Background Cholesterol-lowering therapy with statins has been reported to reduce the morbidity and mortality of cardiovascular diseases. This study aimed to investigate the effects of combined application of extended-...Background Cholesterol-lowering therapy with statins has been reported to reduce the morbidity and mortality of cardiovascular diseases. This study aimed to investigate the effects of combined application of extended-release niacin and atorvastatin on lipid profile modification and the risks of adverse events in patients with coronary artery disease. Methods Consecutive 108 patients with coronary artery disease and serum total cholesterol (TC) 〉 3.5 mmol/L were randomized into two groups: group A using atorvastatin and group B using extended-release niacin (niacin ER) and atorvastatin. Plasma lipid profile, glucose, and adverse events were assessed at the hospitalization, and 6 and 12 months after treatment. In addition, clinical cardiovascular events were evaluated after 12 months of treatment. Results The levels of TC, low density lipoprotein cholesterol (LDL-C) were significantly decreased (P 〈0.05) in groups A and B, but the levels of high density lipoprotein cholesterol (HDL-C) and ApoA increased by 29.36% and 40.81% respectively after 12 months of treatment in group B (P 〈0.01). The medications were generally well tolerated in the two groups. No significant difference of adverse events was found between the two groups (group A: 3.2% vs group B 5.1%, P 〉0.05). Conclusions Combined use of extended-release niacin with atorvastatin was superior to atorvastatin monotherapy alone in lipid profile regulation. Combination therapy with niacin ER and atorvastatin was well tolerated and safe in patients with coronary artery disease.展开更多
The objective of this study is to develop chitosaneanionic polymers based extendedrelease tablets and test the feasibility of using this system for the sustained release of highly water-soluble drugs with high drug lo...The objective of this study is to develop chitosaneanionic polymers based extendedrelease tablets and test the feasibility of using this system for the sustained release of highly water-soluble drugs with high drug loading.Here,the combination of sodium valproate(VPS)and valproic acid(VPA)were chosen as the model drugs.Anionic polymers studied include xanthan gum(XG),carrageenan(CG),sodium carboxymethyl cellulose(CMC-Na)and sodium alginate(SA).The tablets were prepared by wet granulation method.In vitro drug release was carried out under simulated gastrointestinal condition.Drug release mechanism was studied.Compared with single polymers,chitosaneanionic polymers based system caused a further slowdown of drug release rate.Among them,CS exanthan gum matrix system exhibited the best extended-release behavior and could extend drug release for up to 24 h.Differential scanning calorimetry(DSC)and Fourier transform infrared spectroscopy(FTIR)studies demonstrated that polyelectrolyte complexes(PECs)were formed on the tablet surface,which played an important role on retarding erosion and swelling of the matrix in the later stage.In conclusion,this study demonstrated that it is possible to develop highly water-soluble drugs loaded extendedrelease tablets using chitosaneanionic polymers based system.展开更多
The purpose of this study was to develop an extended-release(ER) matrix tablet that shows robust dissolution properties able to account for the variability of pH and mechanical stress in the GI tract using a combinati...The purpose of this study was to develop an extended-release(ER) matrix tablet that shows robust dissolution properties able to account for the variability of pH and mechanical stress in the GI tract using a combination of enteric polymer and hydrophilic polymer. Hypromellose acetate succinate(HPMCAS) and hydroxypropylcellulose(HPC) were selected as ER polymers for the ER matrix tablet(HPMCAS/HPC ER matrix tablet). Oxycodone hydrochloride was employed as a model drug. Dissolution properties of the HPMCAS/HPC ER matrix tablets were evaluated and were not affected by the pH of the test medium or paddle rotating speed.In a USP apparatus 3(bio-relevant dissolution method), dissolution profiles of the HPMCAS/HPC ER matrix tablets containing oxycodone hydrochloride were similar to that of the reference product(OxyC ontin). Moreover, in vivo performance after oral administration of the HPMCAS/HPC ER matrix tablets to humans was simulated by GastroP lus based on dissolution profiles from the USP apparatus 3. The plasma concentration-time profile simulated was similar to that of the reference product. These results suggest that the combination of HPMCAS and HPC shows a robust dissolution profile against pH and paddle rotating speed and indicates the appropriate extended-release profile in humans.展开更多
