Xu Pang

Lycorine Promotes Autophagy and Apoptosis via TCRP1/Akt/mTOR Axis Inactivation in Human Hepatocellular Carcinoma

Lycorine is a multifunctional bioactive compound, and it possesses potential anticancer activities. However, little is known about the underlying mechanism. In this research, we have found that lycorine significantly induces the apoptotic and autophagic capacities of hepatocellular carcinoma (HCC) cells in vitro and in vivo. Treatment with specific autophagy inhibitor (3-methyladenine/Bafilomycin A1) or knockdown of LC-3B/Atg5 by siRNA drastically enhances the apoptotic cell death effect by facilitating the switch from autophagy to apoptosis. Molecular validation mechanistically demonstrates that lycorine-induced apoptosis and autophagy in HCC cells is associated with decreased protein levels of tongue cancer resistance–associated protein 1 (TCRP1), and we further find that inhibition of TCRP1 decreases phosphorylation level of Akt and represses Akt/mTOR signaling. Finally, lycorine-induced apoptosis and autophagy suppress the growth of xenograft hepatocellular tumors without remarkable toxicity. Our results elucidate a novel molecular mechanism whereby lycorine promotes apoptosis and autophagy through the TCRP1/Akt/mTOR pathway in HCC. Our results reveal that lycorine might be a potential therapeutic agent for the treatment of HCC. Mol Cancer Ther; 16(12); 2711–23. ©2017 AACR.

New oleanane-type triterpenoid saponins isolated from the seeds of Celosia argentea

Three new oleanane-type triterpenoid saponins named celosins H (1), I (2), and J (3) were isolated from the seeds of Celosia argentea L. Their structures were characterized as 3-O-β-d-xylopyranosyl-(1 → 3)-β-d-glucuronopyranosyl-polygalagenin 28-O-β-d-glucopyranosyl ester, 3-O-β-d-glucuronopyranosyl-medicagenic acid 28-O-β-d-xylcopyranosyl-(1 → 4)-α-l-rhamnopyranosyl-(1 → 2)-β-d-fucopyranosyl ester, and 3-O-β-d-glucuronopyranosyl-medicagenic acid 28-O-α-l-arabinopyranosyl-(1 → 3)-[β-d-xylcopyranosyl-(1 → 4)]-α-l-rhamnopyranosyl-(1 → 2)-β-d-fucopyranosyl ester by NMR, MS, and chemical evidences, respectively. In our opinion, celosins H–J could be used as chemical markers for the quality control of C. argentea seeds.

New steroidal glycosides from the rhizome of Anemarrhena asphodeloides

Two new steroidal saponins, timosaponin X (1) and timosaponin Y (2), and one new pregnane glycoside, timopregnane B (3), were isolated from the rhizomes of Anemarrhena asphodeloides, as well as three known compounds 25S-timosaponin BII (4), protodesgalactotigonin (5), and timosaponin BII-a (6) isolated from this plant for the first time. By the detailed analysis of 1D, 2D NMR, MS spectra, and chemical evidences, the structures of new compounds were elucidated as 26-O-β-d-glucopyranosyl-(25S)-5β-22-methoxy-furost-3β,26-diol 3-O-β-d-glucopyranosyl-(1 → 2)-α-l-arabinopyranoside (1), 5β-pseudo-spirost-3β,15α,23α-triol 3-O-β-d-glucopyranosyl-(1 → 2)-β-d-galactopyranoside (2), (5β,17α)-Δ16(17)-20-one-pregn-2β,3β-diol 3-O-β-d-glucopyranosyl-(1 → 2)-β-d-galactopyranoside (3).

Two new furostanol saponins from the seeds of Trigonella foenum-graecum

Two new furostanol saponins, together with two known steroidal saponins, were isolated from the seeds of Trigonella foenum-graecum L. The structures of the new compounds were determined by detailed analysis of 1D NMR, 2D NMR, MS spectra and chemical evidences as 26-O-β-d-glucopyranosyl-(25S)-5-en-furost-3β,22α,26-triol 3-O-α-l-rhamnopyranosyl-(1 → 2)-[β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranosyl-(1 → 3)-β-d-glucopyranosyl-(1 → 4)]-β-d-glucopyranoside (1) and 26-O-β-d-glucopyranosyl-(25R)-5-en-furost-3β,22α,26-triol 3-O-α-l-rhamnopyranosyl-(1 → 2)-[β-d-glucopyranosyl-(1 → 6)]-β-d-glucopyranosyl-(1 → 3)-β-d-glucopyranosyl-(1 → 4)]-β-d-glucopyranoside (2).

Prenylated flavonoids and dihydrophenanthrenes from the leaves of Epimedium brevicornu and their cytotoxicity against HepG2 cells

Abstract Phytochemical study on the leaves of Epimedium brevicornu finally led to the isolation of four prenylated flavonoids (1–4) and three dihydrophenanthrenes (5–7), of which 1, 2, 5 and 7 were new compounds. The structures of these compounds were established mainly by spectroscopic techniques, including NMR spectroscopy and mass spectrometry. These isolates exhibited the cytotoxic activities against HepG2 cells with the IC50 values of 32.8–87.3 μM.

