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1.
Heliyon ; 9(2): e13343, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36816283

ABSTRACT

Background: The present study was designed to characterize the role of ethanolic leaf extract of Phrynium pubinerve Blume (EPP) supplement in attenuating allergic inflammation, encouraged by the presence of syringic acid in it, as this phenolic acid is reportedly promising in suppressing serum immunoglobulin E (IgE) and inflammatory cytokine levels. Materials and methods: HPLC-DAD dereplication analysis was performed to determine the presence of the vital polyphenolic metabolites. The efficacy of EPP against lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 cells was evaluated by measuring its inhibitory effects on NO and ROS/RNS production. The expressions of major inflammation-associated molecules (iNOS, COX-2, NF-κB, IL-6, and TNF-α) in RAW 264.7 cells were assessed through Western blot. Physiological and behavioral changes, BMI, and different biochemical parameters in mice blood serum were investigated in the toxicological assays. Formaldehyde-induced paw edema test in mice was conducted using established animal model. TDI-induced allergic model in mice was carried out to determine different allergy-like symptoms, and differential white blood cell (WBC) counts in blood and bronchoalveolar lavage (BAL) fluid. The intermolecular interaction analysis of the identified major metabolite of EPP with H1R and iNOS was studied by molecular docking. Results: HPLC-DAD analysis showed the presence of syringic acid (89.19 mg/100 g EPP) and a few other compounds. LPS-induced NO generation was reduced by EPP in a concentration-dependent manner, showing IC50 of 28.20 ± 0.27 µg/mL. EPP exhibited a similar inhibitory effect on ROS/RNS production with IC50 of 29.47 ± 2.19 µg/mL. Western blotting revealed that EPP significantly downregulated the expressions of iNOS, COX-2, NF-κB, IL-6, and TNF-α in RAW 264.7 cells when challenged with LPS. The toxicological assays confirmed the dosage and organ-specific safety of EPP. In the formaldehyde-induced paw edema test, EPP caused a 66.41% reduction in mice paw volume at 500 mg/kg dose. It ameliorated TDI-induced allergy-like symptoms and decreased different inflammatory WBCs in mice's blood and BAL fluid in a dose-dependent manner. Finally, syringic acid demonstrated mentionable intermolecular binding affinity towards H1R (-6.6 Kcal/moL) and iNOS (-6.7 Kcal/moL). Conclusions: Collectively, considerable scientific reasoning was obtained in favor of the suppressive potential of EPP against allergic inflammatory responses that are proposed to be exerted via the downregulation of iNOS, COX-2, and NF-κB expressions, H1R antagonism and suppression of cytokines, such as IL-6, and TNF-α.

2.
Anticancer Agents Med Chem ; 20(14): 1636-1647, 2020.
Article in English | MEDLINE | ID: mdl-32560616

ABSTRACT

BACKGROUND: Cancer is a dreadful disease causing thousands of deaths per year worldwide, which requires precision diagnostics and therapy. Although the selection of therapeutic regimens depends on the cancer type, chemotherapy remains a sustainable treatment strategy despite some of its known side-effects. To date, a number of natural products and their derivatives or analogues have been investigated as potent anticancer drugs. These drug discoveries have aimed for targeted therapy and reduced side-effects, including natural therapeutic regimens. OBJECTIVE: This review introduces a prospective fungal-derived polyphenol, Hispolon (HIS), as an anticancer agent. Accordingly, this review focuses on exploring the anticancer effect of hispolon based on information extracted from databases such as PubMed, ScienceDirect, MedLine, Web of Science, and Google Scholar. METHODS: A literature search in PubMed, ScienceDirect, MedLine, Web of Science, and Google Scholar was accomplished, using the keyword 'Hispolon', pairing with 'cancer', 'cytotoxicity', 'cell cycle arrest', 'apoptosis', 'metastasis', 'migration', 'invasion', 'proliferation', 'genotoxicity', 'mutagenicity', 'drug-resistant cancer', 'autophagy', and 'estrogen receptor. RESULTS: Database-dependent findings from reported research works suggest that HIS can exert anticancer effects by modulating multiple molecular and biochemical pathways, including cell cycle arrest, apoptosis, autophagy, inhibition of proliferation, metastasis, migration, and invasion. Moreover, HIS inhibits the estrogenic activity and exhibits chemoprevention prospects, possibly due to its protective effects such as anticancer and anti-inflammatory mechanisms. To date, a number of HIS derivatives and analogues have been introduced for their anticancer effects in numerous cancer cell lines. CONCLUSION: Data obtained from this review suggest that hispolon and some of its derivatives can be promising anticancer agents, and may become plant-based cancer chemotherapeutic leads for the development of potent anticancer drugs, alone or in combination with other chemotherapeutic agents.