A procedure to evaluate the quality consistency of generic drugs based on the impurity profile and the similarity analysis methods was presented in this paper. Nifedipine extended-release tablets from six generic fact...A procedure to evaluate the quality consistency of generic drugs based on the impurity profile and the similarity analysis methods was presented in this paper. Nifedipine extended-release tablets from six generic factories of China were used to evaluate the uniformity with the original drug in the study. The procedure includes: choice of chromatographic methods, data collection and conformity test, evaluation of intra-batch similarity of drugs, evaluation of generic drugs with the original drug and weighted similarity evaluation of generic drugs. The data were collected via high-performance liquid chromatography (HPLC), and then calculated by correlation coefficient, cosine, principal component analysis (PCA) and hierarchical clustering analysis (HCA). It is more suitable to use peak areas as the vector when calculating the similarity of impurity profile. After weighting the peak areas of the unspecified impurities in further evaluation of the generic quality, the generic level of different factories was differentiated and the best generic factory was picked out.展开更多
The aim of this study was to design and evaluate extended-release formulations of a model drug,nicorandil,in order to achieve the desired steady-state plasma concentration of drug in vivo.Simulation was employed to es...The aim of this study was to design and evaluate extended-release formulations of a model drug,nicorandil,in order to achieve the desired steady-state plasma concentration of drug in vivo.Simulation was employed to estimate optimum dissolution and absorption rate of nicorandil.The dissolution test was employed using pH 1.2,4.0,6.8 buffer solution,or water,to measure the in vitro release behaviors of nicorandil formulations.A single dose(15 mg)of each formulation was orally administered to four beagle dogs under fasted conditions,and the pharmacokinetic parameters were calculated.The in vitro/in vivo relationship of the extended-release formulation was confirmed using in vitro dissolution profiles and plasma concentrations of drug in beagle dogs.Nicorandil was released completely within 30 min from the immediate-release tablets and released for 24 h from the extended-release tablets.The nicorandil plasma concentration could be modified by adjusting the drug release rate from the extended-release formulation.The release rate of nicorandil was the rate-limiting step in the overall absorption of drug from the extendedrelease formulations.These results highlight the potential of a nicorandil extended-release formulation in the treatment of angina pectoris.展开更多
Background: Drug adherence decreased in patients with Parkinson’ s disease (PD) because of taking many different types of drugs. We evaluated drug adherence after switching from immediate-release (IR) to once-daily e...Background: Drug adherence decreased in patients with Parkinson’ s disease (PD) because of taking many different types of drugs. We evaluated drug adherence after switching from immediate-release (IR) to once-daily extended-release (ER) pramipexole (PPX) in PD. Methods: This study included 35 PD patients (20 men, 15 women);10 were taking oral PPX alone, and 25 were also using another anti-PD drug. PPX-IR was switched overnight to PPX-ER without gradual tapering. One month after switching, improvement in timing adherence and reduction in medication burden were evaluated by a questionnaire using a visual analog scale (VAS) (0: No change;10: Better). Motor function was assessed using part III of the Unified Parkinson’s Disease Rating Scale (UPDRS). Results: The VAS score for improvement in timing adherence was 8.1 ± 0.5 (mean ± standard error), and that for reduction in medication burden was 7.3 ± 0.6. There was a significant negative correlation (ρ = -0.43, p = 0.01) between the VAS score and number of types of medications. The UPDRS part III score improved significantly after switching展开更多
Niacin or nicotinic acid is a form of B3 vitamin prescribed at higher concentrations for the suppression of cholesterol levels. Supplemental doses may cause very little or no side effects. However, higher concentratio...Niacin or nicotinic acid is a form of B3 vitamin prescribed at higher concentrations for the suppression of cholesterol levels. Supplemental doses may cause very little or no side effects. However, higher concentrations of niacin cause hot flushes for most people. Here we propose a biochemical mechanism of niacin induced hot flushes. Orally taken prescription doses of niacin are converted to NAD with the liberation of excess pyrophosphate which in turn releases energy in the form of heat (hot flushes through capsaicin receptor) by the action of pyrophosphatases. The excess pyrophosphate may suppress cholesterol biosynthesis through feedback mechanism. The pathways of NAD and cholesterol biosynthesis were discussed with refence to the production and function of pyrophosphate.展开更多
