, a sesquiterpene, attenuates oxidative stress and inflammation in acetic acid-induced colitis in rats.

Targeting oxidative stress and inflammation by novel dietary compounds of natural origin convincingly appears to be one of the most important therapeutic strategies to keep inflammatory bowel diseases (IBD) such as ulcerative colitis disease in remission. It is imperative to investigate naturally occuring plant-derived dietary phytochemicals that are receiving attention for their therapeutic benefits to overcome the debilitating conditions of IBD. In the present study, the effect of nerolidol (NRD), a monocyclic sesquiterpene found in German Chamomile tea, was investigated in acetic acid-induced colitis model in Wistar rats. NRD was orally administered at a dose of 50 mg/kg/day either for 3 days before or 30 min after induction of IBD for 7 days, after intrarectal administration of acetic acid. The body weight, macroscopic, and microscopic analyses of the colon in different experimental groups were observed on days 0, 2, 4, and 7. Acetic acid caused significant reduction in body weight and induced macroscopic and microscopic ulcer along with a significant decline of antioxidants, concomitant to increased malondialdehyde (MDA), a marker of lipid peroxidation, and myeloperoxidase (MPO) activity, a marker of neutrophil activation. Treatment with NRD significantly improved IBD-induced reduction in body weight, improved histology, inhibited MDA formation, and restored antioxidants along with reduced MPO activity. Acetic acid also induced the release of pro-inflammatory cytokines and increased calprotectin, released by neutrophils under inflammatory conditions. NRD treatment significantly reduced calprotectin and pro-inflammatory cytokines. NRD treatment showed potential to improve disease activity and inhibit oxidative stress, lipid peroxidation, and inflammation along with histological preservation of the colon tissues.

Influence of the Novel Histamine H3 Receptor Antagonist/Inverse Agonist M39 on Gastroprotection and PGE2 Production Induced by (R)-Alpha-Methylhistamine in C57BL/6 Mice.

The role of histamine H3 receptors (H3Rs) in the regulation of gastroprotection and production of prostaglandin E2 (PGE2) as well as somatostatin remains contradictory. Therefore, the effects of the H3R antagonist/inverse agonist M39 on in vivo acidified ethanol-induced gastric ulcers and gastric acid secretion in the C57BL/6 mice were assessed. Results showed that acute systemic administration of H3R agonist (R)-α-methylhistamine (RAMH, 100 mg/kg, i.g.) significantly reduced the severity of ulcer index, increased gastric acid output, and increased mucosal PGE2 production without any alteration of somatostatin concentration in gastric juice. However, only acute systemic administration of the H2R agonist dimaprit (DIM, 10 mg/kg, p.o.) significantly decreased the level of somatostatin measured in gastric juice. Moreover, acute systemic administration of M39 (0.3 mg/kg, i.g.) abrogated the RAMH-induced increase of acid output as well as PGE2 production, but not the DIM (10 mg/kg, i.g.)-stimulated acid secretion, indicating that RAMH as well as M39 modulate the gastroprotective effects through interactions with histamine H3Rs. The present findings indicate that agonistic interaction with H3Rs is profoundly involved in the maintenance of gastric mucosal integrity by modulating PGE2 as well as gastric acid secretion, with no apparent role in the regulation of the inhibitory influence of somatostatin.

Effects of long-term dehydration on oxidative stress, apoptotic markers and neuropeptides in the gastric mucosa of the dromedary camel.

We investigated the effects of 20 days of dehydration and 20 days of dehydration followed by 72 h of rehydration on the gastric mucosa of the one-humped dromedary camel. The parameters addressed include biomarkers of oxidative stress, apoptosis, gastric epithelial histology, gastric neuropeptides, and their receptors. Nineteen clinically healthy, 4-5 year-old male dromedary camels were divided into three groups (five control camels, eight dehydrated for 20 days, six dehydrated for 20 days and then rehydrated for 72 h). Dehydration affected the oxidative stress biomarkers causing a significant increase in malondialdehyde, glutathione, nitric oxide, and catalase values compared with controls. Also the results revealed that dehydration caused different size cellular vacuoles and focal necrosis in the gastric mucosa. Rehydration for 72 h resulted in improvement in some parameters but was not enough to fully abolish the effect of dehydration. Dehydration caused significant increase in apoptotic markers; tumor necrosis factor α, caspases 8 and 3, BcL-x1 and TGFß whereas caspase 9, p53, Beclin 1, and PARP1 showed no significant change between the three groups indicating that apoptosis was initiated by the extrinsic pathway. Also there were significant increases in prostaglandin E2 receptors and somatostatin in plasma and gastric epithelium homogenate, and a significant decrease in cholecystokinin-8 receptors. A significant decrease of hydrogen potassium ATPase enzyme activity was also observed. Pepsinogen C was not affected by dehydration. It is concluded that long-term dehydration induces oxidative stress and apoptosis in camel gastric mucosa and that camels adjust gastric functions during dehydration towards water economy. More than 72 h are needed before all the effects of dehydration are reversed by rehydration.

