Differential effects of synthetic indoloquinolizines on in vitro rat lymphocyte and macrophage functions

Synthesis of Fluorescent, DNA-Binding Benzo[b]indolonaphthyridinium Derivatives by a Misguided Westphal Condensation

A novel type of azoniahetarene, namely, benzo[b]indolonaphthyridinium, was unexpectedly formed by the reaction of N-alkylated β-carbolinium derivatives and the enolizable 1,2-cyclohexadione under typical conditions of a Westphal reaction. The products exhibit high fluorescence intensities in polar solvents (Φ_fl = 0.52-0.67) and bind to DNA by intercalation with high affinity (K_b = 1.5 × 10⁶ M^-1). Furthermore, under the same conditions, DNA-binding sempervirine derivatives were synthesized in a Westphal reaction from 1,2-diketones that have at least one non-enolizable α-carbon atom, which shows that the reaction pathway is determined by the substrate structure.

ATIQCTPC: a nanomedicine capable of targeting tumor and blocking thrombosis in vivo

To overcome the harmful side effects, low tolerance, and undesirable outcomes of the anticancer drugs, we used ethane-1,2-diamine to bridge antitumoral (S)-3-acetyl-4-oxo-tetrahydroindolo[2,3-a]quinolizine-6-carboxylic acid (ATIQC) and tumor-targeting d-glucuronic acid, thereby providing (6S)-3-acetyl-4-oxo-N-(2-(3,4,5,6-tetrahydroxytetrahydro-2H-pyran-2-carboxamido)ethyl)-4,6,7,12-tetrahydroindolo[2,3-a]quinolizine-6-carboxamide (ATIQCTPC). Atomic force microscopy images visualized, that in serum, ATIQCTPC formed particles of height <81 nm. These particles effectively avoided phagocytosis of macrophages and were stable in blood circulation. Distribution analysis indicated that ATIQCTPC accumulated and released ATIQC in the tumor tissue through a targeting manner. Thus, the antitumor and the anti-thrombotic activities of ATIQCTPC were 100-fold higher than those of ATIQC, and ATIQCTPC was able to prevent cancer patients from suffering from thrombosis. Based on the observation that ATIQCTPC decreased serum tumor necrosis factor-α (TNF-α) and interleukin-8 (IL-8) in S180 mice, we hypothesized that this is the mechanism that ATIQCTPC utilized to slow tumor growth. Additionally, we observed that ATIQCTPC inhibited thrombosis by decreasing serum P-selectin of thrombotic rats. The intermolecular association and the hexamerization manner of ATIQCTPC were experimentally evidenced and correlated with the formation of the nanoparticles.

Effects of spider venom toxin PWTX-I (6-Hydroxytrypargine) on the central nervous system of rats

The 6-hydroxytrypargine (6-HT) is an alkaloidal toxin of the group of tetrahydro-β-carbolines (THβC) isolated from the venom of the colonial spider Parawixia bistriata. These alkaloids are reversible inhibitors of the monoamine-oxidase enzyme (MAO), with hallucinogenic, tremorigenic and anxiolytic properties. The toxin 6-HT was the first THβC chemically reported in the venom of spiders; however, it was not functionally well characterized up to now. The action of 6-HT was investigated by intracerebroventricular (i.c.v.) and intravenous (i.v.) applications of the toxin in adult male Wistar rats, followed by the monitoring of the expression of fos-protein, combined with the use of double labeling immunehistochemistry protocols for the detection of some nervous receptors and enzymes related to the metabolism of neurotransmitters in the central nervous system (CNS). We also investigated the epileptiform activity in presence of this toxin. The assays were carried out in normal hippocampal neurons and also in a model of chronic epilepsy obtained by the use of neurons incubated in free-magnesium artificial cerebro-spinal fluid (ACSF). Trypargine, a well known THβC toxin, was used as standard compound for comparative purposes. Fos-immunoreactive cells (fos-ir) were observed in hypothalamic and thalamic areas, while the double-labeling identified nervous receptors of the sub-types rGlu2/3 and NMR1, and orexinergic neurons. The 6-HT was administrated by perfusion and ejection in "brain slices" of hippocampus, inducing epileptic activity after its administration; the toxin was not able to block the epileptogenic crisis observed in the chronic model of the epilepsy, suggesting that 6-HT did not block the overactive GluRs responsible for this epileptic activity.