New kaurene diterpenoid glycosides from fenugreek seeds

Two new kaurene diterpenoid glycosides, named Graecumoside A (1) and B (2), were isolated from fenugreek seeds, along with three known flavonoid-C-glycosides, isoorientin (3), isovitexin (4) and vitexin (5). By combined analyses of 1D- and 2D-NMR, and MS spectroscopy, the structures of two new compounds were elucidated as 3-O-β- D-glucopyranosyl kaur-5, 16-dien-3β, 6, 13β-trihydroxy-7-oxo-18-oic acid methyl ester and 3-O-β-neohesperidosyl kaur-5, 16-dien-3β, 6, 13β-trihydroxy-7-oxo-18-oic acid methyl ester, respectively. The kaurene diterpenoid glycosides were first isolated and identified from fenugreek seeds.

New anthraquinone and eurotinone analogue from the seeds of Senna obtusifolia and their inhibitory effects on human organic anion transporters 1 and 3

Abstract A continuous phytochemical study on the seeds of Senna obtusifolia (Syn.: Cassia obtusifolia) led to the isolation of a new anthraquinone analogue, obtusifolin-2-O-β-D-(6’-O-α,β-unsaturated butyryl)-glucopyranoside (1) and a new eurotinone analogue, epi-9-dehydroxyeurotinone-β-D-glucopyranoside (2). Their structures were established mainly by NMR and MS experiments as well as the necessary chemical evidences. Their inhibitory effects on two organic anion transporters (OAT1 and OAT3) were investigated and the results showed that 1 exhibited a strongly specific inhibitory effect on OAT1 at 100 μM.

Two new naphthalene glycosides from the seeds of Cassia obtusifolia

Abstract A phytochemical study on the seeds of Cassia obtusifolia was carried out, which finally led to obtain two naphthalenes (1 and 2), two naphthopyrans (3 and 4) and twelve anthraquinones (5–16). The structures of all compounds were established mainly by NMR and MS experiments as well as the necessary chemical evidence. Among them, 1 and 2 (obtusinaphthalensides A and B) were identified to be new naphthalene glycosides.

Lycorine Displays Potent Antitumor Efficacy in Colon Carcinoma by Targeting STAT3

Signal transducer and activator of transcription 3 (STAT3) is an attractive therapeutic target for cancer treatment. In this study, we identify lycorine is an effective inhibitor of STAT3, leading to repression of multiple oncogenic processes in colon carcinoma. Lycorine selectively inactivates phospho-STAT3 (Tyr-705), and subsequent molecular docking uncovers that lycorine directly binds to the SH2 domain of STAT3. Consequently, we find that lycorine exhibits anti-proliferative activity and induces cell apoptosis on human colorectal cancer (CRC) in vitro. Lycorine induces the activation of the caspase-dependent mitochondrial apoptotic pathway, as indicated by activation of caspase and increase of the ratio of Bax/Bcl-2 and mitochondrial depolarization. Overexpressing STAT3 greatly blocks these effects by lycorine in CRC cells. Finally, lycorine exhibits a potential therapeutic effect in xenograft colorectal tumors by targeting STAT3 without observed toxicity. Taken together, the present study indicates that lycorine acts as a promising inhibitor of STAT3, which blocks tumorigenesis in colon carcinoma.

Magnolin promotes autophagy and cell cycle arrest via blocking LIF/Stat3/Mcl-1 axis in human colorectal cancers

Magnolin is a multi-bioactive natural compound that possesses underlying anti-cancer properties. However, the mechanisms underlying remain to be elucidated. Here, we report the role of magnolin in suppressing human colorectal cancer (CRC) cells via activating autophagy and cell cycle arrest in vitro and in vivo. Pre-treatment of cells with specific autophagy inhibitor (3-methyladenine) or knockdown of endogenous LC-3B by siRNA significantly abrogates magnolin-induced cell cycle arrest. Molecular validation mechanistically shows that magnolin-induced autophagy and cell cycle arrest in CRC cells is correlated with decreased transcriptional levels of leukemia inhibitory factor (LIF), and we further find that inhibition of LIF decreases phosphorylation level of Stat3 and represses transcriptional expression of Mcl-1. Furthermore, magnolin-induced autophagy and cell cycle arrest suppress the growth of xenograft colorectal tumors without apparent toxicity. Finally, we evaluate the clinical correlation of LIF/Stat3/Mcl-1 in CRC patient tissues. As expected, LIF, p-Stat3, and Mcl-1 levels are high in CRC tissue but are scarcely found in normal colon tissue. High positive expressions of LIF or Mcl-1 are associated with poor prognosis. Doubly positive cases have shown the worst outcome. Taken together, our results have clarified a novel molecular mechanism whereby magnolin induces autophagy and cell cycle arrest through LIF/Stat3/Mcl-1 pathway in CRCs. Our results also have revealed that magnolin has a promising therapeutic potential in CRCs.