Astragalus herb is used by Chinese doctors to stimulate the immune system and to improve cardiovascular health. This plant is native to Northern China and Mongolia and inhabits mostly pine forests and sandy soils. Chinese doctors have used astragalus herb to fight the common cold and the flu.

Human studies
Only a few human studies have been published with astragalus root and extract.

Products on the market, in health food stores and onlinedf
There are dozens of astragalus products available without a prescription.
Astragalus (root) 300 mg per capsule
Astragalus (Astragalus membranaceus) (root) 470 mg
Astragalus root herb extract - 500 mg (standardized to 0.4% methoxyisoflavones). The web site where this product can be purchased has a reliable history of being honest and providing good service to its customers.
Astragalus Root (high grade) - 500 mg
Astragalus Root (Astragalus membranaceus) 500 mg

Liquid
Astragalus membranaceus (Huang Ch'i) - Certified organic grain alcohol (42-46%), distilled water and Astagalus extractives.

Composition of astragalus root
Astragalus root has polysaccharides that have a role in influencing the immune system. Astragalus root also contains saponins called astragalosides and astramembranosides, along with flavonoids and triterpenes. Three major flavonoids are ononin, formononetin, and demethylhomopterocarpin.

Benefits of Astragalus extract

Aplastic anemia
Clinical study on effect of Astragalus Injection and its immuno-regulation action in treating chronic aplastic anemia.
Chin J Integr Med. 2007 June. TCM Hospital of Langfang City, Chinese Hemopathic Therapeutic Center of TCM, Hebei, 065000, China.
Sixty patients with aplastic anemia were randomly assigned to two groups equally, both were treated with Stanozolol three times a day, 2 mg each time through oral intake, but astagalus was given additionally to the patients in the treated group once a day via intravenous dripping. All were treated for 15 days as one therapeutic course and the whole medication lasted for more than 4 months totally, with follow-up adopted. Astragalus injection could promote the recovery of hemopoietic function, which might be through improving T-lymphocyte subsets and reducing the release of negative regulatory factors such as TNF-alpha and IL-2 to alleviate the inhibition on hemopoietic function.

Blood sugar
Hypoglycemic effect of polysaccharide enriched extract of Astragalus membranaceus in diet induced insulin resistant C57BL/6J mice and its potential mechanism.
Phytomedicine. 2009 Feb 5. Department of Pathophysiology, Medical College of Wuhan University, Hubei Provincial Key Laboratory of Allergy and Immune-Related Diseases, 115# Donghu Road, Wuhan 430071, China.
Astragalus polysaccharide exerts insulin-sensitizing and hypoglycemic activities in type 2 diabetic rats. The present study was designed to confirm the hypoglycemic effect of Astragalus polysaccharide and to investigate its possible mechanism underlying the improvement of insulin resistance in vivo and in vitro. We found Astragalus polysaccharide could alleviate insulin resistance induced by high glucose. The hyperglycemia, hypolipemia, and hyperinsulinemia status were controlled with Astragalus polysaccharide therapy. Insulin action in the liver of insulin resistant mice was restored significantly with Astragalus polysaccharide administration. The anti-obesity effect and hypolipidemia effects of Astragalus polysaccharide were probably due partly to decreasing the leptin resistance of mice, which would positively couple with the normalization of plasma insulin levels. We have shown that Astragalus polysaccharide has beneficial effects on insulin resistance and hyperglycemia.

Cancer and use with chemotherapy drugs
Astragalus membranaceus has been used to ameliorate the side effects of anti-neoplastic drugs.

Astragalus membranaceus prevents daunorubicin-induced apoptosis of cultured neonatal cardiomyocytes: role of free radical effect of Astragalus membranaceus on daunorubicin cardiotoxicity.
Phytother Res. 2009 Jan 26. Shanghai Institute of Hematology, School of Medicine, Shanghai Jiao Tong University, Shanghai 20001, China.
Anthracyclines are antitumor antibiotics with significant activity against solid and hematologic malignancies. One problem preventing more widespread use has been the development of cardiotoxicity. To determine whether antioxidant agents can reduce the cardiotoxicity of anthracyclines, Astragalus membranaceus was introduced. Pre-treatment with Astragalus membranaceus significantly attenuated the daunorubicin-induced increases of reactive oxygen species, apoptosis and the secretions of LDH in cultured neonatal cardiomyocytes. Compared with Astragalus membranaceus, N-acetyl-l-cysteine had similar effects on daunorubicin-induced cell injury. Our results suggested that Astragalus membranaceus is potentially protective against daunorubicin cardiotoxicity by decreasing free radical release and apoptosis in cultured neonatal cardiomyocytes.

