An overview on red algae bioactive compounds and their pharmaceutical applications

Abstract

ObjectivesTo review red algae bioactive compounds and their pharmaceutical applications.ContentSeaweed sources are becoming attractive to be used in health and therapeutics. Among these red algae is the largest group containing bioactive compounds utilized in cosmetic, pharmaceutical, food industry, manure and various supplements in food formula. Various significant bioactive compounds such as polysaccharides (aginate, agar, and carrageenan), lipids and polyphenols, steroids, glycosides, flavanoids, tannins, saponins, alkaloids, triterpenoids, antheraquinones and cardiac glycosides have been reported in red algae. The red algae have rich nutritional components Different polysaccharides of red algae possess the antiviral potential namely agarans, carrageenan, alginate, fucan, laminaran and naviculan. Sulfated polysaccharides and carraginans of red algae are rich source of soluble fibers which can account for antitumor activities depending upon chemistry of various secondary metabolites and metabolism of cell line. Flavons-3-ols containing catechins from many red algae block the telomerase activity in colon cancer cells. Contraceptive agents were tested from red algae as a source for post-coital. Lectin of red algae showed pro-healing properties and anti-ulcerogenic activities. Carragenates from red algae also conferred a positive influence on diabetes. Red algae depicted a reducing effect on plasma lipids and obesity. Porphyran from red alga can act as anti-hyperlipidemic agent also reduces the apolipoprotein B100 via suppression of lipid synthesis in human liver.SummaryThe polyphenolic extracts of Laurencia undulate, Melanothamnus afaqhusainii and Solieria robusta extract show anti-inflammatory effects against multiple genera of devastating fungi. Antioxidants such as phlorotannins, ascorbic acids, tocopherols, carotenoids from red algae showed toxicity on some cancer cells without side effects. Red algae Laurencia nipponica was found insecticidal against mosquito larvae. Red algae fibers are very important in laxative and purgative activities. Gracilaria tenuistipitat resisted in agricultural lands polluted with cadmium and copper.OutlookIn the recent decades biotechnological applications of red algae has been increased. Polysaccharides derived from red algae are important tool for formulation of drugs delivery system via nanotechnology.

Antiviral Activity of Carrageenans and Processing Implications

“…The green synthesis of gel micro/nanoparticulate systems [ 165 ] and the development of novel drug-delivery systems [ 37 ] and carriers for antivirals and vaccines [ 17 , 31 ]…”

“…Cheong and co-authors published a new perspective on the potential applications of carrageenan oligomers in the functional food and pharmaceutical industry with an emphasis on the production, purification, analysis, characterization, and biological properties [ 33 ]. The COVID-19 pandemic, caused by the SARS-CoV-2 virus, caused some researchers to reconsider the potential of algal metabolites [ 3 , 34 , 35 ], particularly from seaweeds [ 36 , 37 ]. Chen and co-authors reviewed the antiviral properties, mechanisms, and applications of some polysaccharides as therapeutic agents and vaccine adjuvants for the treatment of coronavirus [ 17 ].…”

Alimentary and Pharmaceutical Approach to Natural Antimicrobials against Clostridioides difficile Gastrointestinal Infection

“…The increasing pharmaceutical application of marine algae bioactives is mainly based on their demonstrated antioxidant, antimicrobial, and anticancerigen properties. Moreover, food and nutraceutical supplements based on raw or purified algae compounds are being developed [ 67 , 68 , 69 ].…”

“…The antimicrobial potential of algae materials is based on the (i) type and algae matrix source (e.g., different algae taxonomic groups, culture conditions, seasonal harvest, and accumulation of bioactives), (ii) structural chemical diversity of compounds, (iii) molecular weight of compounds, (iv) type of extraction and purification methods employed, and (v) modification and way of administration [ 23 , 54 ]. Among the most relevant antimicrobial bioactives from macro- and microalgae are phlorotannins, laminarin, sargafuran, peyssonoic acid, bromophycolides, neurymenolides, acetylmajapolene, phycobiliproteins, scytonemines, carotenoids, polysaccharides, phytohormones, cyanotoxins, phytol, fucosterol, neophytadiene, palmitic, palmitoleic, and oleic acids [ 36 , 37 , 63 , 67 , 69 ].…”

“…The most promising antimicrobial potential has been found in brown algae, namely Phaeophyceae (84% of species with demonstrated antimicrobial capability), followed by Rhodophyceae (67%) and Chlorophyceae (44%) [ 62 ]. Regarding microalgae, Spirulina platensis and Chlorella vulgaris are nowadays the most studied algae substrates in terms of their antibacterial/antiviral capacity [ 67 , 68 , 69 , 70 ].…”