Sulfated iota-carrageenan from marine alga Agardhiella ramosissima prevents gastric injury in rodents via its antioxidant properties

In the present study, the gastroprotective effect of a sulfated polysaccharide isolated from marine alga Agardhiella ramosissima (SP-Ar) was investigated against alcoholic gastropathy. Gastric physiological functions and in vitro antioxidant activity also were studied. It was found that SP-Ar significantly reduced macroscopic injury and histologically maintained the architecture of gastric epithelium altered by ethanol, with maximum effect at 90 mg/kg. Importantly, animals treated with SP-Ar also had preservation of oxidative status, with reduction of nonprotein sulfhydryl groups (NP-SH) consumption and malondialdehyde (MDA) production, reduced vascular permeability, besides preventing gastric hemorrhage. In addition, SP-Ar administration did not modify gastric secretion or emptying. In vitro antioxidant data showed that SP-Ar presented high total antioxidant activity, DPPH radical scavenging, and ferrous iron chelating capacity. It was observed that SP-Ar protected gastric mucosa against alcoholic gastropathy by preventing the formation or neutralizing free radicals, associated with its intrinsic antioxidant activity. In this regard, this macromolecule should have possible application as a new therapeutic alternative or food additive to increase gastric mucosa defense.