Fermentation-Derived Bioactive Components from Seaweeds: Functional Properties and Potential Applications

Algae-derived compounds: Bioactivity, allergenicity and technologies enhancing their values

As a rapidly growing source of human nutrients, algae biosynthesize diverse metabolites which have promising bioactivities. However, the potential allergenicity of algal components hinder their widespread adoption. This review provides a comprehensive review of various macro and micronutrients derived from algal biomass, with particular focus on bioactive compounds, including peptides, polyphenols, carotenoids, omega-3 fatty acids and phycocyanins. The approaches used to produce algal bioactive compounds and their health benefits (antioxidant, antidiabetic, cardioprotective, anti-inflammatory and immunomodulatory) are summarised. This review particularly focuses on the state-of-the-art of precision fermentation, encapsulation, cold plasma, high-pressure processing, pulsed electric field, and subcritical water to reduce the allergenicity of algal compounds while increasing their bioactivity and bioavailability. By providing insights into current challenges of algae-derived compounds and opportunities for advancement, this review contributes to the ongoing discourse on maximizing their application potential in the food nutraceuticals, and pharmaceuticals industries.

Anti-Inflammatory Effects of Bioactive Compounds from Seaweeds, Bryozoans, Jellyfish, Shellfish and Peanut Worms

Inflammation is a defense mechanism of the body in response to harmful stimuli such as pathogens, damaged cells, toxic compounds or radiation. However, chronic inflammation plays an important role in the pathogenesis of a variety of diseases. Multiple anti-inflammatory drugs are currently available for the treatment of inflammation, but all exhibit less efficacy. This drives the search for new anti-inflammatory compounds focusing on natural resources. Marine organisms produce a broad spectrum of bioactive compounds with anti-inflammatory activities. Several are considered as lead compounds for development into drugs. Anti-inflammatory compounds have been extracted from algae, corals, seaweeds and other marine organisms. We previously reviewed anti-inflammatory compounds, as well as crude extracts isolated from echinoderms such as sea cucumbers, sea urchins and starfish. In the present review, we evaluate the anti-inflammatory effects of compounds from other marine organisms, including macroalgae (seaweeds), marine angiosperms (seagrasses), medusozoa (jellyfish), bryozoans (moss animals), mollusks (shellfish) and peanut worms. We also present a review of the molecular mechanisms of the anti-inflammatory activity of these compounds. Our objective in this review is to provide an overview of the current state of research on anti-inflammatory compounds from marine sources and the prospects for their translation into novel anti-inflammatory drugs.

Impact of Monascus purpureus fermentation on antioxidant activity, free amino acid profiles and flavor properties of kelp (Saccharina japonica)

This study evaluated the efficacy of Monascus purpureus fermentation on Saccharina japonica (SJ). Healthy substances and antioxidant activity of fermented SJ (FSJ) were determined. Results showed that fermentation caused the release of phenolic compounds and flavonoids, which resulted in the enhancement of antioxidant activity. Essential amino acids and γ-aminobutyric acid also greatly accumulated in FSJ. Sensory evaluation and gas chromatography-ion mobility spectrometry (GC-IMS) were used to evaluate flavor properties of FSJ. A lexicon consisted of 24 descriptors was established for SJ and FSJ, of which 14 descriptors were regarded as odor attributes. A total of 46 volatile compounds were identified by GC-IMS and showed positive correlation with odor attributes. Fifteen volatile compounds were screened as key compounds, tricarboxylic acid cycle, embden-meyerhof-parnas and amino acid catabolism were main formation metabolisms of them. Advanced properties of FSJ indicated that fermentation is a promising approach for the production of SJ food.

GABA-enriched rice bran inhibits inflammation in LPS-stimulated macrophages via suppression of TLR4-MAPK/NF-κB signaling cascades

Gamma-aminobutyric acid (GABA)-enriched products (GEP) exhibited a wide range of pharmaceutical properties. In this study, anti-inflammatory activity of GEP from Lactobacillus fermentum-fermented water solution of rice bran was evaluated on lipopolysaccharide-activated macrophage model. GABA content in L. fermentum-fermented rice bran solution was determined up to 1.27 g/L. GEP was shown to inhibit the expression levels of inducible nitric oxide synthase and cyclooxygenase-2 enzymes. Moreover, pretreatment of GEP attenuated the generation level of interleukin (IL)-6, IL-1β, tumor necrosis factor α, and monocyte chemoattractant protein-1. Especially, the activation of signaling pathways due to nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs) was interrupted in GEP-exposed cells. Notably, molecular docking result showed a potential binding of GABA to Toll-like receptor 4 with a binding energy of -3.88 kcal/mol, suggesting the role of GABA in suppression of Toll-like receptor 4-MAPK/NF-κB signaling cascades. As the result, GEP from L. fermentum-fermented rice bran solution could be suggested as a promising food for suppression of inflammatory responses. PRACTICAL APPLICATIONS: GABA-enriched products have been evidenced to possess various pharmaceutical properties and health beneficial effects. In this study, GABA-enriched product from L. fermentum-fermented rice bran solution exhibited the inhibition on inflammatory response in macrophages. Hence, it could be used as a potential ingredient for the mitigation of inflammatory responses.

