Nicotinic acid could increase high density lipoprotein and reduce serum total cholesterol, low density lipoprotein cholesterol and triglycerides in human bodies, thus is frequently applied in treating low high-density lipoprotein cholesterol and hypertriglyceridemia in clinic. However, according to the findings, nicotinic acid could also cause adverse effects, such as skin flush, beside its curative effects. In this study, bioisosterism, fragment-based search and Lipinski's Rule of Five were used to preliminarily screen out potential TCM ingredients that may have similar pharmacological effects with nicotinic acid from Traditional Chinese medicine database (TCMD). Afterwards, homology modeling and flexible docking were used to further screen out potential nicotinic acid receptor agonists. As a result, eleven candidate compounds were derived from eight commonly used traditional Chinese medicines. Specifically, all of the candidate compounds' interaction with nicotinic acid receptor was similar to nicotinic acid, and their docking scores were all higher than that of nicotinic acid, but their druggability remained to be further studied. Some of the eight source traditional Chinese medicines were used to lower lipid according to literature studies, implying that they may show effect through above means. In summary, this study provides basis and reference for extracting new nicotinic acid receptor agonists from traditional Chinese medicines and improving the medication status of hyperlipidemia.
Drug Evaluation, Preclinical ; Drugs, Chinese Herbal ; chemistry ; Humans ; Models, Molecular ; Molecular Structure ; Nicotinic Acids ; chemistry ; Nicotinic Agonists ; chemistry ; Protein Binding ; Receptors, G-Protein-Coupled ; agonists ; chemistry ; Receptors, Nicotinic ; chemistry

BACKGROUNDTechnetium-99m or (99m)Tc is widely used for labeling peptide in nuclear medicine. Somatostatin and its analog can inhibit tumor cell growth after binding with its receptor. This research was to study the preclinical effect of a new (99m)Tc-6-hydrazinopyridine-3-carboxylic acid (HYNIC)-depreotide, indirect (99m)Tc labeling of depreotide using HYNIC as a bifunctional chelator.

METHODSThe cyclopeptide, cyclo-[(N-Me) Phe-Tyr-D-Trp-Lys-Val-Hcy], the linear peptide, and [ClCH(2)-CO×b-Dap-Lys- Cys-Lys×amide] were synthesized by Fmoc solid-phase synthesis. The cyclopeptide and the linear peptide were linked by liquid-phase synthesis. The product depreotide was isolated and purified by high performance liquid chromatography and was confirmed by mass spectrography. Depreotide was labeled with (99m)Tc through a direct labeling method, using HYNIC as a bifunctional chelator. Paper chromatography method was used to calculate the labeling rate, and through the comparative analysis selected the best mark conditions. The new (99m)Tc-HYNIC-depreotide was tested by high-performance liquid chromatography (HPLC). The internalization and externalization rates of the new (99m)Tc-HYNIC-depreotide were studied in A549 cells. Furthermore, biodistribution of the radiopeptide was studied in nude mice, bearing tumors from human lung carcinoma cells SPC-A1.

RESULTSThe molecular of synthesize depreotide was 1358, and the purity of it was 95.29%. The labeling efficiency of (99m)Tc-HYNIC-depreotide was highest at pH 6.0 and 15°C, about (70.95 ± 0.84)%. The labeling rate of the new (99m)Tc-HYNIC-depreotide rose to a peak of (20.75 ± 0.48)% at 60 minutes in A549 cells at 37°C and decreased slightly later, while it elevated gradually during the time course at 4°C and 25°C. The internalization rate of the new (99m)Tc-HYNIC-depreotide at 37°C increased gradually and reached the peak of 84.4% in 120 minutes, while the externalization rate of the new (99m)Tc-HYNIC-depreotide was always less than 20%. In mice bearing the experimental SPC-A1 tumor, the new (99m)Tc-HYNIC-depreotide demonstrated a high tumor uptake of (4.05 ± 0.04)% ID/g at 1.5 hpi and remained high ((2.51 ± 0.06)% ID/g) at 4 hpi. The tumor-to-lung activity concentration ratio (T/Lu) was very high for the new (99m)Tc-HYNIC-depreotide at all time points. So did the tumor-to-muscle activity (T/Mu) and tumor-to-blood activity concentration ratios (T/Bl).

