Gold Nanoclusters Eliminate Obesity Induced by Antipsychotics

Obesity induced by antipsychotics have plagued more than 20 million people worldwide. However, no drug is available to eliminate the obesity induced by antipsychotics. Here we examined the effect and potential mechanisms of a gold nanoclusters (AuNCs) modified by N-isobutyryl-L-cysteine on the obesity induced by olanzapine, the most prescribed but obesogenic antipsychotics, in a rat model. Our results showed that AuNCs completely prevented and reversed the obesity induced by olanzapine and improved glucose metabolism profile in rats. Further mechanism investigations revealed that AuNCs exert its anti-obesity function through inhibition of olanzapine-induced dysfunction of histamine H1 receptor and proopiomelanocortin signaling therefore reducing hyperphagia, and reversing olanzapine-induced inhibition of uncoupling-protein-1 signaling which increases thermogenesis. Together with AuNCs’ good biocompatibility, these findings not only provide AuNCs as a promising nanodrug candidate for treating obesity induced by antipsychotics, but also open an avenue for the potential application of AuNCs-based nanodrugs in treating general obesity

Cytosolic Phospholipase A2 is Required for Fexofenadine′s Therapeutic Effects Against Inflammatory Bowel Disease in Mice

Inflammatory Bowel Disease (IBD) is an autoimmune condition with complicated pathology and diverse clinical signs. TNFα is believed to play a crucial role in the pathogenesis of IBD. We recently identified fexofenadine, a well-known antagonist of histamine H1 receptor, as a novel inhibitor of TNFα signaling. Additionally, cytosolic phospholipase A2 (cPLA2) was isolated as a binding target of fexofenadine, and fexofenadine-mediated anti-TNF activity relied on cPLA2 in vitro. The objective of this study is to determine whether fexofenadine is therapeutic against chemically-induced murine IBD model and whether cPLA2 and/or histamine H1 receptor is important for fexofenadine’s anti-inflammatory activity in vivo by leveraging various genetically modified mice and chemically induced murine IBD models. Both dextran sulfate sodium- and 2, 4, 6-trinitrobenzene sulfonic acid-induced murine IBD models revealed that orally delivered fexofenadine was therapeutic against IBD, evidenced by mitigated clinical symptoms, decreased secretions of the proinflammatory cytokine IL-6 and IL-1β, lowered intestinal inflammation, and reduced p-p65 and p-IĸBα. Intriguingly, Fexofenadine-mediated protective effects against IBD were lost in cPLA2 deficient mice but not in histamine H1 receptor-deficient mice. Collectively, these findings demonstrate the therapeutic effects of over-the-counter drug Fexofenadine in treating DSS-induced IBD murine and provide first in vivo evidence showing that cPLA2 is required for fexofenadine’s therapeutic effects in murine IBD model and probably other inflammatory and autoimmune diseases as well.

Signaling Pathway of Histamine H1 Receptor-Mediated Histamine H1 Receptor Gene Upregulation Induced by Histamine in U-373 MG Cells

Histamine H1 receptor (H1R) is one of the targets of histamine in the nervous system and the peripheral tissues. Protein kinase Cδ (PKCδ) signaling is involved in histamine-induced upregulation of H1R gene expression in HeLa cells. Histamine also upregulates H1R gene expression in U-373 MG cells. However, the molecular signaling of this upregulation is still unclear. Here, we investigated the molecular mechanism of histamine-induced H1R gene upregulation in U-373 MG cells. Histamine-induced H1R gene upregulation was inhibited by H1R antagonist d-chlorpheniramine, but not by ranitidine, ciproxifan, or JNJ77777120, and H2R, H3R, or H4R antagonists, respectively. Ro-31-8220 and Go6976 also suppressed this upregulation, however, the PKCδ selective inhibitor rottlerin and the PKCβ selective inhibitor Ly333531 did not. Time-course studies showed distinct kinetics of H1R gene upregulation in U-373 MG cells from that in HeLa cells. A promoter assay revealed that the promoter region responsible for H1R gene upregulation in U-373 MG cells was different from that of HeLa cells. These data suggest that the H1R-activated H1R gene expression signaling pathway in U-373 MG cells is different from that in HeLa cells, possibly by using different promoters. The involvement of PKCα also suggests that compounds that target PKCδ could work as peripheral type H1R-selective inhibitors without a sedative effect.

