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Six new cadinane-type sesquiterpenoids, named Chimnitensin A-F (1-6) were isolated from the leaves of Chimonanthus nitens Oliv. Their structures were elucidated by comprehensive spectroscopic analyses and comparison with structurally related known analogues. In vitro MTT assay showed that all six compounds had cytotoxicity against two selected human breast cancer cell lines (MDA-MB-468 and MDA-MB-231), which indicate their potential of developing into anticancer drugs., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Ethnopharmacological Relevance: Cedrus libani A. Rich (C. libani) is majestic evergreen Mediterranean conifer growing in the mountains of Lebanon. The ethnobotanical and traditional uses of cedar wood oil traces back to ancient times for the treatment of various ailments including cancer. Previous work in our laboratories revealed that himachalol (7-HC), a major sesquiterpene isolated from C. libani, possesses potent cytotoxic activity against various human cancer cell lines as well as promising anti-inflammatory effect in isolated rat monocytes., Aim of the Study: The present study aims to elucidate the mechanism of action behind the cytotoxic activity of 7-HC against murine melanoma cells (B16F-10) and evaluates its chemopreventive effect against chemically-induced skin carcinogenesis in mice., Materials and Methods: 7-HC was extracted and purified from Cedrus libani wood. Cell viability was evaluated using WST-1 kit. Cell cycle analysis and apoptosis were assessed by Flow cytometry using propidium iodide (PI) and fluorescein Isothiocyanate (FITC)-conjugated Annexin V/PI staining respectively. Apoptosis related protein were quantified using western blot. The chemopreventive activity of 7-HC was evaluated for 20 weeks using a DMBA/TPA induced skin carcinogenesis model in Balb/c mice., Results: 7-HC displayed a potent anti-proliferative activity against the melanoma cells with an IC50 of 8.8 μg/ml and 7.3 μg/ml at 24 and 48 h, respectively. Co-treatment with Cisplatin did not show any synergistic or additive effect on cell viability. Flow cytometry analysis using PI revealed that 7-HC treatment (5 and 10 μg/ml) induces the accumulation of cells in the sub-G1 phase and causes a decline in cell populations in the S and G2/M phases. Annexin/PI staining also reveals that 7-HC treatment significantly increases the percentage of cells undergoing early and late apoptosis. Western blot analysis shows that 7-HC treatment decreases the level of the anti-apoptotic protein Bcl-2 and increases the level of the pro-apoptotic protein Bax. A reduction in the level of phosphorylated Erk and Akt was also observed. 7-HC via topical (2.5%), intraperitoneal (10, 25 and 50 mg/kg) or gavage (50 mg/kg) treatment revealed a significant decrease in papilloma volume with no adverse effect on liver and kidney function., Conclusions: The present study demonstrates that 7-HC treatment protects against chemically-induced skin carcinogenesis, promotes cell cycle arrest and induces apoptosis partially through an inhibition of both the MAPK/Erk and PI3K/Akt pathways., Competing Interests: Declaration of competing interest I, Costantine F. Daher, declare that all authors have no competing interests, financial or otherwise., (Copyright © 2020 Elsevier B.V. All rights reserved.)

An investigation of a co-culture of the Armillaria sp. and endophytic fungus Epicoccum sp. YUD17002 associated with Gastrodia elata led to the isolation of eight new compounds, including five protoilludane-type sesquiterpenes (1-5) and three aryl esters (6-8), together with six known analogues (9-14). The assignments of their structures were conducted via extensive analyses of the spectroscopic data and comparison of experimental and calculatedelectronic circular dichroism(ECD)data. Notably, these new compounds were not present in the pure culture controls and were only detected in the co-cultures. Compound 4 is the first example of an ent-protoilludane sesquiterpenoid scaffold bearing a five-membered lactone. Compound 6 exhibited moderate in vitro cytotoxic activities against five human cancer cell lines (HL-60, A549, MCF-7, SMMC-7721, and SW480) with IC 50 values ranging from 15.80 to 23.03 μM. Moreover, 6 showed weak acetylcholinesterase inhibitory activity (IC 50 value of 23.85 μM)., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Sensitizing activities exerted by 3,4-dihydro-7-hydroxycadalene (1), rac-3,7-dihydroxy-3(4H)-isocadalen-4-one (4) and (1R,4R)-4H-1,2,3,4-tetrahydro-1-hydroxycadalen-15-oic acid (9), the major cadinanes isolated from Heterotheca inuloides, towards multidrug-resistant MES-SA/MX2 and parental MES-SA epithelial human uterine sarcoma cell lines were evaluated. We also evaluated the in silico interactions (expressed as ΔG binding in kcal/mol) of cadinanes 1, 4 and 9 in an in vitro assay, and also tested several structurally related natural compounds with the multidrug resistance protein (MDR1, P-glycoprotein), human multidrug resistance protein 1 (MRP1), and breast cancer resistance protein (BCRP) structures as pharmacological targets using AutoDock and AutoDock Vina. Compound 1 potentiated the cytotoxicity of doxorubicin and mitoxantrone drugs in resistant MES-SA/MX2 cells, compared to cells treated with each drug alone. Compound 1 could reverse the resistance to doxorubicin 12.44 fold at a concentration of 5 μM. It also re-sensitized cells to mitoxantrone 3.94 fold. Hence, compound 1 may be considered as a potential chemosensitizing agent to overcome multidrug resistance in cancer. The docking analysis suggested that there are interactions between cadinanes from H. inuloides and MDR1, MRP1, and BCRP proteins mainly through π-π interactions and hydrogen bonds., (Copyright © 2019 Elsevier Inc. All rights reserved.)