Effects of diallyl disulfide (DADS) on expression of apoptosis associated proteins in androgen independent human prostate cancer cells (PC-3)

Prostate cancer is a leading cause of death among the aging men. Surgical or radiotherapy is effective when the cancer is confined to the prostate gland but once the cancer spreads beyond the pelvis even chemotherapy and hormonal ablation therapy fails in curing this disease. Our previous studies have shown that diallyl disulfide (DADS) induces cell cycle arrest and also induces apoptosis in PC-3 cells. And now the present study is focused to see whether there is an activation of caspase cascade pathway. Hence, in the present study the apoptotic effect of DADS is studied by Western blot analysis of caspase-3, -9, -10 and Bcl-2, Bad, and Bax protein. The Apoptotic cells were assessed by Hoechst 33342 staining with 25 and 40 microM concentrations of DADS for 24 h. The results have shown that DADS at 25 and 40 microM concentrations has induced the activation of caspases. There is a significant increase in the expression of caspases (3, 9, and 10). The proapoptotic protein Bax has significantly increased at 40 microM of DADS treatment and there is significant increase of Bad protein at both the concentration. Bcl-2 protein has significantly decreased in DADS treated cells. Therefore, the present investigation serves as evidence that DADS may be a therapeutic drug in the treatment of prostate cancer.     

Mitochondrial DNA mutations and male infertility

Infertility can be defined as difficulty in conceiving a child after 1 year of unprotected intercourse. Infertility can arise either because of the male factor or female factor or both. According to the current estimates, 15% of couples attempting their first pregnancy could not succeed. Infertility is either primary or secondary. Mitochondria have profound effect on all biochemical pathways, including the one that drivessperm motility. Sperm motility is heavily dependent on the ATP generated by oxidative phosphorylation in the mitochondrial sheath. In this review, the very positive role of mitochondrial genome's association with infertility is discussed.     

Anti-hyperglycemic compound (GII) from fenugreek (Trigonella foenum-graecum Linn.) seeds, its purification and effect in diabetes mellitus

An anti-hyperglycemic compound named GII was purified from the water extract of the seeds of fenugreek (T. foenum-graecum) and shown to be different from trigonelline and nicotinic acid isolated earlier from the same plant. GII (50 mg/kg body weight, po) reduced blood glucose in glucose tolerance test (GTT) in the sub-diabetic and moderately diabetic rabbits and significantly reduced the area under the curve (AUC) of GTT. Treatment for 7 days of the sub-diabetic rabbits with GII (50 mg/kg body weight, po) improved glucose tolerance without reducing fasting blood glucose (FBG) which was nearly normal. The results suggest that there is no risk of hypoglycemia in near normal animals (may be humans also) with abnormal GTT. Treatment of the moderately diabetic rabbits with GII (100 mg/kg body weight for 3 weeks) reduced FBG to nearly normal value and improved GTT. GII was more effective than the standard drug tolbutamide. Intermittent therapy given on days 1-5, 11-15, 26-30 and 56-60 to moderately diabetic rabbits leaving in between days without treatment brought down FBG to normal and AUC during GTT was normal. After 15 days treatment with GII (100 mg/kg body weight for 3 weeks) glycosylated hemoglobin came down and insulin increased to normal values in the sub-diabetic, moderately diabetic and severely diabetic rabbits. GII treatment (100 mg/kg body weight for 15 days) brought down all the altered serum lipids (TC, HDLC, TAG, PLs and FFAs) to normal levels. The results suggest that intermittent therapy, instead of daily therapy is possible and GII has good potential as an oral anti-diabetic drug with intermittent therapy.     

Solid Self-Microemulsifying Formulation for Candesartan Cilexetil

Sparingly, water-soluble drugs such as candesartan cilexetil offer challenges in developing a drug product with adequate bioavailability. The objective of the present study was to develop and characterize self-microemulsifying drug delivery system (SMEDDS) of candesartan cilexetil for filling into hard gelatin capsules. Solubility of candesartan cilexetil was evaluated in various nonaqueous careers that included oils, surfactants, and cosurfactants. Pseudoternary phase diagrams were constructed to identify the self-microemulsification region. Four self-microemulsifying formulations were prepared using mixtures of oils, surfactants, and cosurfactants in various proportions. The self-microemulsification properties, droplet size, and zeta potential of these formulations were studied upon dilution with water. The optimized liquid SMEDDS formulation was converted into free flowing powder by adsorbing onto a solid carrier for encapsulation. The dissolution characteristics of solid intermediates of SMEDDS filled into hard gelatin capsules was investigated and compared with liquid formulation and commercial formulation to ascertain the impact on self-emulsifying properties following conversion. The results indicated that solid intermediates showed comparable rate and extent of drug dissolution in a discriminating dissolution medium as liquid SMEDDS indicating that the self-emulsifying properties of SMEDDS were unaffected following conversion. Also, the rate and extent of drug dissolution for solid intermediates was significantly higher than commercial tablet formulation. The results from this study demonstrate the potential use of SMEDDS as a means of improving solubility, dissolution, and concomitantly the bioavailability.     

