The Marine Seagrass Halophila stipulacea as a Source of Bioactive Metabolites against Obesity and Biofouling

Abstract

Marine organisms, including seagrasses, are important sources of biologically active molecules for the treatment of human diseases. In this study, organic extracts of the marine seagrass Halophila stipulacea obtained by different polarities from leaves (L) and stems (S) (hexane [HL, HS], ethyl acetate [EL, ES], and methanol [ML, MS]) were tested for different bioactivities. The screening comprehended the cytotoxicity activity against cancer cell lines grown as a monolayer culture or as multicellular spheroids (cancer), glucose uptake in cells (diabetes), reduction of lipid content in fatty acid-overloaded liver cells (steatosis), and lipid-reducing activity in zebrafish larvae (obesity), as well as the antifouling activity against marine bacteria (microfouling) and mussel larval settlement (macrofouling). HL, EL, HS, and ES extracts showed statistically significant cytotoxicity against cancer cell lines. The extracts did not have any significant effect on glucose uptake and on the reduction of lipids in liver cells. The EL and ML extracts reduced neutral lipid contents on the larvae of zebrafish with EC50 values of 2.2 µg/mL for EL and 1.2 µg/mL for ML. For the antifouling activity, the HS and ML extracts showed a significant inhibitory effect (p < 0.05) against the settlement of Mytilus galloprovincialis plantigrade larvae. The metabolite profiling using HR-LC-MS/MS and GNPS (The Global Natural Product Social Molecular Networking) analyses identified a variety of known primary and secondary metabolites in the extracts, along with some unreported molecules. Various compounds were detected with known activities on cancer (polyphenols: Luteolin, apeginin, matairesinol), on metabolic diseases (polyphenols: cirsimarin, spiraeoside, 2,4-dihydroxyheptadec-16-ynyl acetate; amino acids: N-acetyl-L-tyrosine), or on antifouling (fatty acids: 13-decosenamide; cinnamic acids: 3-hydroxy-4-methoxycinnamic acid, alpha-cyano-4-hydroxycinnamic), which could be, in part, responsible for the observed bioactivities. In summary, this study revealed that Halophila stipulacea is a rich source of metabolites with promising activities against obesity and biofouling and suggests that this seagrass could be useful for drug discovery in the future.

In Vitro Evaluation of Antioxidant Potential of the Invasive Seagrass Halophila stipulacea

“…stipulacea that might fill the role of natural provider of antioxidant agent acting against oxidative stress in fibroblast cell lines. In agreement with other previous reports [ 10 , 11 , 17 ], this species might represent a novel valuable source for human health benefits. This might be a great opportunity since this species is a threat for coastal marine ecosystems because of its invasiveness.…”

“…The potential bioactivity and biological properties of extracts from Halophila stipulacea was previously investigated [ 10 , 17 ]. This species—i.e., extracts from leaves or stems—exerted a reduction of lipid content in fatty acid-overloaded liver cells (steatosis) and displayed antifouling activity [ 17 ]. Moreover, ethanolic leaf extracts showed antioxidant and antibacterial activities [ 18 ].…”

Inhibition of Intestinal Lipid Absorption by Cyanobacterial Strains in Zebrafish Larvae

“…The Global Natural Products Social Networking (GNPS) site is an open-access knowledge base for mass spectrometry data [ 34 ]. This bioinformatic procedure is an interesting way of getting insights into the presence of unique compounds that differ between active and non-active fractions or extracts [ 35 ]. The further development of the methodology incorporating the correlation to bioactivity data resulted in the feature-based molecular networking (FBMN), which allows the profiling of the metabolites related to an observed bioactivity [ 36 ] The application of FBMN on our data from LC-MS/MS allowed the identification of 14 peaks ( p < 0.01; correlation > 0.95), which could be responsible for the observed activity on lipid processing in zebrafish larvae ( Figure S2 , Table 1 ).…”

“…For liquid chromatography-high-resolution electrospray ionization tandem mass spectrometry (LC-HRESI-MS/MS, Thermo Fisher Scientific, Waltham, MA, USA), the fractions were dissolved in UPLC/MS grade acetonitrile at a concentration of 1 mg/mL, and 5 µL was injected per sample. Experimental conditions are described in detail in Ribeiro et al (2020) [41].…”

Testing the Halophila Stipulacea Environmental Threat as A Potential Antioxidant Agent

“…The potential bioactivity and biological properties of Halophila stipulacea has been reported (Mabrouk et al 2020). Organic extracts of H. stipulacea obtained from leaves and stems were evaluated on human cell lines as antiobesity agent and on microfouling and macrofouling organisms as antifouling product (Mabrouk et al 2020). Also, ethanolic leaf extracts have shown antioxidant activity as well as antibacterial activities (Kannan Rengasamy et al 2012).…”