Subject(s)
Antineoplastic Agents/pharmacology , Catechols/pharmacology , Fungi/chemistry , Antineoplastic Agents/chemistry , Apoptosis/drug effects , Catechols/chemistry , Cell Proliferation/drug effects , Drug Screening Assays, Antitumor , Humans , Molecular Structure
3.
Phytother Res ; 32(12): 2376-2388, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30281175

ABSTRACT

Beta (ß)-caryophyllene (BCAR) is a major sesquiterpene of various plant essential oils reported for several important pharmacological activities, including antioxidant, anti-inflammatory, anticancer, cardioprotective, hepatoprotective, gastroprotective, nephroprotective, antimicrobial, and immune-modulatory activity. Recent studies suggest that it also possesses neuroprotective effect. This study reviews published reports pertaining to the neuropharmacological activities of BCAR. Databases such as PubMed, Scopus, MedLine Plus, and Google Scholar with keywords "beta (ß)-caryophyllene" and other neurological keywords were searched. Data were extracted by referring to articles with information about the dose or concentration/route of administration, test system, results and discussion, and proposed mechanism of action. A total of 545 research articles were recorded, and 41 experimental studies were included in this review, after application of exclusion criterion. Search results suggest that BCAR exhibits a protective role in a number of nervous system-related disorders including pain, anxiety, spasm, convulsion, depression, alcoholism, and Alzheimer's disease. Additionally, BCAR has local anesthetic-like activity, which could protect the nervous system from oxidative stress and inflammation and can act as an immunomodulatory agent. Most neurological activities of this natural product have been linked with the cannabinoid receptors (CBRs), especially the CB2R. This review suggests a possible application of BCAR as a neuroprotective agent.


Subject(s)
Neuroprotective Agents/pharmacology , Plant Extracts/pharmacology , Sesquiterpenes/pharmacology , Animals , Biological Products/therapeutic use , Central Nervous System Agents/pharmacology , Central Nervous System Agents/therapeutic use , Central Nervous System Diseases/drug therapy , Central Nervous System Diseases/prevention & control , Humans , Neuroprotective Agents/therapeutic use , Oils, Volatile/therapeutic use , Phytotherapy/methods , Plant Extracts/therapeutic use , Polycyclic Sesquiterpenes , Sesquiterpenes/therapeutic use
4.
Front Pharmacol ; 9: 1164, 2018.
Article in English | MEDLINE | ID: mdl-30374304

