Medicinal Value of Seaweeds and Its Applications–a Review

Abstract

Seaweeds are one of the most important living resources of the ocean. Inspite of their wide applications in food and feed industries, they have gained importance as medicinal sources because of their high healing, antimicrobial and antioxidative properties. As a rich source of valuable chemical components, seaweeds are used in various other industries like cosmetics, Fuel, water treatment etc. Being a plant of unique structure and biochemical composition, seaweed could be used highly for its multi-functional properties in the form of food, energy, medicine and cosmetics. The distribution, properties and wide application of seaweeds are discussed in detail in this manuscript. INTRODUCTION Macroscopic marine algae, popularly known as seaweeds, form one of the important living resources of the ocean. Agar, carrageenan and alginate are popular examples of seaweeds these have been used as food for human beings, feed for animals, fertilizers for plants and source of various chemicals. In the recent past, seaweeds have also been gaining momentum as new experimental systems for biological research and integrated aquaculture systems. Seaweed products are used in our daily lives in one or the other way. For example, some seaweed polysaccharides are employed in the manufacture of toothpastes, soaps, shampoos, cosmetics, milk, ice creams, meat, processed food, air fresheners and a host of other items. In several oriental countries like Japan, China, Korea, etc., seaweeds are a staple part of the diet. Some typical examples of seaweed applications are narrated below. Agar is widely used in paper manufacturing, culture media, packaging material, photography, leather industry, plywood manufacturing, preservation of foodstuffs, dairy industry, cosmetics industry and pharmaceutical industry. Carrageenan is employed in food industry. Its value in the manufacture of sausages, corned beef, meat balls, ham, preparations of poultry and fish, chocolates, dessert gels, ice creams, juice concentrates, marmalade, sardine sauces is well known. It is also used in the manufacturing of non-food items like beer, air fresheners, textiles, toothpastes, hair shampoos, tissues, culture media, fungicides, etc. The applications of alginate find place in frozen foods, pastry fillings, syrups, bakery icings, dry mixes, meringues, frozen desserts, instant puddings, cooked puddings, chiffons, pie and pastry fillings, dessert gels, fabricated foods, salad dressings, meat and flavour sauces. The “folk medicine” in coastal zones made extensive use of a variety of seaweed species. Knowledge of the tonic and healing powers of seaweed was passed down among coastal peoples from generation to generation because the mineral content of sea vegetables is extraordinary, and is seen as the root of most of their healing properties. Seaweed has been part of the traditional diet of all coastal cultures, like Japan and China, Hawaii, Wales, Scotland, Iceland, and Ireland. With advances in medicine today, the reasons behind the success of some of these treatments are being elucidated, because we now understand more of the nutritional and biochemical properties of different seaweeds or algae. There are certain medicinal properties for the seaweeds. Seaweeds rich in iodine such as Asparagopsis taxiformis and Sarconema sp. can also be used for controlling goiter disease caused by enlargement of thyroid gland. Indian marine algae have all the essential amino acids needed in the human diet which are not available in other vegetable food materials. Seaweeds yield the most important products such as agar-agar and algin. Tliey are colloidal carbohydrates present in the cell walls of these algae.