Astragalus
Astragalus membranaceus, a commonly used Chinese medicinal plant, has been shown to be capable of restoring the impaired T cell functions in cancer patients. In this study, the in vitro and in vivo anti-tumor effects of A. membranaceus were investigated.
1: Cancer Lett. 2007 Jan 12; [Epub ahead of print]
In vitro and in vivo anti-tumor effects of Astragalus membranaceus.
Department of Clinical Oncology, Queen Elizabeth Hospital, Hong Kong SAR, People's Republic of China.
Astragalus membranaceus, a commonly used Chinese medicinal plant, has been shown to be capable of restoring the impaired T cell functions in cancer patients. In this study, the in vitro and in vivo anti-tumor effects of A. membranaceus were investigated. Five bioactive fractions were isolated from the root of A. membranaceus, the fraction designated as AI was found to be the most potent among the five fractions with respect to its mitogenicity on murine splenocytes. Besides investigating the cytostatic effect of AI, its activities on macrophage function, tumor necrosis factor production, induction of lymphokine-activated killer cell and tumor cell differentiation were also examined. The macrophage-like tumors and the myeloid tumors were found to be more sensitive to the cytostatic activity of AI, whereas the fibroblast-like tumors and the mouse Ehrlich ascites tumor appeared to be relatively resistant. Moreover, AI could effectively suppress the in vivo growth of syngeneic tumor in mice. Results showed that murine macrophage pretreated with AI had increased in vitro and in vivo cytostatic activities towards MBL-2 tumor. AI could also act as a priming agent for tumor necrosis factor production in tumor-bearing mice. Preincubation of mouse splenocytes with AI could induce in vitro lymphokine-activated killer-like activity towards WEHI-164 cell. Furthermore, AI was able to induce monocytic differentiation of both human and murine cells in vitro. AI administered in vivo could even partially restore the depressed mitogenic response in tumor-bearing mice. Collectively, the results showed that A. membranaceus could exhibit both in vitro and in vivo anti-tumor effects, which might be achieved through activating the anti-tumor immune mechanism of the host.
PMID: 17223259 [PubMed - as supplied by publisher]
This study was designed to investigate the effects of Astragalus membranaceus (AM) and its main components, astragalus saponin (ASP), astragalus polysaccharide (APS) and aminobutyric acid (GABA), on homocysteine (Hcy) induced acute impairment of vascular tone and to explore whether the antioxidant mechanism was involved in AM protective effect.
Effects of Astragalus membranaceus and its main components on the acute phase endothelial dysfunction induced by homocysteine
Bi-Qi Zhanga, Shen-Jiang Hua, e, 
, 
, Li-Hong Qiua, Jian-hua Zhua, Xian-Ji Xieb, Jian Suna, Zhao-Hui Zhua, Qiang Xiac and Ka Biand, e
aDepartment of Cardiology, The First Affiliated Hospital, College of Medicine, Zhejiang University, No. 79, Qingchun St, Hangzhou 310003, Zhejiang, P.R. China
bDepartment of Pharmacy, The First Affiliated Hospital, College of Medicine, Zhejiang University, No. 79, Qingchun St, Hangzhou 310003, Zhejiang, P.R. China
cDepartment of Physiology, College of Medicine, Zhejiang University, No. 353, Yan'an St, Hangzhou 310031, Zhejiang, P.R. China
dDepartment of Integrative Biology and Pharmacology, The University of Texas-Houston Medical School; 6431 Fannin, Houston, Texas, 77030, USA
eE-Institute of Shanghai Universities, Division of Nitric Oxide and Inflammatory Medicine, No.1200, Chailun St, Shanghai 201203, P.R. China
Received 23 January 2006; revised 14 October 2006; accepted 2 November 2006. Available online 10 November 2006.
Abstract
Objective
This study was designed to investigate the effects of Astragalus membranaceus (AM) and its main components, astragalus saponin (ASP), astragalus polysaccharide (APS) and aminobutyric acid (GABA), on homocysteine (Hcy) induced acute impairment of vascular tone and to explore whether the antioxidant mechanism was involved in AM protective effect.
Methods
Inhibitory effects of Hcy and protective effects of AM and its main components on endothelium-dependent relaxation of aortic rings were determined by isometric tension recordings and nitric oxide signaling was assayed with 125I-cGMP RIA Kit. Furthermore, generation of reactive oxygen species (ROS) in endothelial cells was detected using 5-(6)- chloromethyl-2′,7′-dichlorodihydrofluorescein diacetate (CM-H2DCF-DA).