AIM: To investigate nicotinamide’s action on glucose metabolism, and the association between niacin consumption and obesity prevalence. METHODS: Dynamic nicotinamide’s effect on plasma hydrogen peroxide and glucose ...AIM: To investigate nicotinamide’s action on glucose metabolism, and the association between niacin consumption and obesity prevalence. METHODS: Dynamic nicotinamide’s effect on plasma hydrogen peroxide and glucose metabolism was in- vestigated using oral glucose tolerance tests with or without nicotinamide in the same five healthy subjects.Lag-regression analysis was used to examine the association between the niacin consumption and the obesity prevalence among US children using the data from the Economic Research Service of the US Department of Agriculture and from US Centers for Disease Control and Prevention, respectively. RESULTS: Compared with the control oral glucose tolerance test, the 1-h plasma hydrogen peroxide (1.4 ± 0.1 μmol/L vs 1.6 ± 0.1 μmol/L, P = 0.016) and insulin levels (247.1 ± 129.0 pmol/L vs 452.6 ± 181.8 pmol/L, P = 0.028) were signif icantly higher, and the 3-h blood glucose was signif icantly lower (5.8 ± 1.2 mmol/L vs 4.5 ± 1.1 mmol/L, P = 0.002) after coadministration of glucose and 300 mg nicotinamide. The obesity prevalence among American children increased with the increasing per capita niacin consumption, the increasing grain contribution to niacin due to niacin-fortification, and the increasing niacin-fortified ready-to-eat cereal consumption, with a 10-year lag. The regression analyses showed that the obesity prevalence in the US children of all age groups was determined by niacin consumption (R2 = 0.814, 0.961 and 0.94 for 2-5 years, 6-11 years and 12-19 years age groups, respectively). CONCLUSION: The appetite-stimulating effect of nicotinamide appears to involve oxidative stress. Excess niacin consumption may be a major factor in the increased obesity prevalence in US children.展开更多
Neural degeneration is a very complicated process. In spite of all the advancements in the molecular chemistry, there are many unknown aspects of the phenomena of neurodegeneration which need to be put together. It is...Neural degeneration is a very complicated process. In spite of all the advancements in the molecular chemistry, there are many unknown aspects of the phenomena of neurodegeneration which need to be put together. It is a common sequela of the conditions of niacin deficiency. Neural degeneration in Pellagra manifests as chromatolysis mainly in pyramidal followed by other neurons and glial cells. However, there is a gross lack of understanding of biochemi- cal mechanisms of neurodegeneration in niacin deficiency states. Because of the necessity of niacin or its amide derivative NAD in a number of biochemical pathways, it is understandable that several of these pathways may be involved in the common outcome of neural degener- ation. Here, we highlight five pathways that could be involved in the neuraldegeneration for which evidence has accumulated through several studies. These pathways are: 1) the trypto- phan-kyneurenic acid pathway, 2) the mitochondrial ATP generation related pathways, 3) the poly (ADP-ibose) polymerase (PARP) pathway, 4) the BDNF-TRKB Axis abnormalities, 5) the genetic influences of niacin deficiency.展开更多
Textile wastewater is well known as one of the wastewaters to be most difficultly treated. The effects of niacin on textile wastewater treatment efficiency were studied by continuous addition of 1.0 mg·L^-1 niaci...Textile wastewater is well known as one of the wastewaters to be most difficultly treated. The effects of niacin on textile wastewater treatment efficiency were studied by continuous addition of 1.0 mg·L^-1 niacin, the physical and chemical indexes of the water samples, such as COD, ammonia and dehydrogenase activities, were analyzed every day with standard methods, and obvious improvement in wastewater treatment performance was achieved. The exact results showed that:① Niacin could improve the COD removal efficiency signifcantly with removal rates being 1.31 times as to those of the control system; ② under this experimental condition, addition of niacin had almost no effect on the removal of ammonia;③ Addition of niacin could improve the activity of dehydrogenase by 130 %. It proved that the biological treatment performance of textile wastewater treatment system probably could be optimized through micronutrient niacin supplement.展开更多
Objective To estimate the association between three B-vitamin intakes and sociodemographic factors among adults in China.Methods We derived our data from the China Health and Nutrition Survey(CHNS) among 12,241 indivi...Objective To estimate the association between three B-vitamin intakes and sociodemographic factors among adults in China.Methods We derived our data from the China Health and Nutrition Survey(CHNS) among 12,241 individuals aged 18–64 years. Log binomial regression was used to estimate adjusted prevalence ratios for factors associated with the inadequate intake of B-vitamins.Results Females with low incomes and living in the north had a higher prevalence of inadequate riboflavin intake than those with high incomes and living in the south. Both males and females living in a village had a higher prevalence of inadequate riboflavin intake than adults living in a city. Adults with low income, low education, and living in the north or in a village had a higher prevalence of inadequate niacin intake than adults with a high income, high education, and living in the south or in a city.Conclusion We found that income, region, and area of residence were associated with riboflavin intake. Education, income, region, and area of residence were associated with niacin intake. Welltailored strategies and policies are needed to improve nutritional status in China.展开更多
