Evaluation of the Marine AlgaUlva rigidaas a Food Supplement: Effect of Intake on Intestinal, Hepatic, and Renal Enzyme Activities in Rats

Abstract

The use of seaweeds as a food is more widespread in Eastern than in Western countries, although demand for these plants has increased in the West because their possible usefulness as dietary supplements. However, very little is known about the effects of regular consumption of algae. The aim of the present study was to determine the composition of Ulva rigida and to evaluate the effects of dietary supplementation of the diet with 10% alga for 4 weeks on dietary intake, growth, protein efficiency ratio, diet conversion ratio, and some organ weights in growing male rats. We also studied the effect of inclusion of the alga in the diet on intestinal, hepatic, and renal enzymatic activities. U. rigida was found to be a good source of protein and carbohydrates. Food intake was higher in the U. rigida group than in the control group, but ingestion of alga did not have any effect on the other trophic parameters. The intestinal disaccharidase and leucine aminopeptidase activities were lower in rats fed with alga than in control rats, but γ-glutamyl transpeptidase activity was higher in the kidneys of alga-fed rats than in control rats. U. rigida contains high amounts of protein, carbohydrates, vitamins, and minerals and low amounts of lipids. Analysis of the amino acid composition revealed good-quality protein. The addition of alga to the diet inhibited disaccharidase activities, which suggested that alga consumption could be useful in some chronic disorders associated with pertubations of glucose homeostasis caused by carbohydrate absorption.

Antioxidant-related parameters, digestive enzyme activity and intestinal morphology in rainbow trout (Oncorhynchus mykiss) fry fed graded levels of red seaweed,Gracilaria pygmaea

“…Protease activity tends to decrease as the level of dietary Gracilaria was increased, being significantly lower in specimens fed GL-120. Similar results have been described by Taboada, Millán, and Míguez (2011) for rat when fed diets supplemented with U. rigida. The decrease in protease activity…”

Growth, tissue metabolites and digestive functionality inSparus auratajuveniles fed different levels of macroalgae,Gracilaria corneaandUlva rigida

“…Overall, the proteolytic activities in specimens fed on Ulva‐ and Gracilaria‐ supplemented diet were lower than those fed on control diet. A similar effect has also been reported in the level of intestinal aminopeptidase in rats fed on a diet supplemented with U. rigida (Taboada, Millan & Miguez ). In fact, the presence of secondary compounds with antinutritive activity in macroalgae has been documented (Rogers & Hori ).…”

Overview on Biological Activities and Molecular Characteristics of Sulfated Polysaccharides from Marine Green Algae in Recent Years

“…Green seaweeds reportedly contain lipid fractions, proteins, peptides, polysaccharide, carotenoids, phenolic compounds, alkaloids, thallus, holdfast, mucilaginous, and whole plants [1,2,3]. Among all these active ingredients, polysaccharides are the components most intensively investigated for medical purposes [4,5]. …”