Phlorotannins from Undaria pinnatifida Sporophyll: Extraction, Antioxidant, and Anti-Inflammatory Activities

Abstract

Undaria pinnatifida sporophyll (U. pinnatifida) is a major byproduct of U. pinnatifida (a brown algae) processing. Its phenolic constituents, phlorotannins, are of special interest due to their intrinsic ability to precipitate proteins. Herein, a high-temperature extraction procedure was used to isolate these biologically active compounds. The heating temperature, heating time, and extraction solvent (ethanol) concentration were examined with response surface analysis to determine the optimal conditions to achieve the maximum extraction rate. The analysis revealed the optimal conditions to be: 170 °C of heating temperature, 5.2 h of heating time, and 52% ethanol concentration for a yield of 10.7 ± 0.2 mg gallic acid equivalent/g dry weight (GAE/g DW) of sample. Compared to epigallocatechin gallate (EGCG), the extracted phlorotannins displayed higher antioxidant activity on H2O2-induced RAW 264.7 cells with improved efficiency. Furthermore, the compounds exhibited strong anti-inflammatory activity. These findings potentially can be utilized to guide development of novel functional foods and food supplements from sea-originated resources such as brown algae.

A Biorefinery Approach to the Biomass of the Seaweed Undaria pinnatifida (Harvey Suringar, 1873): Obtaining Phlorotannins-Enriched Extracts for Wound Healing

“…Oddly, higher amounts of extract did not result in higher anti-inflammatory activities (data not shown), which was also verified by Catarino et al [ 57 ] with Fucus vesiculosus phlorotannin-enriched extracts. Contrarily, Dong et al [ 58 ] found that higher doses of U. pinnatifida sporophyll extracts had a higher anti-inflammatory effect. Nonetheless, in this work, extracts show an effective reduction of NO in very low concentrations, showing their potential to be used as an anti-inflammatory.…”

Brown Algae Potential as a Functional Food against Hypercholesterolemia: Review

“…It is also necessary to take into account that post-harvesting storage and processing, such as extraction using different solvents (water, organic solvent, water–organic solvent mixtures) can also affect the composition of the obtained algae extract [ 51 ]. These algae species have been intensively studied not only for their anti-hyperlipidaemic activity [ 52 , 53 ], but also for their anti-tumorigenic [ 54 , 55 ], anti-diabetic [ 56 , 57 ], antiviral [ 58 ], anti-inflammatory [ 59 , 60 ], and antioxidant [ 48 , 60 ] capacities, among others.…”

Preparation, Characterization and Antioxidant Activities of Kelp Phlorotannin Nanoparticles

“…Among these active compounds, polyphenolic phlorotannins, a group of complex molecular assemblages from the polymerization of phloroglucinol [ 2 ], represent a large class of well-characterized brown algae secondary metabolites [ 3 ]. They have been revealed to have a range of diverse biological functions and activities, such as antibacterial [ 4 ], anti-inflammatory [ 5 ], anti-oxidant [ 6 ], antidiabetic [ 7 ], anti-HIV [ 8 ] and anticancer [ 9 , 10 , 11 ] activities. However, phlorotannins are highly sensitive to external factors such as light, pH, heat and oxidative reagents, which limit their applications in food, cosmetic, nutraceutical and pharmaceutical industries [ 12 ].…”