Cost-Effectiveness of Newborn Circumcision in Reducing Lifetime HIV Risk among U.S. Males

Background

HIV incidence was substantially lower among circumcised versus uncircumcised heterosexual African men in three clinical trials. Based on those findings, we modeled the potential effect of newborn male circumcision on a U.S. male''s lifetime risk of HIV, including associated costs and quality-adjusted life-years saved.

Methodology/Principal Findings

Given published estimates of U.S. males'' lifetime HIV risk, we calculated the fraction of lifetime risk attributable to heterosexual behavior from 2005–2006 HIV surveillance data. We assumed 60% efficacy of circumcision in reducing heterosexually-acquired HIV over a lifetime, and varied efficacy in sensitivity analyses. We calculated differences in lifetime HIV risk, expected HIV treatment costs and quality-adjusted life years (QALYs) among circumcised versus uncircumcised males. The main outcome measure was cost per HIV-related QALY saved. Circumcision reduced the lifetime HIV risk among all males by 15.7% in the base case analysis, ranging from 7.9% for white males to 20.9% for black males. Newborn circumcision was a cost-saving HIV prevention intervention for all, black and Hispanic males. The net cost of newborn circumcision per QALY saved was $87,792 for white males. Results were most sensitive to the discount rate, and circumcision efficacy and cost.

Conclusions/Significance

Newborn circumcision resulted in lower expected HIV-related treatment costs and a slight increase in QALYs. It reduced the 1.87% lifetime risk of HIV among all males by about 16%. The effect varied substantially by race and ethnicity. Racial and ethnic groups who could benefit the most from circumcision may have least access to it due to insurance coverage and state Medicaid policies, and these financial barriers should be addressed. More data on the long-term protective effect of circumcision on heterosexual males as well as on its efficacy in preventing HIV among MSM would be useful.     

Structure and orientation of pardaxin determined by NMR experiments in model membranes

Pardaxins are a class of ichthyotoxic peptides isolated from fish mucous glands. Pardaxins physically interact with cell membranes by forming pores or voltage-gated ion channels that disrupt cellular functions. Here we report the high-resolution structure of synthetic pardaxin Pa4 in sodium dodecylphosphocholine micelles, as determined by (1)H solution NMR spectroscopy. The peptide adopts a bend-helix-bend-helix motif with an angle between the two structure helices of 122 +/- 9 degrees , making this structure substantially different from the one previously determined in organic solvents. In addition, paramagnetic solution NMR experiments on Pa4 in micelles reveal that except for the C terminus, the peptide is not solvent-exposed. These results are complemented by solid-state NMR experiments on Pa4 in lipid bilayers. In particular, (13)C-(15)N rotational echo double-resonance experiments in multilamellar vesicles support the helical conformation of the C-terminal segment, whereas (2)H NMR experiments show that the peptide induces considerable disorder in both the head-groups and the hydrophobic core of the bilayers. These solid-state NMR studies indicate that the C-terminal helix has a transmembrane orientation in DMPC bilayers, whereas in POPC bilayers, this domain is heterogeneously oriented on the lipid surface and undergoes slow motion on the NMR time scale. These new data help explain how the non-covalent interactions of Pa4 with lipid membranes induce a stable secondary structure and provide an atomic view of the membrane insertion process of Pa4.     

Perturbation of the hydrophobic core of lipid bilayers by the human antimicrobial peptide LL-37

LL-37 is a cationic, amphipathic alpha-helical antimicrobial peptide found in humans that kills cells by disrupting the cell membrane. To disrupt membranes, antimicrobial peptides such as LL-37 must alter the hydrophobic core of the bilayer. Differential scanning calorimetry and deuterium ((2)H) NMR experiments on acyl chain perdeuterated lipids demonstrate that LL-37 inserts into the hydrophobic region of the bilayer and alters the chain packing and cooperativity. The results show that hydrophobic interactions between LL-37 and the hydrophobic acyl chains are as important for the ability of this peptide to disrupt lipid bilayers as its electrostatic interactions with the polar headgroups. The (2)H NMR data are consistent with the previously determined surface orientation of LL-37 (Henzler Wildman, K. A., et al. (2003) Biochemistry 42, 6545) with an estimated 5-6 A depth of penetration of the hydrophobic face of the amphipathic helix into the hydrophobic interior of the bilayer. LL-37 also alters the material properties of lipid bilayers, including the area per lipid, hydrophobic thickness, and coefficient of thermal expansion in a manner that varies with lipid type and temperature. Comparison of the effect of LL-37 on 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC-d(31)) and 1,2-dimyristoyl-phosphatidylcholine (DMPC-d(54)) at different temperatures demonstrates the importance of bilayer order in determining the type and extent of disordering and disruption of the hydrophobic core by LL-37. One possible explanation, which accounts for both the (2)H NMR data presented here and the known surface orientation of LL-37 under identical conditions, is that bilayer order influences the depth of insertion of LL-37 into the hydrophobic/hydrophilic interface of the bilayer, altering the balance of electrostatic and hydrophobic interactions between the peptide and the lipids.