Triterpenoid saponins from Anemone rivularis var. flore-minore

Anti-Inflammatory Triterpenoids from the Caulophyllum robustum Maximin LPS-Stimulated RAW264.7 Cells

Caulophyllum robustum Maxim is widely distributed in China and used as a traditional herbal medicine to induce childbirth, ease the pain of labor, rectify delayed or irregular menstruation, alleviate heavy bleeding and pain during menstruation, and treat external injuries and irregular menses. According to our detailed chemical investigation, three new triterpene derivatives (1–3), together with seven known compounds, were isolated from the root and rhizome of C. robustum Maxim. Their structures were elucidated by 1D- and 2D-NMR spectroscopic analysis and physio-chemical methods. They were identified as (1) 23-hydroxy-3,19-dioxo-olean-12-en-28-oic-acid; (2) 23-hydroxy-3,11-dioxo-olean-12-en-28-oic acid; and (3) 16α,23-dihydroxy-3-oxo-olean-12-en-28-oic acid. Compounds (1–10) inhibited the LPS-activated NO production in RAW264.7 cells. Furthermore, the anti-inflammatory characteristics of these compounds were confirmed on the basis of decreases in iNOS and NF-κB protein expression in RAW264.7 cells.

Triterpenoid Saponins from Anemone rivularis var. Flore-Minore and Their Anti-Proliferative Activity on HSC-T6 Cells

Five previously undescribed triterpenoid saponins (1–5), along with eight known ones (6–13), were isolated from the whole plants of Anemone rivularis var. flore-minore. Their structures were clarified by extensive spectroscopic data and chemical evidence. For the first time, the lupane-type saponins (3 and 12) were reported from the Anemone genus. The anti-proliferative activity of all isolated saponins was evaluated on hepatic stellate cells (HSC-T6). Saponins 12 and 13, which possess more monosaccharides than the others, displayed potent anti-proliferative activity, with IC₅₀ values of 18.21 and 15.56 μM, respectively.

Anemone rivularis inhibits pyruvate dehydrogenase kinase activity and tumor growth

ETHNOPHARMACOLOGICAL RELEVANCE

Anemone rivularis Buch.-Ham. ex DC. (Ranunculaceae) have been used as a traditional remedy for treatment of inflammation and cancer. However, there is no report demonstrating experimental evidence on anti-tumor action of A. rivularis.

AIM OF STUDY

The Warburg's effect, preference of aerobic glycolysis rather than oxidative phosphorylation (OXPHOS) even in oxygen rich condition, is focused as one of major characteristics of malignant tumor. Thus, we investigated the effect of A. rivularis on the Pyruvate dehydrogenase (PDH) kinases (PDHKs), a major molecular targets for reducing aerobic glycolysis.

MATERIALS AND METHODS

The ethanol extract of whole plant of A. rivularis (ARE), fingerprinted by high performance liquid chromatography (HPLC), was applied to in vitro and cell-based PDHK activity assays. The effect of ARE on cell viabilities of several tumor cells was estimated by MTT assay. The expression of phosphor-PDH, PDH and PDHK1 were measured by Western blot analysis. The production of reactive oxygen species (ROS) and apoptosis was measured by fluorescence-activated cell sorting analysis, using 5-(and-6)-carboxy-2',7'-dichlorodihydrofluorescein diacetate (carboxy-H2DCFDA) and Annexin V/propidium iodide (PI) staining, respectively. Mitochondrial membrane potential was examined by tetramethylrhodamine methyl ester (TMRM) staining. In vivo anti-tumor efficacy of ARE was estimated by means of tumor volume and weight using allograft injection of murine Lewis lung carcinoma (LLC) cells to dorsa of C57BL/6 mice.

RESULTS

ARE inhibited the viabilities of several cancer cells, including MDA-MB321, K562, HT29, Hep3B, DLD-1, and LLC. ARE suppressed PDHK activity in in vitro kinase assay, and also inhibited aerobic glycolysis by reducing phosphorylation of PDHA in human DLD-1 colon cancer and murine LLC cells. The expression of PDHK1, a major isoform of PDHKs in cancer, was not affected by ARE treatment. Moreover, ARE increased the both ROS production and mitochondrial damage. In addition, ARE suppressed the in vitro tumor growth through mitochondria-mediated apoptosis. The growth rates of allograft LLC cells were also reduced by ARE treatment.

