Phytoestrogens: food or drug?

Within the past several years, the relation between diet and health has been accepted by the mainstream nutrition community and in this connection interest in the physiological role of bioactive compounds present in plants has dramatically increased over the last decade.The phytoestrogens are bioactive molecules present as nutritional constituents of widely consumed vegetables. Their name derives from the fact that they are able to bind to estrogen receptors and to induce an estrogenic/antiestrogenic response in target tissues. Natural estrogens are involved in a multiplicity of programmed events in target tissues as uterus, breast, pituitary gland and hormone responsive tumors. Phytoestrogens are present in many human foodstuffs including fruits (plum, pear, apple grape berries, …), vegetables (beans, sprouts, cabbage, spinach, soybeans, grains, hops, garlic, onion,…), wine, tea, and they have been identified in a number of botanical dietary supplements. They include a wide variety of structurally different compounds such as isoflavones, mainly found in soy, lignans found in grains, stilbenes found in the skin of grapes. Other less investigated compounds include flavones, flavans, isoflavanes and coumestans. The estrogenic or antiestrogenic activity of any chemicals depends on the ability of the compound to interact with the ERs (ERα , ERß ).This article reported the knowledge about the activity of phytoestrogens from a pharmacological point of view for their estrogenicity or antiestrogenicity.

Carbonic anhydrase inhibitors: design of thioureido sulfonamides with potent isozyme II and XII inhibitory properties and intraocular pressure lowering activity in a rabbit model of glaucoma.

A new series of thioureido-substituted sulfonamides were prepared by reacting 4-isothiocyanato- or 4-isothiocyanatoethyl-benzenesulfonamide with amines, hydrazines, or amino acids bearing moieties that can lead to an enhanced hydrosolubility, such as 2-dimethylamino-ethylamine, fluorine-containing aromatic amines/hydrazines, an aminodiol, heterocyclic polyamines (derivatives of morpholine and piperazine), 4-aminobenzoic acid, or natural amino acids (Gly, Cys, Asn, Arg, and Phe). The new compounds showed good inhibitory properties against three physiologically relevant carbonic anhydrase (CA, EC 4.2.1.1) isozymes, with K(I)s in the range of 24-324 nM against the cytosolic isoform CA I, of 6-185 nM against the other cytosolic isozyme CA II, and of 1.5-144 nM against the transmembrane isozyme CA XII. Some of the new derivatives were also very effective in reducing elevated intraocular pressure in hypertensive rabbits as a glaucoma animal model. Considering that this is the first study in which potent CA II/CA XII inhibitors are designed and investigated in vivo, it may be assumed that the target isozymes of the antiglaucoma sulfonamides are indeed the cytosolic CA II and the transmembrane CA XII.

Calcium bioavailability from a calcium-rich mineral water, with some observations on method.

GOALS: The study was designed to determine whether high-calcium mineral water is an efficient additional source of dietary calcium, optimizing a method for calcium determination never used for mineral waters. BACKGROUND: It is generally agreed that an adequate calcium intake is necessary for the acquisition of an ideal peak bone mass and for the maintenance of the bone mineral density in adults, in postmenopausal women, and in the elderly. Mineral waters are calorie free, and some, with high calcium levels, might be significant sources of calcium. STUDY: The availability of the calcium contained in a high-calcium mineral water was measured in 27 healthy subjects. In 8 subjects the calcium availability of the water was compared with the calcium availability ingested with milk at the same calcium load. Milk and water were labeled extrinsically with 30 mg Ca. Fractional absorption from the oral dose was determined from plasma samples using ICP-MS technique. RESULTS: At an ingested calcium load of 3.18 mmol, percentage of absorption for water averaged 22.53 +/- 2.53 (mean +/- SD) for men, 22.57 +/- 2.10 (mean +/- SD) for premenopausal women and 21.62 +/- 3.12 (mean +/- SD) for postmenopausal women. Percentage absorption from milk was 23.15 +/- 4.06 (mean +/- SD). DISCUSSION: The calcium from the mineral water is thus highly bioavailable, at least as bioavailable as milk calcium, and ICP-MS appears to represent a reliable and reproducible method for calcium absorption from alimentary sources.

Foods and new foods: the role of nutrition in skeletal health.

GOALS: The objective of this paper was to present nutrients for bone health along with traditional foods and new foods that can provide the adequate amount of such nutrients. BACKGROUND: Although bone mass and density are certainly determined by various concurrent factors such as genetics, hormones, physical activity, and nutrition, and although the genetic program has a critical role in growth and in bone peak development, for their realization an adequate nutritional intake of nutrients is always necessary and may represent a way to prevent bone diseases. METHODS: The authors collected scientific data about new possible foods containing potential nutrients for bone health besides milk, dairy products, and supplementation in tablets. RESULTS: There is much scientific evidence that calcium-rich mineral water, functional foods, soy products derived phytoestrogens, fortified foods, and vitamins K and E may play a important nutritional role in skeletal health. CONCLUSION: Currently, it is possible to provide required bone nutrient intake for bone health in population subgroups intolerant or allergic to lactose and in those individuals who need a controlled intake of calories.

Endogenous histamine in the medial septum-diagonal band complex increases the release of acetylcholine from the hippocampus: a dual-probe microdialysis study in the freely moving rat.

The effects of histaminergic ligands on both ACh spontaneous release from the hippocampus and the expression of c-fos in the medial septum-diagonal band (MSA-DB) of freely moving rats were investigated. Because the majority of cholinergic innervation to the hippocampus is provided by MSA-DB neurons, we used the dual-probe microdialysis technique to apply drugs to the MSA-DB and record the induced effects in the projection area. Perfusion of MSA-DB with high-KCl medium strongly stimulated hippocampal ACh release which, conversely, was significantly reduced by intra-MSA-DB administration of tetrodotoxin. Histamine or the H2 receptor agonist dimaprit, applied directly to the hippocampus, failed to alter ACh release. Conversely, perfusion of MSA-DB with these two compounds increased ACh release from the hippocampus. Also, thioperamide and ciproxifan, two H3 receptor antagonists, administered into MSA-DB, increased the release of hippocampal ACh, whereas R-alpha-methylhistamine, an H3 receptor agonist, produced the opposite effect. The blockade of MSA-DB H2 receptors, caused by local perfusion with the H2 receptor antagonist cimetidine, moderated the spontaneous release of hippocampal ACh and antagonized the facilitation produced by H3 receptor antagonists. Triprolidine, an H1 receptor antagonist, was without effect. Moreover, cells expressing c-fos immunoreactivity were significantly more numerous in ciproxifan- or thioperamide-treated rats than in controls, although no colocalization of anti-c-fos and anti-ChAT immunoreactivity was observed. These results indicate a role for endogenous histamine in modulating the cholinergic tone in the hippocampus.