Phytochemical profiles and ethnomedicine preliminary studies on seagrass species in the Southern Coast of Lombok Island Indonesia

Seagrass is a coastal plant that is not only important in maintaining the stability of coastal ecosystems, but also provides many benefits in daily life. Seagrass has long been used as traditional medicine by coastal residents in South Lombok. The purpose of this study was to screen the main types of secondary metabolites contained in seagrass in the southern coast of Lombok Island and to obtain information about the species of seagrass used as traditional medicine for certain types of diseases in local residents. Seagrass samples were taken from the south coast and the extraction process was carried out by maceration method using 96% ethanol as solvent. The crude extract obtained was then subjected to qualitative and quantitative phytochemical tests. The phytochemical qualitative test showed that Syringodium isoetifolium, Enhalus acoroides, Halophila decipiens, Cymodocea rotundata, Thalassia hemprichii, and Cymodocea cerulata contain compounds such as flavonoids, tannins, and phenols. Quantitative phytochemical analysis showed that E. acoroides had the highest total flavonoid content (3.7 mg QE/g) compared to that of other species, while the highest total phenolic content was indicated by T. hemprichii (33 mg GAE/100 g). The results of interviews related to the ethnomedicinal aspects of seagrass indicate that four species commonly used by local residents in healing diseases are E. acoroides, S. isoetifolium, T. hemprichii, and C. cerulata. They are widely used both as an external medicine (itching-skin diseases and external wounds) and internal medicine, such as heart, cancer, and kidney disease. Based on the phytochemical profile and ethnomedicine studies, the four seagrass species can be an alternative source in obtaining bioactive compounds for the development of specific drugs in the future.