Pectic polysaccharide from Smilax china L. ameliorated ulcerative colitis by inhibiting the galectin-3/NLRP3 inflammasome pathway.

Ulcerative colitis (UC) is an inflammatory bowel disease that affects the colon and rectum. Although galectin-3 (Gal-3) has been reported to play a proinflammatory role in UC, it is unknown whether pectic polysaccharide, a Gal-3 inhibitor in tumor metastasis, can alleviate UC by inhibiting Gal-3. The aim of this study was to investigate the anti-inflammatory effects and underlying mechanisms of SCLP, a pectic polysaccharide purified from Smilax china L. in our previous work, on dextran sulfate sodium-induced UC in BALB/c mice. The results showed that SCLP could significantly improve symptoms, alleviate histopathological damage and reduce the secretion of inflammatory mediators in mice with UC. Analysis of the anti-colitis mechanisms indicated that SCLP could inhibit the Gal-3/NLRP3 inflammasome/IL-1ß pathway by suppressing the expression of Gal-3 and the interaction of Gal-3 and NLRP3. Our results suggested that SCLP could be a promising candidate for prevention and treatment of UC.

Oral absorption characteristics and mechanisms of a pectin-type polysaccharide from Smilax china L. across the intestinal epithelium.

The elucidation of the oral absorption of natural polysaccharides contributes to their further research and utilization. Herein, to explore the absorption of a pectin-type polysaccharide from Smilax china L. (SCLP), SCLP was respectively fluorescently labeled with fluorescein-5-thioicarbazide (FSCLP) and Cyanine7 amine (Cy7-SCLP) for in vitro and in vivo tracking. The near-infrared imaging demonstrated that Cy7-SCLP was absorbable in the small intestine and distributed in the liver and kidney after oral administration. Subsequently, in vitro intestinal epithelial tissue experiments showed that the jejunum was the dominant site of FSCLP transport. Further transport studies in the Caco-2 cell monolayer illustrated that FSCLP was delivered across the monolayer via transcellular transport by caveolae-mediated endocytosis and macropinocytosis together with paracellular transport by reversibly affecting tight junctions. In summary, this work presents the oral absorption characteristics and mechanisms of SCLP through the intestinal epithelium, which will facilitate the further development of SCLP and pectin polysaccharides.

Purification, structural elucidation and anti-inflammatory activity in vitro of polysaccharides from Smilax china L.

Smilax china L. is a traditional Chinese medicine mainly used for the treatment of pelvic inflammation. Polysaccharide might be one of the anti-inflammatory components of Smilax china L. Based on this hypothesis, this work aimed at extraction, purification and structural elucidation of Smilax china L. polysaccharides and their preliminary anti-inflammatory effects were also studied. Two polysaccharides named SCLP1 (Smilax china L. polysaccharide 1, 42.1kDa) and SCLP3-2 (Smilax china L. polysaccharide 3-2, 16.8kDa) were for the first time purified from Smilax china L. The structures of SCLP1 and SCLP3-2 were elucidated by chemical and spectral analysis. The results revealed that SCLP1 was a neutral polysaccharide composed of glucose and mannose (54.5:1.0). Its backbone was 1,4­linked α­Glcp interspersed with 1,2­linked α­Glcp and Manp; the branches were 1,6­linked α-Glcp and terminated with α­Glcp. SCLP3-2 was composed of galacturonic acid, arabinose, galactose and rhamnose (23.3:2.1:1.7:1.0) and was a pectin-type polysaccharide with an α­1,4­linked homogalacturonan backbone which was partially methyl-esterified and slightly acetylated. The side chains consisted of α­Rhap, ß­Galp and α­Araf. SCLP1 and SCLP3-2 could inhibit the production of NO, IL-6 and TNF-α in LPS-stimulated RAW264.7 cells via NF-κB and MAPKs (ERK1/2, JNK) pathways, indicating that they possessed a potential anti-inflammatory activity.

Ponicidin, an ent-kaurane diterpenoid derived from a constituent of the herbal supplement PC-SPES, Rabdosia rubescens, induces apoptosis by activation of caspase-3 and mitochondrial events in lung cancer cells in vitro.