AIM: To evaluate the protective effects of lipoic acid-niacin(N2 L) dimers against blue light(BL)-induced oxidative damage to human retinal pigment epithelium(hRPE) cells in vitro.METHODS: h RPE cells were divided int...AIM: To evaluate the protective effects of lipoic acid-niacin(N2 L) dimers against blue light(BL)-induced oxidative damage to human retinal pigment epithelium(hRPE) cells in vitro.METHODS: h RPE cells were divided into a control group(CG), a BL group, an N2 L plus BL irradiation group, an α-lipoic acid(ALA) plus BL group, an ALA-only group, and an N2 L-only group. hRPE cellular viability was detected by performing 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium(MTT) bromide assays, and apoptosis was evaluated by annexin-V-PE/7-AAD staining followed by flow cytometry. Ultrastructural changes in subcellular organelles were observed by transmission electron microscopy. Reactive oxygen species formation was assayed by flow cytometry. The expression levels of the apoptosis-related proteins BCL-2 associated X protein(BAX), B-cell leukmia/lymphoma 2(BCL-2), and caspase-3 were quantified by Western blot analysis.RESULTS: BL exposure with a light density of 4±0.5 mW/cm2 exceeding 6 h caused hRPE toxicity, whereas treatment with a high dose of N2 L(100 mol/L) or ALA(150 mol/L) maintained cell viability at control levels. BL exposure caused vacuole-like degeneration, mitochondrial swelling, and reduced microvillus formation;however, a high dose of N2 L or ALA maintained the ultrastructure of hRPE cells and their organelles. High doses of N2 L and ALA also protected hRPE cells from BL-induced apoptosis, which was confirmed by Western blot analysis: BCL-2 expression significantly increased, while BAX and caspase-3 expression slightly decreased compared to the CG.CONCLUSION: High-dose N2 L treatment(>100 mol/L) can reduce oxidative damage in degenerating hRPE cells exposed to BL with an efficacy similar to ALA.展开更多
Introduction Acne patients are frequently associated with abnormal lipid profile. It may be useful to apply high doseof niacin that regulates the lipid profile along with acne treatment. There is no report about high ...Introduction Acne patients are frequently associated with abnormal lipid profile. It may be useful to apply high doseof niacin that regulates the lipid profile along with acne treatment. There is no report about high dose of niacin in treatment ofacne. Objective To evaluate the therapeutic effect and safety of high-dose niacin in acne vulgaris. Methods Acne patientswere randomly allocated to two treatment groups. Both groups were treated orally with the tablets for 12 weeks; the niacingroup at an increasing dose of niacin tablet: 2000 mg (40 mg/kg/d). The control group (nicotinamide group) at a dose ofnicotinamide tablet: 600 mg (10 mg/kg/d). All patients were asked not to consume certain foods such as milk and alcohol.A high-protein, low-fat and low-glycemic-load diet was recommended in both groups. Results A total of 108 patients werefinished the study. Niacin group: 56 patients; control group: 52 patients. After 12 weeks of treatment, niacin and nicotinamidecaused improvement in acne patients. Percentage Improvement in the niacin group (82.37±7.837) %was significantly higherthan in the nicotinamide group (63.19±10.18)%, P <0.01. The number of successful cases in the niacin group was significantlyhigher than in the nicotinamide group after 12 weeks of treatment, (χ2 = 10.55, P <0.01). Conclusions High dose niacin canreally do it work in treatment of acne vulgaris. The therapeutic effcct of High dose of niacin in treatment of acne vulgaris ismore effective than nicotinamide.展开更多
A simple, sensitive and validated HPTLC method has been developed to determine Niacin and simvastatin simultaneously in synthetic mixture form. Chromatographic separation was achieved on a RP18 plate using a mixture o...A simple, sensitive and validated HPTLC method has been developed to determine Niacin and simvastatin simultaneously in synthetic mixture form. Chromatographic separation was achieved on a RP18 plate using a mixture of Methanol: Water: Acetic acid (60:40:0.1) at a wavelength of 237 nm. Linearity of themethod was found to be in the concentration range of 5000.0-25000.0 μg/ml for niacin and 100.0-500.0 μg/ml for simvastatin with correlation coefficient greater than 0.999. The method can be used for simultaneous determination of Niacin and Simvastatin.展开更多
