Effects of drying methods on nitric oxide inhibition potential of water soluble extracts of Turbinaria turbinata: A brown seaweed species of Malaysian origin

Abstract

This study investigates effect of drying method on anti-inflammatory properties and composition of water soluble extracts obtained from brown seaweed, Turbinaria turbinata. T. turbinata was air-oven dried (50°C for 24 h) and freeze dried prior to extraction with water to obtained crude water extract. The crude extracts were partitioned into polyphenol and polysaccharide fractions. Method of drying did not affect the yield of water soluble components. Composition analysis revealed that extracts obtained from freeze dried biomass contain higher total sugar, uronic acid and polyphenol content, except in crude extract where oven dried matter was higher in total sugar and uronic acid content. Anti-inflammatory potential of the extracts was investigated using inhibition of nitric oxide synthesis in RAW 264.7 macrophage cell line. Although, all extracts reduce secretion of Nitric Oxide (NO) differently, percentage NO inhibition between polyphenol fractions of freeze dried and oven dried sample was not significant. Freeze drying retain anti-inflammatory activities of polysaccharide fraction compared to oven drying. Temperature used during oven drying did not cause damage to bioactive compounds in polyphenol fraction of the seaweed. Therefore, either of the two drying methods can be used for dehydration of seaweed but freeze drying is preferred over oven drying when targeting polysaccharide. © 2013 Academic Journals Inc.