Sasanquasaponin ΙΙΙ from Schima crenata Korth induces autophagy through Akt/mTOR/p70S6K pathway and promotes apoptosis in human melanoma A375 cells.

BACKGROUND: Melanoma is a high fatality skin cancer which lacks effective drugs. Sasanquasaponin, an important sort of constituents in theaceae, has been demonstrated to have potent anti-tumor effect in breast cancer and hepatocellular carcinoma. As a sasanquasaponin, we speculate that Sasanquasaponin III (SQS III) isolated from Schima crenata Korth may also have anti-tumor activity. PURPOSE: This study aims to investigate whether SQS III has anti-melanoma activity and examine the underlying mechanisms of SQS III against melanoma. METHODS/STUDY DESIGNS: The anti-proliferative effect of SQS III was assessed by cells viability assay. Annexin V-FITC/PI double staining assay was utilized for detection of apoptosis. Mitochondrial membrane potential and reactive oxygen species (ROS) production were detected using JC-1 and DCFH-DA assay, respectively. Autophagy was monitored using transmission electron microscopy (TEM) and GFP-LC3 transfection fluorescence analysis. Autophagosome-lysosome fusion and lysosomal degradation were determined using a GFP-LC3 & LAMP1 co-localization assay and DQ-BSA staining. Proteins related to apoptosis and autophagy were analyzed by Western blotting. RESULTS: Our results demonstrated that the SQS III exhibited potent anti-cancer activity in A375 cells by inducing both apoptosis and autophagy. In melanoma cells treated with SQS III, caspases were activated and PARP was cleaved, proving the occurrence of apoptosis. Mechanistic studies indicated that the pro-apoptosis activity of SQS III was mediated by death receptor pathway and mitochondrial dysfunction which was induced by ROS accumulation and reversed by the ROS inhibitor N-acetyl-cysteine (NAC). In addition to triggering apoptosis, SQS III may also cause autophagy in melanoma cells. Our results demonstrated that SQS III induced up-regulated expression of GFP-LC3, autophagosome-lysosomal fusion and lysosomal degradation. Additionally, the ROS accumulation was also involved in the activation of autophagy. Meanwhile, it was also found that after SQS III treatment, the expression of LC3-II was up-regulated and the AKT/mTOR signaling pathway was inhibited. The autophagy inhibitor 3-MA converted cytotoxicity and apoptosis of SQS III in A375 cells, which indicated that autophagy promoted the SQS III-induced apoptosis. CONCLUSION: SQS III showed potent anti-cancer activity by inducing apoptosis and autophagy, which provides insights into its possible use as a therapy for melanoma.

[Alkaloids from Macleaya cordata and their cytotoxicity assay].

OBJECTIVE: To study the alkaloids of Macleaya cordata and their anti-tumor activities. METHOD: Alcohol and liquid-liquid extraction were used methods were used to extract the alkaloids constituents, and silica gel, reverse-phase octadecylsilyl (ODS), sephadex LH-20 chromatographic methods and HPLC were applied to isolate and purify compounds. MS, NMR spectroscopic methods were used to determine their structures. Furthermore, the cytotoxicity of these chemical components for MCF-7 and SF-268 cell lines was measured by MTT method. RESULT: Twelve alkaloids were isolated from the fruits of M. cordata, and their structures were identified as: maclekarpine E (1), 6-acetonyldihyrochelerythrine (2), cavidilinine (3), 6-acetonyldihyrosanguinnarine (4), O-methylzanthoxyline (5), 6-methoxy-dihydrosanguinarine (6), spallidamine (7), 6-hydroxyldihydrochelerythrine (8), arnotianamida (9), dihydrosanguinarine (10), protopine (11), and cryptopine (12). CONCLUSION: Compounds 1, 3, 7-9 were isolated from M. cordata for the first time, and compound 5 is a new natural product. The results of cytotoxic assay indicated that compound 6 showed strong cytotoxicity against MCF-7 and SF-268 cell lines with IC50 values of 0.61 µmol · L(-1) and 0.54 µmol · L(-1), respectively.

A new cytotoxic benzophenanthridine isoquinoline alkaloid from the fruits of Macleaya cordata.

A new cytotoxic benzophenanthridine isoquinoline alkaloid, named cordatine (1), together with one known alkaloid 8-methoxydihydrochelerythrine (2), was isolated from the fruits of Macleaya cordata. The structure of the new compound was elucidated by spectroscopic methods including 1D and 2D NMR, HR-ESI-MS. Both compounds indicated significant cytotoxicity against MCF-7 and SF-268 cell lines.

A new flavonoid glucoside from Rhododendron seniavinii.

The leaves of Rhododendron seniavinii Maxim with little phytochemical information are used as folk remedies for the treatment of acute and chronic bronchitis in China. In our pursuing for the biologically active chemical constituents in the leaves, a new flavonoid glycoside 5,7,3'-trimethoxy-quercetin-3-O-ß-D-glucopyranoside (1) was isolated from the water extract of its leaves, together with two known compounds 5,7,3'-trimethoxy-quercetin (2) and ovafolinin B-9'-O-ß-D-glucopyranoside (3). The structures of the new flavonoid glucoside as well as two known compounds were elucidated by spectroscopic and chemical methods.

A new triterpenoid from the fruits of Gardenia jasminoides var. radicans Makino.

A novel triterpenoid 3α,16ß,23,24-tetrahydroxy-28-nor-ursane-12,17,19,21-tetraen (1) was isolated from the fruits of Gardenia jasminoides var. radicans Makino. The structure of the new compounds was elucidated on the basis of spectroscopic analysis including MS and NMR data. Compound 1 was in vitro tested for cytostatic activity on human throat cancer (Hep-2) cell line by 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide method and showed mild anticancer activity with the IC50 of 31.2 µM.

Two new acetylated flavonoid glycosides from Phyllanthus urinaria.

Two new acetylated flavonoid glycosides, quercetin 3-O-α-l-(2,4-di-O-acetyl) rhamnopyranoside-7-O-α-l-rhamnopyranoside (1) and quercetin 3-O-α-l-(3,4-di-O-acetyl) rhamnopyranoside-7-O-α-l-rhamnopyranoside (2), together with two known compounds, quercetin (3) and quercetin 3-O-α-l-rhamnopyranoside (4), were isolated from the ethanol extract of Phyllanthus urinaria. The structures of the new compounds were determined on the basis of extensive spectroscopic data including IR, HR-ESI-MS, 1D NMR, and 2D NMR.

[Studies on the chemical constituents from Conyza canadensis].

OBJECTIVE: To study the chemical constituents of Conyza canadensis. METHODS: Chromatographic methods including HP20 macroporous resin, silica gel, Sephadex LH-20 and eighteen alkyl silane bonding silica gel (ODS) were used for the isolation and purification of Conyza canadensis. The structures of the obtained compounds were identified by physical chemistry and spectroscopic data. RESULTS: Six compounds were isolated from ethanol-extraction of water area of C. canadensis and identified as Eugenyl beta-Psd (1), scutellarin (2), luteolin-7-O-beta-D-glucuronide (3), quercetin (4), quercetin-3-O-beta-D-glucopyranoside (5) and luteolin (6). CONCLUSION: Compounds 1,3,5 and 6 are isolated from C. canadensis for the first time.