Erectcyanthins A-C from marine sponge Hyrtios erectus: anti-dyslipidemic agents attenuate hydroxymethylglutaryl coenzyme A reductase

Bioactivity-steered chromatographic purification of the solvent extract of marine sponge Hyrtios erectus (Thorectidae) led to the isolation of three undescribed cyanthiwigin-type diterpenoids, erectcyanthins A-C. Erectcyanthin B exhibited comparable attenuation activity against 3-hydroxy-3-methylglutaryl-coenzyme A reductase (IC₅₀ 0.07 mM) with that displayed by anti-dyslipidemic agent atorvastatin (IC₅₀ 0.08 mM). Comparatively greater antioxidant properties of erectcyanthin B (IC₅₀ ∼ 0.4 mM) than that displayed by erectcyanthin A (IC₅₀ ∼ 0.5 mM), erectcyanthin C and the standard α-tocopherol (IC₅₀ 1.5-1.7 mM) against oxidants also corroborated its promising bioactivity. Erectcyanthin B exhibited considerably greater anti-inflammatory activities (IC₅₀ 0.88-1.09 mM) than other erectcyanthin analogues in the series. The potential anti-dyslipidemic activity of erectcyanthins was linearly correlated with electronic parameter (topological polar surface area ∼ 74.6) along with balanced hydrophilic-lipophilic properties (logarithmic octanol-water partition coefficient 1.76). This study recognized the anti-dyslipidemic property of erectcyanthin B as a promising pharmaceutical lead.

Cytotoxic Scalarane Sesterterpenes from the Sponge Hyrtios erectus

Twelve new sesterterpenes along with eight known sesterterpenes were isolated from the marine sponge Hyrtios erectus collected off the coast of Chuuk Island, the Federated State of Micronesia. Based upon a combination of spectroscopic and computational analyses, these compounds were determined to be eight glycine-bearing scalaranes (1–8), a 3-keto scalarane (9), two oxidized-furan-bearing scalaranes (10 and 11), and a salmahyrtisane (12). Several of these compounds exhibited weak antiproliferation against diverse cancer cell lines as well as moderate anti-angiogenesis activities. The antiproliferative activity of new compound 4 was found to be associated with G0/G1 arrest in the cell cycle.

Antimalarial activity of the isolates from the marine sponge Hyrtios erectus against the chloroquine-resistant Dd2 strain of Plasmodium falciparum

This work reports the isolation of the three known compounds, smenotronic acid (1), ilimaquinone (2), and pelorol (3), from the 85% methanol (MeOH)-soluble fraction of the sponge Hyrtios erectus. The structures of the isolated compounds were determined with the help of modern spectroscopic techniques, and the resulting compounds were then subjected to in vitro screening to determine their antimalarial potential against the chloroquine-resistant Dd2 strain of Plasmodium falciparum. Amongst the three compounds, pelorol (3) showed significant activity against P. falciparum with an IC50 value of 0.8 μM. For smenotronic acid (1) and ilimaquinone (2), moderate activities were observed with IC50 values of 3.51 and 2.11 μM, respectively.

Anti-Helicobacter, Antitubercular and Cytotoxic Activities of Scalaranes from the Red Sea Sponge Hyrtios erectus

The Red Sea specimen of the marine sponge Hyrtios erectus (order Dictyoceratida) was found to contain scalarane-type sesterterpenes. 12-O-deacetyl-12,19-di-epi-scalarin (14), a new scalarane sesterterpenoid, along with fourteen previously-reported scalarane-type sesterterpenes (1–13 and 15) have been isolated. The chemical structures of the isolated compounds were elucidated on the basis of detailed 1D and 2D NMR spectral data and mass spectroscopy, as well as by comparison with reported data. The anti-Helicobacter pylori, antitubercular and cytotoxic activities of all fifteen compounds were evaluated to reveal the potency of Compounds 1, 2, 3, 4, 6, 7 and 10. Amongst these, Compounds 1, 3, 4, 6 and 10 displayed a promising bioactivity profile, possessing potent activities in the antitubercular and anti-H. pylori bioassay. Compounds 2 and 7 showed the most promising cytotoxic profile, while Compounds 1 and 10 showed a moderate cytotoxic profile against MCF-7, HCT-116 and HepG2 cell lines.

Cytotoxic activity of alkyl benzoate and fatty acids from the red sea sponge Hyrtios erectus

The chemical investigation of the methylene chloride fraction of marine sponge Hyrtios erectus led to the isolation of the known oxysterol (2) along with a new alkyl benzoate compound identified by spectroscopic methods (NMR and MS) as 4'-methylheptyl benzoate (1), whilst the n-butanol fraction afforded the known indole 3-carbaldehyde and β-carboline derivatives. Moreover, the hexane fraction was analysed by GC-MS for their fatty acids (FAs). A total of 17 FAs with chain lengths between 14 and 25 carbons were identified. Methyl-branched FAs are predominated suggesting the presence of bacterial symbionts in the H. erectus sponge. Furthermore, compounds 1 and 2 displayed significant cytotoxicity against breast adenocarcinoma (MCF-7) with IC₅₀ values of 2.4 and 3.8 μM, respectively, since compound 2 was also shown to have potent cytotoxic effect against hepatocellular carcinoma cells (HepG 2) with IC₅₀ value of 1.3 μM.