ABSTRACT

Present study was undertaken to evaluate the analgesic activity of the ethanol extract of Chrysopogon aciculatus. In addition to bioassays in mice, chemical profiling was done by LC-MS and GC-MS to identify phytochemicals, which were further docked on the catalytic site of COX-2 enzymes with a view to suggest the possible role of such phytoconstituents in the observed analgesic activity. Analgesic activity of C. aciculatus was evaluated by acetic acid induced writhing reflex method and hot plate technique. Phytochemical profiling was conducted using liquid chromatography mass spectrometry (LC-MS) and gas chromatography mass spectrometry (GC-MS). In docking studies, homology model of human COX-2 enzyme was prepared using Easy Modeler 4.0 and the identified phytoconstituents were docked using Autodock Vina. Preliminary acute toxicity test of the ethanol extract of C. aciculatus showed no sign of mortality at the highest dose of 4,000 mg/kg. The whole plant extract significantly (p < 0.05) inhibited acetic acid induced writhing in mice at the doses of 500 and 750 mg/kg. The extract delayed the response time in hot plate test in a dose dependent manner. LC-MS analysis of the plant extract revealed the presence of aciculatin, nudaphantin and 5α,8α-epidioxyergosta-6,22-diene-3ß-ol. Three compounds namely citronellylisobutyrate; 2,4-dihydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one and nudaphantin were identified in the n-hexane fraction by GC-MS. Among these compounds, six were found to be interacting with the binding site for arachidonic acid in COX-2 enzyme. Present study strongly supports the traditional use of C. aciculatus in the management of pain. In conclusion, compounds (tricin, campesterol, gamma oryzanol, and citronellyl isobutyrate) showing promising binding affinity in docking studies, along with previously known anti-inflammatory compound aciculatin can be held responsible for the observed activity.

6.
Chemosphere ; 204: 220-226, 2018 08.
Article in English | MEDLINE | ID: mdl-29656158

ABSTRACT

Omeprazole (OME) is a proton pump inhibitor used for the treatment of various gastric and intestinal disease; however, studies on its effects on the genetic materials are still restricted. The present study aimed to evaluate possible toxicogenic effects of OME in Allium cepa meristems with the application of cytogenetic biomarkers for DNA damage, mutagenic, toxic and cytotoxic effects. Additionally, retinol palmitate (RP) and ascorbic acid (AA) were also co-treated with OME to evaluate possible modulatory effects of OME-induced cytogenetic damages. OME was tested at 10, 20 and 40 µg/mL, while RP and AA at 55 µg/mL and 352.2 µg/mL, respectively. Copper sulphate (0.6 µg/mL) and dechlorinated water were used as positive control and negative control, respectively. The results suggest that OME induced genotoxicity and mutagenicity in A. cepa at all tested concentrations. It was noted that cotreatment of OME with the antioxidant vitamins RP and/or AA significantly (p < 0.05) inhibited and/or modulated all toxicogenic damages induced by OME. These observations demonstrate their antigenotoxic, antimutagenic, antitoxic and anticitotoxic effects in A. cepa. This study indicates that application of antioxidants may be useful tools to overcome OME-induced toxic effects.


Subject(s)
Allium/drug effects , Ascorbic Acid/pharmacology , Omeprazole/toxicity , Toxicogenetics/methods , Vitamin A/analogs & derivatives , Antioxidants/pharmacology , DNA Damage/drug effects , Diterpenes , Mutagenesis/drug effects , Mutagens , Plant Extracts/pharmacology , Retinyl Esters , Vitamin A/pharmacology
7.
J Pharmacol Sci ; 130(4): 212-8, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26980430

ABSTRACT

Antihistamines inhibit histamine signaling by blocking histamine H1 receptor (H1R) or suppressing H1R signaling as inverse agonists. The H1R gene is upregulated in patients with pollinosis, and its expression level is correlated with the severity of nasal symptoms. Here, we show that antihistamine suppressed upregulation of histidine decarboxylase (HDC) mRNA expression in patients with pollinosis, and its expression level was correlated with that of H1R mRNA. Certain antihistamines, including mepyramine and diphenhydramine, suppress toluene-2,4-diisocyanate (TDI)-induced upregulation of HDC gene expression and increase HDC activity in TDI-sensitized rats. However, d-chlorpheniramine did not demonstrate any effect. The potencies of antihistamine suppressive effects on HDC mRNA elevation were different from their H1R receptor binding affinities. In TDI-sensitized rats, the potencies of antihistamine inhibitory effects on sneezing in the early phase were related to H1R binding. In contrast, the potencies of their inhibitory effects on sneezing in the late phase were correlated with those of suppressive effects on HDC mRNA elevation. Data suggest that in addition to the antihistaminic and inverse agonistic activities, certain antihistamines possess additional properties unrelated to receptor binding and alleviate nasal symptoms in the late phase by inhibiting synthesis and release of histamine by suppressing HDC gene transcription.


