Antimicrobial activity and cytotoxicity trait of a bioactive peptide purified from Lactococcus garvieae subsp. bovis BSN307T

A bioactive peptide of 8595 Da was purified from the cell free supernatant of Lactococcus garvieae subsp. bovis BSN307^T. MALDI MS/MS peptide mapping and the data base search displayed no significant similarity to any reported antimicrobial peptide of LAB. This peptide at a dose concentration of 200 µg ml⁻¹ inhibited the growth of both Gram-positive and Gram-negative bacteria by 58–89% and a dose of 500 µg ml⁻¹ scavenged 50% of DPPH-free radicals generated. Interestingly, cytotoxicity assay demonstrated that 17 µg ml⁻¹ of peptide selectively inhibited 50% proliferation of mammalian cancer cell lines HeLa and MCF-7 whereas normal H9c2 cells remained unaffected. Fluorescent microscopic analysis after DAPI nuclear staining of HeLa cells showed characteristics of apoptosis and activation of caspase-3 was ascertained by caspase-3 fluorescence assay.     

Ontogeny of pyruvate dehydrogenase complex and key enzymes involved in glycolysis and tricarboxylic acid cycle in rabbit fetal lung, heart, and liver

The metabolic pathways by which the glycogen is utilized by fetal tissues is not well established. In the present study the ontogeny of seven key enzymes involved in glycolysis and the tricarboxylic acid cycle has been established for rabbit fetal lung, heart, and liver. In the fetal lung the activities of phosphofructokinase, pyruvate kinase, lactic dehydrogenase, citrate synthase, and malate dehydrogenase increase from day 21 to 25. Thereafter the levels either drop to day 19 levels or do not change. The isocitrate dehydrogenase activity continues to increase from day 19 of gestation to maximum level on day 31 of gestation. In fetal heart the pattern of activity is similar, but in fetal liver most of the enzymes reach maximum levels earlier and, with the exception of pyruvate kinase, do not show a significant fall in activity near term. The pattern of development of pyruvate dehydrogenase complex is different; maximum activity is observed on day 27 in fetal lung and heart and on day 21 in fetal liver. These results indicate that all three fetal tissues can oxidize glucose. Also, the accumulation of glycogen, particularly in fetal lung, appears to ensure that at specific times during gestation adequate quantities of energy (ATP) and substrates, required for surfactant phospholipid synthesis, are available independent of maternal supply of glucose or during brief episodes of hypoxia.     

Interaction of ring B unsaturated estrogens with estrogen receptors of human endometrium and rat uterus

The present investigation was undertaken to compare the binding affinities (Ka) of the ring B unsaturated equine estrogens (equilin [Eq], equilenin [Eqn], 17 beta-dihydroequilin [17 beta-Eq], 17 beta-dihydroequilenin [17 beta-Eqn], 17 alpha-dihydroequilin [17 alpha-Eq], and17 alpha-dihydroequilenin [17 alpha-Eqn]) and the classic estrogens (estrone [E1], 17 beta-estradiol [17 beta-E2], and 17 alpha-estradiol [17 alpha-E2]) for estrogen receptors in human endometrium and rat uterus. In both species, the ring B unsaturated estrogens bind with cytosol and nuclear receptors with high affinity (Ka x 10(9) M-1). The relative binding affinities of these estrogens were measured by determining the amount of unlabeled estrogen required to reduce by 50% the specific binding of [3H]17 beta-Eq to endometrial cytosol receptors. The order of activity found was 17 beta-Eq greater than 17 beta-E2 greater than 17 beta-Eqn greater than E1 greater than Eq greater than 17 alpha-Eq greater than 17 alpha-E2 greater than 17 alpha-Eqn greater than Eqn. Essentially the same order of activity was observed when the apparent affinity constants of these estrogens for human and rat cytosol and nuclear receptors were determined by a competitive (inhibition) binding assay. Sucrose density gradient analysis indicated that these estrogens form protein complexes with cytosol and nuclear preparation that sediment at approximately 8S and 4S, respectively. The affinity constants for 17 beta-Eq were approximately two- to six-fold higher than E2 in both species. In a rat uterotropic assay, all nine estrogens were uterotropic. These data indicate that all ring B unsaturated estrogens present in conjugated equine estrogen preparations are biologically active and they express their biologic effects in the human endometrium by mechanisms similar to those described for the classic estrogens.     

Regulation of rabbit fetal glycogen: effect of in utero fetal decapitation on the metabolism of glycogen in fetal heart, lung, and liver

To understand the control mechanisms involved in the regulation of fetal glycogen, we have studied the effect of in utero fetal decapitations on glycogen metabolism in rabbit fetal heart, lung, and liver. In utero fetal decapitations were performed between days 18 and 21 of gestation. Two to four fetuses on one side of the horn were decapitated. Fetuses were delivered between days 23 and 26 or between days 28 and 30 of gestation. Fetal heart, lungs, and liver were analyzed for DNA, protein, glycogen, glycogen synthase (I and D forms), glycogen phosphorylase (a and b forms), phosphofructokinase, pyruvate kinase, and lactic dehydrogenase. In fetal heart and lung, no difference was observed in any of the above measurements in the intact and decapitated fetuses. In contrast, fetal liver does not appear to develop the glycogen system as indicated by the very low levels of glycogen (0.02 mg/mg DNA) in decapitated fetuses as compared with intact fetuses (0.4 mg/mg DNA). Similarly the levels of glycogen synthase and phosphorylase were two to three times lower in livers from decapitated fetuses as compared with the livers from intact fetuses. The three enzymes phosphofructokinase, pyruvate kinase, and lactic dehydrogenase were not affected by fetal decapitation in all three tissues. These results indicate that the fetal hypothalamic-pituitary-adrenal (thyroid) axis is not required at least after day 18 of gestation for the normal accumulation and subsequent utilization of glycogen in fetal heart and lungs, while it is an absolute requirement for the development of the fetal liver glycogen system.(ABSTRACT TRUNCATED AT 250 WORDS)     