I would like to use astragalus herb together with graviola herb for cancer treatment, are there any studies that have combined the two products?
    We are not aware of studies that have combined graviola herb along with this immune herb.

Fatigue
Astragalus membranaceus flavonoids (AMF) ameliorate chronic fatigue syndrome induced by food intake restriction plus forced swimming.
J Ethnopharmacol. 2009 Feb 25; National Research Institute of Chinese Medicine, Taipei, Taiwan, ROC.
Alteration of immune function may be associated with chronic fatigue syndrome (CFS) and this study reveals the immunoregulatory effect of Astragalus membranaceus flavonoids. Rats were induced by food intake restriction plus forced swimming for 6 weeks. An atrophied spleen associated with a significantly decreased spleen/body weight ratio and a reduced spleen cells proliferation was found in these rats when compared with home cage controls. Astragalus membranaceus flavonoids given orally at 20, 50 and 100mg/kg body weight once a day consecutively for 6 weeks recovered the reduced cell proliferation. A switch to Th1-dominated immune regulation was observed in these rats as the cultured splenocytes produced more interleukin-2 (IL-2) but less IL-4 when compared with controls. Supplementation with Astragalus membranaceus flavonoids counteracted the aberrant cytokine production and rats receiving Astragalus membranaceus flavonoids exhibited higher endurance capacity to swim when compared with those without the herb. Alterations of immune function may be associated with CFS and the tonic effects of Astragalus membranaceus flavonoids against CF may be attributable to balance the abnormal cytokine level by isoflavones.

Heart failure
Astragalus has protective effect on heart tissue and may be helpful in congestive heart failure.

Study on effect of Astragalus injection in treating congestive heart failure.
Zhou ZL, Yu P.Third People's Hospital, Hangzhou 310009.
To observe the clinical efficacy and side-effects of Astragalus Injection in treating congestive heart failure (CHF). Eighty-three CHF patients with heart function of II-IV grade assessed by New York Heart Association classification were randomly divided into 2 groups. The 42 patients in the treated group were treated with astragalus 40 ml (equivalent to 80 g crude drug) by adding in 5% glucose solution 500 ml for intravenous dripping, once a day and the 41 patients in the control group were treated by nitrolingual injection. The therapeutic course in both groups was 2 weeks and the patients were followed-up for 1- 6 months. The clinical heart function improvement rate and the total effective rate in the astragalus treated group after 1 month treatment were 26% and 78%, and after 6 months were 34% and 81% respectively, which were superior to those in the control group significantly. The levels of left ventricular ejection fraction, fractional shortening of left ventricular short axis, stroke volume, cardiac output  and the cardiac index were all improved in both groups, but better improvement was shown in the astragalus group. Follow-up study showed that the incidence of cardiac event was lower in the astragalus group than that in the control group. Astragalus can be viewed as one of the important auxiliary drugs for treatment of CHF especially in severe cases.

Immune system
Astragalus improves certain parts of the immune system, and may have some anti-HIV activity. It's not clear whether astragalus would have anti-HIV activity when ingested as a supplement.

Astragalus and kidney disease
Astragalus may be helpful in diabetic nephropathy. This herb may also act as a diuretic.

Protective effects of Astragalus saponin I on early stage of diabetic nephropathy in rats.
J Pharmacol Sci. 2004 Jun;95(2):256-66.
Diabetic nephropathy (DN) has become the leading cause of end stage failure, but no renoprotective treatment has been very available for use in DN. Astragalus saponin I, a component extracted from Astragalus membranaceus, was studied in experimental DN induced by administration of streptozotocin in male rats. The early DN rats were treated with 3 doses of astragalus for 8 weeks to analyze its efficacy with different parameters. By comparison with vehicle-treated DN rats, the renal hypertrophy, the oxidative stress intensity, and the blood glucose level of DN rats were ameliorated by astragalus. Also, the microalbuminuria level, advanced glycated end-products either in serum or in kidney cortex, and the aldose reductase activity were significantly reduced. The results suggest that astragalus has therapeutic effects on several pharmacological targets in the progress of DN and is a potential drug for prevention of early stage DN.

