Pseudostellaria heterophylla is used in China not only as a functional food but also as an herb to tonify the spleen, enhance immunity, and treat palpitation. Our previous investigation showed that a fraction enriched in glycosides obtained from the roots of P. heterophylla possessed pronounced protective effects on H9c2 cells against CoCl2-induced hypoxic injury. However, the active compounds responsible for the observed effects were still unknown. In the current investigation, pseudosterins A–C (1–3), three new alkaloids with a 1-ethyl-3-formyl-β-carboline skeleton, together with polydatin, have been isolated from the active fraction. Their structures were elucidated on the basis of spectroscopic analysis and quantum chemical calculations. The four compounds showed cardioprotective effects against sodium hydrosulfite-induced hypoxia-reoxygenation injury in H9c2 cells, with the three alkaloids being more potent. This is also the first report of alkaloids with a β-carboline skeleton isolated from P. heterophylla as cardioprotective agents.
The roots of Euphorbia fischeriana have been used as a traditional Chinese medicine for the treatment of tuberculosis and ringworm. In the current study, diterpenoids from the ethyl acetate extract of the roots E. fischeriana and their cytotoxic effects against five cancer lines were investigated. Two new ent-abietane diterpenoids, euphonoids H and I (1–2), as well as their two analogues (3–4) were first isolated from this source. The structures of the two new compounds were elucidated on the basis of spectroscopic data and quantum chemical calculation. Their absolute configurations were assigned via ECD spectrum calculation. The isolated compounds were evaluated for their antiproliferative activities against five cancer cell lines. Compounds 1 and 2 exhibited significant inhibitory effects against human prostate cancers C4-2B and C4-2B/ENZR cell lines with IC50 values ranging from 4.16 ± 0.42 to 5.74 ± 0.45 μM.
Liver fibrosis is the initial pathological process of many chronic liver diseases. Targeting hepatic stellate cell (HSC) activation is an available strategy for the therapy of liver fibrosis. We aimed to explore the anti-liver fibrosis activity and potential mechanism of phomopsterone B (PB) in human HSCs. The results showed that PB effectively attenuated the proliferation of TGF-β1-stimulated LX-2 cells in a concentration-dependent manner at doses of 1, 2, and 4 μM. Quantitative real-time PCR and Western blot assays displayed that PB significantly reduced the expression levels of α-SMA and collagen I/III. AO/EB and Hoechst33342 staining and flow cytometry assays exhibited that PB promoted the cells’ apoptosis. Meanwhile, PB diminished the number of autophagic vesicles and vacuolated structures, and the LC3B fluorescent spots indicated that PB could effectively inhibit the accretion of autophagosomes in LX-2 cells. Moreover, rapamycin and MHY1485 were utilized to further investigate the effect of mTOR in autophagy and apoptosis. The results demonstrated that PB regulated autophagy and apoptosis via the mTOR-dependent pathway in LX-2 cells. In summary, this is the first evidence that PB effectively alleviates liver fibrosis in TGF-β1-stimulated LX-2 cells, and PB may be a promising candidate for the prevention of liver fibrosis.
Three new compounds including a meroterpenoid (1) and two isocoumarins (8 and 9), together with thirteen known compounds (2–7, 10–16) were isolated from the metabolites of Talaromyces amestolkiae MST1-15. Their structures were identified by a combination of spectroscopic analysis. The absolute configuration of compound 1 was elucidated on the basis of experimental and electronic circular dichroism calculation, and compounds 8 and 9 were determined by Mo2(OAc)4-induced circular dichroism experiments. Compounds 7–16 showed weak antibacterial activities against Stenotrophomonas maltophilia with MIC values ranging from 128 to 512 μg/mL (MICs of ceftriaxone sodium and levofloxacin were 128 and 0.25 μg/mL, respectively).