Anticonvulsant and reproductive toxicological studies of the imidazole-based histamine H3R antagonist 2-18 in mice.

The imidazole-based H3R antagonist 2-18 with high in vitro H3R antagonist affinity, excellent in vitro selectivity profile, and high in vivo H3R antagonist potency was tested for its anticonvulsant effect in maximal electroshock (MES)-induced convulsions in mice having valproic acid (VPA) as a reference antiepileptic drug (AED). Additionally, H3R antagonist 2-18 was evaluated for its reproductive toxicity in the same animal species. The results show that acute systemic administration (intraperitoneal; i.p.) of H3R antagonist 2-18 (7.5, 15, 30, and 60 mg/kg, i.p.) significantly and dose dependently protected male as well as female mice against MES-induced convulsion. The protective action observed for H3R antagonist 2-18 in both mice sexes was comparable to that of VPA and was reversed when mice were pretreated with the selective H3R agonist (R)-alpha-methylhistamine (RAMH, 10 mg/kg, i.p.). Moreover, the results show that acute systemic administration of single (7.5, 15, 30, or 60 mg/kg, i.p.) or multiple doses (15×3 mg/kg, i.p.) of H3R antagonist 2-18 on gestation day (GD) 8 or 13 did not affect the maternal body weight of mice when compared with the control group. Furthermore, no significant differences were observed in the average number of implantations and resorptions between the control and H3R antagonist 2-18-treated group at the early stages of gestation and the organogenesis period. However, oral treatment with H3R antagonist 2-18 (15 mg/kg) on GD 8 induced a reduced number of live embryos when compared with the i.p.-treated mice. In addition, no significant changes in the fetal body and placental weights were observed after injection of H3R antagonist 2-18 with all selected doses. However, three dose groups of i.p. and oral 15 mg/kg on GD 13 significantly affected the placental weight when compared with control group. Notably, the treatment of pregnant female with the H3R antagonist 2-18 did not produce significant malformation in the fetus in both groups. In conclusion, the novel H3R antagonist 2-18 proves to be a very safe compound and displays a low incidence of malformations, demonstrating that H3R antagonist 2-18 may have a potential future therapeutic value in epilepsy.

Menthol inhibits oxidative stress and inflammation in acetic acid-induced colitis in rat colonic mucosa.

Inflammatory bowel diseases (IBD) such as ulcerative colitis and Crohn's disease are characterized by chronic inflammation of the gastrointestinal system. There is no permanent cure from IBD except constant medication or surgery to keep the disease in remission. In the present study, the effect of menthol, a major ingredient of peppermint has been investigated in acetic acid-induced colitis model in Wistar rats. Menthol (50 mg/kg/day) was orally administered for either 3 days before or 30 min after IBD induction for 7 days. The changes in body weight, macroscopic and microscopic analysis of the colon of rats of different experimental groups were observed on day 0, 2, 4 and 7. Acetic acid caused a significant reduction in mean body weight and induced macroscopic and microscopic ulceration along with a significant decline of glutathione (GSH) levels, an antioxidant substrate concomitant to increased malondialdehyde (MDA) level, a marker of lipid peroxidation and raised myeloperoxidase (MPO) activity, itself a marker for neutrophil activation. Acetic acid also induced the release of pro-inflammatory cytokines. Furthermore, acetic acid also raised the levels of calprotectin, a protein released by neutrophils under inflammatory conditions of the gastrointestinal tract. Treatment with menthol significantly improved IBD-induced reduction in mean body weight and mean macroscopic and microscopic ulcer scores and reduced activities of MPO and levels of MDA with concomitant increase in GSH level. Additionally, menthol treatment significantly reduced the levels of pro-inflammatory cytokines such as interleukin-1, interleukin-23 and tumor necrosis factor-α with no significant change in interleukin-6 levels. The data indicate that menthol improved body weight gain, mean macroscopic and microscopic ulcer scores, attenuated lipid peroxidation, oxidative stress and inflammation in the IBD rat mucosa.

