Thalassosterol, a New Cytotoxic Aromatase Inhibitor Ergosterol Derivative from the Red Sea Seagrass Thalassodendron ciliatum.

Reda F A Abdelhameed,John Refaat Fahim,Marwa S Goda,Enas E Eltamany,Eman S Habib,Shaimaa Fayez,Adel M Abd El-Kader,Hashem A Hassanean,Amany K Ibrahim,Gerhard Bringmann,Usama Ramadan Abdelmohsen,Safwat A Ahmed,Asmaa M Aboulmagd,Tarfah Al-Warhi

doi:10.3390/md18070354

Abstract

Thalassodendron ciliatum (Forssk.) Den Hartog is a seagrass belonging to the plant family Cymodoceaceae with ubiquitous phytoconstituents and important pharmacological potential, including antioxidant, antiviral, and cytotoxic activities. In this work, a new ergosterol derivative named thalassosterol (1) was isolated from the methanolic extract of T. ciliatum growing in the Red Sea, along with two known first-reported sterols, namely ergosterol (2) and stigmasterol (3), using different chromatographic techniques. The structure of the new compound was established based on 1D and 2D NMR spectroscopy and high-resolution mass spectrometry (HR-MS) and by comparison with the literature data. The new ergosterol derivative showed significant in vitro antiproliferative potential against the human cervical cancer cell line (HeLa) and human breast cancer (MCF-7) cell lines, with IC50 values of 8.12 and 14.24 µM, respectively. In addition, docking studies on the new sterol 1 explained the possible binding interactions with an aromatase enzyme; this inhibition is beneficial in both cervical and breast cancer therapy. A metabolic analysis of the crude extract of T. ciliatum using liquid chromatography combined with high-resolution electrospray ionization mass spectrometry (LC-ESI-HR-MS) revealed the presence of an array of phenolic compounds, sterols and ceramides, as well as di- and triglycerides.

Highlights

Seagrasses are marine flowering plants that grow underwater along temperate and tropical coastlines, providing shelter or food for other marine organisms
T. ciliatum were found to be in accordance with those obtained in previous phytochemical studies, which reported the isolation of several phenolic compounds and sterols [6,10]
The seagrass T. ciliatum was collected from Sharm El Sheikh at the Egyptian Red Sea, air-dried and stored at a low temperature (-24 ◦ C) until further processing

Summary

Introduction

Seagrasses are marine flowering plants that grow underwater along temperate and tropical coastlines, providing shelter or food for other marine organisms. They are important components of the near-shore ecosystem and are used as biological indicators of environmental quality [1]. Thalassodendron ciliatum (Forssk.) Den Hartog (Family Cymodoceaceae) is a sub-tidal or shallow-depositional seagrass species that is generally found in extensive and monotonous meadows. This sickle-leaved cymodocea, commonly known as "Majani kumbi", grows in the Red Sea, the western Indian Ocean, and the Indo-Pacific region [3]. The leaves of T. ciliatum are characterized by the presence of many tannin-containing cells and are rich in phenolic constituents [5]

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Results

Conclusion