Cytotoxic steroidal glycosides from the rhizomes of Paris polyphylla var. yunnanensis.

Paris polyphylla var. yunnanensis (Franch.) Hand.-Mazz. (Melanthiaceae), an important specie of the genus Paris, has long been in a traditional Chinese medicine (TCM) for a long time. This study aimed to isolate and identify the structures of bioactive saponins from the rhizomes of P. polyphylla var. yunnanensis and evaluate their cytotoxicity against BxPC-3, HepG2, U373 and SGC-7901 carcinoma cell lines. Seven previously undescribed and seven known saponins were identified, and Paris saponins VII (PSVII) showed significant cytotoxicity against the BxPC-3 cell line with IC50 values of 3.59 µM. Furthermore, flow cytometry, transmission electron microscopy and western-bolt analysis revealed that PSVII inhibited the proliferation of BxPC-3 cells and might be involved in inducing apoptosis and pyroptosis by activating caspase-3, -7 and caspase-1, respectively.

Hyperhubeins A-I, Bioactive Sesquiterpenes with Diverse Skeletons from Hypericum hubeiense.

Nine new sesquiterpenes, hyperhubeins A-I (1-9), and 14 known analogues (10-23) were isolated from the aerial portions of Hypericum hubeiense. Their structures and absolute configurations were determined unambiguously via spectroscopic analysis, single-crystal X-ray diffraction, and electronic circular dichroism calculations. Compounds 1-3 possess an unprecedented sesquiterpene carbon skeleton. Further, a plausible biosynthetic pathway from farnesyl diphosphate (FPP) is proposed. The isolated phytochemicals were evaluated for neuroprotective and anti-neuroinflammatory properties in vitro. Compounds 1, 2, 5-8, 14, and 21 displayed notable neuroprotective activity against hydrogen peroxide (H2O2)-induced lesions in PC-12 cells at 10 µM. Additionally, compounds 1, 2, 12, and 13 exhibited inhibition of lipopolysaccharide (LPS)-induced nitric oxide (NO) production in BV-2 microglial cells, with their IC50 values ranging from 4.92 to 6.81 µM. Possible interactions between these bioactive compounds and inducible nitric oxide synthase (iNOS) were predicted via molecular docking. Moreover, Western blotting indicated that compound 12 exerted anti-neuroinflammatory activity by suppressing LPS-stimulated expression of toll-like receptor-4 (TLR-4) and inhibiting consequent activation of nuclear factor-kappa-B (NF-κB) signaling.

Further sesquiterpenoids from Pittosporum qinlingense and their anti-inflammatory activity.

Four new sesquiterpenoid glycoside esters, Pitqinlingoside N-Q (1-4), together with eleven known metabolites (5-15), were isolated from 95% EtOH extract of the twigs, fruits and leaves of P. qinlingense. The structures of new compounds were elucidated on the basis of extensive spectroscopic analyses, including IR, UV, HRMS, NMR and electronic circular dichroism spectra. Unusal glycoside esters are characterized by the presence of polyacylated ß-D-fucopyranosyl and ß-d-glucopyranosyl units. Pitqinlingoside N (1), O (2), P (3), boscialin (5) and arvoside C (6) showed significant nitric oxide production inhibition in lipopolysaccharide (LPS)-induced BV-2 microglial cells with IC50 values ranging from 1.58 to 28.74 µM. Structure-activity relationships of the isolated compounds are discussed.

Novel RAS inhibitor 25-O-methylalisol F attenuates epithelial-to-mesenchymal transition and tubulo-interstitial fibrosis by selectively inhibiting TGF-ß-mediated Smad3 phosphorylation.