Effect of Aspirin and ibuprofen either alone or in combination on gastric mucosa and bleeding time and on serum prostaglandin E2 and thromboxane A2 levels in the anaesthetized rats in vivo.

There is much evidence that a combination of ibuprofen (IBU) and Aspirin (ASA) can antagonize the irreversible inhibition of platelet function. This study was designed to investigate the degree of gastric damage, bleeding time (BT) and fluctuations in the serum levels of prostaglandin E2 (PGE2) and thromboxane A2 (TXA2) after oral administration of ASA (200 mg/kg) and IBU (50 mg/kg) either alone or in combination in rats in vivo. The stomach was assessed for any damage either after 6 h, 18 h or 6 days and carboxymethylcellulose (1% CMC) served as a vehicle and control. ELISA was used to measure TXA2 and PGE2 in serum. Bleeding time was assessed using tail blood. The results show that ASA and IBU either alone or in combination can cause gastric ulceration in 25-100% of the rats at 6 and 18 h. In contrast, gastric ulceration was seen in 50% of rats with a combination of ASA given before IBU only after 6 days of oral administration. BT was unaffected either by ASA or IBU when administered alone except after 18 h for IBU. In contrast, BT was significantly reduced when IBU was administered before ASA after 18 h and 6 days (P < 0.001). Serum PGE2 levels decreased significantly after ASA administered either alone or in combination with IBU for 6 h, 18 h and 6 days (P < 0.05). Serum TXA2 levels were significantly reduced after 6 h, 18 h and 6 days following ASA and IBU administration except for IBU alone which caused a significant increase in serum TXA2 6 days after its administration (P < 0.01). It can be concluded that ASA and IBU administered either alone or in combination can cause gastric ulcers in the rat stomach after 6 h and 18 h, but less severe after 6 days. IBU either alone or in combination with ASA reduced BT only after 18 h and 6 days of administration. Together, the results show that gastric ulceration correlated well with the inhibition of serum PGE2 and TXA2 levels.

Genetic polymorphisms of cytochrome P450-1A2 (CYP1A2) among Emiratis.

Cytochrome P450 1A2 (CYP1A2) is one of the CYP450 mixed-function oxidase system that is of clinical importance due to the large number of drug interactions associated with its induction and inhibition. In addition, significant inter-individual differences in the elimination of drugs metabolized by CYP1A2 enzyme have been observed which are largely due to the highly polymorphic nature of CYP1A2 gene. However, there are limited studies on CYP1A2 phenotypes and CYP1A2 genotypes among Emiratis and thus this study was carried out to fill this gap. Five hundred and seventy six non-smoker Emirati subjects were asked to consume a soft drink containing caffeine (a non-toxic and reliable probe for predicting CYP1A2 phenotype) and then provide a buccal swab along with a spot urine sample. Taq-Man Real Time PCR was used to determine the CYP1A2 genotype of each individual. Phenotyping was carried out by analyzing the caffeine metabolites using High Performance Liquid Chromatography (HPLC) analysis. We found that 1.4%, 16.3% and 82.3% of the Emirati subjects were slow, intermediate and rapid CYP1A2 metabolizers, respectively. In addition, we found that 1.4% of the subjects were homozygote for derived alleles while 16.1% were heterozygote and 82.5% were homozygote for the ancestral allele. The genotype frequency of the ancestral allele, CYP1A2*1A/*1A, is the highest in this population, followed by CYP1A2 *1A/*1C and CYP1A2 *1A/*1K genotypes, with frequencies of 0.825, 0.102 and 0.058, respectively. The degree of phenotype/genotype concordance was equal to 81.6%. The CYP1A2*1C/*1C and CYP1A2*3/*3 genotypes showed significantly the lowest enzyme phenotypic activity. The frequency of slow activity CYP1A2 enzyme alleles is very low among Emiratis which correlates with the presence of low frequencies of derived alleles in CYP1A2 gene.

Studies on N-Acetyltransferase (NAT2) Genotype Relationships in Emiratis: Confirmation of the Existence of Phenotype Variation among Slow Acetylators.

