Discovery of a botanical compound as a broad-spectrum inhibitor against gut microbial ß-glucuronidases from the Tibetan medicine Rhodiola crenulata.

Gut microbial ß-glucuronidases (gmß-GUS) played crucial roles in regulating a variety of endogenous substances and xenobiotics on the circulating level, thus had been recognized as key modulators of drug toxicity and human diseases. Inhibition or inactivation of gmß-GUS enzymes has become a promising therapeutic strategy to alleviate drug-induced intestinal toxicity. Herein, the Rhodiola crenulata extract (RCE) was found with potent and broad-spectrum inhibition on multiple gmß-GUS enzymes. Subsequently, the anti-gmß-GUS activities of the major constituents in RCE were tested and the results showed that 1,2,3,4,6-penta-O-galloyl-ß-d-glucopyranose (PGG) acted as a strong and broad-spectrum inhibitor on multiple gmß-GUS (including EcGUS, CpGUS, SaGUS, and EeGUS). Inhibition kinetic assays demonstrated that PGG effectively inhibited four gmß-GUS in a non-competitive manner, with the Ki values ranging from 0.12 µM to 1.29 µM. Docking simulations showed that PGG could tightly bound to the non-catalytic sites of various gmß-GUS, mainly via hydrogen bonding and aromatic interactions. It was also found that PGG could strongly inhibit the total gmß-GUS activity in mice feces, with the IC50 value of 1.24 µM. Collectively, our findings revealed that RCE and its constituent PGG could strongly inhibit multiple gmß-GUS enzymes, suggesting that RCE and PGG could be used for alleviating gmß-GUS associated enterotoxicity.

Isochamaejasmin induces apoptosis in leukemia cells through inhibiting Bcl-2 family proteins.

The biflavonoid isochamaejasmin is mainly distributed in the root of Stellera chamaejasme L. (Thymelaeaceae) that is used in traditional Chinese medicine (TCM) to treat tumors, tuberculosis, and psoriasis. Herein, isochamaejasmin was found to show similar bioactivity against Bcl-2 family proteins to the reference Bcl-2 ligand (-)-gossypol through 3D similarity search. It selectively bound to Bcl-xl and Mcl-1 with Ki values being 1.93 ± 0.13 µmol·L(-1) and 9.98 ± 0.21 µmol·L(-1), respectively. In addition, isochamaejasmin showed slight growth inhibitory activity against HL-60 with IC50 value being 50.40 ± 1.21 µmol·L(-1) and moderate growth inhibitory activity against K562 cells with IC50 value being 24.51 ± 1.62 µmol·L(-1). Furthermore, isochamaejasmin induced apoptosis of K562 cells by increasing the intracellular expression levels of proteins of the cleavage of caspase-9, caspase-3, and PARP which involved in the Bcl-2-induced apoptosis pathway. These results indicated that isochamaejasmin induces apoptosis in leukemia cells by inhibiting the activity of Bcl-2 family proteins, providing evidence for further studying the underlying anti-cancer mechanism of S. chamaejasme L.

γ-Hydroxynitrile glucosides from the seeds of Prinsepia utilis.

γ-Hydroxynitrile glucosides (prinsepicyanosides A-E) were isolated alongside 11 known compounds from seeds of Prinsepia utilis Royle. Their structures were determined by detailed analysis of NMR and MS spectroscopic data. The relative configuration of prinsepicyanoside C was established by Cu-Kα X-ray crystallography. Prinsepicyanoside A, osmaronin, and 4-(hydroxylmethyl)-5H-furan-2-one exhibited borderline antibacterial activity against Salmonella gallinarum, Vibrio parahaemolyticus, and Vibrio cholera with MIC values of 30.1, 20.7, and 22.8µg/mL, respectively.

Selective cytotoxicity, inhibition of cell cycle progression, and induction of apoptosis in human breast cancer cells by sesquiterpenoids from Inula lineariifolia Turcz.

Four new sesquiterpenoid dimers (lineariifolianoids E-H, 1-4), five new sesquiterpenoids (5-9), and seven known sesquiterpenoids (10-16) were isolated from the aerial parts of Inula lineariifolia Turcz. Their structures were determined by spectroscopic data analysis and X-ray diffraction studies. The compounds were then evaluated for their in vitro cytotoxicity against two human breast cancer cell lines (MCF-7 and MDA-MB-231) and one normal breast cell line (MCF-10A). Lineariifolianoid E (1) showed IC50 values of 1.56 µM and 2.75 µM against MCF-7 and MDA-MB-231, respectively. However, lineariifolianoid E demonstrated low toxicity to MCF-10A cells, which indicated a selective cytotoxicity for tumor cells. Further studies also presented that lineariifolianoid E had significant, dose-dependent effects on cell cycle progression and apoptosis in breast cancer cells.

Sesquiterpene lactones from Inula hupehensis inhibit nitric oxide production in RAW264.7 macrophages.

Phytochemical investigation of the aerial parts of Inula hupehensis Ling. led to the isolation and identification of 27 sesquiterpene lactones (1-27), including three new eudesmanolides (3-5), three new germacranolides (9-11), one new xanthanolide (16), two new carabrone derivatives (25-26), and 18 known sesquiterpene lactones. The structures were elucidated by extensive spectroscopic methods and comparison to previously reported spectroscopic data. All compounds were evaluated for their inhibitory effects against LPS-induced nitric oxide production in RAW264.7 macrophages, and compound 5 showed the strongest activity with the IC50 value of 3.2 ± 0.4 µM.