CONCLUSIONThe findings suggested that the new (99m)Tc-HYNIC-depreotide might be a promising candidate radiopharmaceutical for imaging somatostatin receptor positive lung cancer.

Animals ; Cell Line, Tumor ; Humans ; Hydrazines ; chemistry ; Lung Neoplasms ; metabolism ; pathology ; Male ; Mice ; Mice, Nude ; Nicotinic Acids ; chemistry ; Receptors, Somatostatin ; metabolism ; Technetium ; chemistry

OBJECTIVETo investigate the molecular mechanism of dermal damage in heat shock-induced skin aging by observing the expressions of metalloproteinase-1 (MMP-1) and tissue inhibitor of MMP-1 (TIMP-1) in retinoic acid-treated cultured human fibroblasts with heat shock.

METHODSCultured human fibroblasts were treated with tazarotene or all-trans-retinioic acid (at-RA) after heat shock for 30 min in 43 degrees celsius; water bath. Twenty-four hours later, MMP-1 and TIMP-1 contents in the supernatant of the cell culture medium were measured using enzyme-linked immunosorbent assay (ELISA).

RESULTSBoth tazarotene and at-RA dose-dependently reduced the expression of MMP-1 and increased the expression of TIMP-1 in cultured human fibroblasts exposed to heat shock, and tazarotene produced stronger effect than at-RA.

CONCLUSIONRetinoic acid can reduce the expression of MMP-1 and increase the expression of TIMP-1 in cultured human fibroblasts, suggesting its therapeutic potential for heat shock-induced skin aging.

Cells, Cultured ; Fibroblasts ; cytology ; metabolism ; Heat-Shock Response ; Humans ; Matrix Metalloproteinase 1 ; genetics ; metabolism ; Nicotinic Acids ; pharmacology ; Skin Aging ; radiation effects ; Tissue Inhibitor of Metalloproteinase-1 ; genetics ; metabolism ; Tretinoin ; pharmacology

The aimed of this study was to prepare stabilized thiomers to overcome the poor stability character of traditional thiomers. Poly(acrylic acid)-cysteine (PAA-Cys) was synthesized by conjugating cysteine with poly(acrylic acid) and poly(acrylic acid)-cysteine-6-mercaptonicotinic acid (PAA-Cys-6MNA, stabilized thiomers) was synthesized by grafting a protecting group 6-mercaptonicotinic acid (6MNA) with PAA-Cys. The free thiol of PAA-Cys was determined by Ellmann's reagent method and the ratio of 6MNA coupled was determined by glutathione reduction method. The study of permeation enhancement and stabilized function was conducted by using Franz diffusion cell method, with fluorescein isothiocyanate dextran (FD4) used as model drug. The influence of polymers on tight junctions of Caco-2 cell monolayer was detected with laser scanning confocal fluorescence microscope. The results indicated that both PAA-Cys and PAA-Cys-6MNA could promote the permeation of FD4 across excised rat intestine, and the permeation function of PAA-Cys-6MNA was not influence by the pH of the storage environment and the oxidation of air after the protecting group 6MNA was grafted. The distribution of tight junction protein of Caco-2 cell monolayer F-actin was influenced after incubation with PAA-Cys and PAA-Cys-6MNA. In conclusion, stabilized thiomers (PAA-Cys-6MNA) maintained the permeation function compared with the traditional thiomers (PAA-Cys) and its stability was improved. The mechanism of the permeation enhancement function of the polymers might be related to their influence on tight junction relating proteins of cells.
Acrylic Resins ; chemistry ; Actins ; metabolism ; Animals ; Caco-2 Cells ; Cysteine ; chemistry ; Dextrans ; Fluorescein-5-isothiocyanate ; analogs & derivatives ; Glutathione ; Humans ; Intestinal Absorption ; Intestinal Mucosa ; drug effects ; Nicotinic Acids ; chemistry ; Rats ; Sulfhydryl Compounds ; chemistry

OBJECTIVETo investigate the mechanism of tazarotene against active psoriasis vulgaris.

