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
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
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
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
Biomimetic nanocarriers are emerging as efficient vehicles to facilitate dietary absorption of biomacromolecules. In this study, two vitamins, thiamine and niacin, are employed to decorate liposomes loaded with insuli...Biomimetic nanocarriers are emerging as efficient vehicles to facilitate dietary absorption of biomacromolecules. In this study, two vitamins, thiamine and niacin, are employed to decorate liposomes loaded with insulin, thus facilitating oral absorption via vitamin ligand–receptor interactions. Both vitamins are conjugated with stearamine, which works to anchor the ligands to the surface of liposomes.Liposomes prepared under optimum conditions have a mean particle size of 125–150 nm and an insulin entrapment efficiency of approximately 30%–36%. Encapsulation into liposomes helps to stabilize insulin due to improved resistance against enzymatic disruption, with 60% and 80% of the insulin left after 4 h when incubated in simulated gastric and intestinal fluids, respectively, whereas non-encapsulated insulin is broken down completely at 0.5 h. Preservation of insulin bioactivity against preparative stresses is validated by intra-peritoneal injection of insulin after release from various liposomes using the surfactant Triton X-100. In a diabetic rat model chemically induced by streptozotocin, both thiamine-and niacindecorated liposomes showed a comparable and sustained mild hypoglycemic effect. The superiority of decorated liposomes over conventional liposomes highlights the contribution of vitamin ligands. It is concluded that decoration of liposomes with thiamine or niacin facilitates interactions with gastrointestinal vitamin receptors and thereby facilitates oral absorption of insulin-loaded liposomes.展开更多
To understand the effects of niacin on the ruminal microbial ecology of cattle under high-concentrate diet condition, Illumina MiSeq sequencing technology was used. Three cattle with rumen cannula were used in a 3 x 3...To understand the effects of niacin on the ruminal microbial ecology of cattle under high-concentrate diet condition, Illumina MiSeq sequencing technology was used. Three cattle with rumen cannula were used in a 3 x 3 Latin-square design trial. Three diets were fed to these cattle during 3 periods for 3 days, respectively: high-forage diet(HF; forage-to-concentrate ratio = 80:20), high-concentrate diet(HC;forage-to-concentrate ratio=20:80), and HC supplemented with 800 mg/kg niacin(HCN). Ruminal pH was measured before feeding and every 2 h after initiating feeding. Ruminal fluid was sampled at the end of each period for microbial DNA extraction. Overall, our findings revealed that subacute ruminal acidosis(SARA) was induced and the a-diversity of ruminal bacterial community decreased in the cattle of HC group. Adding niacin in HC could relieve the symptoms of SARA in the cattle but the ruminal pH value and the Shannon index of ruminal bacterial community of HCN group were still lower than those of HF group. Whatever the diet was, the ruminal bacterial community of cattle was dominated by Bacteroidetes,Firmicutes and Proteobacteria. High-concentrate diet significantly increased the abundance of Prevotella,and decreased the abundance of Paraprevotella, Sporobacter, Ruminococcus and Treponema than HF.Compared with HC, HCN had a trend to decrease the percentage of Prevotella, and to increase the abundance of Succiniclasticum, Acetivibrio and Treponema. Increasing concentrate ratio could decrease ruminal pH value, and change the ruminal microbial composition. Adding niacin in HC could increase the ruminal pH value, alter the ruminal microbial composition.展开更多
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
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 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.
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.
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.
基金financially supported by Shanghai Commission of Science and Technology (15ZR1403000)National Natural Science Foundation of China (81573363, 81690263, and 21372063)
文摘Biomimetic nanocarriers are emerging as efficient vehicles to facilitate dietary absorption of biomacromolecules. In this study, two vitamins, thiamine and niacin, are employed to decorate liposomes loaded with insulin, thus facilitating oral absorption via vitamin ligand–receptor interactions. Both vitamins are conjugated with stearamine, which works to anchor the ligands to the surface of liposomes.Liposomes prepared under optimum conditions have a mean particle size of 125–150 nm and an insulin entrapment efficiency of approximately 30%–36%. Encapsulation into liposomes helps to stabilize insulin due to improved resistance against enzymatic disruption, with 60% and 80% of the insulin left after 4 h when incubated in simulated gastric and intestinal fluids, respectively, whereas non-encapsulated insulin is broken down completely at 0.5 h. Preservation of insulin bioactivity against preparative stresses is validated by intra-peritoneal injection of insulin after release from various liposomes using the surfactant Triton X-100. In a diabetic rat model chemically induced by streptozotocin, both thiamine-and niacindecorated liposomes showed a comparable and sustained mild hypoglycemic effect. The superiority of decorated liposomes over conventional liposomes highlights the contribution of vitamin ligands. It is concluded that decoration of liposomes with thiamine or niacin facilitates interactions with gastrointestinal vitamin receptors and thereby facilitates oral absorption of insulin-loaded liposomes.
基金supported by grants from National Natural Science Foundation of China(31260561,31560648)Special Fund for Agro-scientific Research in the Public Interest(201303143)
文摘To understand the effects of niacin on the ruminal microbial ecology of cattle under high-concentrate diet condition, Illumina MiSeq sequencing technology was used. Three cattle with rumen cannula were used in a 3 x 3 Latin-square design trial. Three diets were fed to these cattle during 3 periods for 3 days, respectively: high-forage diet(HF; forage-to-concentrate ratio = 80:20), high-concentrate diet(HC;forage-to-concentrate ratio=20:80), and HC supplemented with 800 mg/kg niacin(HCN). Ruminal pH was measured before feeding and every 2 h after initiating feeding. Ruminal fluid was sampled at the end of each period for microbial DNA extraction. Overall, our findings revealed that subacute ruminal acidosis(SARA) was induced and the a-diversity of ruminal bacterial community decreased in the cattle of HC group. Adding niacin in HC could relieve the symptoms of SARA in the cattle but the ruminal pH value and the Shannon index of ruminal bacterial community of HCN group were still lower than those of HF group. Whatever the diet was, the ruminal bacterial community of cattle was dominated by Bacteroidetes,Firmicutes and Proteobacteria. High-concentrate diet significantly increased the abundance of Prevotella,and decreased the abundance of Paraprevotella, Sporobacter, Ruminococcus and Treponema than HF.Compared with HC, HCN had a trend to decrease the percentage of Prevotella, and to increase the abundance of Succiniclasticum, Acetivibrio and Treponema. Increasing concentrate ratio could decrease ruminal pH value, and change the ruminal microbial composition. Adding niacin in HC could increase the ruminal pH value, alter the ruminal microbial composition.
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.