Ponicidin, an ent-kaurane diterpenoid derived from a constituent of the herbal supplement PC-SPES, Rabdosia rubescens, is recently reported to have anti-tumor effects on a large variety of cancers. In this study, we demonstrate that ponicidin exhibits cytotoxicity, induces apoptosis, disrupts the mitochondrial membrane potential, and triggers the activation of caspase-3, -8 and -9 in lung cancer A549 and GLC-82 cells. Ponicidin treatment of lung cancer cells caused downregulation of anti-apoptotic protein Bcl-2 and survivin as well as upregulaton of pro-apoptotic protein Bax in a time dependent manner when apoptosis ocurred. Ponicidin induced activation of caspase-3 can be blocked by a caspase-3-specific inhibitor z-DEVD-FMK Furthermore, the caspase-8-specific inhibitor z-IETD-FMK could block the ponicidin-induced activation of caspase-3, PARP cleavage, and prevented the release of cytochrome c from mitochondria into the cytoplasm. This indicate that activated caspase-8 initiates the release of cytochrome c during ponicidin-induced apoptosis. We therefore conclude that ponicidin has significant apoptosis-inducing effects by activation of caspase-3 -8, and -9 as well as downregulation of anti-apoptotic protein Bcl-2, survivin and upregulation of pro-apoptotic protein Bax, with caspase-8 acting as an upstream activator. The data offer a potential mechanism for ponicidin-induced apoptosis in lung cancer cells, suggesting that ponicidin may severve as an effective reagent for the treatment of lung cancer, and that in vivo anti-cancer effects as well as its potential clinical effectiveness need further investigation.

Antiproliferation effects of ponicidin on human myeloid leukemia cells in vitro.

Ponicidin, an extract from the Chinese herb Rabdosia rubescens, is currently one of the most important traditional Chinese herbal medicines. Ponicidin has been reported to have anti-tumor effects on a large variety of malignant diseases. In this study, we investigated the anti-proliferation effects of ponicidin on human myeloid K562 and HL-60 cells. Cell viability was measured by MTT assay; cell apoptosis was assessed by flow cytometry, DNA fragmentation analysis and Hoechst 33258 staining. Caspase-3 and poly(ADP-ribose) polymerase (PARP) activation and Bax and Bcl-2 expression were detected by Western blot analysis. The results revealed that ponicidin could significantly inhibit the growth of K562 and HL-60 cells by induction of apoptosis. The suppression was both time- and dose-dependent. Cell apoptosis was observed clearly after the cells were treated with ponicidin for 48-72 h. Western blotting showed cleavage of the caspase-3 zymogen protein (32 kDa) with the appearance of its 17 kDa subunit, together with a cleaved 89-kDa fragment of 116 kDa PARP when apoptosis occurred. Bcl-2 expression was down-regulated while Bax expression up-regulated concurrently when the cells were treated with ponicidin for 24-48 h. Therefore, we conclude that ponicidin has significant anti-proliferation effects by induction of apoptosis on myeloid leukemia cells in vitro, down-regulation of Bcl-2, and up-regulation of Bax, and that activation of caspase-3 and PARP may be an important apoptosis-inducing mechanism. The results suggest that ponicidin may serve as a potential therapeutic agent for leukemia.

Anti-proliferation effect of oridonin on HL-60 cells and its mechanism.

OBJECTIVE: To investigate the anti-proliferation effect of oridonin on leukemic HL-60 cells and its mechanism. METHODS: HL-60 cells in vitro in culture medium were given different concentrations of oridonin. The inhibitory rate of cells were measured by microculture tetrazolium (MTT) assay, cell apoptotic rate was detected by flow cytometry (FCM), morphology of cell apoptosis was observed by hoechst 33258 fluorescence staining, and the activity of telomerase was detected using telomere repeat amplification protocol (TRAP) PCR-ELISA before and after apoptosis occurred. RESULTS: Oridonin could decrease telomerase activity, inhibit growth of HL-60 cells, and cause apoptosis significantly. The suppression was both in time- and dose-dependent manner. Marked morphological changes of cell apoptosis including condensation of chromatin and nuclear fragmentation were observed clearly by hoechst 33258 fluorescence staining especially after cells were treated 48-60 hours by oridonin. CONCLUSIONS: Oridonin has apparent anti-proliferation and apoptotic effects on HL-60 cells in vitro, decreasing telomerase activity of HL-60 cells may be one of its most important mechanisms. These results will provide strong laboratory evidence of oridonin for clinical treatment of acute leukemia.