In vivo investigation of antidiabetic, hepatoprotective, anti-inflammatory and antipyretic activities of Centaurea tougourensis Boiss. & Reut.

Centaurea species are widely used in traditional medicine to treat several illnesses, especially by Mediterranean populations due to their pharmacological properties. The present study aimed to evaluate for the first time some in vivo activities of n-butanol (n-BuOH) extract of the aerial part of Centaurea tougourensis. For this approach; the antidiabetic (streptozotocin-induced diabetes), hepatoprotective (paracetamol induced hepatotoxicity), anti-inflammatory (croton oil induced ear edema assay) and antipyretic activities of this plant extract were tested. The pharmacological results suggest that C. tougourensis has a non-negligible anti-inflammatory effect on the formation of ear edema with a maximum inhibition percentage of (39.58%) for the highest tested concentration of 400 mg/kg. However, the antipyretic activity of the plant was remarkable for both tested concentrations (200 and 400 mg/kg) 5 h after treatment with a significant (P < 0.05) reduction of rectal temperature to (32.88 ± 0.23°C) and (32.36 ± 0.18°C) which correspond to a pyrexia inhibition of (78.9%) and (90.18%) respectively. C. tougourensis exhibited also a good anti-hyperglycemic effect which reached an inhibition percentage of (68.29%) at the end of the 3rd week of treatment for the tested concentration of 400 mg/kg and was considered almost similar to those of standard value (71.83%) at the same time. The n-BuOH extract C. tougourensis showed also a remarkable hepatoprotective effect which was confirmed by biochemical and histological approaches of note is that natural silymarin was also used as reference drug and showed a remarkable hepatoprotective effect. These encouraging results demonstrated once again the pharmacological potential of Centaurea species.

[Relationship between hyperhomocysteinemia and C677T polymorphism of methylene tetrahydrofolate reductase gene in a healthy Algerian population]. / Relation entre hyperhomocystéinémie et polymorphisme C677T du gène de la méthylène tétrahydrofolate réductase dans la population algérienne saine.

Plasmatic homocysteine concentration depends mostly on 5,10 methylene tetrahydrofolate reductase (MTHFR) polymorphisms, a key enzyme in folate metabolism. The most common point mutation C677T is associated to cardiovascular and neurological pathologies; its ethnic repartition is quite heterogenic. In the present study, we proposed to describe the genotypic and allelic frequencies of C677T polymorphism and its influence on plasmatic homocysteine level in a healthy Algerian population. The investigation was turned on 100 apparently healthy voluntary subjects. Homocysteine concentration was determined using an immunoassay by fluorescence polarisation on IMx. Genotypes were determined by RT-PCR (Light cycle 480). Mean homocysteine concentration value was 14,69 +/- 7,30 micromol/L. 41% of people sample show a moderate hyperhomocysteinemia (>15 micromol/L). For the MTHFR C677T, estimated frequency of the allele T in the 100 people sample was about 35,5% with genotypic frequency of 6%. Plasmatic homocysteine is significantly higher in people carrying allele T: (CC vs CT: 11,8 +/- 2,97 micromol/L vs 15,47 +/- 6,74 micromol/L, p = 0,0004); (CC vs TT: 11,8 +/- 2,97 micromol/L vs 30,05 +/- 13,35 micromol/L, p = 0,01) and (CT vs TT: 15,47 +/- 6,74 micromol/L vs 30,05 +/- 13,35 micromol/L, p = 0,021). Our study shows an intermediate allelic frequency that joins the North-South world gradient and a high hyperhomocysteinemia prevalence. C677T polymorphism of MTHFR seems playing a predominant role in the moderate hyperhomocyteinemia. These two observations should be taken into consideration in the evaluation of morbid and/or lethal pathologies predisposition in the Algerian population.

Concentration and physicochemical characterisation of unsaturated cobalamin binding proteins in amniotic fluid.

Indirect evidence for the presence of intrinsic factor in amniotic fluid has been provided recently, using either a radioisotope binding assay or a radioimmunoassay. We have determined the unsaturated cobalamin binding capacity and the physicochemical properties of the 3 cobalamin binding proteins in 59 amniotic fluids using radioisotope binding assay, gel filtration and isoelectrofocussing. A good correlation with gestational age was found for the total unsaturated Cbl binding capacity (r = 0.735) and for the concentration of unsaturated haptocorrin (r = 0.746), but not for the concentration of unsaturated intrinsic factor (r = 0.003). When their binding capacities were expressed as a percentage of the total unsaturated Cbl binding capacity, the percentage of intrinsic factor, transcobalamin II and transcobalamin III (the less acidic fraction of haptocorrin) decreased and the percentage of haptocorrin increased in function of gestational age. The physicochemical properties of intrinsic factor in amniotic fluid were close to those in gastric juice: the molecular mass was estimated to 49,200 +/- 4,900 Da (n = 24) in Sephacryl S 300 gel filtration, the cobalamin-protein complex was resolved in 2-6 isoproteins isoelectric at a pH range of 4.6-5.8 and with a mean isoelectric point of 5.18 +/- 0.16 (n = 5) in isoelectrofocusing and it crossreacted with anti-intrinsic factor autoantibodies (from a Biermer anaemia serum). Amniotic fluid collected at 13 wk of gestational age was found to contain intrinsic factor and haptocorrin with less acidic isoproteins than those usually observed in gastric juice and serum. This could indicate that sialic acid is less involved in the composition of the carbohydrate core of cobalamin binding glycoproteins in this period of the gestational age than later on and that cobalamin binding proteins have mainly a foetal origin.

Unsaturated B12-binding proteins in amniotic fluid of cystic fibrosis-affected foetus.

The authors hypothesized the possibility of quantitative or qualitative abnormalities of amniotic fluid B12-binding proteins in cystic fibrosis. Seven cystic fibrosis and 59 normal amniotic fluids sampled between 17.5 and 18.5 gestational weeks were studied by radioimmunogel filtration, radioisotope technique, and isoelectric focusing chromatography. In normal amniotic fluid there was an increase of unsaturated B12-binding capacity from 16 to 41 weeks of gestation. There was no statistically significant difference in unsaturated B12-binding capacity, molecular weights and isoelectric points of haptocorrin, transcobalamin 2, and intrinsic factor between cystic fibrosis and normal amniotic fluid. Cobalamin-binding proteins study cannot help in the antenatal diagnosis of cystic fibrosis.

Gastric intrinsic factor hypersecretion stimulated by pentagastrin in cystic fibrosis.

The gastric pentagastrin-stimulated secretions of acid (peak acid output) and of unsaturated intrinsic factor in eight cystic fibrosis patients (1.4 +/- 0.5 mEq/kg/h and 0.27 +/- 0.12 nmol/kg/h, respectively) were significantly enhanced (p less than 0.05) when compared with six normal controls (0.27 +/- 0.16 mEq/kg/h and 0.10 +/- 0.02 nmol/kg/h, respectively). Despite the gastric hypersecretion of intrinsic factor, no significant physicochemical modification of this glycoprotein was observed in cystic fibrosis when using gel filtration and isoelectrofocusing. Haptocorrin (a cobalamin glycoproteic binder that does not promote the assimilation of cobalamin) also increased in gastric juice after stimulation. Since the sequestration of cobalamin to haptocorrin is pH dependent, the gastric acid hypersecretion observed in cystic fibrosis may explain that the malabsorption of crystalline cobalamin is much more frequent in cystic fibrosis than in chronic pancreatitis.