Biological properties and potential of compounds extracted from red seaweeds

Extraction and antioxidant capacity of mycosporine-like amino acids from red algae in Japan

Mycosporine-like amino acids (MAAs) are the natural UV-absorbing compounds with antioxidant activity found in microalgae and macroalgae. We collected red algae Asparagopsis taxiformis, Meristotheca japonica, and Polysiphonia senticulosa from Nagasaki, where UV radiation is more intense than in Hokkaido, and investigated the effect of UV radiation on MAA content. It was suggested that A. taxiformis and M. japonica contained shinorine and palythine, while UV-absorbing compound in P. senticulosa could not be identified. The amounts of these MAAs were lower compared to those from Hokkaido. Despite an increase in UV radiation in both regions from February to April, MAA contents of red algae from Nagasaki slightly decreased while those from Hokkaido significantly decreased. This difference was suggested the amount of inorganic nitrogen in the ocean. Antioxidant activity of MAAs increased under alkaline conditions. The extract containing MAAs from P. senticulosa showed the highest antioxidant activity among 4 red algae.

Marine seaweed endophytic fungi-derived active metabolites promote reactive oxygen species-induced cell cycle arrest and apoptosis in human breast cancer cells

BACKGROUND

Endophytic fungi have an abundant sources rich source of rich bioactive molecules with pivotal pharmacological properties. Several studies have found that endophytic fungi-derived bioactive secondary metabolites have antiproliferative, anti-oxidant, and anti-inflammatory properties, but the molecular mechanism by which they induce cell cycle arrest and apoptosis pathways is unknown. This study aimed to determine the molecular mechanism underlying the anticancer property of the endophytic fungi derived active secondary metabolites on human breast cancer cells.

METHODS

In this study, we identified four endophytic fungi from marine seaweeds and partially screened its phytochemical properties by Chromatography-Mass Spectrometry (GC-MS) analysis. Moreover, the molecular mechanism underlying the anticancer property of these active secondary metabolites (FA, FB, FC and FE) on human breast cancer cells were examined on MCF-7 cells by TT assay, Apoptotic assay by Acridine orang/Ethidium Bromide (Dual Staining), DNA Fragmentation by DAPI Staining, reactive oxygen species (ROS) determination by DCFH-DA assay, Cell cycle analysis was conducted Flow cytometry and the apoptotic signalling pathway was evaluated by westernblot analysis. Doxorubicin was used as a positive control drug for this experiment.

RESULTS

The GC-MS analysis of ethyl acetate extract of endophytic fungi from the marine macro-algae revealed the different functional groups and bioactive secondary metabolites. From the library, we observed the FC (76%), FB (75%), FA (73%) and FE (71%) have high level of antioxidant activity which was assessed by DPPH scavenging assay. Further, we evaluated the cytotoxic potentials of these secondary metabolites on human breast cancer MCF-7 cells for 24 h and the IC50 value were calculated (FA:28.62 ± 0.3 µg/ml, FB:49.81 ± 2.5 µg/ml, FC:139.42 ± µg/ml and FE:22.47 ± 0.5 µg/ul) along with positive control Doxorubicin 15.64 ± 0.8 µg/ml respectively by MTT assay. The molecular mechanism by which the four active compound induced apoptosis via reactive oxygen species (ROS) and cell cycle arrest in MCF-7 cells was determined H2DCFDA staining, DAPI staining, Acridine orange and ethidium bromide (AO/EtBr) dual staining, flowcytometry analysis with PI staining and apoptotic key regulatory proteins expression levels measured by westernblot analysis.

CONCLUSION

Our findings, revealed the anticancer potential of endophytic fungi from marine seaweed as a valuable source of bioactive compounds with anticancer properties and underscore the significance of exploring marine-derived endophytic fungi as a promising avenue for the development of novel anticancer agents. Further investigations are necessary to isolate and characterize specific bioactive compounds responsible for these effects and to validate their therapeutic potential in preclinical and clinical settings.

