Targeting inhibitory Siglec-3 to suppress IgE-mediated human basophil degranulation.

BACKGROUND: Sialic acid-binding immunoglobulin-like lectin-3 (Siglec-3 [CD33]) is a major Siglec expressed on human mast cells and basophils; engagement of CD33 leads to inhibition of cellular signaling via immunoreceptor tyrosine-based inhibitory motifs. OBJECTIVE: We sought to inhibit human basophil degranulation by simultaneously recruiting inhibitory CD33 to the IgE-FcεRI complex by using monoclonal anti-IgE directly conjugated to CD33 ligand (CD33L). METHODS: Direct and indirect basophil activation tests (BATs) were used to assess both antigen-specific (peanut) and antigen-nonspecific (polyclonal anti-IgE) stimulation. Whole blood from donors with allergy was used for direct BAT, whereas blood from donors with nonfood allergy was passively sensitized with plasma from donors with peanut allergy in the indirect BAT. Blood was incubated with anti-IgE-CD33L or controls for 1 hour or overnight and then stimulated with peanut, polyclonal anti-IgE, or N-formylmethionyl-leucyl-phenylalanine for 30 minutes. Degranulation was determined by measuring CD63 expression on the basophil surface by flow cytometry. RESULTS: Incubation for 1 hour with anti-IgE-CD33L significantly reduced basophil degranulation after both allergen-induced (peanut) and polyclonal anti-IgE stimulation, with further suppression after overnight incubation with anti-IgE-CD33L. As expected, anti-IgE-CD33L did not block basophil degranulation due to N-formylmethionyl-leucyl-phenylalanine, providing evidence that this inhibition is IgE pathway-specific. Finally, CD33L is necessary for this suppression, as monoclonal anti-IgE without CD33L was unable to reduce basophil degranulation. CONCLUSIONS: Pretreating human basophils with anti-IgE-CD33L significantly suppressed basophil degranulation through the IgE-FcεRI complex. The ability to abrogate IgE-mediated basophil degranulation is of particular interest, as treatment with anti-IgE-CD33L before antigen exposure could have broad implications for the treatment of food, drug, and environmental allergies.

Design, synthesis, characterizing and DFT calculations of a binary CT complex co-crystal of bioactive moieties in different polar solvents to investigate its pharmacological activity.

Imidazole (IM) and salicylic acid (SA) have a significant class among the medical compound. These are widely used as topical drugs like antifungal, antibacterial, anticancer, immunosuppressive agent, etc. These two bioactive organic moieties are combined by a weak hydrogen bond formed by hydrogen transfer. The charge transfer (CT) complex of acceptor (SA) and donor (IM), has been synthesized at room temperature in methanol and confirmed by signal-crystal XRD, conductance and UV-visible spectroscopy. The X-ray crystallography provides the original structural information of CT complex and displays the existence of N+-H--O- bond between IM and SA. The physical properties such as (ECT), (RN), (ID), (f), (D) and (Δ G0) along with molar extinction coefficient (εCT) and formation constant (KCT) were estimated through UV-visible spectroscopy. Job's method and Benesi-Hildebrand equation suggested 1:1 stoichiometry of ([IM]+[SA]-). The results indicate a complete transfer of hydrogen atom and CT complex formation with 1:1 molar ratio of IM and SA. Antimicrobial activity was veiled against different bacteria like Escherichia coli, Bacillus subtilis and Staphylococcus aureus; and different fungi as Fusarium oxysporum, Candida albicans and Aspergillus niger by disc diffusion method. CT complex was also tested for cytotoxic activity against lung cancer cell lines in comparison to breast cancer cell lines. Molecular docking provides the information of binding of [(IM)+(SA)-] with the cancer marker (1M17), which has substantial application for drug designing. The investigational studies were supplemented through time-dependent density functional theory (TD-DFT) using basis set B3LYP/6-311G**. Through DFT calculations, HOMO→LUMO electronic energy gap (ΔE) was obtained.

Herb and Spices in Colorectal Cancer Prevention and Treatment: A Narrative Review.