BACKGROUND AND PURPOSE: Individuals with slow N-acetylation phenotype often experience toxicity from drugs such as isoniazid, sulfonamides, procainamide, and hydralazine, whereas rapid acetylators may not respond to these medications. The highly polymorphic N-acetyltransferase 2 enzyme encoded by the NAT2 gene is one of the N-acetylators in humans with a clear impact on the metabolism of a significant number of important drugs. However, there are limited studies on N-acetylation phenotypes and NAT2 genotypes among Emiratis, and thus this study was carried out to fill this gap. METHODS: Five hundred seventy-six Emirati subjects were asked to consume a soft drink containing caffeine (a nontoxic and reliable probe for predicting the acetylation phenotype) and then provide a buccal swab along with a spot urine sample. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to determine the genotype of each individual. Phenotyping was carried out by analyzing the caffeine metabolites using high-performance liquid chromatography (HPLC) analysis. RESULTS: We found that 78.5%, 19.1%, and 2.4% of the Emirati subjects were slow, intermediate, and rapid acetylators, respectively. In addition, we found that 77.4% of the subjects were homozygous or heterozygous for two nonreference alleles, whereas 18.4% and 4.2% were heterozygous or homozygous for the reference allele (NAT2*4), respectively. The most common genotypes found were NAT2*5B/*7B, NAT2*5B/*6A, NAT2*7B/*14B, and NAT2*4/*5B, with frequencies of 0.255, 0.135, 0.105, and 0.09, respectively. The degree of phenotype/genotype concordance was 96.2%. The NAT2*6A/*6A, NAT2*6A/*7B, NAT2*7B/*7B, and NAT2*5A/*5B genotypes were found to be associated with the lowest 5-acetylamino-6-formylamino-3-methyluracil/1-methylxanthine (AFMU/1X) ratios. CONCLUSIONS: There is a high percentage of slow acetylators among Emiratis, which correlates with the presence of nonreference alleles for the NAT2 gene. Individuals who carried NAT2*6A/*6A, NAT2*6A/*7B, NAT2*7B/*7B, or NAT2*5A/*5B genotypes might be at higher risk of toxicity with some drugs and some diseases compared to others, as these genotypes are associated with the slowest acetylation status.

Effect of turmeric on colon histology, body weight, ulcer, IL-23, MPO and glutathione in acetic-acid-induced inflammatory bowel disease in rats.

BACKGROUND: This study investigates the protective effects of turmeric (Curcuma longa, CL) on acetic acid-induced colitis in rats. METHOD: Inflammatory bowel disease (IBD) was induced in male Wistar rats by intra-rectal administration of 1 ml of 4% acetic acid at 8 cm proximal to the anus for 30 s. Curcuma longa (CL) powder, (1, 10, or 100 mg/kg/day) was administered for either 3 days before or after IBD for 7 days. The body weight, macroscopic and microscopic analysis of the colon of CL-treated IBD rats and that of control rats (no IBD, no CL) were performed on 0 day, 2, 4 and 7th day. Myeloperoxidase (MPO), IL-23 and glutathione levels in control, untreated and treated rats were measured by ELISA. RESULTS: CL significantly (P < 0.05) improved IBD-induced reduction in mean body weight and mean macroscopic ulcer score. Administration of CL also significantly (P < 0.01) reduced the mean microscopic ulcer score when compared to untreated IBD control. Intake of CL by rats resulted in a significant (P < 0.05) increase in the mean serum glutathione level compared to untreated control. CL reduced both MPO and IL-23 levels in the colonic mucosa of the rat. CONCLUSION: CL improved body weight gain, mean macroscopic and microscopic ulcer scores in the colon of rats suffering from acetic acid-induced IBD. CL reduced both MPO and IL-23 in the mucosa of the colon. The increase in the mean serum glutathione level may help in the reduction of oxidative stress associated with IBD.

Identification of new alleles and the determination of alleles and genotypes frequencies at the CYP2D6 gene in Emiratis.

