A highly purified vegetal fraction able to modulate HMGB1 and to attenuate septic shock in mice.

High-mobility group box protein 1 (HMGB1) is an intracellular protein that may be released actively from monocytes and macrophages or passively from necrotic or damaged cells. Its inhibition in animal experiments, even in the late phase of septic shock, significantly enhanced the survival rate of rodents. The aim of our study was to investigate the effect of a vegetal fraction isolated and highly purified from Helleborus purpurascens regarding the modulation of HMGB1 release either from tumor cells or human blood mononuclear cells. Our results showed that the vegetal fraction was able to down-regulate the release of HMGB1 from activated human blood mononuclear cells (PBMCs) and tumor cells. By combining the purified fraction with Cyclophosphamide the release of HMGB1 from tumor cells was strongly decreased. This synergism was not noticed when the ve getal product was associated with Doxorubicin. We also studied the effect of the purified fraction in mice with septic shock induced by cecal ligation and puncture (CLP) method. The tested vegetal product increased significantly the survival rate of animals compared to the mice not treated with it. Our data suggest that the purified vegetal fraction may modulate inflammation by down-regulating the HMGB1, which can also explain its efficacy in septic shock in mice.

Substance MCS-18 isolated from Helleborus purpurascens is a potent antagonist of the capsaicin receptor, TRPV1, in rat cultured sensory neurons.

Extracts of Helleborus roots were traditionally used in the Balkan area for their analgesic action. We report that the pure natural product MCS-18 isolated from this source is a potent, specific and reversible antagonist of the capsaicin receptor, TRPV1, expressed in rat dorsal root ganglion (DRG) neurons. TRPV1 is a non-selective cation channel expressed in a subset of cutaneous and visceral sensory nerve endings and activated by noxious heat, acidity and fatty acid metabolites of arachidonic acid, with a decisive role in inflammatory heat hyperalgesia. MCS-18 inhibited the increase in intracellular calcium concentration evoked in DRG neurons by capsaicin (300 nM) and low pH (5.5) but not by heat (43 degrees C). The substance had no effect on the responses mediated by acid-sensing ion channels (ASICs) or the irritant receptor TRPA1. Whole-cell patch-clamp was used to confirm the inhibition of capsaicin-induced currents by MCS-18 which was dose-dependent. The mechanism of inhibition does not require an intact cell, as capsaicin-induced currents were also inhibited in the excised outside-out configuration. The antagonism of the capsaicin and proton action on native TRPV1 by MCS-18 may be of interest for pain therapy.

Recognition and modulation of Dectin-1 and TLR-2 receptors by curdlan derivatives and purified natural extracts.

Toll-like receptors (TLRs) and Dectin-1, as members of Pattern Recognition Receptors play an essential role in innate immune response against bacteria and fungi respectively, contributing to pathogens recognition, phagocytosis, etc. Dectin-1 and TLR-2/TLR-6 can interact for intracellular signal transduction. Dectin-1 is expressed at low levels on macrophages and at high levels on dendritic cells. Dectin-1 and TLRs are synergistic in mediating cytokines production, such as IL-12 and tumor necrosis factor alpha (TNF alpha). In the present paper we studied the expression of Dectin-1 (beta-Glucan Receptor C-type lectin receptor class V) and TLR-2 on human normal monocytes cells and also the role of different Curdlan derivatives and highly purified natural extracts, especially their capacity to recognize these receptors and their Dectin-1 agonist/antagonist properties. Our results demonstrated that Curdlan derivatives containing sulfopropyl or palmythoil/carboximethyl/sulfopropyl groups and natural extracts could be potent immunomodulators with many potential applications (possible antagonists of Dectin-1, blockers of Dectin-1 cooperation with TLR-2).

The effects of cold atmospheric plasma jets on B16 and COLO320 tumoral cells.

Cold atmospheric plasma treatment acts at the cellular level to remove diseased tissue without inflammation and damage, to suppress infections and to modulate the viability (apoptosis/necrosis) of tumoral cells. It is also known that, a major cause of anti-tumor chemotherapy failure is the development of multidrug resistance (MDR) of tumors. This study reveals the effect of high voltage pulsed, repetitive cold atmospheric plasma jets which are chemically activated with oxygen, on B16 tumoral cells (murine melanoma cell line) and COLO320DM multidrug resistant cells (human colon cancer cell line). The tests have been performed on human colon cancer cell line COLO320DM and murine melanoma cell line B16-F10. These cell lines have been treated with cold helium or helium-oxygen generated plasma jets and the consequent apoptosis has been analyzed by means of flow cytometric method. A treatment time-dependent apoptosis has been observed only in the case of 816-F10 cells interacting with helium-oxygen plasma and no apoptosis has been identified when the cells were treated only with helium plasma jets. These results indicate the need of oxygen for the chemical activation of plasma. The COLO320DM cells (that over-express the MDR efflux pumps) have been exposed to helium-oxygen plasmas only, or in a combination with vegetal extract MCS D161 as MDR efflux pumps inhibitor. For the secondly mentioned case the results have showed an increased apoptosis rate compared to the plasma treatment alone. The obtained data represent a starting point for the study of a possible combined treatment (atmospheric pressure cold plasmas and a MDR efflux pumps inhibitor applied with chemotherapy).

The novel arthritis-drug substance MCS-18 attenuates the antibody production in vivo.

