Cellular Stress and p53-Associated Apoptosis by Juniperus communis L. Berry Extract Treatment in the Human SH-SY5Y Neuroblastoma Cells

Plant phenolics have shown to activate apoptotic cell death in different tumourigenic cell lines. In this study, we evaluated the effects of juniper berry extract (Juniperus communis L.) on p53 protein, gene expression and DNA fragmentation in human neuroblastoma SH-SY5Y cells. In addition, we analyzed the phenolic composition of the extract. We found that juniper berry extract activated cellular relocalization of p53 and DNA fragmentation-dependent cell death. Differentially expressed genes between treated and non-treated cells were evaluated with the cDNA-RDA (representational difference analysis) method at the early time point of apoptotic process when p53 started to be activated and no caspase activity was detected. Twenty one overexpressed genes related to cellular stress, protein synthesis, cell survival and death were detected. Interestingly, they included endoplasmic reticulum (ER) stress inducer and sensor HSPA5 and other ER stress-related genes CALM2 and YKT6 indicating that ER stress response was involved in juniper berry extract mediated cell death. In composition analysis, we identified and quantified low concentrations of fifteen phenolic compounds. The main groups of them were flavones, flavonols, phenolic acids, flavanol and biflavonoid including glycosides of quercetin, apigenin, isoscutellarein and hypolaetin. It is suggested that juniper berry extract induced the p53-associated apoptosis through the potentiation and synergism by several phenolic compounds.Peer reviewe

Influence of tamsulosin on the iris and its implications for cataract surgery. Invest Ophthalmol Vis Sci 2006; 47:3766–3771. Available at: http://www.iovs.org/cgi/ reprint/47/9/3766

PURPOSE. To study iris-related complications during cataract surgery in patients on tamsulosin medication. METHODS. Twenty-one consecutive cataract patients administered tamsulosin and 21 control patients were studied. Characteristics of the iris during surgery were recorded. Pupillary diameters of 16 patients were measured before and after iris dilatation. Tamsulosin concentrations in the aqueous humor and serum were analyzed. In five patients, surgery on the second eye was carried out after a 7-to 28-day pause in tamsulosin medication. RESULTS. Each patient administered tamsulosin had a sluggish hypotonic iris, along with a tendency toward miosis and a tendency for prolapse of the iris into the phaco tunnel or into the side port during cataract surgery. Sluggish irises also often adhered to the phaco tip or to the irrigation-aspiration tip. Despite a pause of 7 to 28 days in the use of tamsulosin, the adverse effects persisted. Tamsulosin concentrations varied between 0.1 and 1.0 ng/mL in the anterior chamber fluid. In three of five cases, tamsulosin remained in detectable amounts the aqueous humor after the 7-to 28-day pause. Preoperative pupillary diameter was smaller in the patients using tamsulosin than in the controls. CONCLUSIONS. Tamsulosin has selective ␣ 1A -adrenoreseptor antagonistic properties and obviously binds for a long period to the postsynaptic nerve endings of the iris dilator muscle, thus affecting iris dilatation and leading to complications in cataract surgery. The iris remained floppy after 7-to 28-day interruption of the tamsulosin regimen. (Invest Ophthalmol Vis Sci

Glucuronidation of Psilocin and 4-Hydroxyindole by the Human UDP-Glucuronosyltransferases

We have examined the glucuronidation of psilocin, a hallucinogenic indole alkaloid, by the 19 recombinant human UDP-glucuronosyltransferases (UGTs) of subfamilies 1A, 2A, and 2B. The glucuronidation of 4-hydroxyindole, a related indole that lacks the N,N-dimethylaminoethyl side chain, was studied as well. UGT1A10 exhibited the highest psilocin glucuronidation activity, whereas the activities of UGTs 1A9, 1A8, 1A7, and 1A6 were significantly lower. On the other hand, UGT1A6 was by far the most active enzyme mediating 4-hydroxyindole glucuronidation, whereas the activities of UGTs 1A7–1A10 toward 4-hydroxyindole resembled their respective psilocin glucuronidation rates. Psilocin glucuronidation by UGT1A10 followed Michaelis-Menten kinetics in which psilocin is a low-affinity high-turnover substrate (K(m) = 3.8 mM; V(max) = 2.5 nmol/min/mg). The kinetics of psilocin glucuronidation by UGT1A9 was more complex and may be best described by biphasic kinetics with both intermediate (K(m1) = 1.0 mM) and very low affinity components. The glucuronidation of 4-hydroxyindole by UGT1A6 exhibited higher affinity (K(m) = 178 μM) and strong substrate inhibition. Experiments with human liver and intestinal microsomes (HLM and HIM, respectively) revealed similar psilocin glucuronidation activity in both samples, but a much higher 4-hydroxyindole glucuronidation rate was found in HLM versus HIM. The expression levels of UGTs 1A6–1A10 in different tissues were studied by quantitative real-time-PCR, and the results, together with the activity assays findings, suggest that whereas psilocin may be subjected to extensive glucuronidation by UGT1A10 in the small intestine, UGT1A9 is likely the main contributor to its glucuronidation once it has been absorbed into the circulation

Characterization of proton-bound acetate dimers in ion mobility-spectrometry

Ionized acetates were used as model compounds to describe gas-phase behavior of oxygen containing compounds with respect to their formation of dimers in ion mobility spectrometry (IMS). The ions were created using corona discharge at atmospheric pressure and separated in a drift tube before analysis of the ions by mass spectrometry. At the ambient operational temperature and pressure used in our instrument, all acetates studied formed dimers. Using a homolog series of n-alkyl-acetates, we found that the collision cross section of a dimer was smaller than that of a monomer with the same reduced mass. Our experiments also showed that the reduced mobility of acetate dimers with different functional groups increased in the order n-alkyl ≤ branched chain alkyl ≤ cyclo alkyl < aromat. For mixed n-alkyl dimers we found that the reduced mobility of acetate dimers having the same number of carbons, for example a dimer of acetyl acetate and hexyl acetate has the same reduced mobility as a dimer composed of two butyl acetates. The fundamental behavior of acetate monomers and dimers described in this paper will assist in a better understanding of the influence of dimer formation in ion mobility spectrometry