Exogenous niacin treatment increases NADPH oxidase in kiwifruit / O tratamento com niacina exógena NADPH oxidase em kiwis

Abstract Kiwifruit are a popular fruit worldwide; however, plant growth is threatened by abiotic stresses such as drought and high temperatures. Niacin treatment in plants has been shown to increase NADPH levels, thus enhancing abiotic stresses tolerance. Here, we evaluate the effect of niacin solution spray treatment on NADPH levels in the kiwifruit cultivars Hayward and Xuxiang. We found that spray treatment with niacin solution promoted NADPH and NADP+ levels and decreased both O2·- production and H2O2 contents in leaves during a short period. In fruit, NADPH contents increased during early development, but decreased later. However, no effect on NADP+ levels has been observed throughout fruit development. In summary, this report suggests that niacin may be used to increase NADPH oxidases, thus increasing stress-tolerance in kiwifruit during encounter of short-term stressful conditions.

Resumo Kiwis são uma fruta popular em todo o mundo; No entanto, o crescimento das plantas é ameaçado por estresses abióticos como a seca e as altas temperaturas. O tratamento com niacina em plantas mostrou aumentar os níveis de NADPH, aumentando assim a tolerância a stress abiótico. Aqui, avaliamos o efeito do tratamento com spray de solução de niacina sobre os níveis de NADPH nos cultivares de kiwis Hayward e Xuxiang. Descobrimos que o tratamento por spray com solução de niacina promoveu níveis de NADPH e NADP + e diminuiu a produção de O2·- e os teores de H2O2 nas folhas durante um curto período. Nos frutos, os teores de NADPH aumentaram durante o desenvolvimento precoce, mas diminuíram mais tarde. No entanto, não se observou qualquer efeito nos níveis de NADP + ao longo do desenvolvimento do fruto. Em resumo, este relatório sugere que a niacina pode ser utilizada para aumentar NADPH oxidases, aumentando assim a tolerância ao estresse em kiwis durante o encontro de condições estressantes de curto prazo.

El ácido nicotínico aumenta el transporte celular de colesterol de las lipoproteínas de alta densidad en pacientes con hipoalfalipoproteinemia / Nicotinic acid increases cellular transport of high density lipoprotein cholesterol in patients with hypoalphalipoproteinemia

Background: Plasma high density lipoproteins (HDL) are involved in reverse cholesterol transport mediated by the scavenger receptor class B type I (SR-BI). Nicotinic acid increases HDL cholesterol levels, even though its specific impact on SR-BI dependent-cellular cholesterol transport remains unknown. Aim: To determine the effect of nicotinic acid on HDL particle functionality in cholesterol efflux and uptake mediated by SR-BI in cultured cells in hypoalphalipoproteinemic patients. Material and Methods: In a pilot study, eight patients with low HDL (≤ 40 mg/dL) were treated with extended release nicotinic acid. HDL cholesterol and phospholipid levels, HDL2 and HDL3 fractions and HDL particle sizes were measured at baseline and post-therapy. Before and after nicotinic acid treatment, HDL particles were used for cholesterol transport studies in cells transfected with SR-BI. Results: Nicotinic acid treatment raised total HDL cholesterol and phospholipids, HDL2 levels as well as HDL particle size. Nicotinic acid significantly increased HDL cholesterol efflux and uptake capacity mediated by SR-BI in cultured cells. Conclusions: Nicotinic acid therapy increases SR-BI-dependent HDL cholesterol transport in cultured cells, establishing a new cellular mechanism by which this lipid-lowering drug appears to modulate HDL metabolism in patients with hypoalphalipoproteinemia.

Dislipidemias: ¿qué hay de nuevo? / Dyslipidemia: what's new?

En los últimos años han surgido algunas investigaciones y guías de práctica clínica relacionadas con el diagnóstico y tratamiento de las dislipidemias, que aportaron nuevos conocimientos (y controversias) sobre dicha problemática. En este resumen se describen, en primer lugar, las características de las "nuevas guías" norteamericanas para el manejo del colesterol publicadas a fines de 2013 y se comparan con las recomendaciones tradicionales. En segundo lugar, se analizan los últimos estudios que evaluaron el impacto cardiovascular de otros fármacos hipolipemiantes (ezetimibe y ácido nicotínico) en pacientes en prevención secundaria tratados con estatinas. Finalmente, se mencionan las nuevas drogas hipolipemiantes desarrolladas en los últimos años, como el lomitapide, el mipomersen y los inhibidores de la PCSK9, y se comentan el mecanismo de acción, su eficacia, sus efectos colaterales y los escenarios clínicos en donde podrían utilizarse. (AU)

In recent years, some research and clinical practice guidelines related to the diagnosis and treatment of dyslipidemia, which provided new knowledge (and controversy) about this problem have emerged. In this review, the characteristics of the American "new guidelines" for cholesterol management published by the end of 2013 are described, and they are compared with the traditional recommendations. In addition, recent studies assessing the cardiovascular impact of other lipid-lowering drugs (ezetimibe and nicotinic acid) in patients in secondary prevention treated with statins are analyzed. Finally, new hypolipidemic drugs developed in recent years are mentioned (lomitapide, mipomersen and PCSK9 inhibitors), discussing the mechanism of action, efficacy, side effects and clinical settings where they could be used. (AU)

[Effects of combination of vitamin E and nicotinic acid on serum lipids and apoproteins of hypertriglyceridemic hemodialyzed patients]

Oxidative stress and lipid abnormalities are two major risk factors for development of atherosclerosis among hemodialyzed patients. Administrating of Lipidnormalising agents, solely or in combination together, can not correct all lipid abnormalities in hemodialyzed patients. The present study, therefore, was desinged to evaluate the effects of combination therapy of vitamin E and tolerable doses of nicotinic acid on serum lipids and apoproteins in hypertriglyceridemic hemodialyzed patients. The study was a double-blind randomized clinical trial. Thirty-nine hemodialyzed patients with fasting triglyceride range between 230 and 500 mg/dl were randomly assigned into three groups, receiving combination of vitamin E [600mg/d] and nicotinic acid [500mg/d], nicotinic acid alone [500mg/d], and placebo, respectively. All patients received their supplements for 13 weeks. The blood samples were collected after a 12 to 14-hour duration of fasting at the beginning of the study, followed by other samplings performed at the end of sixth and thirteenth weeks, respectively, and serum lipids and apoproteins were measured. accordingly. During the study, the mean serum triglyceride level was significantly reduced in the group receiving combination therapy of vitamin E and nicotinic acid, compared to the placebo group. Compared to that of placebo group, mean serum HDL-C levels were significantly increased two groups of combination therapy, and nicotinic acid alone, although LDL-C/HDL-C ratios were significantly decreased. There was no significant difference in the means of total cholesterol of serum, LDL-C, apoAI, apoB100 and Lp[a] between three groups. It is concluded that combination therapy of vitamin E and nicotinic acid in hypertriglyceridemic hemodialyzed patients can result in improvement in almost every lipid abnormalities, but except high levels of Lp[a]

Ionization potentials and electron affinities of nicotinic acid and nicotinamide calculated with HAM/3

Ionization potentials and electron affinities of nicotinic acid and nicotinamide were calculated by HAM/3. Observed photoelectron spectra of the molecules were analyzed with the aid of the calculated ionization potentials. Chemical reactivity of the molecules was discussed.