Effects of Syo-seiryu-to and Its Constituent Crude Drugs on Phorbol Ester-Induced Up-Regulation of IL-33 and Histamine H1 Receptor mRNAs in Swiss 3T3 and HeLa Cells

Syo-seiryu-to (SST) is a traditional herbal medicine that has been used clinically to treat allergic rhinitis (AR) in Japan. SST improves acute symptoms, such as sneezing and rhinorrhea, as well as chronic symptoms, such as nasal obstruction, in patients with AR. However, its therapeutic mechanisms remain unknown. We examined the effects of SST and eight constituent crude drugs on phorbol 12-myristate-13-acetate (PMA)-induced gene up-regulation of IL-33 and histamine H1 receptor (H1R), which are responsible for the pathogenesis of AR. We found that SST and its crude drugs, except for Pinellia tuber, significantly and dose-dependently suppressed PMA-induced both IL-33 and H1R mRNA up-regulation in vitro. The half-maximal inhibitory concentration values of the seven crude drugs to inhibit PMA-induced IL-33 mRNA up-regulation were correlated with those related to H1R mRNA up-regulation, suggesting that they act on a common signal molecule. These results suggest that SST improves nasal congestion that is induced by IL-33-related eosinophil infiltration and inhibits sneezing and rhinorrhea that are induced by H1R-mediated histamine signaling in the nasal mucosa of AR patients through its inhibition of a common molecule in the gene expression pathways of IL-33 and H1R. The results could explain the advantages of traditional herbal medicine, in which mixing various crude drugs not only acts on a common target to enhance its pharmacological action, similar to the effect of a high concentration of a single crude extract but also has the benefit of reducing the side effects of each crude drug.

Anti-inflammatory activity of the antiallergic drug 7-[4-(4-benzhydrylpiperazinyl-1)butyl]-3-methylxanthine succinate (theoritin)

BACKGROUND: Many antagonists of histamine (H1) receptor, in addition to antihistamine action, suppress allergic inflammation by inhibiting the formation and secretion of proinflammatory cytokines. The new antiallergic drug benzhydrylpiperazinyl butylmethylxanthine succinate (theoritin), which has an antihistamine activity comparable to the known second generation H1-antihistamines, surpasses them in the ability to suppress the allergic inflammatory reaction, which allows this drug to have additional anti-inflammatory properties associated with the inhibition of the formation of proinflammatory cytokines. AIM: This study aimed to determine the effect of theoritin on the induced release of proinflammatory cytokines interleukin (IL)-6, IL-8, and tumor necrosis factor (TNF)- in cell culture in comparison with the action of the inverse agonist of H1 receptor cetirizine and a known inflammation inhibitor glucocorticosteroid dexamethasone. MATERIALS AND METHODS: U937 cells differentiated toward macrophage-like cells were used. Cytotoxicity of the substances used was assessed in the methyltetrazolium test at different incubation times (up to 24 h). Cells were stimulated with lipopolysaccharide (LPS). The tested compounds (theoritin and cetirizine) were evaluated at concentrations from 0.001 to 100 M and dexamethasone at 10 M was tested when added to cells 1 h before (prophylactic effect) or 1 h after (therapeutic effect) the addition of LPS. The presence of IL-6, IL-8, and TNF in the supernatants was determined by enzyme immunoassay. RESULTS: For cetirizine and theoritin, no cytotoxic action was found in the tested concentrations and time points. Dexamethasone inhibited the formation of IL-6 and TNF to the initial level and IL-8 to 50%60%. Theoritin led to a significant concentration-dependent decrease in the LPS-induced production of IL-6, IL-8, and TNF, and at a concentration of 100 M, the effect of theoritin was comparable with that of dexamethasone at a concentration of 10 M. The prophylactic test scheme for theoritin was more effective in suppressing LPS-induced production of proinflammatory cytokines than the curative one. The described effect of theoritin on LPS-induced production of proinflammatory cytokines exceeded that of the reference drug cetirizine. CONCLUSION: In addition to its antihistaminic action, theoritin, a new antiallergic agent, inhibits LPS-induced production of proinflammatory cytokines, which may be of clinical importance in suppressing allergic inflammation.