Colorectal cancer (CRC) is the second most deadly cancer worldwide. CRC management is challenging due to late detection, high recurrence rate, and multi-drug resistance. Herbs and spices used in cooking, practised for generations, have been shown to contain CRC protective effect or even be useful as an anti-CRC adjuvant therapy when used in high doses. Herbs and spices contain many bioactive compounds and possess many beneficial health effects. The chemopreventive properties of these herbs and spices are mainly mediated by the BCL-2, K-ras, and MMP pathways, caspase activation, the extrinsic apoptotic pathway, and the regulation of ER-stress-induced apoptosis. As a safer natural alternative, these herbs and spices could be good candidates for chemopreventive or chemotherapeutic agents for CRC management because of their antiproliferative action on colorectal carcinoma cells and inhibitory activity on angiogenesis. Therefore, in this narrative review, six different spices and herbs: ginger (Zingiber officinale Roscoe), turmeric (Curcuma longa L.), garlic (Allium sativum L.), fenugreek (Trigonella foenum-graecum L.), sesame (Sesamum indicum L.), and flaxseed (Linum usitatissimum L.) used in daily cuisine were selected for this study and analyzed for their chemoprotective or chemotherapeutic roles in CRC management with underlying molecular mechanisms of actions. Initially, this study comprehensively discussed the molecular basis of CRC development, followed by culinary and traditional uses, current scientific research, and publications of selected herbs and spices on cancers. Lead compounds have been discussed comprehensively for each herb and spice, including anti-CRC phytoconstituents, antioxidant activities, anti-inflammatory properties, and finally, anti-CRC effects with treatment mechanisms. Future possible works have been suggested where applicable.

Development of a Lung Cancer Model in Wistar Rat and In Silico Screening of its Biomarkers.

BACKGROUND: Cancer is usually caused by three factors: Nutrition, inflammation and cigarette smoke. This study on rat experimental models would enable us to understand the mechanism of lung cancer caused by NNK to which humans are continuously exposed, help us understand possible molecular targets, and assist in designing drugs for humans against lung cancer. AIM: A lung cancer model was developed by administering tobacco-specific carcinogen: NNK [4- methylnitrosamino)-1-(3-pyridyl)-1-butanone] to male Wistar rats for 24 weeks. Furthermore, in silico approach was followed to screen the molecular targets. METHODS: A method was established in which subcutaneous and intraperitoneal injections of NNK were administered to male Wistar rats simultaneously. For authentication of lung cancer in vivo, we performed molecular docking simulations with protein biomarkers: Cox-2, p53, p38 MAPKs and EGFR using Hex-Discovery Studio, Schrödinger-maestro software. RESULTS: Lung morphology and histopathology indicated the initiation of bronchiolar epithelial hyperplasia and squamous dysplasia in the cancer 1 group after 16 weeks of NNK exposure. 66.66% incidence of squamous cell carcinoma (SCC) and 33.3% incidence of adenocarcinoma were observed in cancer 2 group after being exposed to NNK. Results indicated that the incidence of SCC and adenocarcinoma gradually increased from 66.66% to 85.71% in cancer 2 group and from 33.33% to 42.58% in cancer 3 group, respectively. Docking results indicate the total binding energy and glide energy of Cox-2, p53, p38 MAPKs, EGFR : 38.14, -211.58, -181.58, -213.05 Kcal/mol and -39.25, -32.16,-36.49, -40.19 Kcal/mol, respectively. CONCLUSION: Pulmonary adenocarcinoma model was developed by administering tobacco-specific carcinogen: NNK [4-methylnitrosamino)-1-(3-pyridyl)-1-butanone] to male Wistar rats in 24 weeks. In silico experiments confirmed EGFR to be the most potential target for NNK induced lung Cancer.

Small molecule-RNA interaction: spectroscopic and calorimetric studies on the binding by the cytotoxic protoberberine alkaloid coralyne to single stranded polyribonucleotides.

BACKGROUND: RNA has attracted recent attention for its key role in gene expression and hence targeting by small molecules for therapeutic intervention. This study is aimed to elucidate the specificity of the alkaloid coralyne to poly(G), poly(C), poly(I) and poly(U) in the light of its ability in inducing self-structure in poly(A). METHODS: Multifaceted experimental techniques like competition dialysis, absorption, fluorescence, circular dichroism and calorimetry were employed. Salt dependence and temperature dependence of the binding was also elucidated. RESULTS: Results of competition dialysis, absorption and fluorescence studies revealed that coralyne binds strongly to the polypurines, poly(G) and poly(I) compared to the polypyrimidines, poly(U) and poly(C). Partial intercalative binding due to the stacking of the molecules between the bases was envisaged. The binding was predominantly enthalpy driven with favourable entropy term with a large favourable non-electrostatic contribution revealed from salt dependent data and the dissection of the free energy. The heat capacity change of -125 and -119 cal/mol K(-1) respectively for poly(G) and poly(I) and the partial enthalpy-entropy compensation phenomenon observed confirmed the involvement of multiple weak noncovalent interactions. Circular dichroism studies provided evidence for significant perturbation of the conformation of the RNAs, but no self-structure induction was evident in any of the polymers under the condition of the study. CONCLUSIONS: This study presents a complete structural and thermodynamic profile of coralyne interaction to four single stranded RNA polymers. GENERAL SIGNIFICANCE: The study for the first time elucidates the base specificity of coralyne-RNA complexation at the single stranded level.