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PDB-1 is a new C-27-carboxylated-lupane-triterpenoid derivative isolated from Potentilla discolor Bunge. In our previous research, PDB-1 was suggested to have an obvious selectivity for tumor cells. This study focused on clarifying PDB-1's anticancer mechanism in the inhibition of proliferation and in the induction of apoptosis and autophagy in A549 cells. In general, A549 cells were treated with PDB-1 for different times, and cell survival was assessed by a CCK8 assay. The assessment of intracellular reactive oxygen species, a mitochondrial membrane potential assay, a cell cycle assay, an annexin V-FITC/PI assay, and MDC staining were performed in A549 cells treated with PDB-1. Moreover, the mRNA and protein expression of cell cycle-, apoptosis- and autophagy-related factors were detected by RT-qPCR and western blotting. The results showed that PDB-1 inhibited A549 cell proliferation and colony formation in a dose- and time-dependent manner. The decrease in the viability of A549 cells was due to a G2/M cell cycle arrest. Moreover, PDB-1 induced cell apoptosis, accompanied by an increase in the Bax/Bcl-2 ratio and an increase in the expression levels of cleaved caspase-3/caspase-9. We also found that PDB-1 induced autophagy by increasing the conversion of LC3-I to LC3-II and elevating Beclin-1. In addition, further studies indicated that pretreatment with a specific PI3K inhibitor (LY294002) enhanced the effects of PDB-1 on the expression of proteins associated with apoptosis and autophagy, demonstrating that the PI3K/Akt/mTOR pathway was related to PDB-1-induced apoptosis and autophagy. These results indicated that PDB-1 may be considered a potential candidate for the future treatment of lung adenocarcinoma. These findings should benefit the development of the C 14 -COOH type of pentacyclic triterpenoids., (Copyright © 2020. Published by Elsevier Masson SAS.)

Background: The use of plant essential oils as pharmaceuticals is a fast-growing market especially in China. Throughout the 20th century, a rapid increase took place in the use of many essential oil-derived products in the medicinal industry as nutraceuticals, medicinal supplements, and pharmaceuticals., Purpose: The objective of this study was to explore the chemical composition of Croton crassifolius essential oil as well as its potential anti-tumour properties and related anti-proliferative, autophagic, and apoptosis-inducing effects., Methods: Supercritical CO 2 fluid extraction technology was used to extract CCEO and the chemical constituents of the essential oil were identified by comparing the retention indices and mass spectra data taken from the NIST library with those calculated based on the C7-C40 n-alkanes standard. The cytotoxic activity and anti-proliferative effects of CCEO were evaluated against five cancer cell lines and one normal human cell line via CCK-8 assays. In addition, flow cytometry was used to detect cell cycle arrest. The efficacy of CCEO treatments in controlling cancer cell proliferation was assessed by cell cycle analysis, clonal formation assays, RT-qPCR, and western blot analysis. Autophagic and apoptosis-inducing effects of oils and the associated molecular mechanisms were assessed by flow cytometry, cell staining, reactive oxygen species assays, RT-qPCR, and western blot analysis., Conclusion: Forty compounds representing 92.90% of the total oil were identified in CCEO. The results showed that CCEO exerted a measurable selectivity for cancer cell lines, especially for A549 with the lowest IC 50 value of 25.00 ± 1.62 μg/mL. Assessment of the anti-proliferative effects of CCEO on A549 cells showed that the oil inhibited cell proliferation and colony formation in a dose- and time-dependent manner. Investigation of the molecular mechanisms of cell cycle regulation confirmed that the oil arrested A549 cells in G2/M phase by decreasing the expression of cyclin B1-CDK1 and cyclin A-CDK1 and increasing the expression of cyclin-dependent kinase inhibitor (CKI) P21 at both the transcriptional and translational levels. Autophagy staining assays and western blot analysis revealed that CCEO promoted the formation of autophagic vacuoles in A549 cells and increased the expression of autophagy-related proteins beclin-1 and LC3-II in a dose-dependent manner. A series of apoptosis analyses indicated that CCEO induces apoptosis through a mitochondria-mediated intrinsic pathway. This study revealed that CCEO is a promising candidate for development into an anti-tumour drug of the future., (Copyright © 2019 Elsevier GmbH. All rights reserved.)