Aqueous extract of Astragali Radix induces human natriuresis through enhancement of renal response to atrial natriuretic peptide.
J Ethnopharmacol. 2008 Mar 28; Department of Nephrology & Rheumatology, Shanghai Tenth People's Hospital, Tongji University, Shanghai 200072, China.
The diuretic effect of astragalus root in humans was described in ancient books, but its mechanism has not been identified. To evaluate its diuretic / natriuretic effect, we conducted a double-blind, randomized, crossover study in 12 healthy men. They were randomized to receive either placebo or a single oral dosage of 0.3g/kg body weight of aqueous extract of astragalus root. Compared with placebo, astragalus root treatment markedly increased urinary sodium excretion, fractional sodium excretion, and urinary excretion of chloride during the first 4h. No significant changes of these parameters were observed during 12h or 24h. We show here that astragalus root induces a marked natriuresis in healthy men, which is attributed to enhanced renal responses to endogenous A-type Natriuretic Peptide. The Astragaloside IV in the astragalus root is not the active component for natriuresis.

Effect of Astragalus membranaceus and Angelica sinensis combined with Enalapril in rats with obstructive uropathy.
Phytother Res. 2009 Dec 3. Wojcikowski K, Wohlmuth H, Johnson DW, Gobe G. Molecular and Cellular Pathology, School of Medicine, University of Queensland, Brisbane, Queensland, Australia.
ACE inhibitors (ACEi) reduce renal tubulointerstitial fibrosis but are not completely effective. Combined extract of Astragalus membranaceus and Angelica sinensis (A&A) is a traditional antifibrotic agent in China. The present investigation aimed to determine whether an ACEi (Enalapril) and A&A together have a better antifibrotic effect in unilateral ureteral obstruction (UUO) than monotherapy with either agent. Male Sprague-Dawley rats (N = 4 per group) had either sham operation or UUO alone, with A&A (combined aqueous and ethanol extract equivalent to 2.1 g dried herbs), with Enalapril (in drinking water at 200 mg/mL) or with both treatments. Kidney and liver were collected for protein extraction or fixed for histologic stains, immunohistochemistry (IHC), microscopy. Enalapril or A&A individually were antifibrotic. Transforming growth factor-beta1, fibroblast activation, collagen deposition, macrophage accumulation and tubular cell apoptosis were all decreased. The combination of the two drugs was significantly more effective than Enalapril alone in reducing tumor necrosis factor-alpha, collagen accumulation, activation of fibroblasts, and tubular cell apoptosis. In conclusion, Enalapril with A&A significantly decreased tubulointerstitial fibrosis to a greater extent than treatment with Enalapril alone.

Skin and melanin
Inhibitory effects of calycosin isolated from the root of Astragalus membranaceus on melanin biosynthesis.
Biol Pharm Bull. 2009 Feb; Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea.
Tyrosinase is a key enzyme for melanin biosynthesis, and hyperpigmentation disorders are associated with abnormal accumulation of melanin pigments, which can be reduced by treatment with depigmenting agents. A methanol extract of Astragalus membranaceus showed inhibitory activity against mushroom tyrosinase. The active compound was purified from the methanol extract of Astragalus membranaceus and, following several chromatographic methods, was identified as calycosin. The results showed that calycosin exhibited tyrosinase inhibitory activity. Calycosin showed a melanin biosynthesis inhibition zone in a culture plate of Streptomyces bikiniensis, which is commonly used as an indicator organism. Furthermore, calycosin dramatically reduced melanin synthesis of Melan-a cells without any apparent cytotoxicity and reduced expression of melanogenic enzyme, tyrosinase. These results suggest that calycosin may be an effective skin-lightening agent that regulates the expression of melanogenic enzymes.

Astragalus root supplement side effects and safety
No major side effect have been reported in humans as of April 2010.