Medicinal value
Seaweeds offer a wide range of therapeutic possibilities both internally and externally. The medicinal value of seaweed depends on the type and particular species. There are several types of seaweed both wild and cultivated (106) , this means seaweeds can be classified by its use such as medicine, fertilizer and industrial raw materials (105). Utilization of seaweeds as medicine date back to 13,000 years ago in Chile at late Pleistocene settlement (107). Also, there was more archaeological evidence as to the inclusion of seaweed in folk medicine for thousands of years ago in Japan, China, Egypt and India (108). Between 1977 and 1987, the newly discovered chemicals from seaweeds were 35%, followed by sponges 27% and cnidarians 22%.(108). Since then, there is an increasing trend of discovering pharmacologically active compounds from seaweed. This indicates that marine organisms can be utilized as a source of variety compounds with pharmacological activities including anticancer, antimicrobial, antifungal, antiviral and anti-inflammatory which are potential sources of new therapeutic agents (109).
Yi, et al. (2001) (110) investigated the extract from 23 species of marine algae belonging to the Chlorophyta, Phaeophyta, and Rhodophyta, using different solvents such as ethanol, acetone, and methanol-toluene. The results indicated that ethanol extract had the strongest antifungal activity, while the methanol-toluene extract had the weakest, indicating the possibility of using ethanol extract as antifungal agent. Similarly, Khanzada et al. (2007) (111) tested several fractions of an ethanolic extract of Solieria robusta (Rhodophyta) for antifungal activity against five fruit rotting fungi isolated from fruits in Pakistan and found that all fractions inhibited fungal growth ; ethanol had the highest inhibition ratios, followed by aqueous fraction. On the other hand, Saidani, et al. (2012) investigated antifungal action of four species of marine algae of Bejaia coast and reported that all experimented extracts displayed antifungal action, the maximum inhibiting effect was noted for Rhodomela confervoides (red algae) and Padin apavonica (brown algae), respectively against Candida albicans and Mucor ramaniannus (112). Furthermore, Indira, et al. (2013) presented the antifungal property of seaweed Halimeda tuna against nine fungal strains (Aspergillus niger, Aspergillus flavus, Alternaria , Candida albicans, Epidermophyton floccossum, Trichophyton mentagrophytes, Trichophyton rubrum, Pencillium sp. and Rhizopus sp.) (113). Therefore, there is a need to investigate further medical applicability of seaweeds present in the WIO in order to explore its benefits for sustainable ecosystem.