Seaweed as a Source of Natural Antioxidants: Therapeutic Activity and Food Applications

Seaweed is a valuable source of bioactive compounds, polysaccharides, antioxidants, minerals, and essential nutrients such as fatty acids, amino acids, and vitamins that could be used as a functional ingredient. The variation in the composition of biologically active compounds in seaweeds depends on the environmental growth factors that make seaweed of the same species compositionally different across the globe. Nevertheless, all seaweeds exhibit extraordinary antioxidant potential which can be harnessed for a broad variety of food applications such as in preparation of soups, pasta, salads, noodles, and other country specific dishes. This review highlights the nutritional and bioactive compounds occurring in different classes of seaweeds while focusing on their therapeutic activities including but not limited to blood cell aggregation, antiviral, antitumor, anti-inflammatory, and anticancer properties. The review also explores the existing and potential application of seaweeds as a source of natural antioxidant in food products. Seaweed-derived compounds have great potential for being used as a supplement in functional foods due to their high stability as well as consumer demand for antioxidant-rich foods.

Impact of Dietary Supplementation of Lactic Acid Bacteria Fermented Rapeseed with or without Macroalgae on Performance and Health of Piglets Following Omission of Medicinal Zinc from Weaner Diets

The feeding of medicinal zinc oxide (ZnO) to weaner piglets will be phased out after 2022 in Europe, leaving pig producers without options to manage post-weaning disorders. This study assessed whether rapeseed meal, fermented alone (FRM) or co-fermented with a single (Ascophylum nodosum; FRMA), or two (A. nodossum and Saccharina latissima; FRMAS) brown macroalagae species, could improve weaner piglet performance and stimulate intestinal development as well as maturation of gut microbiota in the absence of in-feed zinc. Weaned piglets (n = 1240) were fed, during 28-85 days of age, a basal diet with no additives (negative control; NC), 2500 ppm in-feed ZnO (positive control; PC), FRM, FRMA or FRMAS. Piglets fed FRM and FRMA had a similar or numerically improved, respectively, production performance compared to PC piglets. Jejunal villus development was stimulated over NC in PC, FRM and FRMAS (gender-specific). FRM enhanced colon mucosal development and reduced signs of intestinal inflammation. All fermented feeds and PC induced similar changes in the composition and diversity of colon microbiota compared to NC. In conclusion, piglet performance, intestinal development and health indicators were sustained or numerically improved when in-feed zinc was replaced by FRM.

The Effects of Fermented Laminaria japonica on Short-Term Working Memory and Physical Fitness in the Elderly

Considering the neuroprotective and antioxidant potential of fermented Laminaria japonica A. (FST), the purpose of the present study is to establish whether FST may be considered a viable, efficacious supplement that can be administered in later life to offset neurodegenerative conditions associated with aging. Forty senior subjects participated in a randomized, double-blind, and placebo-controlled study. Two groups were formed, one FST group (n = 32, 72.35 ± 5.54 yrs) and one placebo (CON) (n = 28, 74.57 ± 5.69 yrs), which received 1.5 g/day of FST for 6 weeks. Subjects were asked to abstain from any regular exercise. In order to analyze short-term memory, a variety of neuropsychological tests were implemented. Body composition, physical fitness evaluations, antioxidant function, and inflammatory markers were also included in the analyses pre- and posttest. We demonstrated that FST significantly improved neuropsychological test scores, including higher scores in the K-MMSE, numerical memory test, Raven test, and iconic memory, compared to the CON group. Shorter test trial times in the 6-meter [corrected] walk test were observed in the FST group (p<0.001 and p<0.05, trials 1 and 2, respectively). FST also significantly increased antioxidant activity of GPx, GSR, and SOD, reduced the production of TBARS, and lowered 8-oxoDG levels. The present study highlights the potential widespread application of FST in protecting against the degenerative effects of aging on short-term memory and physical function. Neuropsychological evaluation indicates that FST may provide a protective mechanism against cognitive impairment associated with dementia. Neuromuscular integrity and physical function are typically compromised in aging and dementia patients; thus, whether by stimulation of muscle-related growth factors or an increase in serum BDNF, FST supplementation may act to preserve physical function in the elderly. The bioactive constituents of FST such as GABA and fucoidan acting to provide improvements in antioxidant activity following FST supplementation may protect against progressive degeneration purportedly caused by reactive oxygen species.