CYP2D6 belongs to the cytochrome P450 superfamily of enzymes and plays an important role in the metabolism of 20-25% of clinically used drugs including antidepressants. It displays inter-individual and inter-ethnic variability in activity ranging from complete absence to excessive activity which causes adverse drug reactions and toxicity or therapy failure even at normal drug doses. This variability is due to genetic polymorphisms which form poor, intermediate, extensive or ultrarapid metaboliser phenotypes. This study aimed to determine CYP2D6 alleles and their frequencies in the United Arab Emirates (UAE) local population. CYP2D6 alleles and genotypes were determined by direct DNA sequencing in 151 Emiratis with the majority being psychiatric patients on antidepressants. Several new alleles have been identified and in total we identified seventeen alleles and 49 genotypes. CYP2D6*1 (wild type) and CYP2D6*2 alleles (extensive metaboliser phenotype) were found with frequencies of 39.1% and 12.2%, respectively. CYP2D6*41 (intermediate metaboliser) occurred in 15.2%. Homozygous CYP2D6*4 allele (poor metaboliser) was found with a frequency of 2% while homozygous and heterozygous CYP2D6*4 occurred with a frequency of 9%. CYP2D6*2xn, caused by gene duplication (ultrarapid metaboliser) had a frequency of 4.3%. CYP2D6 gene duplication/multiduplication occurred in 16% but only 11.2% who carried more than 2 active functional alleles were considered ultrarapid metabolisers. CYP2D6 gene deletion in one copy occurred in 7.5% of the study group. In conclusion, CYP2D6 gene locus is heterogeneous in the UAE national population and no significant differences have been identified between the psychiatric patients and controls.

Toxicokinetics of aflatoxin in pregnant mice.

Our objective was to study the toxicokinetics of aflatoxin (AF) in pregnant mice. Aflatoxin B1 (AFB1) was administered intraperitoneally (IP) to groups of pregnant mice in single doses of 20 mg/kg on gestation day (GD) 13 and orally at the same gestational age. Controls received (IP and oral) a proportionate volume of solvent only. Maternal blood was collected at 15, 30, 45, 60, 90, 120, and 150 minutes posttreatment. Their AFB1 contents were determined. Aflatoxin B1 concentrations following maternal exposure to AFB1 were highly correlated with time after exposure. The serum concentrations were predictable and the highest serum levels were seen immediately at 15 minutes in mice given AFs IP and at 30 minutes in those given it orally. The absorption was 5.0 microg/min and elimination was 3.0 microg/min. The toxicokinetics of AFB1 have been delineated. Aflatoxins are easily and rapidly absorbed both from the gastrointestinal tract (GI) tract and through the peritoneum.

Effects of streptozotocin-induced long-term diabetes on parietal cell function and morphology in rats.

Gastric pathology is a common complication in diabetes mellitus. The aim of the study was to evaluate the functions and morphological changes of the parietal cells of the rat stomach after streptozotocin-induced diabetes. Diabetes mellitus was induced in Wistar rats by a single intraperitoneal injection of streptozotocin (60 mg/kg body weight). The rats were weighed weekly and sacrificed after 6 months. The glandular portion of the stomach was removed and processed for H(+)-K(+)-ATPase immunohistochemistry and light and electron microscopy studies. Acid secretion was measured in vivo. After 6 months of diabetes, the mean weight of the rats was significantly lower (P < 0.001) compared to control. The mean weight of the stomach to body weight percentage increased significantly (P < 0.001) compared to control. The blood glucose level in diabetic rats was significantly higher (P < 0.001) than in normal control. Diabetic rats showed significant (P < 0.001) decrease in basal and stimulated acid secretion when compared to control. Electron micrographs of the parietal cells of glandular stomach of diabetic rats revealed significant (P < 0.0002) reduction in the number of mitochondria and a small though not significant increase in the number of canaliculi in the parietal cells compared with normal. Immunohistochemistry showed reduced H(+)-K(+)-ATPase (P < 0.00001) compared to control. Long-term diabetes induces morphological as well as functional changes in gastric parietal cells. The decrease in the number of mitochondria accompanied by reduced in H(+)-K(+)-ATPase in parietal cells may explain the reduced acid secretion observed in diabetics.

Resistance patterns of bacterial isolates to antimicrobials from 3 hospitals in the United Arab Emirates.

