Overweight and obesity in Eastern Morocco: Prevalence and associated risk factors among high school students.

BACKGROUND: Overweight and obesity in children and adolescents have become a major public health problem affecting most countries worldwide. The purpose of the study was to assess the prevalence and risk factors of overweight and obesity among public high school students in Eastern Morocco. METHODS: A cross-sectional survey was conducted between February and May 2014 among a sample of 2271 students (1086 girls and 1185 boys). References from the International Obesity Task Force (IOTF) were used to determine the prevalence of overweight and obesity. RESULTS: The prevalence of overweight and obesity reached 12.2% (14.2% in girls vs 10.4% in boys, P<0.01) and 3.0% (3.1% in girls vs 2.8% in boys), respectively. Risk factors associated with overweight and obesity were urban residence (OR=1.76; [1.18-2.63]; P<0.01), father's income≥5000MAD (OR=1.32; [1.02-1.70]; P<0.05), father's overweight (including obesity) (OR=1.87; [1.38-2.54]; P<0.001) and female sex (OR=1.31; [1.02-1.68]; P<0.05). CONCLUSION: The prevalence of overweight/obesity has reached an alarming rate among high school students in the Eastern region of Morocco. The findings of the present study suggest an urgent need to set up a strategy to prevent and combat this epidemic.

Effects of Juglans regia Root Bark Extract on Platelet Aggregation, Bleeding Time, and Plasmatic Coagulation: In Vitro and Ex Vivo Experiments.

Platelets have an important role in thrombosis and haemostasis. Hyperactivity of the platelets has been associated with thromboembolic diseases and represents the main cause of complications of cardiovascular diseases. Crude aqueous extract (CAE) of Juglans regia root bark was evaluated for bleeding time, antiaggregant activity by using agonists, thrombin, ADP, collagen, or arachidonic acid (in vitro and ex vivo), and anticoagulant activity by measuring the clotting parameters: activated partial thromboplastin time, prothrombin time, thrombin time, and fibrinogen dosage (in vitro and ex vivo). The result of this study reported that the strongest antiaggregant effect of CAE in vitro was observed on the ADP-induced aggregation with inhibitions up to 90 %, while, in ex vivo experiments, the inhibition (more than 80 %) was observed with all agonists. Anticoagulant effect of CAE significantly prolonged the TT and decreased the fibrinogen level in vitro and ex vivo without interfering with APTT and PT. The bleeding time in mice and rats was significantly increased by CAE. The antiplatelet and anticoagulant effect observed in this study suggest that Juglans regia could have antithrombotic and/or thrombolytic activities and provide an alternative therapy against thrombotic complications related to cardiovascular diseases.

Antihyperglycemic activity of Arbutus unedo, Ammoides pusilla and Thymelaea hirsuta.

The effect of the water extract (WE) of three medicinal plants used as antidiabetic medication in Eastern Morocco (Arbutus unedo: Au, Ammoides pusilla: Ap and Thymelaea hirsuta: Th) was tested in rats with the Oral Glucose Tolerance Test (OGTT) and Intravenous Glucose Tolerance Test (IVGTT). In the OGTT the rats received water, glibenclamide (2 mg/kg) or WE (500 mg/kg for Au and 250 mg/kg for Th and Ap) 30 min before glucose loading (glucose: 1 g/kg). The WE of Au, Ap and Th produced a significant decrease in glycemia after glucose loading. In the IVGTT the WE of Ap and Th produced a significant decrease in glycemia 60 min after i.v. glucose loading (0.5 g/kg). The addition of the WE of Au (500 mg/kg), Ap or Th (250 mg/kg) induced a significant inhibition of jejunal glucose absorption, (31.6%, 28.5% and 40.5% respectively). This effect could explain in part the significant antihyperglycemic effect observed in the OGTT model but it does not exclude other effects on glucose homeostasis, particularly for Ap and Th. Toxicity tests (high LD50 value) suggest no adverse effect of the use of these plants.

Role of creatine kinase in force development in chemically skinned rat cardiac muscle.