Neuroinflammation plays a critical role in the pathological process of multiple neurological disorders and pathological pain conditions.GPR109A,a Gi protein-coupled receptor,has emerged as an important therapeutic tar...Neuroinflammation plays a critical role in the pathological process of multiple neurological disorders and pathological pain conditions.GPR109A,a Gi protein-coupled receptor,has emerged as an important therapeutic target for controlling inflammation in various tissues and organs.In this review,we summarized current data about the role of GPR109A in neuroinflammation.Specifically,we focused on the pharmacological features of GPR109A and signaling pathways used by GPR109A to ameliorate neuroinflammation and symptoms in Alzheimer’s disease,Parkinson’s disease,multiple sclerosis,stroke,and pathological pain conditions.展开更多
文摘Background Cholesterol-lowering therapy with statins has been reported to reduce the morbidity and mortality of cardiovascular diseases. This study aimed to investigate the effects of combined application of extended-release niacin and atorvastatin on lipid profile modification and the risks of adverse events in patients with coronary artery disease. Methods Consecutive 108 patients with coronary artery disease and serum total cholesterol (TC) 〉 3.5 mmol/L were randomized into two groups: group A using atorvastatin and group B using extended-release niacin (niacin ER) and atorvastatin. Plasma lipid profile, glucose, and adverse events were assessed at the hospitalization, and 6 and 12 months after treatment. In addition, clinical cardiovascular events were evaluated after 12 months of treatment. Results The levels of TC, low density lipoprotein cholesterol (LDL-C) were significantly decreased (P 〈0.05) in groups A and B, but the levels of high density lipoprotein cholesterol (HDL-C) and ApoA increased by 29.36% and 40.81% respectively after 12 months of treatment in group B (P 〈0.01). The medications were generally well tolerated in the two groups. No significant difference of adverse events was found between the two groups (group A: 3.2% vs group B 5.1%, P 〉0.05). Conclusions Combined use of extended-release niacin with atorvastatin was superior to atorvastatin monotherapy alone in lipid profile regulation. Combination therapy with niacin ER and atorvastatin was well tolerated and safe in patients with coronary artery disease.
文摘The objective of this study is to develop chitosaneanionic polymers based extendedrelease tablets and test the feasibility of using this system for the sustained release of highly water-soluble drugs with high drug loading.Here,the combination of sodium valproate(VPS)and valproic acid(VPA)were chosen as the model drugs.Anionic polymers studied include xanthan gum(XG),carrageenan(CG),sodium carboxymethyl cellulose(CMC-Na)and sodium alginate(SA).The tablets were prepared by wet granulation method.In vitro drug release was carried out under simulated gastrointestinal condition.Drug release mechanism was studied.Compared with single polymers,chitosaneanionic polymers based system caused a further slowdown of drug release rate.Among them,CS exanthan gum matrix system exhibited the best extended-release behavior and could extend drug release for up to 24 h.Differential scanning calorimetry(DSC)and Fourier transform infrared spectroscopy(FTIR)studies demonstrated that polyelectrolyte complexes(PECs)were formed on the tablet surface,which played an important role on retarding erosion and swelling of the matrix in the later stage.In conclusion,this study demonstrated that it is possible to develop highly water-soluble drugs loaded extendedrelease tablets using chitosaneanionic polymers based system.
文摘The purpose of this study was to develop an extended-release(ER) matrix tablet that shows robust dissolution properties able to account for the variability of pH and mechanical stress in the GI tract using a combination of enteric polymer and hydrophilic polymer. Hypromellose acetate succinate(HPMCAS) and hydroxypropylcellulose(HPC) were selected as ER polymers for the ER matrix tablet(HPMCAS/HPC ER matrix tablet). Oxycodone hydrochloride was employed as a model drug. Dissolution properties of the HPMCAS/HPC ER matrix tablets were evaluated and were not affected by the pH of the test medium or paddle rotating speed.In a USP apparatus 3(bio-relevant dissolution method), dissolution profiles of the HPMCAS/HPC ER matrix tablets containing oxycodone hydrochloride were similar to that of the reference product(OxyC ontin). Moreover, in vivo performance after oral administration of the HPMCAS/HPC ER matrix tablets to humans was simulated by GastroP lus based on dissolution profiles from the USP apparatus 3. The plasma concentration-time profile simulated was similar to that of the reference product. These results suggest that the combination of HPMCAS and HPC shows a robust dissolution profile against pH and paddle rotating speed and indicates the appropriate extended-release profile in humans.