METHODSA randomized, controlled trial was conducted in 43 patients with active psoriasis vulgaris, who were divided into tazarotene and control groups. Promyelocytic leukemia (PML) mRNA in active psoriatic lesions before and 14 days after tazarotene treatment was detected by in situ hybridization.

RESULTSPML mRNA expression was detected not only in the basal layer (86.96%), but also in the suprabasal layers of the epidermis in the manner of focal expression (78.26%). After tazarotene treatment, virtually no PML mRNA expression could be detected in the psoriatic lesions (8.69% in the basal layer and 4.35% in the suprabasal layers). PML mRNA expression in the control group underwent no obvious changes during the observation.

CONCLUSIONSTazarotene may inhibit abnormal proliferation of keratinocytes through down-regulating PML gene expression in active psoriatic epidermis.

Adolescent ; Adult ; Double-Blind Method ; Down-Regulation ; drug effects ; genetics ; Epidermis ; drug effects ; metabolism ; pathology ; Female ; Gene Expression ; drug effects ; Humans ; In Situ Hybridization ; Keratolytic Agents ; administration & dosage ; therapeutic use ; Male ; Middle Aged ; Neoplasm Proteins ; genetics ; Nicotinic Acids ; administration & dosage ; therapeutic use ; Nuclear Proteins ; genetics ; Promyelocytic Leukemia Protein ; Psoriasis ; drug therapy ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Transcription Factors ; genetics ; Tumor Suppressor Proteins ; genetics

Human immunodeficiency virus type 1 (HIV-1) transcription is a crucial step in the viral replication cycle, which is considered to be a potential target for inhibition of HIV-1 replication. Among the factors involved in this step, the cellular protein nuclear factor NF-kappaB is the most powerful inducer of HIV-1 transcription. HIV-1 transcription is initiated by the binding of NF-kappaB to the enhancer region in the long terminal repeat (LTR) of HIV-1. Several compounds suppress HIV-1 transcription through the inhibition of NF-kappaB activation. The mechanisms of NF-kappaB in the transcription of HIV-1 and progress of the current inhibitors of NF-kappaB are reviewed.
Anti-HIV Agents ; pharmacology ; HIV Long Terminal Repeat ; HIV-1 ; genetics ; Humans ; I-kappa B Kinase ; metabolism ; I-kappa B Proteins ; metabolism ; NF-KappaB Inhibitor alpha ; NF-kappa B ; antagonists & inhibitors ; metabolism ; Nicotinic Acids ; pharmacology ; Nitriles ; pharmacology ; Transcription, Genetic ; drug effects ; Virus Replication

The ability of nicotinic acid and its substitutes to increase cutaneous blood flow has been measured by laser Doppler flowmeter in 30 healthy human volunteers. We applied nicotinarnide, nicotinic acid ethyl ester, nicotinic acid methyl ester, hexyl nicozinate each in an acqeous solution at a concentration of 10 mM/liter for 10 minutes occlusion on the forearm. The change of blood flow was serially checked at 5 to 10 minutes intervals for one hour. The study results were as follows : l. The relative maximum cutaneous blood flow response was in following order nicotinic acid methyl ester(100%), nicotinic acid ethyl ester(98%), hexyl nicotinate (84%) and nicotinic acid(63%). However, there was no statistically significant difference(p>0.05) between each drug. There was statististically significant difference between nicotinamide and all other nicotinic acid substitutes(p<0.05). 2. The time required to reach maximum blood flow response was 6.7 minutes for hexyl nicotinste, 10 minutes for nicotinic acid ethyl ester, 12.5 minutes for nicotinic acid methyl ester and 20 minutes for nicotinic acid. However, there was statistically significant difference between hexyl nicotinate and nicotinic acid only(p<0.05). 3. Significant decrease of cutaneous blood flow was observed one hour after the removal of the patches in all drugs.
Flowmeters ; Forearm ; Healthy Volunteers ; Niacin* ; Niacinamide