An Update on the Chemical Constituents and Biological Properties of Selected Species of an Underpinned Genus of Red Algae: Chondrus

Macroalgae, particularly red seaweeds, have attracted significant attention due to their economic and health benefits. Chondrus, a red algae genus, despite its economic importance, seems to be undervalued. Among all its species, Chondrus crispus has been meticulously documented for its biological properties, and little is known about other species. No comprehensive review of the biological properties of this genus has been acknowledged. Thus, this review aimed to summarize the available information on the chemical constituents and biological properties of a few selected species, including Chondrus crispus, Chondrus ocellatus, Mazzaella canaliculata, and Chondrus armatus. We compiled and discovered that the genus is offering most of the important health-promoting benefits evidenced from in vitro and in vivo studies focused on antimicrobial, immunomodulation, neuroprotection, anti-atopic, anti-inflammatory, anti-viral, anti-diabetic, cytoprotective, antioxidant, anti-coagulation, nephroprotective, anti-tumor, and anti-venom activity, which speaks about the potential of this genus. Data on clinical studies are limited. Further, around 105 chemical constituents have been reported from Chondrus spp. Given its significance, further investigation is warranted, in the form of meticulously planned cell, animal, and clinical studies that concentrate on novel health-enhancing endeavors, in order to unveil the full potential of this genus. The review also outlines challenges and future directions.

Impact of Different Light Conditions on the Nitrogen, Protein, Colour, Total Phenolic Content and Amino Acid Profiles of Cultured Palmaria palmata

The impact of different light conditions during culture on the nitrogen, protein, colour, total phenolic content (TPC) and amino acid profile of Palmaria palmata biomass was investigated. P. palmata was cultured using different light regimes, i.e., white (1 and 2), red, blue and green over 12 days. A significant decrease (p < 0.05) in total nitrogen (TN), non-protein nitrogen (NPN) and protein nitrogen (PN) was observed on day 6 while an increase was observed on day 12 in P. palmata samples cultured under blue light. The protein content (nitrogen conversion factor of 4.7) of the initial sample on day 0 was 15.0% (w/w) dw whereas a maximum protein content of 16.7% (w/w) was obtained during exposure to blue light following 12 days culture, corresponding to an 11.2% increase in protein content. Electrophoretic along with amino acid profile and score analyses showed light-related changes in protein composition. The lighting regime used during culture also influenced the colour parameters (lightness L*, redness a*, yellowness b* and colour difference ΔE) of milled algal biomass along with the TPC. Judicious selection of lighting regime during culture may allow the targeted production of sustainable high-quality proteins from P. palmata.

Antioxidant Activity and Inhibition of Liver Cancer Cells' Growth of Extracts from 14 Marine Macroalgae Species of the Mediterranean Sea

Macroalgae exhibit beneficial bioactivities for human health. Thus, the aim of the present study was to examine the antioxidant and anticancer potential of 14 macroalgae species' extracts, namely, Gigartina pistillata, Gigartina teedei, Gracilaria gracilis, Gracilaria sp., Gracilaria bursa pastoris, Colpomenia sinuosa, Cystoseira amentacea, Cystoseira barbata, Cystoseira compressa, Sargassum vulgare, Padina pavonica, Codium fragile, Ulva intestinalis, and Ulva rigida, from the Aegean Sea, Greece. The antioxidant activity was assessed using DPPH, ABTS^•+, ^•OH, and O₂^•- radicals' scavenging assays, reducing power (RP), and protection from ROO^•-induced DNA plasmid damage assays. Moreover, macroalgae extracts' total polyphenol contents (TPCs) were assessed. Extracts' inhibition against liver HepG2 cancer cell growth was assessed using the XTT assay. The results showed that G. teedei extract's IC₅₀ was the lowest in DPPH (0.31 ± 0.006 mg/mL), ABTS^•+ (0.02 ± 0.001 mg/mL), ^•OH (0.10 ± 0.007 mg/mL), O₂^•- (0.05 ± 0.003 mg/mL), and DNA plasmid breakage (0.038 ± 0.002 mg/mL) and exhibited the highest RP (RP_0.5AU 0.24 ± 0.019 mg/mL) and TPC (12.53 ± 0.88 mg GAE/g dw). There was also a significant correlation between antioxidant activity and TPC. P. pavonica (IC₅₀ 0.93 ± 0.006 mg/mL) exhibited the highest inhibition against HepG2 cell growth. Conclusively, some of the tested extracts exhibited significant chemopreventive properties, and so they may be used for food products.