文摘A procedure to evaluate the quality consistency of generic drugs based on the impurity profile and the similarity analysis methods was presented in this paper. Nifedipine extended-release tablets from six generic factories of China were used to evaluate the uniformity with the original drug in the study. The procedure includes: choice of chromatographic methods, data collection and conformity test, evaluation of intra-batch similarity of drugs, evaluation of generic drugs with the original drug and weighted similarity evaluation of generic drugs. The data were collected via high-performance liquid chromatography (HPLC), and then calculated by correlation coefficient, cosine, principal component analysis (PCA) and hierarchical clustering analysis (HCA). It is more suitable to use peak areas as the vector when calculating the similarity of impurity profile. After weighting the peak areas of the unspecified impurities in further evaluation of the generic quality, the generic level of different factories was differentiated and the best generic factory was picked out.
基金supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Korean Ministry of Education,Science and Technology(NRF-2012R1A1A1013210)by a grant of the Korean Health Technology R&D Project,Ministry of Health,Welfare&Family Affairs,Republic of Korea(A092018).
文摘The aim of this study was to design and evaluate extended-release formulations of a model drug,nicorandil,in order to achieve the desired steady-state plasma concentration of drug in vivo.Simulation was employed to estimate optimum dissolution and absorption rate of nicorandil.The dissolution test was employed using pH 1.2,4.0,6.8 buffer solution,or water,to measure the in vitro release behaviors of nicorandil formulations.A single dose(15 mg)of each formulation was orally administered to four beagle dogs under fasted conditions,and the pharmacokinetic parameters were calculated.The in vitro/in vivo relationship of the extended-release formulation was confirmed using in vitro dissolution profiles and plasma concentrations of drug in beagle dogs.Nicorandil was released completely within 30 min from the immediate-release tablets and released for 24 h from the extended-release tablets.The nicorandil plasma concentration could be modified by adjusting the drug release rate from the extended-release formulation.The release rate of nicorandil was the rate-limiting step in the overall absorption of drug from the extendedrelease formulations.These results highlight the potential of a nicorandil extended-release formulation in the treatment of angina pectoris.
文摘Background: Drug adherence decreased in patients with Parkinson’ s disease (PD) because of taking many different types of drugs. We evaluated drug adherence after switching from immediate-release (IR) to once-daily extended-release (ER) pramipexole (PPX) in PD. Methods: This study included 35 PD patients (20 men, 15 women);10 were taking oral PPX alone, and 25 were also using another anti-PD drug. PPX-IR was switched overnight to PPX-ER without gradual tapering. One month after switching, improvement in timing adherence and reduction in medication burden were evaluated by a questionnaire using a visual analog scale (VAS) (0: No change;10: Better). Motor function was assessed using part III of the Unified Parkinson’s Disease Rating Scale (UPDRS). Results: The VAS score for improvement in timing adherence was 8.1 ± 0.5 (mean ± standard error), and that for reduction in medication burden was 7.3 ± 0.6. There was a significant negative correlation (ρ = -0.43, p = 0.01) between the VAS score and number of types of medications. The UPDRS part III score improved significantly after switching
文摘Niacin or nicotinic acid is a form of B3 vitamin prescribed at higher concentrations for the suppression of cholesterol levels. Supplemental doses may cause very little or no side effects. However, higher concentrations of niacin cause hot flushes for most people. Here we propose a biochemical mechanism of niacin induced hot flushes. Orally taken prescription doses of niacin are converted to NAD with the liberation of excess pyrophosphate which in turn releases energy in the form of heat (hot flushes through capsaicin receptor) by the action of pyrophosphatases. The excess pyrophosphate may suppress cholesterol biosynthesis through feedback mechanism. The pathways of NAD and cholesterol biosynthesis were discussed with refence to the production and function of pyrophosphate.