Spinal gabapentin has been known to show the antinociceptive effect. Although several assumptions have been suggested, mechanisms of action of gabapentin have not been clearly established. The present study was undertaken to examine the action mechanisms of gabapentin at the spinal level. Male SD rats were prepared for intrathecal catheterization. The effect of gabapentin was assessed in the formalin test. After pretreatment with many classes of drugs, changes of effect of gabapentin were examined. General behaviors were also observed. Intrathecal gabapentin produced a suppression of the phase 2 flinching, but not phase 1 in the formalin test. The antinociceptive action of intrathecal gabapentin was reversed by intrathecal NMDA, AMPA, D-serine, CGS 15943, atropine, and naloxone. No antagonism was seen following administration of bicuculline, saclofen, prazosin, yohimbine, mecamylamine, L-leucine, dihydroergocristine, or thapsigargin. Taken together, intrathecal gabapentin attenuated only the facilitated state. At the spinal level, NMDA receptor, AMPA receptor, nonstrychnine site of NMDA receptor, adenosine receptor, muscarinic receptor, and opioid receptor may be involved in the antinociception of gabapentin, but GABA receptor, L-amino acid transporter, adrenergic receptor, nicotinic receptor, serotonin receptor, or calcium may not be involved.
Acetic Acids/administration & dosage ; Acetic Acids/metabolism ; Acetic Acids/pharmacology* ; Adrenergic Antagonists/metabolism ; Adrenergic alpha-Antagonists/metabolism ; Analgesics/administration & dosage ; Analgesics/metabolism ; Analgesics/pharmacology* ; Animals ; Atropine/metabolism ; Dihydroergocristine/metabolism ; Enzyme Inhibitors/metabolism ; Excitatory Amino Acid Agonists/metabolism ; GABA Antagonists/metabolism ; Injections, Spinal ; Leucine/metabolism ; Male ; Mecamylamine/metabolism ; Muscarinic Antagonists/metabolism ; N-Methylaspartate/metabolism ; Naloxone/metabolism ; Narcotic Antagonists/metabolism ; Nicotinic Antagonists/metabolism ; Pain Measurement ; Quinazolines/metabolism ; Rats ; Rats, Sprague-Dawley ; Serine/metabolism ; Spinal Cord/drug effects* ; Thapsigargin/metabolism ; Triazoles/metabolism ; alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid/metabolism

Pellagra is a chronic wasting disorder characterized by 3 clinical distinct symptoms; dermatitis; dementia; and diarrhea. It results from a marked cellular deficiency of water-soluble vitamin B3, also called niacin. Dermatitis begins as an erythema and shows bilateral symmetrical eruption at cutaneous sites of solar exposure. Herein we report 2 cases of pellagra in chronic alcoholics.
Alcoholics* ; Dementia ; Dermatitis ; Diarrhea ; Erythema ; Humans ; Niacin ; Niacinamide ; Pellagra*

A Case of Pellagra Induced by Isoniazid during Treatment of Pulmonary Tuberculosis Pellagra is a disease caused by a deficiency of nicotinic acid or niacin. It is mostly found among people eating corn-based diets in parts of China, Africa and India. It is also induced by drugs, such as isoniazid or 5-fluorouracil. Isoniazid inhibits the conversion of tryptophan to niacin and may induce pellagra, particularly in poorly nourished patients. Pellagra should be suspected whenever tuberculous patients under the treatment with isoniazid develop mental, neurological or gastrointestinal symptoms, even in the absence of typical skin changes. Herein, our experienced of a case of pellagra induced by isoniazid during treatment of pulmonary tuberculosis is reported. The patient was referred due to a skin rash and drowsy mental status. Her skin lesion developed during treatment for pulmonary tuberculosis. Her symptoms were improved after discontinuation of antituberculous agents and on the administration of nicotinamide.
Africa ; China ; Diet ; Eating ; Exanthema ; Fluorouracil ; Humans ; India ; Isoniazid* ; Niacin ; Niacinamide ; Pellagra* ; Skin ; Tryptophan ; Tuberculosis, Pulmonary*