Astragalus and Cancer
Astragalus radix (Astragalus) is a Chinese medicinal herb that has been used for 2000 years. The active component is arabinoxylan which is a component in the plant cell wall and is isolated for use medicinally. It has been credited with a number of benefits; however, the scope of this blog post will focus on its use and benefit in cancer.
Benefits in Cancer
1. Inhibits tumour growth
In vitro studies using transplantable tumour into experimental mice demonstrated inhibition of tumour growth particularly when used in combination with chemotherapy (cisplatin) and compared to chemotherapy alone.
Further investigation to assess the mechanism of action for this showed that astragalus induced apoptosis (programmed cell death) in tumour tissues through the upregulation of p53 (a tumour suppressor gene), a reduction in Bcl-2 (a protein that prevents apoptosis) and an upregulation in Bax (a protein that induces apoptosis). (Li et al 2019).
A meta-analysis of RCTs conducted in 2006 by McCulloch et al analysed 34 RCTS including 2815 patients being treated with cisplatin for advanced non-small cell lung cancer. It found a reduced risk of death at 12 months (RR 0.67) and improved tumour response (RR 1.34) with the addition of astragalus.
2. Modulates the immune system
Astragalus improves immunity by modulating the immune system to enhance the tumour fighting cytokines (IL-2, IL-6, TNF-α) and down-regulating the tumour-promoting cytokines. (Li et al 2019, Bamodu et al 2019). It also promotes immune function through the thymus and spleen.
3. Works synergistically with chemotherapy
It works synergistically with chemotherapy specifically with platinum and taxane based chemotherapies to enhance the action of the chemotherapy on tumour cells and counteracting the immunodepleting effects of chemotherapy. That is, it enhances the recovery of white blood cells that are otherwise depleted using chemotherapy alone. This is through modulation of G-CSF and CD4+ and CD8+ T cells.
4. Improves Quality of Life
Wang et al 2018 showed an improvement in cancer-related fatigue with the use of astragalus in patients with metastatic cancer receiving palliative care. Huang et al 2019 showed a reduction in pain, nausea, vomiting and fatigue and an improvement in appetite, sleep and overall quality of life. This was a double-blind RCT in patients with metastatic disease, however, the study sample size was low.
Recommendations
Halsa Naturopathic Medicine recommend 2 capsules of Vital Nutrients high dose extract three times a day beginning the day before chemotherapy and throughout. As always, it is important that this is taken under professional guidance through a Naturopathic or Integrative consultant and in collaboration with the treating medical team as it is important to monitor for adverse effects and to measure blood counts.
References
Li K, Li S, Wang D, Li X, Wu X, Liu X, Du G, Li X, Qin X, Du Y. Extraction, Characterization, Antitumor and Immunological Activities of Hemicellulose Polysaccharide from Astragalus radix Herb Residue. Molecules. 2019 Oct 9;24(20):3644. doi: 10.3390/molecules24203644. PMID: 31601012; PMCID: PMC6833037.
McCulloch M, See C, Shu XJ, Broffman M, Kramer A, Fan WY, Gao J, Lieb W, Shieh K, Colford JM Jr. Astragalus-based Chinese herbs and platinum-based chemotherapy for advanced non-small-cell lung cancer: meta-analysis of randomized trials. J Clin Oncol. 2006 Jan 20;24(3):419-30. doi: 10.1200/JCO.2005.03.6392. PMID: 16421421.
Bamodu OA, Kuo KT, Wang CH, Huang WC, Wu ATH, Tsai JT, Lee KY, Yeh CT, Wang LS. Astragalus polysaccharides (PG2) Enhances the M1 Polarization of Macrophages, Functional Maturation of Dendritic Cells, and T Cell-Mediated Anticancer Immune Responses in Patients with Lung Cancer. Nutrients. 2019 Sep 20;11(10):2264. doi: 10.3390/nu11102264. PMID: 31547048; PMCID: PMC6836209.
Wang CH, Lin CY, Chen JS, Ho CL, Rau KM, Tsai JT, Chang CS, Yeh SP, Cheng CF, Lai YL. Karnofsky Performance Status as A Predictive Factor for Cancer-Related Fatigue Treatment with Astragalus Polysaccharides (PG2) Injection-A Double Blind, Multi-Center, Randomized Phase IV Study. Cancers (Basel). 2019 Jan 22;11(2):128. doi: 10.3390/cancers11020128. PMID: 30678249; PMCID: PMC6406819.
Huang WC, Kuo KT, Bamodu OA, Lin YK, Wang CH, Lee KY, Wang LS, Yeh CT, Tsai JT. Astragalus polysaccharide (PG2) Ameliorates Cancer Symptom Clusters, as well as Improves Quality of Life in Patients with Metastatic Disease, through Modulation of the Inflammatory Cascade. Cancers (Basel). 2019 Jul 25;11(8):1054. doi: 10.3390/cancers11081054. PMID: 31349728; PMCID: PMC6721312.
Jiang D, Rasul A, Batool R, Sarfraz I, Hussain G, Mateen Tahir M, Qin T, Selamoglu Z, Ali M, Li J, Li X. Potential Anticancer Properties and Mechanisms of Action of Formononetin. Biomed Res Int. 2019 Jul 28;2019:5854315. doi: 10.1155/2019/5854315. PMID: 31467899; PMCID: PMC6699357.