Subject(s)
Gene Expression/drug effects , Histamine Antagonists/metabolism , Histamine Antagonists/pharmacology , Histidine Decarboxylase/genetics , Histidine Decarboxylase/metabolism , Receptors, Histamine H1/metabolism , Toluene 2,4-Diisocyanate/pharmacology , Up-Regulation/drug effects , Animals , Depression, Chemical , Dose-Response Relationship, Drug , Histamine/physiology , Histamine Agonists , Histamine H1 Antagonists , Humans , Hypersensitivity/drug therapy , Hypersensitivity/genetics , Male , Molecular Targeted Therapy , Protein Binding , RNA, Messenger/metabolism , Rats , Signal Transduction/drug effects
8.
Int Immunopharmacol ; 11(10): 1504-9, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21601015

ABSTRACT

Previously, we have shown that hot water extract from Kujin, the dried roots of Sophora flavescens alleviates allergic symptoms by suppressing histamine signaling at the transcription level in toluene 2,4-diisocyanate (TDI)-sensitized rats. To know more insights into the mechanism of the anti-allergic action of Kujin, we carried out the microarray analysis to explore genes that were up-regulated by treatment with TDI and also were suppressed these up-regulated gene expression by Kujin. Microarray analysis revealed the substantial up-regulation of FAT10 (also called UbD) mRNA due to TDI sensitization and Kujin extract significantly suppressed this up-regulation. FAT10 is an ubiquitin like protein having an active role in the immune system and is induced by proinflammatory cytokines. Activation of NF-κB by FAT10 also has been reported. However, the role of FAT10 in allergic pathogenesis remains unknown. Here we investigated the correlation of FAT10-NF-κB signaling with histamine signaling in TDI-sensitized rats. Real time RT-PCR analysis confirmed that treatment with TDI up-regulated FAT10 mRNA expression in the nasal mucosa of TDI-sensitized rats and Kujin extract suppressed this elevation. Treatment with H(1)-antihistamines suppressed the TDI-induced up-regulation of FAT10 mRNA expression in TDI-sensitized rats. Direct administration of histamine into the nasal cavity of non-TDI-treated normal rats up-regulated the expression of FAT10 mRNA. Our data suggest that Kujin might alleviate allergic symptoms by inhibition of NF-κB activation through suppression of histamine-induced up-regulation of FAT10 mRNA expression.


Subject(s)
Histamine H1 Antagonists/administration & dosage , Hypersensitivity/drug therapy , Phytotherapy , Plant Extracts/administration & dosage , Ubiquitins/metabolism , Animals , Disease Models, Animal , Down-Regulation/drug effects , Histamine/metabolism , Histamine H1 Antagonists/adverse effects , Humans , Hypersensitivity/immunology , Male , Microarray Analysis , Nasal Mucosa/drug effects , Nasal Mucosa/metabolism , Plant Extracts/adverse effects , Plant Extracts/metabolism , Rats , Rats, Inbred Strains , Signal Transduction/drug effects , Sophora/immunology , Toluene 2,4-Diisocyanate/administration & dosage , Ubiquitins/genetics , Ubiquitins/immunology
9.
Australas Med J ; 4(1): 26-42, 2011.
Article in English | MEDLINE | ID: mdl-23393500