The influence of phosphocreatine in the presence or absence of MgATP and MgADP was studied in Triton X-100-treated thin papillary muscles and ventricular strips of the rat heart. The pCa/tension relationships, the pMgATP/tension relationships, and the tension responses to quick length changes were analyzed. The results show three major consequences of the reduction of the phosphocreatine concentration in the presence of millimolar concentrations of the MgATP. (a) The resting tension and the maximal Ca2+-activated tension were increased, and the pCa/tension relationship was shifted toward higher pCa values and its steepness was decreased; these effects were enhanced by the inclusion of MgADP. (b) The time constant of tension recoveries after quick stretches applied during maximal activation was increased, while the extent of these recoveries was decreased. (c) The study of pMgATP/tension relationships in low Ca concentrations showed that the decrease in phosphocreatine induced a shift toward higher MgATP values with no changes in maximal rigor tension or the slope coefficient; these effects were increased by the increase in MgADP and were independent of the preparation diameter. Thus, modifications of the apparent Ca sensitivity and resting and maximal tension when phosphocreatine is decreased seem to be due to an increasing participation of rigor-like or slowly cycling cross-bridges spending more time in the attached state. These results suggest that endogenous creatine kinase is able to ensure maximal efficiency of myosin ATPase by producing a local high MgATP/MgADP ratio.

Acute diuretic, natriuretic and hypotensive effects of a continuous perfusion of aqueous extract of Urtica dioica in the rat.

This study was performed on anaesthetized male Wistar rats that received a continuous intravenous perfusion during 1.25 h of an aqueous extract of aerial parts of Urtica dioica L. (Urticaceae) at a low dose of 4 mg/kg/h or at a high dose of 24 mg/kg/h, or furosemide (control diuretic) at a dose of 2 mg/kg/h. As compared with a control period in each rat, the arterial blood pressure was reduced proportionally to the dose of the perfusion of the plant extract (15 and 38%, P<0.001, respectively). These effects were accompanied by a correlative increase of diuresis (11 and 84%, P<0. 001, respectively) and natriuresis (28 and 143%, P<0.001, respectively). In the rats perfused by furosemide, the arterial blood pressure was reduced by 28% (P<0.001). The diuresis and natriuresis were also increased proportionally in this case (85 and 155%, P<0.001, respectively). Nevertheless, the hypotensive action of U. dioica was reversible during the recovery periods in about 1 h with the lower dose of the plant extract and furosemide, while the effect of the higher dose was persistent, indicating a possible toxic effect. In conclusion, the results demonstrate an acute hypotensive action of U. dioica that indicates a direct effect on the cardiovascular system. Moreover, diuretic and natriuretic effects were also observed, suggesting an action on the renal function. Finally, the plant extract seems to have a toxic effect at the higher dose.

Phytotherapy of hypertension and diabetes in oriental Morocco.

In order to select the main medicinal plants used in folk medicine to treat arterial hypertension and/or diabetes, a survey was undertaken in different areas of oriental Morocco. The patients (370 women and 256 men) were divided into three groups: diabetics (61%), hypertensives (23%) and hypertensive diabetic persons (16%). On average, 67.51% of patients regularly use medicinal plants. This proportion is perceptibly the same in all groups and does not depend on sex, age and socio-cultural level. This result shows that phytotherapy is widely adopted in northeastern Morocco. For diabetes, 41 plants were cited, of which the most used were Trigonella foenum-graecum L. (Leguminosae), Globularia alypum L. (Globulariaceae), Artemisia herba-alba Asso. (Compositae), Citrullus colocynthis (L.) Schrad. (Cucurbitaceae) and Tetraclinis articulata Benth. (Cupressaceae). In the hypertension's therapy 18 vegetal species were reported, of which the most used were Allium sativum L. (Liliaceae), Olea europea L. (Oleaceae), Arbutus unedo L. (Ericaceae), Urtica dioica L. (Urticaceae) and Petroselinum crispum A.W. Hill (Apiaceae). Among the 18 species used for hypertension, 14 were also employed for diabetes. Moreover, these two diseases were associated in 41% of hypertensives. These findings suggest that hypertension observed in this region would be in a large part related to diabetes.

Hypertensive effects of oral administration of the aqueous extract of Solanum torvum fruits in L-NAME treated rats: evidence from in vivo and in vitro studies.