基金Supported by National Natural Science Foundation of China, No. 30570665the Foundation of Dalian Technology Bureau, No. 2008E13SF182the Foundation of Key Laboratory of Education Department of Liaoning Province, No. 2009S005
文摘AIM: To investigate nicotinamide’s action on glucose metabolism, and the association between niacin consumption and obesity prevalence. METHODS: Dynamic nicotinamide’s effect on plasma hydrogen peroxide and glucose metabolism was in- vestigated using oral glucose tolerance tests with or without nicotinamide in the same five healthy subjects.Lag-regression analysis was used to examine the association between the niacin consumption and the obesity prevalence among US children using the data from the Economic Research Service of the US Department of Agriculture and from US Centers for Disease Control and Prevention, respectively. RESULTS: Compared with the control oral glucose tolerance test, the 1-h plasma hydrogen peroxide (1.4 ± 0.1 μmol/L vs 1.6 ± 0.1 μmol/L, P = 0.016) and insulin levels (247.1 ± 129.0 pmol/L vs 452.6 ± 181.8 pmol/L, P = 0.028) were signif icantly higher, and the 3-h blood glucose was signif icantly lower (5.8 ± 1.2 mmol/L vs 4.5 ± 1.1 mmol/L, P = 0.002) after coadministration of glucose and 300 mg nicotinamide. The obesity prevalence among American children increased with the increasing per capita niacin consumption, the increasing grain contribution to niacin due to niacin-fortification, and the increasing niacin-fortified ready-to-eat cereal consumption, with a 10-year lag. The regression analyses showed that the obesity prevalence in the US children of all age groups was determined by niacin consumption (R2 = 0.814, 0.961 and 0.94 for 2-5 years, 6-11 years and 12-19 years age groups, respectively). CONCLUSION: The appetite-stimulating effect of nicotinamide appears to involve oxidative stress. Excess niacin consumption may be a major factor in the increased obesity prevalence in US children.
文摘Neural degeneration is a very complicated process. In spite of all the advancements in the molecular chemistry, there are many unknown aspects of the phenomena of neurodegeneration which need to be put together. It is a common sequela of the conditions of niacin deficiency. Neural degeneration in Pellagra manifests as chromatolysis mainly in pyramidal followed by other neurons and glial cells. However, there is a gross lack of understanding of biochemi- cal mechanisms of neurodegeneration in niacin deficiency states. Because of the necessity of niacin or its amide derivative NAD in a number of biochemical pathways, it is understandable that several of these pathways may be involved in the common outcome of neural degener- ation. Here, we highlight five pathways that could be involved in the neuraldegeneration for which evidence has accumulated through several studies. These pathways are: 1) the trypto- phan-kyneurenic acid pathway, 2) the mitochondrial ATP generation related pathways, 3) the poly (ADP-ibose) polymerase (PARP) pathway, 4) the BDNF-TRKB Axis abnormalities, 5) the genetic influences of niacin deficiency.
基金Supported by the National High Technology Research and De-velopment Programof China (863 Program) (2002AA601150) China Postdoc-toral Science Foundation (2003034137) .
文摘Textile wastewater is well known as one of the wastewaters to be most difficultly treated. The effects of niacin on textile wastewater treatment efficiency were studied by continuous addition of 1.0 mg·L^-1 niacin, the physical and chemical indexes of the water samples, such as COD, ammonia and dehydrogenase activities, were analyzed every day with standard methods, and obvious improvement in wastewater treatment performance was achieved. The exact results showed that:① Niacin could improve the COD removal efficiency signifcantly with removal rates being 1.31 times as to those of the control system; ② under this experimental condition, addition of niacin had almost no effect on the removal of ammonia;③ Addition of niacin could improve the activity of dehydrogenase by 130 %. It proved that the biological treatment performance of textile wastewater treatment system probably could be optimized through micronutrient niacin supplement.
基金The National Institute for Nutrition and Health,China Center for Disease Control and Prevention,Carolina Population Center[P2C HD050924,T32 HD007168]the University of North Carolina at Chapel Hill,the NIH[R01-HD30880,DK056350,R24 HD050924,and R01-HD38700]+3 种基金the NIH Fogarty International Center[D43 TW009077,D43 TW007709]the China-Japan Friendship Hospitalthe Chinese Ministry of HealthBeijing Municipal Center for Disease Prevention and Control and Chinese Nutrition Society(CNS)Nutrition Research Foundation-DSM Research Fund[No.CNS2015075B].
文摘Objective To estimate the association between three B-vitamin intakes and sociodemographic factors among adults in China.Methods We derived our data from the China Health and Nutrition Survey(CHNS) among 12,241 individuals aged 18–64 years. Log binomial regression was used to estimate adjusted prevalence ratios for factors associated with the inadequate intake of B-vitamins.Results Females with low incomes and living in the north had a higher prevalence of inadequate riboflavin intake than those with high incomes and living in the south. Both males and females living in a village had a higher prevalence of inadequate riboflavin intake than adults living in a city. Adults with low income, low education, and living in the north or in a village had a higher prevalence of inadequate niacin intake than adults with a high income, high education, and living in the south or in a city.Conclusion We found that income, region, and area of residence were associated with riboflavin intake. Education, income, region, and area of residence were associated with niacin intake. Welltailored strategies and policies are needed to improve nutritional status in China.
