The pro-apoptotic activity of sinueracasbanone D isolated from Sinularia Leptoclados in hepatocellular carcinoma cells

The soft-bodied corals of the genera Sarcophyton and Sinularia (Alcyoniidae) are known as a warehouse of casbane and cembranoid diterpenoids with remarkable antitumor effects. Two casbane-type diterpenoids (1, 2) along with four cembrane-type diterpenoids (3-6) were isolated from the diethyl ether soluble fraction of the organic extracts of the Red Sea soft corals Sinularia leptoclados and Sarcophyton glaucum, respectively. The antiproliferative activity of all isolated compounds (1-6) against three hepatocellular carcinoma cells, namely, Huh-7, SNU 499, and HepG2, along with the normal cells EA.hy 926, was evaluated. Sinueracabanone D (1) displayed a remarkable antiproliferative effect against the examined cancer cell lines, especially HepG2 cells with IC₅₀ of 4.0 ± 0.37 µM. Cell cycle analysis indicated compound 1 caused the accumulation of HepG2 cells in the G2/M-phase. Further, compound 1 exhibited significant pro-apoptotic activities in HepG2 cells as evidenced by annexin V staining, enhanced mRNA expression of Bax, cytochrome C, and caspase 3, as well as inhibition of Bcl2 expression. Also, challenging HepG2 cells with sinueracabanone D (1) enhanced the active oxygen species generation and decreased mitochondrial membrane potential. In conclusion, compound 1 possesses potent antiproliferative activities against HepG2 cells. These antiproliferative activities are mediated, at least partly, by their ability to induce apoptosis, mitochondrial dysfunction, and oxidative stress.

Green Synthesis of TiO2 Nanoparticles Using Natural Marine Extracts for Antifouling Activity

Titanium dioxide (TiO₂) nanoparticles were synthesized via a novel eco-friendly green chemistry approach using marine natural extracts of two red algae (Bostrychia tenella and Laurencia obtusa), a green alga (Halimeda tuna), and a brown alga (Sargassum filipendula) along with a marine sponge sample identified as Carteriospongia foliascens. X-ray diffraction (XRD), scanning electron microscope (SEM), UV-Vis, X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR) were employed to characterize the crystal structure, surface morphology, and optical properties of the synthesized nanoparticles. Each of the as-synthesized marine extract based TiO₂ nanoparticles was individually incorporated as an antifouling agent to form a newly fabricated marine paint formulation. The newly prepared formulations were applied on unprimed steel panels. A comparative study with a commercial antifouling paint (Sipes Transocean Coatings Optima) was carried out. After 108 days of the coated steel panels' immersion in the Eastern Harbour seawater of Alexandria-Egypt, the prepared paints using B. tenella and C. foliascens extracts demonstrated an excellent antifouling performance toward fouling organisms by inhibiting their settlement and controlling their adhesion onto the immersed panels. In contrast, heavy fouling with barnacles was observed on the surface of the coated panel with the commercial paint. The physicochemical parameters of the seawater surrounding the immersed coated panels were estimated to investigate the influence of the fabricated paint formulations. Interestingly, no effects of the immersed coated panels on the physicochemical characteristics of the surrounding seawater were observed. Based on the obtained results and a comparison with commercially available antifouling products, the marine extract based TiO₂ nanoparticle preparations of B. tenella and C. foliascens are promising candidates for eco-friendly antifouling agents. Based on the obtained results and a comparison with commercially available antifouling products, the marine extract based TiO₂ nanoparticle preparations of B. tenella and C. foliascens are promising candidates for eco-friendly antifouling agents, which could be attributed to the small crystallite sizes of 22.86 and 8.3 nm, respectively, in addition to the incorporation of carbon in the crystal structure of the nanoparticles.

Exploring the Mangrove Fruit: From the Phytochemicals to Functional Food Development and the Current Progress in the Middle East

Nowadays, the logarithmic production of existing well-known food materials is unable to keep up with the demand caused by the exponential growth of the human population in terms of the equality of access to food materials. Famous local food materials with treasury properties such as mangrove fruits are an excellent source to be listed as emerging food candidates with ethnomedicinal properties. Thus, this study reviews the nutrition content of several edible mangrove fruits and the innovation to improve the fruit into a highly economic food product. Within the mangrove fruit, the levels of primary metabolites such as carbohydrates, protein, and fat are acceptable for daily intake. The mangrove fruits, seeds, and endophytic fungi are rich in phenolic compounds, limonoids, and their derivatives as the compounds present a multitude of bioactivities such as antimicrobial, anticancer, and antioxidant. In the intermediary process, the flour of mangrove fruit stands as a supplementation for the existing flour with antidiabetic or antioxidant properties. The mangrove fruit is successfully transformed into many processed food products. However, limited fruits from species such as Bruguiera gymnorrhiza, Rhizophora mucronata, Sonneratia caseolaris, and Avicennia marina are commonly upgraded into traditional food, though many more species demonstrate ethnomedicinal properties. In the Middle East, A. marina is the dominant species, and the study of the phytochemicals and fruit development is limited. Therefore, studies on the development of mangrove fruits to functional for other mangrove species are demanding. The locally accepted mangrove fruit is coveted as an alternate food material to support the sustainable development goal of eliminating world hunger in sustainable ways.