BACKGROUND: Tubulo-interstitial fibrosis (TIF) is the common pathway in the chronic kidney disease (CKD). Epithelial-to-mesenchymal transition (EMT) is a major contributor to the TIF by the increased myofibroblasts. Renin-angiotensin system (RAS) is critical mediator on EMT in progressive CKD. Angiotensin II (ANG) mediates EMT and causes TIF by stimulating transforming growth factor-ß1 (TGF-ß1). RAS activation could further activate TGF-ß1. Inhibition of the RAS is one of the most powerful therapies for progressive CKD. 25-O-methylalisol F (MAF) is a new tetracyclic triterpenoid compound isolated from the Alismatis rhizoma, which is extensively used for anti-hypertensive, diuretic and anti-hyperlipidemic effects. METHODS: Inhibitory effect of MAF on EMT is investigated in both TGF-ß1- and ANG-induced tubular epithelial cells (NRK-52E) and fibroblasts (NRK-49F). Western blot analysis, qRT-PCR, siRNA, immunofluorescence staining and co-immunoprecipitation techniques were used to evaluate the inhibition of MAF on EMT and further revealed the intervention effects on RAS, TGF-ß/Smad and Wnt/ß-catenin pathways. RESULTS: MAF treatment significantly inhibited TGF-ß1 and ANG-induced expressions of collagen I, fibronectin, α-SMA, vimentin and E-cadherin at both mRNA and protein levels in the NRK-52E and NRK-49F cells. The action mechanism revealed that MAF significantly ameliorated upregulation of angiotensinogen, renin, ACE and AT1R expressions. Further, MAF attenuated upregulation of Smad3 phosphorylation and downregulation of Smad7, but did not affect the phosphorylation of Smad2, PI3K, ERK1/2 and p38 expressions and Smad4 expression in NRK-52E cells. Co-immunoprecipitation analysis indicated that MAF selectively blocked the combination of Smad3 with TGFßRI and Smad3 with SARA without interfering with the Smad2, TGFßRI and SARA interaction. Additionally, MAF suppressed the expressions of Wnt1 and ß-catenin as well as its downstream target Snail1, Twist, MMP-7, PAI-1 and FSP1 expressions in NRK-52E cells. CONCLUSIONS: MAF simultaneously targeted multiple RAS components and it was a novel RAS inhibitor. MAF inhibited EMT by Smad3-specific signaling in the TGF-ß/Smad-dependent pathway and Wnt/ß-catenin pathway. MAF has an important effect on crosstalk between the TGF-ß/Smad and Wnt/ß-catenin pathway in EMT process by activation of RAS.

Poricoic acid ZA, a novel RAS inhibitor, attenuates tubulo-interstitial fibrosis and podocyte injury by inhibiting TGF-ß/Smad signaling pathway.

BACKGROUND: The pathogenesis of tubulo-interstitial fibrosis and glomerulosclerosisis was characterized by cellular hypertrophy, extracellular matrix accumulation and podocyte detachment. Poricoic acid ZA (PZA) is a tetracyclic triterpenoid compound extracted from the surface layer of Poria cocos (LPC), which have been used extensively for diuretic and renoprotective effects. METHODS: The anti-fibrotic effect of PZA is investigated in HK-2 cells and podocytes induced by TGF-ß1 and angiotensin II (ANGII). qRT-PCR, siRNA, immunofluorescence staining, co-immunoprecipitation and Western blot analyses are used to evaluate the expression of RAS signaling, TGF-ß/Smad pathway, epithelial-to-mesenchymal transition (EMT) and podocyte markers. RESULTS: PZA restores the mRNA and protein expression of EMT in HK-2 cells. Specific TGF-ß1-siRNA efficiently blocks ANGII-induced protein expression of TGF-ß1 and further inhibits activated Smad signaling. PZA significantly attenuates up-regulation of angiotensinogen, renin, ACE and AT1. Further, PZA reverses up-regulation of TGFßRII and suppresses Smad proteins. Simultaneously, PZA inhibits the protein interaction of TGF-ß receptor and Smads and PZA also inhibits activated RAS and TGF-ß/Smad signaling cascade and up-regulates protein expression of podocyte markers and mitigates podocyte injury. CONCLUSIONS: This study demonstrated the beneficial role of PZA in renal fibrosis and podocyte injury. Our study highlighted that PZA inhibits RAS and further suppresses TGF-ß/Smad pathway through inhibiting Smad2/3 phosphorylation via blocking Smad2/3-TGFßRI protein interaction. PZA is implicated in activation of RAS/TGF-ß/Smad axis in HK-2 cells and podocytes. PZA could be considered as a novel RAS inhibitor for treating CKD.

Triterpenoid saponins with anti-myocardial ischemia activity from the whole plants of Clematis tangutica.

Four new triterpenoid saponins named clematangosides A-D (1-4) along with six known saponins (5-10) were isolated from the whole plants of Clematis tangutica. Their structures were determined by extensive spectral analysis and chemical evidences. All saponins were evaluated for their protective effects in hypoxia-induced myocardial injury model. Compounds 2-4, 6, and 10 exhibited anti-myocardial ischemia activities with ED50 values in the range of 75.77-127.22 µM.