Effects of aegeline, a main alkaloid of aegle marmelos correa leaves, on the histamine release from mast cells

Aegeline or 7V-[2-hydroxy-2[4-methoxyphenyl] ethyl]-3-phenyl-2-propenamide is a main alkaloid isolated from Aegle marmelos Correa collected in Yogyakarta Indonesia. In our study, we investigated the effects of aegeline on the histamine release from mast cell. The study was performed by using [1] rat basophilic leukemia [RBL-2H3] cell line, and [2] rat peritoneal mast cells [RPMCs]. DNP[2]4-BSA, thapsigargin, ionomycin, compound 48/80 and PMA were used as inducers for histamine release from mast cell. In our study, aegeline inhibited the histamine release from RBL-2H3 cells induced by DNP24-BSA. Indeed, aegeline showed strong inhibition when RBL-2H3 cells induced by Ca[2+] stimulants such as thapsigargin and ionomycin. Aegeline is suggested to influence the intracellular Ca[2+] pool only since could not inhibit the [45]Ca[2+] influx into RBL-2H3 cells. Aegeline showed weak inhibitory effects on the histamine release from RPMCs, even though still succeed to inhibit when the histamine release induced by thapsigargin. These findings indicate that aegeline altered the signaling pathway related to the intracellular Ca[2+] pool in which thapsigargin acts. Based on the results, the inhibitory effects ofaegeYme on the histamine release from mast cells depended on the type of mast cell and also involved some mechanisms related to intracellular Ca[2+] signaling events via the same target of the action of thapsigargin or downstream process of intracellular Ca[2+] signaling in mast cells

Effect of pH and sodium ions on intestinal uptake of lysine in rats.

Intestinal uptake of lysine in rats progressively decreased with an increase in pH from 5.2 to 8.5, both in the presence and absence of Na+ ions. At pH 5.2 lysine uptake was 30-35% more than that at neutral pH. Na+ activated lysine uptake by 40-50% at pH 5.2 and it was increased to 110-120% at neutral pH. The observed increase in lysine uptake in response to Na+ and H+ gradients was due to enhanced maximal velocity (Vmax), with little change in affinity constant (Kt). Arrhenius analysis revealed a biphasic curve for lysine uptake with transition temperature (Tc) around 20 degrees C (24 degrees C at pH 5.2 in presence of Na+). The energy of activation (Ea) below (16.1-23.4 Kcal/mole) and above (6.7-8.6 Kcal/mole) the Tc was similar at pH 5.2 and 7.0 both in the presence and absence of Na+ ions. The sensitivity of lysine uptake to various inhibitors was also dependent upon pH and Na+ ions.

Post-metaphase mitotic events in cells treated with dinitrophenol.

The sequence of post-metaphase mitotic events, such as anaphase movement A and B, chromosome decondensation, nuclear envelope reformation and cytokinesis, has been studied in 2,4-initrophenol (DNP)-treated HeLa cells. The effects of DNP were found to be dose dependent and at concentrations higher than 3 mM, both anaphase A and B movements were totally and nearly instantaneously arrested. It could be shown that cytokinesis did not depend on the completion of anaphase movements. This was also true for nuclear envelope reformation which could take place even around condensed chromosomes arrested in anaphase. The post-metaphase mitotic events do not follow a strict causal sequence, but they can be dissociated from each other in anaphase-arrested cells.

Immunopharmacological studies on Picrorhiza kurroa Royle-ex-Benth. Part IV: Cellular mechanisms of anti-inflammatory action.

In this work abroagation of anti-inflammatory effect of Picrorhiza kurroa extract (PK) by beta-adrenergic blockade was confirmed, which suggests alteration in cell-surface biology by PK treatment. Blockade of protein synthesis by cycloheximide pretreatment reduced PK effect, suggesting protein mediation. Metabolic inhibitor dinitrophenol inhibited inflammatory cedema equally in control and PK treated animals, and masking of PK effect was concluded. Discriminations of anti-inflammatory mechanism(s) of PK and the latter two cytotoxic agents was inferred from these observations and from existing knowledge. Selective PK influence on membrane linked activation events in inflammatory effector cells could be the basis of anti-inflammatory and perhaps other biological activities reported with the herb.

Determinación del pH intracelular por distribución de ácido benzoico en S. cerevisiae, transporte de aminoácidos y gradiente de protones / Determination of internal pH of S. cerevisiae from the distribution of benzoic acid: amino acids transport and proton gradient

El (pHi) de Saccjaromyces cerevisiae, cepa silvestre y su mutante rhose determinó por el método de distribución intra-extracelilar del ácido 14C-benzoico. Los valores de pHi obtenidos (con un pH externo de 4,5) variarón con la depa de levadura y dependieron de las condiciones metabólicas de las mismas. En células de la cepa silvestre, energizada por incubación previa con glucosa 5 mM, el pHi osció entre 6,15-6,40 y el gradiente de protones a través de la membrana deltapH entre 1,65-1,90 ó -97 a -112 mV. Esos valores fueron mayores que los de células ayunadas: pHi 5,90, deltapH 1,40 ó -82 mV. En esas dos condiciones metabólicas, los valores en la mutante rho- fueron algo menores que en la cepa silvestre; levadura rho- energizada pHi 6,05, deltapH 1,55 ó -91 mV; levadura rho- ayunada pHi 5,70, deltapH 1,20 ó -71 mV. Los protonófros DNP y PCP produjeron una disminución del pHi del deltapH y una inhibición de la entrada de L-leucina por los sistemas S1, alta afinidad y baja velocidad y S2, baja afinidad y alta velocidad. Los valores de la disminución del deltapH y la inhibición del transporte de L-leucina obtenidos indican que no hay una relación estricta entre el deltapH y el proceso de transporte