valorization-red-seaweed-gracilaria-gracilis-through-biorefinery

Valorization of the Red Seaweed <em>Gracilaria gracilis</em> Through a Biorefinery Approach

The interest in seaweeds as an abundant feedstock to obtain valuable and multitarget bioactive ingredients is continuously growing. In this work, we ...

Polytechnic of Leiria

Polytechnic University of Leiria

The ever-increasing interest in keeping a young appearance and healthy skin has leveraged the skincare industry. This, coupled together with the increased concern regarding the safety of synthetic products, has boosted the demand for new and safer natural ingredients. Accordingly, the aim of this study was to evaluate the dermatological potential of the brown seaweed  The antioxidant, anti-enzymatic, antimicrobial, photoprotective and anti-inflammatory properties of five  fractions (F1-F5) were evaluated. The ethyl acetate fraction (F3) demonstrated the most promising results, with the best ability to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals (EC of 140.1 µg/mL) and the capacity to reduce reactive oxygen species (ROS) production promoted by UVA and UVB radiation in 3T3 cells, revealing its antioxidant and photoprotective potential. This fraction also exhibited the highest anti-enzymatic capacity, inhibiting the activities of collagenase, elastase and tyrosinase (IC of 7.2, 4.8 and 85.9 µg/mL, respectively). Moreover, F3 showed anti-inflammatory potential, reducing TNF-α and IL-6 release induced by LPS treatment in RAW 264.7 cells. These bioactivities may be related to the presence of phenolic compounds, such as phlorotannins, as demonstrated by NMR analysis. The results highlight the potential of  as a source of bioactive ingredients for further dermatological applications.

Unravelling the Dermatological Potential of the Brown Seaweed .

Berlengas archipelago is a UNESCO world heritage site and the only location where  is found. This species faces various threats, namely, human disturbance, the presence of  yellow-legged gull, common-rabbit, and black-rat populations. Thus, exclusion areas were installed, which blocked the access of most Gulls, aiming to promote the recovery of . Additionally, rabbits and rats were removed from the island. After six years of surveys, there has been an increase in the number of individuals of  in the exclusion areas, and a clear shift in the size structure of the  population. Significant changes in the height and diameter of the individuals were also noted. These findings indicate that the population of  is changing and becoming a healthier population. Principal component analysis results show a straightforward dissimilarity between the areas with  and those without the species and allowed the clustering of two groups: the rupicolous species and the nitrophilous species.  produces few seeds (seed set 3.4%), which raises concern regarding the long-term survival of the species. Thus, further conservation efforts must be implemented, such as the control of invasive species, gulls, and ruderals, to allow for the recovery of .

Recent Efforts to Recover  an Endemic Species from Berlengas Archipelago, Portugal.

Seaweeds exhibit high nutritional value due to a balanced concentration of proteins, vitamins and minerals, a high concentration of low digestibility polysaccharides, and reduced levels of lipids, many of which are n-3 and n-6 fatty acids. The species  is no exception and, as such, a comprehensive study of the chemical and nutritional profile of this red seaweed was carried out for 1 year. Seasonal variations in moisture, ash, protein and amino acids content, crude fibers, ascorbic acid, agar, lipids, and the corresponding fatty acid profile, were analyzed. We found low levels of fatty acids and a high protein content, but also noticed interesting seasonal change patterns in these compounds. The present study gives insights on the environmental conditions that can lead to changes in the nutritional composition of this species, aiming, therefore, to bring new conclusions about the manipulation of environmental conditions that allow for maximizing the nutritional value of this seaweed.

Seasonal Changes in the Nutritional Composition of  (Rhodophyta, Gracilariales) from the Center of Portugal.

 is a well-known agarophyte, harvested worldwide for its high agar quality. However, the species also exhibits an interesting nutritional profile, but with seasonal variations. Therefore, to evaluate the nutritional value of , ash, crude protein, total lipids, and carbohydrates were analyzed at different times of the year. The heavy metals mercury, arsenic, lead, cadmium, and tin, as well as iodine were also measured. Finally, the seasonal antioxidant capacity of  extracts was evaluated. Our results indicate that the biomass is rich in protein (up to 16.25 ± 0.33%) and carbohydrates (up to 39.5 ± 3.29%), and low in lipids (up to 2.75 ± 0.28%), and especially in the summer, the AI, TI indexes, n-6/n-3 and h/H ratios (0.93, 0.6, 0.88 and 1.08, respectively) are very interesting. None of the contaminants exceeded the legally established limits, and the iodine values were adequate for a healthy diet. Finally, the antioxidant capacity is fair, with the DPPH ≤ 10.89 ± 1.46%, and ABTS ≤ 13.90 ± 1.54% inhibition, FRAP ≤ 0.91 ± 0.22 AAE.g, and TPC ≤ 6.82 ± 0.26 GAE.g. The results show that  is an attractive resource, with potential use as food or as a food supplement.

Seasonal Nutritional Profile of  (Rhodophyta, Gelidiaceae) from the Center of Portugal.

In recent decades, seaweeds have proven to be an excellent source of bioactive molecules. Presently, the seaweed  is harvested in a small area of the Portuguese coast exclusively for agar extraction. The aim of this work was to fully disclosure  as a sustainable source of antimicrobial ingredients for new dermatological formulations, highlighting its potential to be explored in a circular economy context. For this purpose, after a green sequential extraction, these seaweed fractions (F1-F5) were chemically characterized (H NMR) and evaluated for their antimicrobial potential against ,  and . The most active fractions were also evaluated for their effects on membrane potential, membrane integrity and DNA damage. Fractions F2 and F3 displayed the best results, with IC values of 16.1 (7.27-23.02) μg/mL and 51.04 (43.36-59.74) μg/mL against , respectively, and 53.29 (48.75-57.91) μg/mL and 102.80 (87.15-122.30) μg/mL against , respectively. The antimicrobial effects of both fractions seem to be related to membrane hyperpolarization and DNA damage. This dual mechanism of action may provide therapeutic advantages for the treatment of skin dysbiosis-related diseases.

Article	Year
Unravelling the Dermatological Potential of the Brown Seaweed . Marine drugs\| PubMed ID: 33671016	2021
Recent Efforts to Recover an Endemic Species from Berlengas Archipelago, Portugal. Plants (Basel, Switzerland)\| PubMed ID: 33800079	2021
Seasonal Changes in the Nutritional Composition of (Rhodophyta, Gracilariales) from the Center of Portugal. Foods (Basel, Switzerland)\| PubMed ID: 34065392	2021
Seasonal Nutritional Profile of (Rhodophyta, Gelidiaceae) from the Center of Portugal. Foods (Basel, Switzerland)\| PubMed ID: 34681442	2021
Gelidiales Are Not Just Agar-Revealing the Antimicrobial Potential of for Skin Disorders. Antibiotics (Basel, Switzerland)\| PubMed ID: 35453232	2022

Teresa Mouga

Biography

JoVE Journal Publications

Other Publications