Neuronal control of lipid metabolism by STR‐2 G protein‐coupled receptor promotes longevity in Caenorhabditis elegans

The G protein‐coupled receptor (GPCR) encoding family of genes constitutes more than 6% of genes in Caenorhabditis elegans genome. GPCRs control behavior, innate immunity, chemotaxis, and food search behavior. Here, we show that C. elegans longevity is regulated by a chemosensory GPCR STR‐2, expressed in AWC and ASI amphid sensory neurons. STR‐2 function is required at temperatures of 20°C and higher on standard Escherichia coli OP50 diet. Under these conditions, this neuronal receptor also controls health span parameters and lipid droplet (LD) homeostasis in the intestine. We show that STR‐2 regulates expression of delta‐9 desaturases, fat‐5, fat‐6 and fat‐7, and of diacylglycerol acyltransferase dgat‐2. Rescue of the STR‐2 function in either AWC and ASI, or ASI sensory neurons alone, restores expression of fat‐5, dgat‐2 and restores LD stores and longevity. Rescue of stored fat levels of GPCR mutant animals to wild‐type levels, with low concentration of glucose, rescues its lifespan phenotype. In all, we show that neuronal STR‐2 GPCR facilitates control of neutral lipid levels and longevity in C. elegans.     

Biotic elicitors enhance diosgenin production in Helicteres isora L. suspension cultures via up-regulation of CAS and HMGR genes

In an attempt to find an alternative and potent source of diosgenin, a steroidal saponin in great demand for its pharmaceutical importance, Helicteres isora suspension cultures were explored for diosgenin extraction. The effect of biotic elicitors on the biosynthesis of diosgenin, in suspension cultures of H. isora was studied. Bacterial as well as fungal elicitors such as Escherichia coli, Bacillus subtilis, Saccharomyces cerevisiae and Aspergillus niger were applied at varying concentrations to investigate their effects on diosgenin content. The HPLC based quantification of the treated samples proved that amongst the biotic elicitors, E. coli (1.5%) proved best with a 9.1-fold increase in diosgenin content over respective control cultures. Further, the scaling-up of the suspension culture to shake-flask and ultimately to bioreactor level were carried out for production of diosgenin. During all the scaling-up stages, diosgenin yield obtained was in the range between 7.91 and 8.64 mg l−1, where diosgenin content was increased with volume of the medium. The quantitative real-time PCR (qRT-PCR) analysis showed biotic elicitors induced the expression levels of regulatory genes in diosgenin biosynthetic pathway, the 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) and cycloartenol synthase (CAS), which can be positively correlated with elicited diosgenin contents in those cultures. The study holds significance as H. isora represents a cleaner and easy source of diosgenin where unlike other traditional sources, it is not admixed with other steroidal saponins, and the scaled-up levels of diosgenin achieved herein have the potential to be explored commercially.     

Solvent-Free Synthesis,Characterization, and In Vitro Biological Activity Study of Xanthenediones and Acridinediones

Russian Journal of Bioorganic Chemistry - The present work highlights the broad range of oxygen and nitrogen heterocycles and their applications in medicinal field. A facial approach has been...     

Controlled Release of Ropinirole Hydrochloride from a Multiple Barrier Layer Tablet Dosage Form: Effect of Polymer Type on Pharmacokinetics and IVIVC

The purpose of the present study was to control in vitro burst effect of the highly water-soluble drug, ropinirole hydrochloride to reduce in vivo dose dumping and to establish in vitro–in vivo correlation. The pharmacokinetics of two entirely different tablet formulation technologies is also explored in this study. For pharmacokinetics study, FDA recommends at least 10% difference in drug release for formulations to be studied but here a different approach was adopted. The formulations F8A and F9A having similar dissolution profiles among themselves and with Requip® XL™ (f₂ value 72, 77, 71 respectively) were evaluated. The C_max of formulation F8A comprising hypromellose 100,000 cP was 1005.16 pg/ml as compared to 973.70 pg/ml of formulation F9A comprising hypromellose 4000 cP irrespective of T_max of 5 and 5.75 h, respectively. The difference in release and extent of absorption in vivo was due to synergistic effect of complex RH release mechanism; however, AUC_0–t and AUC_0–∞ values were comparable. The level A correlation using the Wagner–Nelson method supported the findings where R² was 0.7597 and 0.9675 respectively for formulation F8A and F9A. Thus, in vivo studies are required for proving the therapeutic equivalency of different formulation technologies even though f₂ ≥ 50. The technology was demonstrated effectively at industrial manufacturing scale of 200,000 tablets.KEY WORDS: controlled release polymer, in vitro–in vivo correlation (IVIVC), multiple barrier layer tablets, pharmacokinetics, ropinirole hydrochloride (RH)