Interaction of Jania rubens Polyphenolic Extract as an Antidiabetic Agent with α-Amylase, Lipase, and Trypsin: In Vitro Evaluations and In Silico Studies

Jania rubens red seaweed has various bioactive compounds that can be used for several medicinal and pharmaceutical applications. In this study, we investigate the antidiabetic, anti-inflammatory, and antioxidant competency of Jania rubens polyphenolic extract (JRPE) by assessing their interactions with α-amylase, lipase, and trypsin enzymes. HPLC analysis revealed the dominance of twelve polyphenolic compounds. We performed computational analysis using α-amylase, lipase, and trypsin as target proteins for the polyphenols to explore their activities based on their predicted modes of binding sites following molecular modeling analysis. The molecular docking analysis demonstrated a good affinity score with a noticeable affinity to polyphenolic compositions of Jania rubens. The compounds with the highest affinity score for α-amylase (PDB: 4W93) were kaempferol, quercetin, and chlorogenic acid, with −8.4, −8.8 and −8 kcal/mol, respectively. Similarly, lipase (PDB: 1LPB) demonstrated high docking scores of −7.1, −7.4, and −7.2 kcal/mol for kaempferol, quercetin, and chlorogenic acid, respectively. Furthermore, for trypsin (PDB: 4DOQ) results, kaempferol, quercetin, and chlorogenic acid docking scores were −7.2, −7.2, and −7.1 kcal/mol, respectively. The docking findings were verified using in vitro evaluations, manifesting comparable results. Overall, these findings enlighten that the JRPE has antidiabetic, anti-inflammatory, and antioxidant properties using different diabetics’ enzymes that could be further studied using in vivo investigations for diabetes treatment.

Rhodophyta as Potential Sources of Photoprotectants, Antiphotoaging Compounds, and Hydrogels for Cosmeceutical Application

Seaweeds are macroscopic, multicellular, eukaryotic and photosynthetic organisms, and are a source of chemical diversity with powerful biological activities for diversified industrial applications including cosmeceuticals. Red seaweeds (Rhodophyta) are good sources of Mycosporine-like amino acids (MAA) for photoprotectant and antiphotoaging compounds. In addition, Rhodophyta are also good sources for hydrogel compounds that are used widely in the food, pharmaceutical and cosmeceutical industries as gelling agents, moisturizers or for their antiphotoaging effects. Our survey and ongoing studies revealed that the biodiversity of Indonesian Rhodophyta is rich and is a treasure trove for cosmeceutical agents including MAA and hydrogels. This study delivers valuable information for identifying potential red seaweeds in screening and searching for cosmeceutical agents.

Global seaweed farming and processing in the past 20 years

Seaweed has emerged as one of the most promising resources due to its remarkable adaptability, short development period, and resource sustainability. It is an effective breakthrough to alleviate future resource crises. Algal resources have reached a high stage of growth in the past years due to the increased output and demand for seaweed worldwide. Several aspects global seaweed farming production and processing over the last 20 years are reviewed, such as the latest situation and approaches of seaweed farming. Research progress and production trend of various seaweed application are discussed. Besides, the challenges faced by seaweed farming and processing are also analyzed, and the related countermeasures are proposed, which can provide advice for seaweed farming and processing. The primary products, extraction and application, or waste utilization of seaweed would bring greater benefits with the continuous development and improvement of applications in various fields.

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