Red Seaweed Pigments from a Biotechnological Perspective

Algae taxa are notably diverse regarding pigment diversity and composition, red seaweeds (Rhodophyta) being a valuable source of phycobiliproteins (phycoerythrins, phycocyanin, and allophycocyanin), carotenes (carotenoids and xanthophylls), and chlorophyll a. These pigments have a considerable biotechnological potential, which has been translated into several registered patents and commercial applications. However, challenges remain regarding the optimization and subsequent scale-up of extraction and purification methodologies, especially when considering the quality and quantity needs, from an industrial and commercial point of view. This review aims to provide the state-of-the-art information on each of the aforementioned groups of pigments that can be found within Rhodophyta. An outline of the chemical biodiversity within pigment groups, current extraction and purification methodologies and challenges, and an overview of commercially available products and registered patents, will be provided. Thus, the current biotechnological applications of red seaweeds pigments will be highlighted, from a sustainable and economical perspective, as well as their integration in the Blue Economy.

The Red Seaweed Grateloupia turuturu Prevents Epidermal Dysplasia in HPV16-Transgenic Mice

The role of dietary profiles in promoting or reducing the risk of multiple types of cancer is increasingly clear, driving the search for balanced foods and nutraceuticals. The red seaweed Grateloupia turuturu has been used as human food showing a balanced nutritional profile. This study aims to test in vivo chemopreventive effects of G. turuturu against cutaneous pre-malignant lesions in transgenic mice for the human papillomavirus type 16 (HPV16). Forty-four female HPV+/− or HPV−/− mice received a standard diet or were supplemented with 10% G. turuturu for 22 consecutive days. Cutaneous lesions (ear and chest skin) were identified histologically. Complementarily, the weights and histology of internal organs as well as blood biochemical and DNA integrity parameters were also assessed. G. turuturu consistently reduced the incidence of epidermal dysplasia induced by HPV16 on both cutaneous sites. Moreover, biochemical, DNA integrity and histological analyses confirmed G. turuturu edibility as no signs of toxicity were found. Dietary supplementation with G. turuturu is an effective and safe chemopreventive strategy in this model.

Antitumor Efficacy of Silver Nanoparticles Biosynthe-sized from Marine Red Seaweed Halymenia porphyroides Boergesen on Dalton’s Lymphoma Ascites in Mice

The biosynthesized silver nanoparticles from marine red seaweed Halymenia porphyroides against Dalton’s lymphoma ascites (DLA)-induced tumor inoculation was studied for antitumor activity. The biosynthesized silver nanoparticles from marine red seaweed Halymenia porphyroides were given orally to Swiss albino mice (50 mg/kg/day) for 14 days showed a significant reduction in body weight, packed cell volume, andviable tumor cell count when compared to the mice of the DLA control group.The haematological parameters of the treatment group with biosynthesized silver nanoparticles also exhibited increased haemoglobin, RBCs, Platelets, and decreased WBCs compared to the DLA control group of mice. Similarly, the biochemical parameters like total cholesterol, aspartate amino-transferase (AST), alanine aminotransferase (ALT), triglycerides (TL), and alkaline phosphatase (ALP) of the treatment control group with biosynthesized silver nanoparticles reversed the parameters to normal levels compared to the DLA control group of mice. The antitumor efficacy of the biosynthesized silver nanoparticles from Halymenia porphyroides was confirmed based on the haematological, biochemical, life span, packed cell volume, cell count, and histopathological analysis.

Potential Use of Carrageenans against the Limestone Proliferation of the Cyanobacterium Parakomarekiella sesnandensis

Stone biodeterioration by cyanobacteria is a common issue in the field of cultural heritage. As they are considered the first stone colonizers, the need to control their growth has increased. In this study, we evaluated the effectiveness of kappa/iota carrageenans from the red seaweed Chondracanthus teedei var. lusitanicus against the limestone proliferation of the cyanobacterium Parakomarekiella sesnandensis, under laboratory conditions. For this purpose, 200 μL of kappa/iota carrageenans (0.01 g mL−1) were applied into the surface of the limestone replicas prior to their inoculation with P. sesnandensis. Results were evaluated after 4 months of incubation through visual inspection, stereomicroscopy, scanning electron microscopy and colorimetric analyses. The gathered data demonstrated that these types of carrageenans have the potential to reduce the colonization of P. sesnandensis. With one sole application, the aesthetical alterations caused by the proliferation of P. sesnandensis were drastically reduced. This study highlights the need to explore marine-based products, particularly those derived from seaweeds with antimicrobial properties, as alternative methods for biocleaning cultural heritage assets.