Antiproliferative Isoprenoid Derivatives from the Red Sea Alcyonacean Xenia umbellata

From the soft coral Xenia umbellata, seven isoprenoid derivatives were isolated, including a new xenicane diterpene, xeniolide O (5) and a new gorgostane derivative gorgst-3β,5α,6β,11α,20(S)-pentol-3-monoacetate (7), along with three known sesquiterpenes (1-3), a known diterpene (4), and a known steroid (6). The extensive analyses of the NMR, IR, and MS spectral data led to determination of their chemical structures. Compounds 1-7 displayed a cytotoxic effect against breast adenocarcinoma (MCF-7), hepatocellular carcinoma (HepG2), and cervix adenocarcinoma (HeLa), with IC50 values ranging between 1.5 ± 0.1-23.2 ± 1.5; 1.8 ± 0.1-30.6 ± 1.1 and 0.9 ± 0.05-12.8 ± 0.5 μg/mL, respectively. Compound 3 showed potent cytotoxic effects against MCF-7, HepG2, and HeLa with IC50 values = 2.4 ± 0.20, 3.1 ± 0.10 and 0.9 ± 0.05 μg/mL, respectively. Compounds 2, 5, and 7 displayed cytotoxic effect against Hela cells with IC50 values = 12.8 ± 0.50, 6.7 ± 1.00 and 11.5 ± 2.20 μg/mL, respectively. Two DNA binding dyes, acridine orange (AO) and ethidium bromide (EtBr) were used for the detection of viable, apoptotic, and necrotic cells. The early apoptotic cell death was observed in all types of treated cells. The late apoptotic cells were highly present in HepG2 cells. Compounds 5 and 7 induced a high percentage of necrosis towards HepG2 and HeLa cells. The late apoptosis was recorded as a high rate after treatment with 7 on all cancer cells.

Cytotoxic effect of acetogenins and sesquiterpenes obtained from the Red alga <i>Laurencia majuscula</i>

Purpose: To evaluate the cytotoxicity of n-hexane extract and its metabolites obtained from the red alga, Laurencia majuscula, against three cancer cell lines HCT-116 (colon cancer), PC-3 (prostate cancer) and HepG2 (liver cancer) cells; and to identify the phytochemical compound(s) involved. Methods: Solvent extraction, thin layer chromatography, aluminum oxide column chromatography, and preparative thin layer chromatography (PTLC) were employed for isolating pure compounds from nhexane extract of Laurencia majuscula. Nuclear magnetic resonance (NMR) and mass spectrometry (MS) measurements were used for structural elucidation of the compounds. The cytotoxicity of the nonpolar extract and isolated compounds were evaluated against HCT, PC-3, and HepG2 cells using MTT assay, relative to the standard cytotoxic drug (cisplatin). Results: Three sesquiterpenes (1, 2 and 8), and five acetogenins (3-7) were isolated from the n-hexane extract. The n-hexane extract showed higher potent cytotoxic effect than sesquiterpenes and the acetogenins (3-7). Conclusion: These results indicate that the n-hexane extract of Laurencia majuscula exerts significant cytotoxicity against HCT-116, PC-3 and HepG2 cell lines, thus suggesting that the plant extract may be effective chemotherapeutic agents for the management of colon, postrate and liver cancer. Keywords: Red Sea alga, Rhodomelaceae, Polyketides, Terpenes, Anticancer

A new steroid glycoside from Begonia sp.: cytotoxic activity and docking studies

Chemical investigation on the ethyl acetate extract of the aerial parts of Begonia sp. afforded a new steroid glycoside, 9(11)α,16(17)α-dioxirane-20,25-dihydroxy-β-sitosterol-3-O-β-glucopyranoside (1) along with a known steroidal glycoside, β-sitosterol-3-O-β-D-glucopyranoside (2). The Chemical structures were elucidated by 1D and 2D NMR and mass spectroscopic analysis. Cytotoxicity against four different cancer cell lines (HeLa, T47D, WiDr and Vero) was assessed. Compound 1 was more potent and selective against breast cancer cell line (T47D) than other cell lines with an IC₅₀ value of 0.16 µg/mL. Further docking study of 1 exhibited the preference of molecule to bind in the epidermal growth factor receptor tyrosine kinase (EGFR-TK) binding pockets with docking scores of -97.8800 (PLANTS) and -3.56 kcal/mol (AutoDock 4.2.6).