Three new lupane-triterpenoids (1–3) along with six known compounds (4–9) were isolated from the ethanolic extract of whole plant of Potentilla discolor Bunge. The structures of Compounds 1–3 were established by extensive 1D and 2D NMR together with other spectrum analysis, indicating that their C-27 positions were highly oxygenated, which were rarely found in nature. Their in vitro anti-proliferative activities against HepG-2, MCF-7 and T-84 cell lines were evaluated by Cell Counting Kit-8 (CCK-8) assay, and the results showed different activities for three cell lines with IC50 values ranging from 17.84 to 40.64 μM. In addition, the results from Hoechst 33258 and AO/EB staining as well as annexinV-FITC assays exhibited Compound 1 caused a markedly increased HepG-2 cellular apoptosis in a dose-dependent manner. The further mechanisms of Compound 1-induced cellular apoptosis were confirmed that 1 induced the production of ROS and the alteration of pro- and anti-apoptotic proteins, which led to the dysfunction of mitochondria and activation of caspase-9 and caspase-3 and finally caused cellular apoptosis. These results would be useful in search for new potential antitumor agents and for developing semisynthetic lupane-triterpenoid derivatives with high antitumor activity. [ABSTRACT FROM AUTHOR]

The root of Croton crassifolius has been used as a traditional Chinese medicine (TCM), called Radix Croton Crassifolius, and commonly known as "Ji Gu Xiang" in Chinese. Its medicinal value has been recorded in several medical books or handbooks, such as "Sheng Cao Yao Xing Bei Yao", "Ben Cao Qiu Yuan" and "Zhong Hua Ben Cao". It has been traditional employed for treating sore throat, stomach-ache, rheumatism and cancer. At present, there are limited studies on the evaluation of low-polarity extracts of roots in C. crassifolius. Consequently, the aim of this study was to evaluate the antitumor effect of the low-polarity extract of C. crassifolius root. Extracts were obtained by supercritical fluid extraction. The extracts were tested for antitumor effects in vitro on several cancer cell lines. A CCK-8 kit was used for further analysis of cell viability. A flow cytometer and propidium iodide staining were used to evaluate the cell cycle and apoptosis. Hoechst staining, JC-1 staining and the fluorescence probe DCFH-DA were used to evaluate apoptotic cells. Molecular mechanisms of action were analyzed by quantitative RT‒PCR and Western blotting. Immunohistochemistry was used for the evaluation of xenograft tumors in male BALB/c mice. Finally, molecular docking was employed to predict the bond between the desired bioactive compound and molecular targets. Eleven diterpenoids were isolated from low-polarity C. crassifolius root extracts. Among the compounds, chettaphanin II showed the strongest activity (IC 50 = 8.58 μM) against A549 cells. Evaluation of cell viability and the cell cycle showed that Chettaphanin II reduced A549 cell proliferation and induced G2/M-phase arrest. Chttaphanin II significantly induced apoptosis in A549 cells, which was related to the level of apoptosis-related proteins. The growth of tumor tissue was significantly inhibited by chettaphanin II in experiments performed on naked mice. The antitumor mechanism of chettaphanin II is that it can obstruct the mTOR/PI3K/Akt signaling pathway in A549 cells. Molecular docking established that chettaphanin II could bind to the active sites of Bcl-2 and Bax. Taken together, the natural diterpenoid chettaphanin II was identified as the major antitumor active component, and its potential for developing anticancer therapies was demonstrated for the first time by antiproliferation evaluation in vitro and in vivo. [Display omitted] • Eleven diterpenoids were obtained from the SFE extract of C. crassifolius roots. • Chettaphanin II showed the strongest antitumor activity against A549 cells. • Chettaphanin II inhibited A549 cell proliferation and arrested cells in G2/M-phase. • Chettaphanin II induced A549 cell apoptosis by inhibiting PI3K/AKT/mTOR pathway. • Chettaphanin II significantly inhibited the growth of tumor tissue in nude mice. [ABSTRACT FROM AUTHOR]

Potentilla discolor has been used as the Traditional Chinese Medicine ingredient in prescription for over 400 years, and scientific evidences have confirmed its effectiveness as an anticancer agent. The present study is undertaken to assess, for the first time, the chemical composition, potential in vitro anti-tumor activities and related mechanisms of the essential oil, which was extracted from Potentilla discolor fresh roots by supercritical CO 2 fluid extraction technology. Twenty-nine compositions were identified by gas chromatography-mass spectrometry. The anti-tumor activity of the essential oil was screened against four cancer cell lines and the lowest IC 50 value was 19.02 μg/mL on T24 cell line. Then, T24 was selected as a representative cell line for the related mechanism research. As a result, cell cycle assay confirmed that the cell growth was inhibited by Potentilla discolor essential oil and cell cycle was arrested in DNA synthesis phase. A series of apoptosis analysis indicated that Potentilla discolor essential oil induced apoptosis through mitochondrion-mediated intrinsic pathway. This study revealed that Potentilla discolor essential oil has significant anti-tumor activity. It should be useful in the search for new potential anti-tumor agents and pharmaceutical industries. [ABSTRACT FROM AUTHOR]