ABSTRACT

BACKGROUND: Indiscriminate usage of injections and lack of safe practices during injection administration have been reported worldwide. Unnecessary and unsafe injection usage not only increases the financial burden but are also responsible for spreading blood borne diseases including HIV, HBV and HCV. To attain a better understanding of the situation of injection usage in Bangladesh, a study was conducted at six Upazilla Health Complexes (UHCs), which are primary healthcare units in Bangladesh. METHOD: The study involved the retrospective collection of treatment sheets of 1048 in-patients at six UHCs from January 2009 to June 2009. The data was then analyzed using statistical tests. RESULTS: Among the patients investigated, 60.11% of the patients received injections and among them the male population received more injection than the female population (males vs. females = 62.50% vs. 55.85%). Patients below 12 years of age received the highest proportion of injections and highest usage of injections was observed in the month of March. The average number of injection(s) prescribed to a patient was 2.44 incurring a prescription cost of 280.22 Taka (USD 3.92 approx.). Injections were mostly prescribed in patients who were diagnosed with physical assault and acute watery diarrhea where intravenous fluids and antibiotics were most widely prescribed. Non-compliance to recapping of used injections was very common which accounted for 22.22% needle stick injuries. CONCLUSION: The data suggest that indiscriminate and unsafe injection practices were occurring in all UHCs. Such practices resulted in financial losses as well as compromising safety for healthcare providers and patients.

10.
J Pharmacol Sci ; 109(4): 606-17, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19352071

ABSTRACT

Kujin, the dried root of Sophorae flavescensis, has been used in Chinese folklore medicine against allergy. Evaluation of its anti-allergic potential as well as its mechanism of action has rarely been established. We investigated the effect of Kujin on toluene-2,4-diisocyanate (TDI)-induced allergic behavior and related histamine signaling including mRNA levels of histamine H(1) receptor (H1R) and histidine decarboxylase (HDC), H1R and HDC activities, and histamine content in rat nasal mucosa. We also investigated the effect of Kujin on the mRNA levels of helper T cell type 2 (Th2)-cytokine genes closely related to histamine signaling. TDI provocation caused acute allergic symptoms accompanied with up-regulations of H1R and HDC mRNAs and increases in HDC activity, histamine content, and [(3)H]mepyramine binding activity in the nasal mucosa, all of which were significantly suppressed by pretreatment with Kujin for 3 weeks. Kujin also suppressed the TDI-induced IL-4 and IL-5 mRNA elevations. These data suggest that oral administration of Kujin showed anti-allergic activity through suppression of histamine signaling by the inhibition of TDI-induced H1R and HDC mRNA elevations followed by decrease in H1R, HDC protein level, and histamine content in the nasal mucosa of TDI-sensitized rats. Suppression of Th2-cytokine signaling by Kujin also suggests that it could affect the histamine-cytokine network.


Subject(s)
Fabaceae/chemistry , Histamine Antagonists/pharmacology , Histamine/physiology , Hypersensitivity/drug therapy , Toluene 2,4-Diisocyanate/toxicity , Animals , Cytokines/drug effects , Cytokines/metabolism , Histamine H1 Antagonists/metabolism , Histamine Release/drug effects , Histidine Decarboxylase/biosynthesis , Male , Nasal Mucosa/drug effects , Nasal Mucosa/metabolism , Plant Roots/chemistry , Pyrilamine/metabolism , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , Rats , Rats, Inbred BN , Receptors, Histamine H1/biosynthesis , Receptors, Histamine H1/genetics , Reverse Transcriptase Polymerase Chain Reaction , Signal Transduction/drug effects , Th2 Cells/drug effects , Th2 Cells/metabolism , Transcription, Genetic/drug effects
11.
Allergol Int ; 58(1): 81-8, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19050374

