Investigation of Hydrogel Isolated from Seeds of Ocimum basilicum as Binder.

Ayurvedic powders are widely used as therapeutic agents but most of them have unpleasant taste and large doses. One of the possible approach to overcome these drawbacks is to represent them in unit dosage form i.e. tablet dosage form. The purpose of this study is to elucidate and quantify the compressibility and compactibility of herbal granules prepared by using hydrogel isolated from whole seeds of Ocimum basilicum as a novel binder. The compressibility is the ability of the powder to deform under pressure and the compactibility is the ability of a powder to form coherent compacts. To test the functionality of novel excipients, Sonnergaard proved a simple linear model to confirm compactability, which is an uncomplicated tool for quantification. The tablets were compressed at increasing compression pressures and were evaluated for various mechanical properties. The linear relationship between specific crushing strength and compression pressure revealed the compactibility of the herbal granules and the linear relationship between porosity and logarithm of compression pressure revealed the compressible nature of the herbal granules according to the model developed by Sonnergaard. Thus the hydrogel isolated from whole seeds of Ocimum basillicum had potential as a granulating and binding agent.

Activation of the human estrogen receptor by estrogenic and antiestrogenic compounds in Saccharomyces cerevisiae: a positive selection system.

The yeast URA3 gene was used as a reporter to investigate the activities of estrogenic and antiestrogenic compounds in yeast Saccharomyces cerevisiae. The control sequences of the wild type (wt) URA3 promoter were replaced with zero, two, or six copies of estrogen-response elements (ERE). Insertion of two and six copies of ERE rendered the expression of the URA3 gene to be dependent on the presence of the human estrogen receptor (ER) and the hormone 17beta-estradiol (E2). Two versions of the ER genes were constructed: a full-length wild-type ER (ERa-f) and a truncated ER with domains C, D, and E (ERcde). Both forms of the ER were able to activate the ERE-URA3 reporter in a hormone-dependent manner. The growth of yeast transformants were hormone-dependent when the reporter constructs were inserted into chromosomes using yeast integrating vectors (YIp) but not with the 2mu-based episomal (high-copy number, YEp) or centromeric (low-copy number, YCp) vectors. The integrated transformants were employed to investigate the effects of estrogenic and antiestrogenic compounds. The estrogenic compounds, E2, diethylstilbestrol (DES), and estrone (EST), activated expression of the reporter genes at 1 nM concentration, which is the same concentration exhibiting activity in mammalian cells. None of the antiestrogens, at concentrations up to 1 microM, including tamoxifen (TAM), raloxifene (RAL), and ICI 164,384 (ICI) antagonized 1 nM of E2 against either form of the ER. In fact, TAM, RAL, and ICI displayed slight agonistic activity at high concentrations of 300 nM or greater to the ERcde. This system can be used to investigate or clone the missing factor(s) that is responsible for the antagonistic activity of the ER in yeast, and is also suitable for screening for the effectors of the ER.

Identification of an estrogen response element activated by metabolites of 17beta-estradiol and raloxifene.

17beta-Estradiol modulates gene transcription through the estrogen receptor and the estrogen response element in DNA. The human transforming growth factor-beta3 gene was shown to be activated by the estrogen receptor in the presence of estrogen metabolites or estrogen antagonists. Activation was mediated by a polypurine sequence, termed the raloxifene response element, and did not require the DNA binding domain of the estrogen receptor. Interaction of the estrogen receptor with the raloxifene response element appears to require a cellular adapter protein. The observation that individual estrogens modulate multiple DNA response elements may explain the tissue-selective estrogen agonist or antagonist activity of compounds such as raloxifene.

Estrogen and raloxifene stimulate transforming growth factor-beta 3 gene expression in rat bone: a potential mechanism for estrogen- or raloxifene-mediated bone maintenance.

Estrogen or raloxifene (LY156758) prevent estrogen deficiency-induced bone loss in animals and humans. We demonstrated in the rat that a 22% reduction in bone mineral density generated by ovariectomy was associated with a 2-fold reduction of transforming growth factor-beta 3 (TGF beta 3) messenger RNA expression in the femur. Administration of 17 beta-estradiol or raloxifene to ovariectomized rats restored both bone mineral density and TGF beta 3 messenger RNA expression in the femur to levels measured in intact animals. In transient transfection assays, the promoter sequence from -38 to + 110 of the human TGF beta 3 gene, which contains no palindromic estrogen response element, was sufficient to mediate 17 beta-estradiol or raloxifene induced-reporter gene expression in presence of the estrogen receptor. Raloxifene activated TGF beta 3 promoter as a full agonist at nanomolar concentrations. In the same cellular system, raloxifene inhibited the estrogen response element-containing vitellogenin promoter expression as a pure estrogen antagonist. In two well characterized osteoclast differentiation models, TGF beta 3 significantly inhibited the differentiation and bone-resorptive activities of murine and avian osteoclasts. These findings suggest that regulation of TGF beta 3 gene expression by raloxifene or estrogen in bone may be an important target to mediate bone maintenance.

Myeloproliferative disorders: usefulness of X-linked probes in diagnosis.

Myeloproliferative disorders are neoplasms of the pluripotent hematopoietic stem cell. Accurate diagnosis and distinction from reactive processes can be difficult therein with cytogenetic analysis only being useful in a minority of patients. Use of X-linked restriction fragment length polymorphism and methylation analysis has enabled clonal analysis to be performed in up to 50% of females, significantly increasing the proportion of analyzable patients over methods dependent on glucose-6-phosphate dehydrogenase heterozygosity. Using hypoxanthine phosphoribosyl transferase and phosphoglycerate kinase probes, we have demonstrated monoclonality of peripheral blood leukocytes in three females with myeloproliferative disorders who had uninformative chromosomal analysis. This technique greatly enhances the diagnosis of early myeloproliferative disorder.