ETHNOPHARMACOLOGICAL RELEVANCE: Solanum torvum fruits are commonly used in Cameroonian traditional medicine for treatment of arterial hypertension. It has been previously shown that intravenous administration of aqueous extract from dried fruits (AEST) reduced blood pressure. AIM: The present work evaluates acute toxicity and effects of oral administration of AEST in chronic arterial hypertension induced by L-NAME. Effects of AEST were also evaluated on isolated aorta. MATERIALS AND METHODS: AEST (200 mg/kg/day, p.o.) was given solely or concomitantly with L-NAME (40 mg/kg/day, p.o.) for 30 consecutive days. Animal body weight, systolic blood pressure and heart rate were measured before stating the treatment and at the end of each week. Urinary volume and urinary sodium and potassium contents were quantified before and at days 1, 15 and 30 of the treatment. Aorta from treated animals was tested for their sensitivity to noradrenaline and carbachol. Aorta from normal untreated rats was used to evaluate the in vitro vascular effect of AEST. RESULTS: The results showed that AEST did induce neither mortality nor visible signs of toxicity. When given solely or in co-administration with L-NAME, AEST significantly reduced animal's body weight. It amplified the hypertensive and cardiac hypertrophy effect of L-NAME and did not affect these parameters in normotensive animals. AEST increased the sensitivity to noradrenaline in normotensive and significantly reduced it in hypertensive animals. AEST significantly increased urinary volume and sodium excretion in L-NAME treated animals while reducing the sodium excretion in normotensive. In vitro, AEST induced a potent partial endothelium-dependent contraction of aortic ring; contractions that were partially antagonized by prazosin and verapamil and were not relaxed by carbachol. CONCLUSION: These results suggest that oral chronic administration of AEST induced potentiation of arterial hypertension and cardiac hypertrophy in L-NAME treated rats. These effects may result from a reduction in sensitivity to vasorelaxant agents and increase in hypersensitivity to contractile factors. AEST possess potent in vitro vasocontractile activity that may result from activation of both alpha(1)-adrenergic pathway and calcium influx.

Dependence upon high-energy phosphates of the effects of inorganic phosphate on contractile properties in chemically skinned rat cardiac fibres.

The effects of inorganic phosphate (Pi) on mechanical properties of Triton X100 treated ventricular fibres have been studied in different substrate conditions. In the presence of both MgATP and phosphocreatine, increasing concentrations of Pi progressively decreased maximal active force, up to 50-60% at 20 mM Pi. The reduction in stiffness was slightly less. These effects appeared nearly independent of the diameter of the preparations. 20 mM Pi decreased Ca sensitivity of the myofilaments and increased the Hill coefficient of the tension/pCa relationship; furthermore, the time constant of tension recovery was decreased from 12.9 to 8.9 ms suggesting that the cycling rate of cross-bridges was increased in the presence of Pi. When MgATP was regenerated by the myofilament bound creatine kinase in the presence of phosphocreatine, Pi was less efficient in decreasing the maximal tension and it weakened the relaxing effect of MgATP upon rigor tension. These effects are related to the inhibition of creatine kinase by Pi. The effects of Pi on maximal force and kinetics of contraction were antagonized by the effects of a decrease in phosphocreatine. The results are discussed in terms of the antagonistic role of Pi increase and phosphocreatine decrease upon contractile properties of myofilaments during hypoxia in heart muscle.

Pressure overload changes cardiac skinned-fiber mechanics in rats, not in guinea pigs.

The mechanical properties of detergent-treated skinned fibers from pressure-overloaded rat and guinea pig hearts have been compared with those of sham-operated animals. Overload was obtained 4 wk after abdominal aortic stenosis, an intervention that increases ventricular weight by 56% in rats and 57% in guinea pigs. The time constant (T, in ms) for tension recovery after a quick stretch was significantly lower in normal guinea pig than in rat. It was lengthened by the process of overload in both species, but this was much more pronounced in rats where T increases by 84% than in guinea pig where it was only slightly augmented by 14% for a doubling of the heart weight. By contrast the maximum tension obtained at pCa 4.5, the stiffness, and the sensitivity to calcium of the fibers were unmodified by chronic overload. In rat, not in guinea pig, a slight decrease in MgATP sensitivity was also observed, whereas no change in creatine kinase efficiency was seen. These results are interpreted as indicating that the slowing of the turnover rate of cross-bridge cycling explains the drop in shortening velocity observed on papillary muscles in rat but not in guinea pig; a species in which membrane modifications must be predominant in the process of adaptation.