ABSTRACT

BACKGROUND: The therapeutic use of Kampo medicine, Sho-seiryu-to (SST) in allergic disorders is well known. As histamine plays a central role in allergic diseases, it is possible that SST affects the allergy-related histamine signaling. In this study, we investigated the effect of SST on allergy-related histamine signaling in the nasal mucosa of toluene 2, 4-diisocyanate (TDI)-sensitized nasal allergy model rats. METHODS: Six-week-old male, Brown Norway rats were sensitized for 2 weeks with 10 microl of 10% TDI, and after a 1 week interval, provocation was initiated with the same amount of TDI. SST (0.6g/rat) was given orally 1 hour before TDI treatment began for a period of 3 weeks. Nasal symptoms were scored for 10 minutes immediately after TDI-provocation. The genes expression in nasal mucosa was determined using real-time quantitative RT-PCR. RESULTS: SST significantly suppressed TDI-induced nasal allergy-like symptoms. TDI provocation showed a significant up-regulation of histamine H(1) receptor (H1R) and histidine decarboxylase (HDC) gene expressions. Prolonged pre-treatment of SST significantly suppressed the mRNA levels of H1R and HDC that was up-regulated by TDI. SST also suppressed TDI-induced interleukin (IL)-4 and IL-5 mRNA elevation. However, SST showed no significant effect for TDI-induced mRNA elevation of IL-13. CONCLUSIONS: These results demonstrate that SST alleviates nasal symptoms by the inhibition of histamine signaling through suppression of TDI-induced H1R and HDC gene up-regulation. SST also suppresses cytokine signaling through suppression of IL-4 and IL-5 gene expression. Suppression of histamine signaling may be a novel mechanism of SST in preventing allergic diseases.


Subject(s)
Drugs, Chinese Herbal/pharmacology , Histamine/physiology , Hypersensitivity/drug therapy , Medicine, Kampo , Signal Transduction/drug effects , Toluene 2,4-Diisocyanate/pharmacology , Animals , Cytokines/genetics , Disease Models, Animal , Drugs, Chinese Herbal/therapeutic use , Histidine Decarboxylase/genetics , Male , Nasal Mucosa/drug effects , RNA, Messenger/analysis , Rats , Rats, Inbred BN , Receptors, Histamine H1/genetics
12.
J Pharmacol Sci ; 107(2): 159-66, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18544899

ABSTRACT

It has been shown that probiotic bacteria are effective for the treatment of allergic diseases. As histamine plays a central role in allergic diseases, it is possible that probiotic bacteria affect the allergy-related histamine signaling. Here, we investigated the effect of Lac-B, a mixture of freeze-dried Bifidobacterium infantis and Bifidobacterium longum, on the allergy-related histamine signaling. In the nasal allergy model rats made by sensitization and provocation with toluene 2,4-diisocyanate (TDI) for 3 weeks, TDI provocation caused acute allergy-like behaviors along with significant up-regulation of histamine H(1) receptor (H1R) and histidine decarboxylase (HDC) mRNA expression, increased HDC activity, histamine content, and [(3)H]mepyramine binding activity in nasal mucosa. Prolonged treatment with Lac-B (40 mg/rat, p.o.) significantly suppressed both the allergy-like behaviors and all of the above mentioned factors involved in histamine signaling. Our findings indicate that oral administration of Lac-B showed significant anti-allergic effect through suppression of both H1R and HDC gene expression followed by decrease in H1R, HDC protein level, and histamine content. Suppression of histamine signaling may be a novel target of probiotics in preventing allergic diseases.


Subject(s)
Anti-Allergic Agents/pharmacology , Histamine Antagonists/pharmacology , Probiotics/pharmacology , Signal Transduction/drug effects , Animals , Cytokines/genetics , Histidine Decarboxylase/genetics , Male , RNA, Messenger/analysis , Rats , Rats, Inbred BN , Receptors, Histamine H1/genetics , Toluene 2,4-Diisocyanate/pharmacology
13.
J Pharmacol Sci ; 103(4): 374-82, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17409634