Results
Hcy significantly inhibited endothelium-dependent relaxation to acetylcholine (ACh) in a dose-dependent manner, and decreased cGMP levels increased by ACh in aorta. Furthermore, superoxide dismutase (SOD), AM, and ASP markedly attenuated inhibition of vasorelaxation and downregulation of cGMP level by Hcy, and APS exerted a tendency to reverse both of the depressive responses, while GABA had no similar effects. Additionally, partially impaired relaxation by Hcy was completely blocked due to the presence of N(ω)-nitro-l-arginine-methyl ester (l-NAME), which could not be further altered by treatment with AM, ASP, APS or GABA. Finally, Hcy significantly increased intracellular ROS levels in endothelial cells as measured by CM-H2DCF-DA fluorescence. SOD, AM, ASP, and APS, but not GABA, inhibited Hcy-stimulated ROS generation.
Conclusion
This study demonstrated that AM and ASP, potently protected endothelium-dependent relaxation against the acute injury from Hcy through nitric oxide regulatory pathways, in which antioxidation played a key role.
Astragalus saponins induce growth inhibition and apoptosis in human colon cancer cells and tumor xenograft.
Carcinogenesis Advance Access published online on December 5, 2006
Carcinogenesis, doi:10.1093/carcin/bgl238
Astragalus saponins induce growth inhibition and apoptosis in human colon cancer cells and tumor xenograft
Mandy M.Y. Tin1, Chi-Hin Cho2, Kelvin Chan3, Anthony E. James4 and Joshua K.S. Ko1,*
1 Pharmacology and Toxicology Laboratory, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China,
2 Department of Pharmacology, Faculty of Medicine, The University of Hong Kong, Hong Kong, China,
3 School of Applied Sciences, University of Wolverhampton, United Kingdom,
4 Laboratory Animal Services Center, The Chinese University of Hong Kong, Hong Kong, China
* To whom correspondence should be addressed: Hong Kong Baptist University, School of Chinese Medicine Building, Room 405, 7 Baptist University Road, Kowloon Tong, Hong Kong, China. Tel: +852 3411 2907; Fax: +852 3411 2461;
Astragalus memebranaceus is used as immunomodulating agent in treating immunodeficiency diseases and to alleviate the adverse effects of chemotherapeutic drugs. In recent years, it has been proposed that Astragalus may possess anti-tumorigenic potential in certain cancer cell types. In this study, the anti-carcinogenic effects of Astragalus saponin extract were investigated in HT-29 human colon cancer cells and tumor xenograft. Our findings have shown that Astragalus saponins (AST) inhibit cell proliferation through accumulation in S phase and G2/M arrest, with concomitant suppression of p21 expression and inhibition of cyclin-dependent kinase activity. Besides, AST promotes apoptosis in HT-29 cells through caspase-3 activation and poly(ADP-ribose) polymerase (PARP) cleavage, which is indicated by DNA fragmentation and nuclear chromatin condensation. Nevertheless, we also demonstrate the anti-tumorigenic effects of AST in vivo, of which the reduction of tumor volume as well as pro-apoptotic and anti-proliferative effects in HT-29 nude mice xenograft are comparable to that produced by the conventional chemotherapeutic drug 5-fluorouracil (5-FU). In addition, the side effects (body weight drop and mortality) associated with the drug combo 5-FU and oxaliplatin are not induced by AST. These results indicate that AST could be an effective chemotherapeutic agent in colon cancer treatment, which might also be used as an adjuvant in combination with other orthodox chemotherapeutic drugs to reduce the side effects of the latter compounds.
To observe the TH cell subset function in children with recurrent tonsillitis (RT) at the remission stage and to study the effects of astragalus membranacus (AM) on TH cell subset function
1: Zhongguo Dang Dai Er Ke Za Zhi. 2006 Oct;8(5):376-8.
[Effects of astragalus membranaceus on TH cell subset function in children with recurrent tonsillitis]
[Article in Chinese]
Department of Pediatrics, First People's Hospital of Yulin, Yulin, Shangxi 718000, China.
OBJECTIVE: To observe the TH cell subset function in children with recurrent tonsillitis (RT) at the remission stage and to study the effects of astragalus membranacus (AM) on TH cell subset function. METHODS: The peripheral blood mononuclear cells (PBMC) from 27 children with RT at the remission stage were stimulated with either phytohemagalutinin (PHA) (RT-PHA group) or PHA together with AM (RT-AM group) and were then cultured in vitro for 48 hrs. The samples from 21 healthy children stimulated with PHA were used as the Control group. The levels of interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) in the supernatants of PBMC were detected using ELISA. RESULTS: The IFN-gamma level and the ratio of IFN-gamma/IL-4 in the RT-PHA group were statistically lower than those in the Control group (P < 0.01). The level of IFN-gamma and the ratio of IFN-gamma/IL-4 in the RT-AM group were markedly higher than those in the RT-PHA group (P < 0.01), but were significantly lower than those in the Control group (P < 0.05). There were no differences in the IL-4 level among the three groups. CONCLUSIONS: TH1 cell subset dysfunction may exit in RT children at the remission stage, suggesting that TH1 cell subset dysfunction plays an important role in the pathogenesis of RT. AM can improve TH1 cell subset function and therefore shows an important significance in treating RT.
PMID: 17052394 [PubMed - indexed for MEDLINE]