UNLABELLED: Influence of the novel arthritis drug-substance MCS-18 on the antibody (Ab) production against tetanus toxoid (TT) and diphtheria toxoid (DT) antigens was tested in vivo. Possible involvement of MCS-18 in Toll-like receptor (TLR) signalling pathway was further considered. MATERIALS AND METHODS: Immunization of male CD1 mice was done with subcutaneous injection of TT emulsified in Freund's Complete (FCA) or Incomplete Adjuvant (FIA) and mixed diversly with MCS-18 and different test substances. To investigate the influence of TLR activation Pam3Cys and lipopolysaccharide (LPS) emulsified in FIA were tested in combinations with MCS-18. Antibody production was analysed in vivo by tetanus- or diphtheria-toxin neutralization test. RESULTS: Immunogenicity of TT was significantly enhanced if administered together with FCA or TLR agonists Pam3Cys or LPS emulsified in FIA. It was shown that MCS-18 attenuated strongly the production of anti-TT Ab if administered together with the Ab elicitor FCA or TLR agonists in various combinations. MCS-18 was also active via oral administration. DISCUSSION: These findings suggest that MCS-18 could be a potent, non-toxic antagonist or a down-regulator of TLR signalling pathway. Investigations on further models are needed to establish ifMCS-18 may influence particularly the production of RA-specific auto-antibodies, too.

Study of apoptosis induced by cytostatics and vegetal extracts on human endothelial cell line.

Angiogenesis, the biological process by which new capillaries are formed from pre-existing vessels, is a tightly controlled and complex process involving several factors with both stimulating and inhibiting steps. In solid tumor growth, a specific clinical turning point is the transition to the vascular phase. Once it develops an intrinsic vascular network, a tumor grows indefinitely. Tumor angiogenesis depends mainly on the release by neoplasic cells of growth factors specific for endothelial cells (ECs), able to stimulate growth of the host blood vessels. The aim of this study was to analyze the apoptotic effect of some cytostatics, Vinblastine, Rapamycin and Doxorubicin, and vegetal extracts (called VOB) isolated and purified from Vitis sp., on human EA.hy926 endothelial cell line. In a proliferation assay using Crystal Violet, we demonstrated that Vinblastine and Rapamycin cytostatics have synergistic effect on endothelial cell line EA.hy926 growth inhibition. The inhibitory effects of Vinblastine and Doxorubicin were enhanced by VOB vegetal extracts. A combined treatment of cytostatics and VOB vegetal extracts resulted in a stronger antiproliferative effect of EA.hy926 endothelial cells. Results obtained regarding the apoptosis induced on EA.hy926 endothelial cells showed that each compound alone was able to induce a significant percent of apoptotic cells in a dose-dependent manner.

COX-2 inhibitors can down-regulate in vivo antibody response against T-dependent antigens.

There are many studies demonstrating by different experimental models that non-steroidal antiinflammatory drugs (NSAIDs), also known as cyclooxygenase-2 (COX-2) inhibitors, can modulate immune response such as lymphoid cells differentiation and proliferation. There are experimental data which show that activated B cells can express mRNA COX-2, release prostaglandins (PGs) and produce immunoglobulins in PGs dependent manner. In this study, using different COX-2 inhibitors and applying personalized immunization scheme, we confirmed that it is possible to modulate in vivo antibody response against T cell dependent antigens, substantiating the importance of PGE2 and E prostanoid receptor (EP-R) in antibody generation. Our results point out the fact that we must be more careful when we apply vaccines containing T-cell dependent antigens, such as tetanus or diphteric anatoxin, to the patients under an intense antiinflammatory treatment.

Mechanism of the Na,K-ATPase inhibition by MCS derivatives.

The previously reported class of potent inorganic inhibitors of Na,K-ATPase, named MCS factors, was shown to inhibit not only Na,K-ATPase but several P-type ATPases with high potency in the sub-micromolar range. These MCS factors were found to bind to the intracellular side of the Na, K-ATPase. The inhibition is not competitive with ouabain binding, thus excluding its role as cardiac-steroid-like inhibitor of the Na,K-ATPase. The mechanism of inhibition of Na,K-ATPase was investigated with the fluorescent styryl dye RH421, a dye known to report changes of local electric fields in the membrane dielectric. MCS factors interact with the Na,K-ATPase in the E(1) conformation of the ion pump and induce a conformational rearrangement that causes a change of the equilibrium dissociation constant for one of the first two intracellular cation binding sites. The MCS-inhibited state was found to have bound one cation (H(+), Na(+) or K(+)) in one of the two unspecific binding sites, and at high Na(+) concentrations another Na(+) ion was bound to the highly Na(+)-selective ion-binding site.

The structure of the digitalislike and natriuretic factors identified as macrocyclic derivatives of the inorganic carbon suboxide.

The Natriuretic and Endogenous DigitalisLike Factors (EDLFs) are disclosed to be cyclomeric and macroring closed derivatives of the inorganic carbon suboxide. The macrocyclic cyclohexamer with six carbon suboxide units has a molar mass of 408.2 Da, as previously been found for the EDLF of animal origin. The anhydrous cyclohexameric factor is lipophilic but is transformed into more hydrophilic derivatives by the stepwise addition of water. Based on the present findings, it appears that EDLFs exist in solution as an equilibrium mixture of lipophilic and hydrophilic forms and not as a single chemical substance. This structural assumption better accounts for the earlier observed highly anomalous properties of EDLFs. The simultaneously found higher molar mass (4,100 and 4,900 Da) macrocyclic carbon suboxide derivatives are tentatively identified as the Natriuretic factors.

Steric mapping of some prostaglandin receptor sites.

The Minimal Steric (Topologic) Difference method was applied to map some prostaglandin receptors. Experimental data concerning luteinizing activity of corpora lutea, and pressor respectively depressor activity on sheep blood were considered. The linear correlation coefficients obtained were r = 0.927 (N = 12) for luteinizing activity, r = 0.943 (N = 15) for depressor activity, and r = 0.943 (N = 12) for pressor activity. Similarities and differences between these three receptors are discussed.