ABSTRACT

Histamine is a major mediator in allergy acting mainly through the histamine H(1) receptor (H1R). Although H1R up-regulation has been suggested as an important step for induction of allergic symptoms, little is known about the regulation of H1R level. Here we report that the activation of H1R up-regulates H1R through augmentation of H1R mRNA expression in HeLa cells. Histamine stimulation significantly increased both H1R promoter activity and mRNA level without alteration in mRNA stability. H1R protein was also up-regulated by histamine. An H1R antagonist but not histamine H(2) receptor antagonist blocked histamine-induced up-regulation of both promoter activity and mRNA expression. A protein kinase C (PKC) activator, phorbol-12-myristate-13-acetate, increased H1R mRNA expression, whereas an activator of PKA or PKG (8-Br-cAMP or 8-Br-cGMP, respectively) did not. Furthermore, histamine-induced up-regulation of both promoter activity and mRNA level were completely suppressed by the PKC inhibitor Ro-31-8220. H1R antagonists have long been thought to block H1R and inhibit immediate allergy symptoms. In addition to this short-term effect, our data propose their long-term inhibitory effect against allergic diseases by suppressing PKC-mediated H1R gene transcription. This finding provides new insights into the therapeutic target of H1R antagonist in allergic diseases.


Subject(s)
Histamine/pharmacology , Receptors, Histamine H1/genetics , Transcription, Genetic/drug effects , Up-Regulation/drug effects , 8-Bromo Cyclic Adenosine Monophosphate/pharmacology , Carbazoles/pharmacology , Cyclic GMP/analogs & derivatives , Cyclic GMP/pharmacology , Enzyme Inhibitors/pharmacology , HeLa Cells , Histamine H1 Antagonists/pharmacology , Humans , Indoles/pharmacology , Luciferases/genetics , Luciferases/metabolism , Protein Kinase C/antagonists & inhibitors , Protein Kinase C/metabolism , Pyrilamine/pharmacology , Pyrroles/pharmacology , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptors, Histamine H1/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Tetradecanoylphorbol Acetate/pharmacology , Thionucleotides/pharmacology , Transfection , Tritium , Up-Regulation/genetics
14.
Allergol Int ; 55(3): 279-86, 2006 Sep.
Article in English | MEDLINE | ID: mdl-17075268

ABSTRACT

BACKGROUND: Histamine synthesized by histidine decarboxylase (HDC) from L-histidine is a major chemical mediator in the development of nasal allergy which is characterized by nasal hypersensitivity. However the regulatory mechanism of histamine synthesis by HDC remains to be elucidated. The objectives of the present study were to examine the changes of histamine content, HDC activity and HDC mRNA expression in the nasal mucosa of allergy model rats sensitized by the exposure to toluene diisocyanate (TDI) and to investigate the effect of dexamethasone on the above mentioned allergic parameters. METHODS: Rats were sensitized and provocated by TDI and the nasal allergy-like behaviors were scored during a 10 minute period after provocation. Histamine content and HDC activity in the nasal mucosa were determined using fluorometric high performance liquid chromatography. The expression of HDC mRNA in nasal mucosa was determined using real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: In TDI-sensitized rats, nasal allergy-like behaviors such as sneezing and watery rhinorrhea were induced. Histamine content, HDC activity and HDC mRNA expression in nasal mucosa were also significantly increased after TDI provocation. Pretreatment with dexamethasone significantly suppressed nasal allergy-like behaviors, up-regulation of histamine content, HDC activity and HDC mRNA induced by TDI in TDI-sensitized rats. CONCLUSIONS: These findings indicate that increased synthesis of histamine through up-regulation of HDC gene expression and HDC activity in nasal mucosa plays an important role in the development of nasal hypersensitivity. Repression of HDC gene expression and HDC activity by dexamethasone may underlie its therapeutic effect in the treatment of allergy.


Subject(s)
Anti-Inflammatory Agents/pharmacology , Dexamethasone/pharmacology , Histamine Antagonists/pharmacology , Histamine/biosynthesis , Histidine Decarboxylase/antagonists & inhibitors , Hypersensitivity/drug therapy , Animals , Histidine Decarboxylase/genetics , Histidine Decarboxylase/metabolism , Male , Rats , Rats, Inbred BN
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