Evaluation of sulfated polysaccharides from the brown seaweed Dictyopteris justii as antioxidant agents and as inhibitors of the formation of calcium oxalate crystals.

Karoline Teodosio Melo,Rafael Gomes Camara,Hugo Oliveira Rocha,Moacir Queiroz,Jailma Almeida-Lima,Camila Machado Lima,Arthur Jacome Vidal,Raniere Melo-Silveira

doi:10.3390/molecules181214543

Karoline Teodosio Melo, Rafael Gomes Camara + Show 6 more

Open Access

https://doi.org/10.3390/molecules181214543

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Abstract

Oxalate crystals and other types of crystals are the cause of urolithiasis, and these are related to oxidative stress. The search for new compounds with antioxidant qualities and inhibitors of these crystal formations is therefore necessary. In this study, we extracted four sulfated polysaccharides, a fucoglucoxyloglucuronan (DJ-0.3v), a heterofucan (DJ-0.4v), and two glucans (DJ-0.5v and DJ-1.2v), from the marine alga Dictyopteris justii. The presence of sulfated polysaccharides was confirmed by chemical analysis and FT-IR. All the sulfated polysaccharides presented antioxidant activity under different conditions in some of the in vitro tests and inhibited the formation of calcium oxalate crystals. Fucan DJ-0.4v was the polysaccharide that showed the best antioxidant activity and was one of the best inhibitors of the crystallization of calcium oxalate. Glucan DJ-0.5v was the second most potent inhibitor of the formation of oxalate crystals, as it stabilized dehydrated oxalate crystals (less aggressive form), preventing them from transforming into monohydrate crystals (more aggressive form). The obtained data lead us to propose that these sulfated polysaccharides are promising agents for use in the treatment of urolithiasis.

Highlights

The marine environment provides endless supplies of compounds that offer human health benefits such as fatty acids, minerals, vitamins, and bioactive peptides [1,2]
Sulfated polysaccharides (SPs) of D. justii were solubilized in the presence of proteolytic enzymes, which degraded the contaminating proteins
They were separated into four fractions with the use of differential precipitation with acetone. These fractions were termed DJ-0.3v, DJ-0.4v, DJ-0.5v, and DJ-1.2v, and subjected to the analyses described below

Summary

Introduction

The marine environment provides endless supplies of compounds that offer human health benefits such as fatty acids, minerals, vitamins, and bioactive peptides [1,2]. When thinking of important activities for the food industry, cosmetics, and medicines, one of the algal compounds that stand out are the sulfated polysaccharides [4]. L-fucose (sulfated homo- and heterofucans) [5], yet other sulfated heteropolysaccharides have been found in these algae too. These polysaccharides have been described as having various activities such as antithrombotic [6], antinociceptive [7], anti-inflammatory [8], antiviral, antitumor [9], and antioxidant properties [10]. The substances discovered up to now which act as antioxidants, usually have only one or some of those characteristics [11]

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Conclusion