[Contractile properties and creatine kinase activity of myofilaments after ischemia and reperfusion of the rat heart]. / Sokratitel'nye svoistva i kreatinkinaznaia aktivnost' miofilamentov posle ishemii i reperfuzii serdtsa krysy.

The state of myofibril creatinkinase and contractile properties of chemically skinned myocardial fibers of rat after 70-90 min ischemia and 15-30 min reperfusion was studied. In spite of sharp fall in the total creatinkinase activity in the tissue, the enzyme activity in myofibrils does not change greatly. Ischemia does not change the functional abilities of myofibril creatinkinase as well as characteristics of Ca-activated contraction of skinned fibers. The results show that irreversible loss of myocardial contractile activity after prolonged ischemia and reperfusion is not connected with violation of myofilament characteristics or deterioration of functional association between myofibril creatinkinase and ATPase.

Functional tissue and developmental specificities of myofibrils and mitochondria in cardiac muscle.

To understand the factors underlying the functional differences between atrial and ventricular tissues, intrinsic properties of myofibrils and mitochondria of atrial skinned fibers were compared with those of fibers from adult or immature (1 and 2 weeks old) ventricular muscle. Isometric mechanical parameters were determined at various calcium concentrations in fibers treated with Triton X-100 to solubilize all cellular membranes. Maximal active tension and stiffness measured at pCa 4.5, as well as calcium sensitivity, were not different in adult atria and ventricles. Both force and stiffness increased in adult ventricles, while calcium sensitivity diminished in adult ventricles, compared with immature muscles. Myofibrillar contractile kinetics, assessed by the rate constant of tension fall following quick stretches, were similar in adult atria (79.7 +/- 6.9 s-1) and ventricles (72.4 +/- 6.8 s-1) and higher in adult atria and ventricles than in immature ventricles (24.1 +/- 2.3 s-1 in 1-week-old rats and 49.3 +/- 4.2 s-1 in 2-week-old rats). Sensitivity of rigor tension development to MgATP in the presence and in the absence of phosphocreatine was not markedly different in the different tissues. Mitochondrial function was assessed in saponin-skinned fibers. Tissue oxidative capacities, expressed as nmol O2.min-1.mg-1 fiber dry weight, were lower in immature ventricles and atria than in adult ventricles. Creatine failed to stimulate respiration in ventricles of young rats and in adult atria, whereas a 74 +/- 10% increase in respiration was observed in adult ventricles. Since mitochondrial creatine kinase was present in adult atria, this suggests an absence of coupling between oxidative phosphorylation and mitochondrial creatine kinase in this tissue. Thus, adult atrial tissue differs from neonatal ventricular tissue but it exhibits contractile properties similar to adult ventricular properties and differs from adult ventricle mainly in metabolic properties.

Creatine kinase is the main target of reactive oxygen species in cardiac myofibrils.