OBJECTIVE: To compare the resistance pattern of common bacterial pathogens to commonly used drugs. METHODS: Information and statistics of antimicrobial resistance for 1994 and 2005 were collected from the 3 hospital microbiology laboratories in the United Arab Emirates. The resistance patterns of Staphylococcus aureus, Escherichia coli, Klebsiella spp, and Pseudomonas aeruginosa to several front-line drugs were estimated. All laboratories used automatic machines (Vitek 2), which identifies and determines minimum inhibitory concentrations simultaneously. RESULTS: Increased resistance was observed for Staphylococcus aureus, (n=315, 2005) to erythromycin (approximately 6 fold, Al-Ain Hospital only), cloxacillin (Al-Ain Hospital), and gentamicin (more than 3-10 folds in all hospitals). Increased penicillin resistance was not observed. For the common gram-negative organisms, there was a high resistance to ampicillin, gentamicin, ceftriaxone, ciprofloxacin, and imipenem, which seemed to increase for Escherichia coli, (by 4.2-200%, n=305, 2005); however, there was very little resistance to imipenem (0.4%) in Tawam Hospital. Variable resistance patterns were obtained for Pseudomonas aeruginosa (n=316, 2005) and Klebsiella spp, (n=316, 2005) against aminoglycosides, cephalosporins, ciprofloxacin, and norfloxacin. CONCLUSION: Overall, there was an obvious increase in resistance of bacteria and the prevalence rate to a number of drugs from 1-120 folds during the 11-year period.

Intrauterine growth restriction and skeletal variations in mouse fetuses induced by vigabatrin administered at preimplantation stages of development.

Epileptic women do not withdraw antiepileptic drug (AED) therapy during pregnancy, therefore, exposure to AED during preimplantation stages might result in considerable embryonic concentrations endangering development. Neither clinical nor experimental research has addressed this important issue adequately. Vigabatrin (VGB), a second generation AED, is both effective and well tolerated as an add-on therapy in epilepsy with partial seizures. However, there is little data on the possible reproductive toxicity of this widely used drug. The objective of the present study was to evaluate the effects of VGB on pregnancy and pregnancy outcome in an experimental model. VGB was administered in single doses of 450 mg/kg intraperitoneally (i.p.) to groups of mice on one of gestation days (GD) 1, 3, or 5. The treated animals consumed moderately reduced amounts of food and water on the day of treatment, so the controls were saline-injected and food and water-restricted to match the amounts consumed by the experimental animals. All animals were killed on GD 18. VGB treatment did not interfere with implantation, nor did it cause significant embryo resorption. However, it caused significant reduction in fetal bodyweight and increased frequency of growth restricted fetuses which weighed two standard deviations (SD) less than the mean of the controls. The VGB group fetuses also had retarded development of the skeletal system in terms of delay in maturity of the suproccipital bone development, cervical and coccygeal vertebral hypoplasia, and poor ossification of the bones of the fore and hind paws. Another major finding was the increased incidence of minor malformations, such as the presence of cervical ribs and sternal anomalies. The results of this study show that VGB administered at preimplantation stages of development causes intrauterine growth restriction (IUGR) and augments minor malformation rates in mice. Future studies must address the mechanisms of VGB-induced IUGR and minor malformations.

The anti-secretory and anti-ulcer activities of esomeprazole in comparison with omeprazole in the stomach of rats and rabbits.

Proton pump inhibitors (PPIs) are widely used to treat hyperacid secretion and stomach ulcers. The study investigated the anti-secretory and anti-ulcer effects of esomeprazole, the S-isomer of omeprazole on dimaprit, histamine and dibutyryl adenosine 3, 5 cyclic monophosphate (dbcAMP)-evoked gastric acid secretion, acidified ethanol (AE) and indomethacin (INDO)-induced haemorrhagic lesions and on prostaglandin E2 (PGE2) level in the rat in vivo and rabbit in vitro preparations. The effect of omeprazole was also investigated for comparison. Dimaprit-induced acid secretion was significantly (P < 0.05) inhibited by both PPIs in a dose-dependent manner. In the isolated rabbit gastric glands, both PPIs elicited marked reductions in histamine- and dbcAMP-evoked acid secretion with similar potency. The lesions induced by either AE or INDO were significantly (P < 0.05) reduced in the presence of either esomeprazole or omeprazole compared to control values. Increasing doses of esomeprazole before AE treatment resulted in a marked degree of cytoprotection and an elevation in the concentration of bound PGE2 in the stomach tissue homogenate. The results show that esomeprazole and omeprazole were equally effective against gastric haemorrhagic lesions induced by either AE or INDO and in inhibiting dimaprit-, dbcAMP- and histamine-induced gastric acid secretion in the rat and rabbit stomach both in vivo and in vitro. The gastro-protective effect of esomeprazole was found to be proportional to the bound PGE2 levels in the glandular area of the stomach.