Short-Term Bixin Supplementation of Healthy Subjects Decreases the Susceptibility of LDL to Cu2+-Induced Oxidation Ex Vivo.

Lisiane Conte,Miguel Roehrs,Silvino Sasso Robalo,Cristine Rampelotto,Tatiana Emanuelli,Sabrina Marafiga Nichelle,Sabrina Somacal

doi:10.1155/2019/9407069

Abstract

Lycopene-based medications and supplements have been developed to prevent atherosclerosis, primarily because of their ability to decrease low-density lipoprotein (LDL) oxidation. Bixin and norbixin are carotenoids found in the seeds of annatto (Bixa orellana) and are colorants widely used by the food industry. Some studies have already demonstrated that these compounds have antioxidant and antiatherogenic potential in vitro and in animal models, but there is no evidence supporting the effects of their long-term or short-term consumption by humans. The aim of this study was to evaluate the effects of short-term intake of annatto carotenoids on biochemical and oxidative stress biomarkers as well as on the susceptibility of LDL oxidation in healthy individuals, using lycopene as a positive control. The effect of daily supplementation (0.05 mg/kg of body weight (b.w.)) with bixin, norbixin, lycopene, or placebo for 7 days was evaluated in a randomized, controlled crossover study in 16 healthy volunteers (8 men and 8 women). The susceptibility of LDL to Cu2+-induced oxidation ex vivo, biochemical parameters, and oxidative stress biomarkers were evaluated. No treatment affected biochemical parameters or most oxidative stress biomarkers. However, bixin reduced the oxidation rate of the LDL lipid moiety (−275%, p < 0.1) and nitric oxide metabolites (NOx) (−460%, p < 0.1), compared to the placebo group. Moreover, we observed that the changes in these parameters were positively associated, supporting the hypothesis that bixin decreases the susceptibility of LDL to Cu2+-induced oxidation by decreasing NOx levels, probably by downregulating the inducible nitric oxide synthase.

Highlights

Lisiane Conte,1,2 Sabrina Somacal,2 Sabrina Marafiga Nichelle,2 Cristine Rampelotto,2 Silvino Sasso Robalo,3 Miguel Roehrs,2 and Tatiana Emanuelli 1,2
We investigated the effects of shortterm bixin and norbixin supplementation on biochemical parameters, oxidative stress biomarkers, and low-density lipoprotein (LDL) susceptibility to oxidation ex vivo in healthy subjects. e effects were compared to lycopene supplementation as a positive standard as this carotenoid is considered to have cardiovascular benefits
Undergraduate and graduate students aged between 18 and 35 years, with blood pressure, anthropometric measurements, and biochemical parameters within normal values, were recruited from Federal University of Santa Maria and gave their written consent to participate in the study (Figure 1). e study was conducted according to Declaration of Helsinki, and the study protocol was approved by the local ethics committee (CAAE number: 68801917.0.0000.5346)

Summary

Introduction

Lisiane Conte ,1,2 Sabrina Somacal ,2 Sabrina Marafiga Nichelle, Cristine Rampelotto, Silvino Sasso Robalo, Miguel Roehrs ,2 and Tatiana Emanuelli 1,2. E aim of this study was to evaluate the effects of short-term intake of annatto carotenoids on biochemical and oxidative stress biomarkers as well as on the susceptibility of LDL oxidation in healthy individuals, using lycopene as a positive control. Due to its highly reactive nature, ONOO- triggers lipid and LDL oxidation [5] beyond promoting oxidative changes in proteins and nucleic acids [6] Beyond their role in oxidative stress damaging mechanisms, some oxidative biomarkers, such as advanced oxidation protein products (AOPP), are markers of protein oxidative damage, which can be produced after the modification of plasma albumin and has been shown to be implicated in the pathogenesis of atherosclerosis [7] by the amplification of proinflammatory pathways [8]. Nonenzymatic defenses comprising endogenous small molecules, such as uric acid, glutathione, and coenzyme Q, and dietary antioxidants (vitamins, polyphenols, and carotenoids) help to keep the homeostasis between the synthesis and removal of reactive species (RS) [6]

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Results

Conclusion