Isolation, antimicrobial and antitumor activities of a new polyhydroxysteroid and a new diterpenoid from the soft coral Xenia umbellata

A new C-30 steroid, 3β-,5α-,6β-,11α-,20β-pentahydroxygorgosterol (1), and a new diterpenoid, xeniumbellal (2), along with three known aromadendrane-type sesquiterpenes, aromadendrene (3), palustrol (4) and viridiflorol (5), were isolated from the soft coral Xenia umbellata. Chemical structures were determined by analyzing their NMR and MS data. The antimicrobial and antitumor activities of the isolated compounds were examined. Both 1 and 2 showed moderate antibacterial activities, especially against the multidrug-resistant Acinetobacter baumannii (MIC 0.22 and 0.28 mM, respectively); while 2 showed antitumor activity against a lymphoma cell line with LD50 0.57 mM and was nontoxic to Artemia salina at all tested concentrations up to about 4 mM.

Antimicrobial sesquiterpenoids from Laurencia obtusa Lamouroux

Purification of the organic extract of Laurencia obtusa Lamouroux by column chromatography and preparative thin layer chromatography provided four new compounds: a eudesmane-type sesquiterpenoid [eudesma-4(15),11-diene-5,7-diol (1)], a cuparane-type sesquiterpenoid [10-hydroxycuparaldehyde (2)], and two nor-cuparanes [3-hydroxy-15-nor-cuparan-10β-ol (3) and 2-bromo-3-hydroxy-15-nor-cuparan-10β-ol (4)]. Structural identification was made possible by comparison of spectral data with those reported in the literature. Compounds 3 and 4 are significant as nor-cuparanes are rarely isolated from marine environment. 1 showed moderate anticandidal activity, whereas 2 exhibited reasonable antibacterial activity against multidrug-resistant bacteria (especially Gram-positive). All the compounds are nontoxic to Artemia salina.

Isolaurenidificin and Bromlaurenidificin, Two New C15-Acetogenins from the Red Alga Laurencia obtusa

Chromatographic fractionation of the CH₂Cl₂/MeOH extract of the Red Sea red alga Laurencia obtusa gave two new hexahydrofuro[3,2-b]furan-based C15-acetogenins, namely, isolaurenidificin (1) and bromlaurenidificin (2). The chemical structures were elucidated based on extensive analyses of their spectral data. Compounds 1 and 2 showed no toxicity (LC50 > 12 mM) using Artemia salina as test organism. Both compounds showed weak cytotoxicity against A549, HepG-2, HCT116, MCF-7, and PC-3 cells, however, they exhibited a relatively potent cytotoxic activity against peripheral blood neutrophils. This can be attributed partly to induction of apoptosis.

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.

Two new polyacetylene derivatives from the Red Sea sponge Xestospongia sp

Two new polyacetylenes (1 and 2), along with two known C-30 steroids (3 and 4) were identified from the Red Sea sponge, Xestospongia sp. The chemical structures were determined based on extensive spectroscopic measurements 1D (1H, 13C and DEPT) and 2D (COSY, HSQC and HMBC) NMR, UV, IR and MS. The new compounds 1 and 2 were evaluated for their antimicrobial and antitumor activities. 1 and 2 were active against multidrug- resistant bacteria with MICs ranged from 2.2 to 4.5 μM. No toxicity was recorded for the two tested compounds up to 5 μM using Artemia salina as a test organism. Compound 2 showed excellent antifungal activity against some pathogenic fungi such as Aspergillus niger and Candida albicans (MIC 2.2-2.5 μM) and antitumor activity against both Ehrlich ascites carcinoma and lymphocytic leukemia (LD50 5.0 μM).

Differential cytotoxic activity of the petroleum ether extract and its furanosesquiterpenoid constituents from Commiphora molmol resin

This study revealed a differential cytotoxic activity of the petroleum ether extract (IC₅₀ =5 μg/mL) of the resinous exudates of Commiphora molmol against two mouse cell lines KA31T and NIH3T3 (untransformed and transformed mouse fibroblasts, respectively). Four new compounds (1-4) and five known compounds (5-9) were isolated from the petroleum ether extract. The identity of these new compounds was determined as γ-elemane lactone (1), 5-αH,8-βH-eudesma-1,3,7(11)-trien-8,12-olide (2), 2-hydroxy-11,12-dihydrofuranodiene (3), and 2-hydroxyfuranodiene (4). 1 and 2 displayed the highest cytotoxic activity against NIH3T3 cells. 7 and 9 exhibited moderate cytotoxic activity against KA31T cells. Compounds 3-6 showed weak cytotoxic activities against both cell lines. These results may explain the high efficacy of the petroleum ether fraction in several myrrh-derived pharmaceutical preparations.