基金Supported by the Guangzhou Science and Technology Foundation of Guangdong Province (No.2014J4100035 No.2014KP000071)
文摘AIM: To evaluate the protective effects of lipoic acid-niacin(N2 L) dimers against blue light(BL)-induced oxidative damage to human retinal pigment epithelium(hRPE) cells in vitro.METHODS: h RPE cells were divided into a control group(CG), a BL group, an N2 L plus BL irradiation group, an α-lipoic acid(ALA) plus BL group, an ALA-only group, and an N2 L-only group. hRPE cellular viability was detected by performing 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium(MTT) bromide assays, and apoptosis was evaluated by annexin-V-PE/7-AAD staining followed by flow cytometry. Ultrastructural changes in subcellular organelles were observed by transmission electron microscopy. Reactive oxygen species formation was assayed by flow cytometry. The expression levels of the apoptosis-related proteins BCL-2 associated X protein(BAX), B-cell leukmia/lymphoma 2(BCL-2), and caspase-3 were quantified by Western blot analysis.RESULTS: BL exposure with a light density of 4±0.5 mW/cm2 exceeding 6 h caused hRPE toxicity, whereas treatment with a high dose of N2 L(100 mol/L) or ALA(150 mol/L) maintained cell viability at control levels. BL exposure caused vacuole-like degeneration, mitochondrial swelling, and reduced microvillus formation;however, a high dose of N2 L or ALA maintained the ultrastructure of hRPE cells and their organelles. High doses of N2 L and ALA also protected hRPE cells from BL-induced apoptosis, which was confirmed by Western blot analysis: BCL-2 expression significantly increased, while BAX and caspase-3 expression slightly decreased compared to the CG.CONCLUSION: High-dose N2 L treatment(>100 mol/L) can reduce oxidative damage in degenerating hRPE cells exposed to BL with an efficacy similar to ALA.
文摘Introduction Acne patients are frequently associated with abnormal lipid profile. It may be useful to apply high doseof niacin that regulates the lipid profile along with acne treatment. There is no report about high dose of niacin in treatment ofacne. Objective To evaluate the therapeutic effect and safety of high-dose niacin in acne vulgaris. Methods Acne patientswere randomly allocated to two treatment groups. Both groups were treated orally with the tablets for 12 weeks; the niacingroup at an increasing dose of niacin tablet: 2000 mg (40 mg/kg/d). The control group (nicotinamide group) at a dose ofnicotinamide tablet: 600 mg (10 mg/kg/d). All patients were asked not to consume certain foods such as milk and alcohol.A high-protein, low-fat and low-glycemic-load diet was recommended in both groups. Results A total of 108 patients werefinished the study. Niacin group: 56 patients; control group: 52 patients. After 12 weeks of treatment, niacin and nicotinamidecaused improvement in acne patients. Percentage Improvement in the niacin group (82.37±7.837) %was significantly higherthan in the nicotinamide group (63.19±10.18)%, P <0.01. The number of successful cases in the niacin group was significantlyhigher than in the nicotinamide group after 12 weeks of treatment, (χ2 = 10.55, P <0.01). Conclusions High dose niacin canreally do it work in treatment of acne vulgaris. The therapeutic effcct of High dose of niacin in treatment of acne vulgaris ismore effective than nicotinamide.
文摘A simple, sensitive and validated HPTLC method has been developed to determine Niacin and simvastatin simultaneously in synthetic mixture form. Chromatographic separation was achieved on a RP18 plate using a mixture of Methanol: Water: Acetic acid (60:40:0.1) at a wavelength of 237 nm. Linearity of themethod was found to be in the concentration range of 5000.0-25000.0 μg/ml for niacin and 100.0-500.0 μg/ml for simvastatin with correlation coefficient greater than 0.999. The method can be used for simultaneous determination of Niacin and Simvastatin.
文摘Neuroinflammation plays a critical role in the pathological process of multiple neurological disorders and pathological pain conditions.GPR109A,a Gi protein-coupled receptor,has emerged as an important therapeutic target for controlling inflammation in various tissues and organs.In this review,we summarized current data about the role of GPR109A in neuroinflammation.Specifically,we focused on the pharmacological features of GPR109A and signaling pathways used by GPR109A to ameliorate neuroinflammation and symptoms in Alzheimer’s disease,Parkinson’s disease,multiple sclerosis,stroke,and pathological pain conditions.