Reactive oxygen species (ROS) have been reported to alter cardiac myofibrillar function as well as myofibrillar enzymes such as myosin ATPase and creatine kinase (CK). To understand their precise mode and site of action in myofibrils, the effects of the xanthine/xanthine oxidase (X/XO) system or of hydrogen peroxide (H2O2) have been studied in the presence and in the absence of phosphocreatine (PCr) in Triton X-100-treated cardiac fibers. We found that xanthine oxidase (XO), with or without xanthine, induced a decrease in maximal Ca(2+)-activated tension. We attributed this effect to the high contaminating proteolytic activity in commercial XO preparations, since it could be prevented a protease inhibitor, phenylmethylsulfonyl fluoride (PMSF), and it could be mimicked by trypsin. In further experiments, XO was pre-treated with 1 mmo1/L PMSF. Superoxide anion production by the X/XO system, characterized by electron paramagnetic resonance spin-trapping technique, was not altered by PMSF. A slight increase in maximal force was then observed either with X/XO (100 mumol/L per 30 mIU/mL) or H2O2. pMgATP-rigor tension relationships have been established in the presence and in the absence of PCr to separate the effects of ROS on myosin ATPase and myofibrillar-bound CK. In the absence of PCr, pMgATP50, the pMgATP necessary to induce half-maximal rigor tension, was reduced from 5.03 +/- 0.17 (n = 21) to 4.22 +/- 0.22 (n = 4) after 25 minutes of incubation in the presence one of 30 mIU/mL. XO and 100 mumol/L xanthine or to 4.04 +/- 0.1 (n = 11) after incubation in the presence of 2.5 mmol/L H2O2. The ROS effects were partially prevented or antagonized by 1 mmol/L dithiothreitol. No effect was observed on pMgATP50 when PCr was absent. pCa-tension relationships have been evaluated to assess the effects of ROS on active tension development. Incubations with H2O2 induced on increase in Ca2+ sensitivity and resting tension when MgATP was provided through myofibrillar CK (PCr and MgADP as substrates) but not when MgATP was added directly. These results suggest that myofibrillar CK was inhibited by ROS. Active stiffness and the time constant of tension changes after quick stretches applied to the fibers were dose-dependently increased by H2O2 only in the presence of PCr. In addition, myofibrillar CK but not myosin ATPase enzymatic activity was depressed after incubation with either ROS. These results suggest that ROS mainly alters CK in myofibrils, probably by the oxidation of its essential sulfhydryl groups. Such CK inactivation results in a decrease in the intramyofibrillar ATP-to-ADP ratio. The effects of ROS on cytosolic and bound CKs may take part in the overall process of myocardial stunning after cardiac ischemia and reperfusion.

Myocardial adaptation to creatine deficiency in rats fed with beta-guanidinopropionic acid, a creatine analogue.

A creatine analogue, beta-guanidinopropionic acid (GPA), was fed to 12 young rats for several weeks. Another 12 animals were kept in the same conditions and age matched. Six pairs of animals were used to measure some energetic and mechanical parameters of the isovolumic perfused heart and to measure the accumulation of the phosphorylated form of GPA (GPAP) by 31P-nuclear magnetic resonance (NMR) spectroscopy. As a result of GPAP accumulation, phosphocreatine and ATP content decreased by 90 and 40%, respectively, and mechanical performance was impaired. Six other pairs of animals were used to assess the mechanical performances of Triton X-100-skinned fibers and the myosin isoenzyme distribution. It was found that the maximal force, Ca and ATP sensitivities, and myofibrillar creatine kinase efficacy of creatine-depleted hearts were similar to control values. There was, however, a decrease in the rate of cross-bridge cycling, and the isoenzymic expression of myosin was changed from the fast myosin V1 to the slower forms V2 and V3. In all animals, hypertrophy was observed in both right and left ventricles. We conclude that rat hearts subjected to a slow and persistent decrease in creatine and phosphocreatine respond with both quantitative and qualitative changes. These alterations, which most probably lead to an improvement in the economy of cardiac contraction, are nonetheless not sufficient to maintain maximal force.

Contractile properties and creatine kinase activity of myofilaments following ischemia and reperfusion of the rat heart.

After prolonged ischemia followed by reperfusion of the isolated rat heart, irreversible heart failure is associated with creatine kinase leakage from the cells. The possible implications of MM creatine kinase leakage from myofibrillar compartments on the contractile properties of ventricular muscle have been studied in control versus ischemic hearts. Total creatine kinase activity decreased in ischemic cells while creatine kinase and ATPase activities were not modified in isolated myofibrils. The efficiency of creatine kinase and phosphocreatine in the relaxation of rigor tension in skinned ventricular preparations was not changed after ischemia. Furthermore, neither the pCa/tension relationship nor the rate of tension development following length changes were modified by ischemia. These results show that the contractile properties of myofilaments as well as the functional coupling between myosin ATPase and creatine kinase are preserved in ischemic hearts suffering irreversible contractile failure.