CONCLUSIONS

Here, we firstly report that ARE inhibits PDHK activity and growth of tumor in both in vitro and in vivo experiments. Therefore, we suggest ARE as a potential candidate for developing anti-cancer drugs.

Five new alkaloids from the stem bark of Daphniphyllum macropodum

Five new alkaloids, daphnicyclidins M and N (compounds 1 and 2) and calyciphyllines Q-S (compounds 3-5), along with four known ones, paxiphylline C (6), macropodumine B (7), macropodumine C (8) and daphnicyclidin A (9) were isolated from the stem bark of Daphniphyllum macropodum. Calyciphylline Q (3) is the first calyciphylline A derivative possessing a double bond between C-18 and C-19. Their structures and relative configurations were elucidated on the basis of spectroscopic methods, especially 2D NMR techniques. Compounds 1, 2, 8 and 9 exhibited cytotoxic activity against P-388 cells with IC₅₀ values of 5.7, 6.5, 10.3 and 13.8 µM, respectively. Compounds 1 and 2 also showed cytotoxic activity against SGC-7901 cells with IC₅₀ values of 22.4 and 25.6 µM.

Cytotoxic oleanane-type triterpenoid saponins from the Rhizomes of Anemone rivularis var. flore-minore

Phytochemical investigation of the n-BuOH extract of the rhizomes of Anemone rivularis var. flore-minore led to the isolation of five new oleanane-type triterpenoid saponins 1-5, together with five known saponins 6-10. Their structures were determined by the extensive use of 1D and 2D NMR experiments, along with ESIMS analyses and acid hydrolysis. The aglycone of 4 and 5 was determined as 21α-hydroxyoleanolic acid, which was reported in this genus for the first time. The cytotoxicity of these compounds was evaluated against four human cancer cell line, including HL-60 (promyelocytic leukemia), HepG2 (hepatocellular carcinoma), A549 (lung carcinoma) and HeLa (cervical carcinoma). The monodesmosidic saponins 6-8 exhibited cytotoxic activity toward all tested cancer cell lines, with IC50 values in the 7.25-22.38 μM range.

Bioactive oleanane-type saponins from the rhizomes of Anemone taipaiensis

Investigation of the n-BuOH extract of the rhizomes of Anemone taipaiensis led to the isolation of five new oleanane-type triterpenoid saponins (1-5), together with seven known saponins (6-12). Their structures were determined by the extensive use of (1)D and (2)D NMR experiments along with ESIMS analyses and acid hydrolysis. The aglycone of 1, 2 and 4 was determined as siaresinolic acid, which was reported in this genus for the first time. The cytotoxicities of the saponins 1-12, prosapogenins 4a, 5a, 10a-12a and sapogenins siaresinolic acid (SA), oleanolic acid (OA), hederagenin (HE) were evaluated against five human cancer cell lines, including HepG2, HL-60, A549, HeLa and U87MG. The monodesmosidic saponins 6-8, 5a, 10a-12a and sapogenins SA, OA, HE exhibited cytotoxic activity toward all cancer cell lines, with IC50 values ranging from 2.25 to 57.28 μM. Remarkably, the bisdesmosidic saponins 1-4 and 9 showed selective cytotoxicity against the U87MG cells.

Triterpenoids

This review covers the isolation and structure determination of triterpenoids including squalene derivatives, lanostanes, holostanes, cycloartanes, cucurbitanes, dammaranes, euphanes, tirucallanes, tetranortriterpenoids, quassinoids, lupanes, oleananes, friedelanes, ursanes, hopanes, onoceranes and saponins; 308 references are cited.

Oleanane-type saponins from Anemone taipaiensis and their cytotoxic activities

Phytochemical investigation of the n-BuOH extract of the rhizomes of Anemone taipaiensis led to the isolation of three new oleanane-type triterpenoid saponins (1-3), together with four known saponins (4-7). Their structures were elucidated on the basis of spectroscopic analysis and chemical derivatization. All the compounds were isolated for the first time from A. taipaiensis. The cytotoxicity of these compounds was evaluated in five human cancer cell lines including A549 (lung carcinoma), HeLa (cervical carcinoma), HepG2 (hepatocellular carcinoma), HL-60 (promyelocytic leukemia), and U87MG (glioblastoma). The monodesmosidic saponin 4 exhibited cytotoxic activity toward all cancer cell lines, with IC50 values ranging from 6.42 to 18.16 μM. In addition, the bisdesmosidic saponins 1 and 7 showed selective cytotoxicity against the U87MG cells.