ABSTRACT
OBJECTIVES@#To reveal the mechanisms behind the dual effects of Crataegus aronia (C. aronia) aqueous extract on platelet aggregation by focusing on function, regulation, expression, and signaling of platelets P@*METHODS@#Adult male Wistar rats (120 ± 10 g) were classified as control received the vehicle, C. aronia (200 mg/kg), and C. aronia (2,000 mg/kg)-treated rats. After treatments for consecutive 7 days, hematological and molecular experiments were conducted to detect alterations in platelet aggregation, thromboxane B2 (THXB2) and intracellular reactive oxygen species (ROS) content; protein levels of P@*RESULTS@#At a concentration of 200 mg/kg, C. aronia inhibited platelet aggregation through multiple interconnected mechanisms including downregulation P@*CONCLUSION@#Oral administration of C. aronia at low dose inhibits platelet aggregation by reducing THXB2 release, expression of P-selectin and activating cAMP and Akt signaling through two major mechanisms including downregulation of P
ABSTRACT
To compare the serum levels of inflammatory mediators in high altitude [HA] native rats, and to search for the possible underlying mechanism[s]. The study was carried out between January and April 2013. Fifty male rats from the same genetic pool were bred at either a HA or low altitude [LA] area. The study was carried out in 2 stages. In the first stage, serum levels of inflammatory markers, adhesive molecules, lipid profiles, catecholamines, magnesium [Mg[+2]], and lipid peroxidation were compared between theses 2 groups. In the second stages, inflammatory response and lipid peroxidation were analyzed in HA native rats after treatment with either alpha [Prazosin] or beta [propranolol] adrenergic blockage. The HA native rats showed significant increases in the serum levels of inflammatory cytokines, lipid profiles, as well as a significant increase in the urinary norepinephrine with a concomitant decrease in the serum levels of Mg[+2] and increased lipid peroxidation. Blockage of the beta and alpha adrenergic receptors of the HA rats caused partial or complete decreases in both inflammatory and oxidative stress mediators. Living under HA conditions results in an increased systemic inflammatory reaction; an effect that is mediated through the sympathetic nervous system mainly via alpha-adrenergic receptors and could be attributed to low Mg[+2] levels
ABSTRACT
To study the effect of chronic exposure to native high altitude [HA] on blood pressure, and to investigate the underlying mechanism of action. This study was carried out between February and April 2011. A total of 20 male rats were divided into 2 groups [n=10 rats]. The low altitude [LA] group were rats born and lived in an LA environment at King Saud University, College of Pharmacy, Riyadh, Kingdom of Saudi Arabia [KSA], and the HA group were rats born in the same LA area, then acclimatized to HA area in Physiology Department, King Khalid University, College of Medicine, Abha, KSA for 90 days. At the end of day 90, hematocrit, plasma renin activity, aldosterone, norepinephrine and vasopressin levels were determined in both groups. Invasive arterial blood pressure was also measured, and fractional excretion of sodium [FENa], and potassium [FE[K]] were calculated. The quantitative real time-polymerase chain reaction of renin was carried out in the kidneys of both rat groups. When compared to LA native rats, HA rats exhibited a significant increase in systolic and diastolic blood pressure with a significant increase in renin plasma activity as well as an increase in the levels of aldosterone, norepinephrine, and vasopressin. Furthermore, HA rats showed a significant increase in renin expression in their kidneys, as well as decreased FENa. Data shows that prolonged exposure to HA results in elevated blood pressure precipitated by the activation of the renin-angiotensin-aldosterone system
ABSTRACT
To investigate the effect of Khat [Catha edulis] acute administration on blood pressure [BP] and electrocardiogram [ECG] in vivo. This study was performed between January and February 2009 at the Physiology Laboratory, Medical College of King Khalid University, Abha, Kingdom of Saudi Arabia. Two groups of Wistar rats [n=10], weighing 190-200 g were divided into control group and Khat treated group. Throughout the study, arterial BP and ECG were recorded for 60 consecutive minutes. The data were collected and analyzed by Power Lab Data Acquisition System every 10 minutes, and were compared within and between the groups. Oral administration of Khat resulted in significant time dependent increases in both systolic and diastolic BP with a maximum increase at minute 60 after extract administration [systolic BP - 34.1%; and diastolic BP - 46.2%]. Heart rate was significantly increased at all minutes of the study with a maximum increase occurring at minute 40 [12.8%]. There was a significant decrease in PR interval through the experiment, and the maximum decrease was observed at minute 40 [-15.2%]. However, QT and QTc started to widen 20 minutes after extract administration with a maximum prolongation in both intervals to occur at minute 40 [QT - 11.6%; QTc - 9.1%]. These newly reported changes in the ECG of rats after Khat administration should be a warning regarding the cardiac hazards of Khat chewing
ABSTRACT
To investigate the blood glucose lowering effect of khat [Catha edulis] extract in normal, glucose-loaded, and alloxan diabetic rats. Three experimental protocols were used in this study. In each of the first 2 protocols, 3 groups of rats [6 rats per group] were used as control group [NS], Catha edulis [CE] treated, and glibenclamide treated groups. This study was carried out at the Physiological Laboratory of the Medical School of King Khalid University, Abha, Saudi Arabia between October and November, 2009. Normal rats were used in the first protocol while alloxan diabetic rats were used in the second protocol. Blood glucose levels were measured in all 3 groups after single dose injections of saline, CE or glibenclamide. In the third protocol, another 6 groups of rats [6 rats per group] were prepared as in the first 2 protocols and oral glucose tolerance test [OGTT] was performed on each rat after oral administration of glucose [1.5g/kg]. Oral administration of a hydro-ethanol extract of CE caused no statistically significant change in blood glucose levels in normal rats with or without glucose loading. There were slight, non significant increases in blood glucose levels of extract-treated diabetic rats, with and without glucose loading, as compared to the corresponding untreated rats. Oral administration of CE extract does not exert a hypoglycemic effect in normal, glucose-loaded, and diabetic rats
Subject(s)
Animals, Laboratory , Blood Glucose/drug effects , Diabetes Mellitus, Experimental/drug therapy , Plant Extracts , Administration, Oral , Rats , Hypoglycemic Agents , Disease Models, AnimalABSTRACT
A 55 year old Saudi male with bronchial asthma and allergic rhinitis presented with a palpable purpuric skin rash, mononeuritis multiplex and marked eosinophilia developing during allergic desensitisation therapy. Based on the above finding a clinical diagnosis of Churg-Strauss Syndrome was made. The patient responded very well to steroids and cyclophosphamide. It has been postulated that repeated antigenic stimulation such as repeated injections of allergens during desensitisation therapy, drugs or parasitic infections may provoke systemic vasculitis in atopic individuals. In this article, we present the first reported case from Saudi Arabia with Churg-Strauss syndrome developing during desensitisation therapy. Until further proof, clinicians should be aware that allergic desensitisation therapy can rarely be complicated by Churg-Strauss Syndrome