Investigating the Antioxidant Characteristics of Saccharina Latissima and Its Ability to Reduce Inflammation in RAW 264.7 Cells (P06-091-19)

Abstract

ObjectivesThe goal of this study is to understand the anti-inflammatory characteristics of Saccharina latissima (sugar kelp). Sugar kelp is a brown macroalga that grows readily off the coast of Maine. Other seaweeds are known to contain bioactive chemicals that reduce inflammation—a contributing factor to metabolic syndrome and type 2 diabetes. It is hypothesized that injuring farmed sugar kelp by trimming the kelp may increase the beneficial bioactives and promote anti-inflammatory effects. The specific aims are (1) to produce extracts of Maine-grown sugar kelp through accelerated solvent extraction (ASE), (2) to measure the samples’ antioxidant capacity, and (3) to investigate the samples’ anti-inflammatory effect in vitro. MethodsSugar kelp samples were freeze-dried and extracts were produced using ASE. Total phenolic content was measured using the Folin-Ciocalteau assay, and radical scavenging capacity was measured with a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The sugar kelp extracts were tested for cytotoxicity in RAW 264.7 macrophages using a 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Lipopolysaccharide (LPS) was used to induce inflammation in the cells, and the attenuation effect of extract doses ranging from 12.5–50 μg total phenolics (TP)/mL was observed by measuring nitric oxide (NO) secretion with the Griess assay. ResultsPreliminary data shows that sugar kelp contains polyphenols (8.4–16.0 mg gallic acid equivalent/g dried biomass) and radical scavenging capacity (IC50 = 61.8–79.5 μg/mL). The data did not demonstrate the trimming the kelp has a beneficial effect to increase phenolic compounds. The polyphenolic contents of the trimmed samples were lower than the untrimmed (9.5 vs. 13.1 mg gallic acid equivalent/g dried biomass). The radical scavenging capacity decreased when the samples were trimmed (14.7%). The greatest decrease in NO production was at a concentration of 50 μg TP/mL for a trimmed sample (up to 78.5%), which supports the hypothesis. ConclusionsThis data suggests that sugar kelp may be a good source of antioxidants and trimmed samples may contain additional bioactives to help decrease inflammation. Further investigation is needed to confirm the hypothesis. Funding SourcesThe University of MaineThe University of New England