Antiproliferative and Proapoptotic Activities of Marine Sponge Hyrtios erectus Extract on Breast Carcinoma Cell Line (MCF-7)

Background:

Marine sponge is a rich natural resource of many pharmacologically important compounds.

Objective:

Marine sponge Hyrtios erectus, collected from North Bay, South Andaman Sea, India, was screened for potential antiproliferative and proapoptotic properties on a breast adenocarcinoma cell line (MCF-7).

Materials and Methods:

3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to test the antiproliferative and cytotoxicity effects of the sponge extract. Analysis of apoptosis and cell cycle stages were done by flow cytometry. The expression of several apoptotic-related proteins in MCF-7 cells treated by the extract was evaluated by Western blot analysis. Various analytical techniques including Fourier transform infrared spectroscopy, gas chromatography-mass spectrometry, and nuclear magnetic resonance were employed to determine the identity of the active compounds in the sponge extract.

Results:

N-Hexane extract of the sponge inhibited proliferation of the MCF-7 cell line in a dose- and time-dependent manner. Exposure of the sponge extract triggered apoptosis of the MCF-7 cells, induced DNA fragmentation, and arrested the cells in G₂/M phase. Treatment of the sponge extract induced downregulation of antiapoptotic Bcl-2 protein and upregulation of Bax, caspase-3, caspase-9, and fragmented poly(ADP ribose)polymerase proteins in MCF-7 cells. Five bioactive compounds have been identified in the extract.

Conclusion:

The antiproliferative and proapoptotic activities of the tested extract suggested the pharmacologic potential of the identified compounds. Further characterization of the identified compounds are in progress.

SUMMARY

The N-hexane extract of the marine sponge Hyrtios erectus, collected from North Bay, South Andaman Sea, India, showed potential antiproliferative and proapoptotic properties against a breast adenocarcinoma cell line (MCF-7).

The sponge extract retarded the growth of breast carcinoma cell line MCF-7 cells in a time- and dose-dependent manner.

The sponge extract induced apoptosis of breast cancer cell line MCF-7 and arrested cells in G₂/M phase.

The sponge extract induced downregulation of Bcl-2 protein in MCF-7 cell line and upregulation of Bax, caspase-3, and cleaved PARP. Five bioactive compounds have been identified in the extract.

Abbreviations used: GC-MS: Gas chromatography-mass spectrometry; FT-IR: Fourier transform infrared spectroscopy; NMR: Nuclear magnetic resonance; MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide.

Antiproliferative Scalarane-Based Metabolites from the Red Sea Sponge Hyrtios erectus

Two new sesterterpenes analogs, namely, 12-acetoxy,16-epi-hyrtiolide (1) and 12β-acetoxy,16β-methoxy,20α-hydroxy-17-scalaren-19,20-olide (2), containing a scalarane-based framework along with seven previously reported scalarane-type sesterterpenes (3–9) have been isolated from the sponge Hyrtios erectus (order Dictyoceratida) collected from the Red Sea, Egypt. The structures of the isolated compounds were elucidated on the basis of their spectroscopic data and comparison with reported NMR data. Compounds 1–9 exhibited considerable antiproliferative activity against breast adenocarcinoma (MCF-7), colorectal carcinoma (HCT-116) and hepatocellular carcinoma cells (HepG2). Compounds 3, 5 and 9 were selected for subsequent investigations regarding their mechanism of cell death induction (differential apoptosis/necrosis assessment) and their influence on cell cycle distribution.

Cytotoxic scalarane-type sesterterpenes from the Saudi Red Sea sponge Hyrtios erectus

The CHCl3/MeOH extract of the marine sponge Hyrtios erectus showed cytotoxicity against three cancer cell lines HepG2, A549, and PC-3 with IC50 0.055, 0.044, and 0.023 μg/ml, respectively. The CH2Cl2 soluble fraction afforded three scalarane sesterterpenes (1-3) along with a cholestane derivative (4) and an indole alkaloid (5). Chemical structures were established by spectroscopic techniques and comparison with data reported in the literature. Scalarinol (1) was found as a new metabolite, while heteronemin (2) and 12-O-deacetyl-19-deoxyscalarin (3) are known compounds. 1-3 exhibited cytotoxic activity against the cancer cell lines with IC50 values ranging from 14 to 230 μM. The molecular affinity to the DNA was employed as marker to examine the proposed mechanism of cytotoxic activities. Compound 2, with IC50 28 μg/ml, displayed the highest affinity to the DNA.

A New Bioactive Metabolite Isolated from the Red Sea Marine Sponge Hyrtios erectus

Chemical investigation of the lipophilic fraction of Hyrtios erectus, a Red Sea sponge, yielded a new pentacyclic nitrogen-containing scalarane; 24-methoxypetrosaspongia C (1), together with the previously reported scalaranes sesterstatin 3 (2), 12-deacetyl-12-epi-scalaradial (3) and 12-deacetyl-12,18-di-epi-scalaradial (4). The compounds were identified using HRESIMS, 1D and 2D NMR experiments. The isolated compounds showed growth inhibitory activity against hepatocellular carcinoma (HepG2), colorectal carcinoma (HCT-116) and breast adenocarcinoma cells (MCF-7).