Effects of neuropeptide S on the proliferation of splenic lymphocytes, phagocytosis, and proinflammatory cytokine production of pulmonary alveolar macrophages in the pig

Neuropeptide S (NPS), a newly identified neuropeptide, is involved in many physiological and pathological activities through the NPS receptor (NPSR). Recently, the NPS and NPSR have been detected in peripheral systems of pigs including immune tissues, suggesting that NPS may play an important role in the regulation of immune function. The aim of this study was to demonstrate the presence and function of NPS and NPSR in splenic lymphocytes (SPLs) and pulmonary alveolar macrophages (PAMs) of pigs. By RT-PCR, the expression of NPS and NPSR mRNA was detected in the SPLs and PAMs. NPS immunoreactivity was observed in the membrane and cytoplasm of both SPLs and PAMs. We found that NPS could stimulate the proliferation of SPLs, when NPS was added at concentrations of 0.01, 0.1, 1, 10, 100 and 1000 nM alone or in combination with PHA/LPS in vitro. In macrophages from bronchoalveolar lavage (BAL) fluid of pigs, various doses of NPS (0.01, 0.1, 1, 10, 100 and 1000 nM) up-regulated the phagocytosis of PAMs in comparison to controls. In PAMs, NPS could induce the production of the pro-inflammatory cytokines IL-1β, IL-6 and TNF-α. Taken together, all data suggest that NPS is capable of inducing phagocytosis of non-opsonized E. coli. NPS might act as potent neuroimmunomodulatory factors and affects the maintenance of immune homeostasis.

Enzymatic preparation of immunomodulating hydrolysates from soy proteins

Soy protein hydrolysates with lower molecular weight were enzymatically prepared by several commercially available proteases (Alcalase 2.4L, Flavourzyme, Trypsin, Papain, Protease A and Peptidase R) with protein recovery varied from 42.59% to 79.87%. Relative content of positively charged peptides was determined on SP Sephadex C-25 using gradient sodium chloride solution as eluents. Immunomodulating properties were evaluated by measuring their effect on in vitro proliferation of murine spleen lymphocytes and phagocytic activity of peritoneal macrophages. The results showed that soy protein hydrolysates (SPHs) prepared with Alcalase and insoluble soy protein (InSP), preferable to other enzymes and soy proteins, have the highest immunomodulating activity and the optimum conditions were determined as follows: E/S=2% (Alcalase), 60 degrees C, pH 8.0, InSP concentration 6% and 225min. Positive correlations were obtained between the immunomodulating activity and content of positively charged peptides. The results suggested that lower molecular weight and positively charged peptides released from soy protein were effective in stimulating immunomodulating activity, thus provided insights into the preparation of potent immunomodulating products.

Different effects of arborinine alkaloid obtained from Brazilian Erthela baihensis on spleen and thymus cells stimulated in vitro with different mitogens

The present study has examined the effects of arborinine, an alkaloid obtained from Erthela bahiensis, a Brazilian plant popularly used as diuretic, antidiabetic, antithermic and expectorant, on the viability and function of immune system cells in vitro using a murine model. Rat spleen and thymus cells were cultured with 10 nM, 1 microM, 10 microM of the drug in the presence or absence of pokeweed (PWM), lipopolysaccharide (LPS), or concanavallin (ConA) mitogens. Cellular proliferation was analyzed by H3-thymidin uptake after 48 and 72 hr. Our results showed an inhibitory effect of arborinine on splenocytes proliferation under ConA or PWM stimulation and increased apoptosis on splenocytes and thymocytes stimulated with PWM in 24 hr. A decrease was observed on Interferon gamma (IFN-gamma) production by ConA- or LPS-stimulated splenocytes in 48 hr and 72 hr and ConA- or PWM-stimulated thymocytes in 72 hr. In contrast, an increase on lymphoproliferation was observed on LPS-stimulated splenocytes and ConA- or PWM-stimulated thymocytes in 48 hr. On this period, apoptosis decreased on LPS- or PWM-stimulated splenocytes and IFN-gamma production increased in PWM stimulated thymocytes. Arborinine also induced a decrease on Interleukin-10 production by splenocytes and thymocytes stimulated with ConA or PWM. There was no significant variation on the necrosis rate of the cells treated with arborinine or any change on their viability or function values in the absence of mitogenic stimulus.

Potentiation of rat lymphocyte proliferation by novel non-peptidic synthetic opioids

Opioids represent a major source of relief for acute and chronic, moderate to severe nonmalignant pain. However, opioid abuse may cause immunosuppression leading to infections and cancer development. Recently we reported results on novel non-peptidic delta- and mu-selective opioids that induced immunopotentiation in vitro and ex vivo. In the present study, we investigated the effects of the delta agonist SNC 80, and mu agonists, naltrindole and naltrexone derivatives for their capacity to alter lymphoproliferation in vitro. They were observed to stimulate lymphoproliferation at concentrations ranging from 10(-10) to 10(-5) M. SNC 80 significantly (p<0.05) stimulated (43-311%) proliferation of resident and concanavalin A (Con A)-treated lymphocytes; the naltrindole derivatives 9332 and 9333 caused significant (p<0.05) 26-47% and 13-43%, respectively, stimulation of Con A-treated lymphoproliferation; whereas the naltrexone derivatives 9334 and 9336 significantly (p<0.05) stimulated 9-40% and 15-69%, respectively, proliferation of resident and Con A-treated lymphocytes. These novel opioid ligands could serve as immunotherapeutic agents by increasing the pool of lymphocytes with potential use in the treatment of infectious diseases including AIDS. This study provides evidence of the relationship structure/function of opioids on lymphoproliferation, and supports further evaluation of opioids with immunomodulatory potential in preclinical and clinical studies.