Sesquiterpene lactones from Inula hookeri.

Four new sesquiterpene lactones, (1 S,5 R,6 S,7 S,8 R,9 R,10 S,11 S)-6-acetoxy-9-hydroxy-4-oxo-pseudoguai-2(3)-en-12,8-olide, (1 S,2 R,5 R,6 S,7 R,8 S,10 R)-6-acetoxy-2-ethoxy-4-oxo-pseudoguai-11(13)-en-12,8-olide, (1 S,2 R,5 R,6 S,7 R,8 S,10 R)-6-acetoxy-2-hydroxy-4-oxo-pseudoguai-11(13)-en-12,8-olide, and 14-acetoxy-1 ß,5 α,7 αH-4 ß-hydroxy-guai-9(10),11(13)-dien-12,8 α-olide, along with 26 known sesquiterpene lactones, were isolated from the whole plants of Inula hookeri C. B. Clarke. Their structures were established based on spectroscopic methods including HRESIMS, 1D and 2D NMR, and CD techniques. All compounds were evaluated for their cytotoxic activities against HepG2, HeLa, PC-3, and MGC-803 cell lines by CCK-8 assay. Some of the isolates, especiallly pseudoguaianolides and guaianolides, exhibited significant cytotoxicities against these four examined cell lines.

Sesquiterpenoids from Inula racemosa Hook. f. inhibit nitric oxide production.

A novel trinorsesquiterpene (1), three new (2-4), and 10 known sesquiterpenes were isolated from the roots of Inula racemosa Hook. f. The structures and absolute configurations of the new sesquiterpenes were elucidated by extensive spectroscopic and computational methods. All compounds were evaluated for their inhibition of LPS-induced nitric oxide production in RAW264.7 macrophages, and the results indicated that compounds 9, 12, and 13 moderately inhibited nitric oxide production with IC50 values of 7.39 ± 0.36, 6.35 ± 0.26, and 5.39 ± 0.18 µM, respectively.

Sesquiterpenoids and triterpenoids from Abies holophylla and their bioactivities.

Six previously unreported and 11 known terpenoids were isolated from Abies holophylla. The structures of the six compounds were established as two unusual bisabolane sesquiterpenoids, three nortriterpenoids, and one 3,4-seco-triterpenoid based on the detailed analysis of their 1D and 2D NMR spectroscopic data. In addition, electronic circular dichroism (ECD) calculations and molecular orbital (MO) analysis were used to assign the absolute configuration of one bisabolane sesquiterpenoid, abiesesquine A. Abiesesquine A showed the strongest inhibitory effects against LPS-induced nitric oxide (NO) production in RAW264.7 macrophages with an IC(50) value of 113.1 µM. Lanosta-7,9(11),24-trien-26-oic acid showed potent cytotoxic activity against COLO-205, LOVO, and QGY-7703 tumor cells with IC(50) values of 0.9, 4.2, and 2.0 µM, respectively. (23R,25R)-3,4-seco-9ßH-Lanosta-4(28),7-dien-26,23-olid-3-oic acid, exhibited a significant antiproliferation effect against A549 cells (IC(50)=14.7 µM).

Pseudoguaianolides and guaianolides from Inula hupehensis as potential anti-inflammatory agents.

Eight new pseudoguaianolides (1-8), two new guaianolides (9 and 10), and 14 known sesquiterpenes were isolated from the aerial parts of Inula hupehensis. The structures were elucidated using spectroscopic methods and circular dichroism analysis. All compounds were tested for inhibitory activities against LPS-induced nitric oxide production in RAW264.7 macrophages. Compounds 13 and 22 were found to inhibit nitric oxide production potently, with IC50 values of 0.9 and 0.6 µM, respectively. Preliminary structure-activity relationships for these compounds are proposed.

[Application of small molecule compounds inducing differentiation of stem cells].

With the development of stem cells and regenerative medicine (treatment of various diseases using stem cells) research, the induction of differentiation of human stem cell technology has also made significant progress. The development of chemical biology offers a variety of small biological molecules for stem cell biology. This review focuses on how small molecule compounds (natural and synthetic) induce differentiation of stem cells.

Compounds from Platycladus orientalis and their inhibitory effects on nitric oxide and TNF-α production.

Four new compounds: an abietane (1), two isopimarane (2 and 3) diterpenes, and a dihydrobenzofuran neolignan (5), together with a sesquiterpene glycoside (6) firstly isolated from a natural source, and a known phenol glycoside (4) were isolated from leaves of Platycladus orientalis. The structures and relative configurations of these compounds were assigned on the basis of MS, IR, 1D and 2D NMR data. The absolute configuration of compound 1 was determined via density functional theory calculations of its electronic circular dichroism. In addition, the results of bioassays indicated that compounds 4 and 6 showed a potent inhibitory effect on NO production with IC50 values of 24.4 and 11.9 µM, respectively. Meanwhile, compounds 1, 2, and 3 moderately inhibited TNF- α release.