PDR for Herbal Medicines

HERBAL MONOGRAPHS ASTRAGALUS (HUANG-QI) /55

abnormal action potential in animal models infected with

CB3V, suggesting its possible use for prevention and

treatment of acute myocarditis involving CB3V (Rui, 1994).

Antioxidant—Astragalus membranaceus inhibits lipid perox-

idation in rat heart mitochondria (Hong, 1994).

Cardiovascular Effects—Astragalus membranaceus in-

creases cardiac output in patients with angina pectoris (Lei,

1994). Astragaloside IV improves left ventricular end-dia-

stolic volume, left ventricular end-systolic volume and slows

heart rate in heart failure. The compound also alleviates

chest distress and dyspnea associated with heart failure (Luo,

1995). The herb has therapeutic effects on sodium and water

retention in aortocaval fistula-induced heart failure, improv-

ing cardiac and renal functions in heart failure. The

mechanism is partly through correction of abnormal mRNA

expressions of hypothalmic arginine vasopresin system and

aquaporin-2, and amelioration of blunted renal response to

atrial natriuretic peptide (Ma, 1998).

Fibrinolytic—Astragaloside IV increases the fibrinolytic

potential of endothelial ells by upregulating the expression of

tissue-type plasminogen activator and by downregulating the

A^, expression of plasminogen activator inhibitor type 1 (Zhang,

1997).

Gastrointestinal Effects—The herb strengthens the move-

ment and muscle tonus in the intestine, especially the

jejunum, to increase movements in the digestive tract, as

evidenced by positive effects on the cycle duration of

interdigestive myoelectric complex (Lei, 1994).

Hepatoprotective—An ethanol extract of the root of Astraga-
lus membranaceus alleviated liver injury through a reduction
of elevated SGPT levels and subacute toxicity. The herb also
decreased loss of righting reflex and protected hepatic cells
from pathological changes (Zhang, 1990).
Immuno-modulating—The herb stimulates macrophages,
promotes antibody formation, and increases T lymphocyte
proliferation. F3, an immuno-regulatory component of the
herb reverses macrophage suppression induced by urological
tumors (Rittenhouse, 1991). Astragalus membranaceus ex-
tracts enhance the antibody response to a T-dependent
antigen associated with an increase of Th cell activity in
£ normal and immunodepressed animal models (Zhao, 1990).
A fractionated extract of Astragalus membranaceus potenti-
ates lymphokine-activated killer (LAK) cell cytotoxicity
generated by low-dose recombinant interleukin-2 (rIL-2).
This immune response occurs through a 10-fold potentiation
of rIL-2 activity manifested by tumor cell killing activity
resulting from LAK cell generation (Chu, 1990).

Memory Improvement—Aqueous extracts of Astragalus

demonstrated improvement of anisodine-induced impairment

on memory acquisition as well as the alcohol-elicited deficit

of memory retrieval (a reduction in errors and prolonged

latent period) (Hong, 1994).

CLINICAL TRIALS

Immune-stimulating

The effect of pure Astragalus preparation (PAP) in treating

115 patients with leukopenia was determined after 8 weeks

of therapy. Group I was treated by a concentrated PAP (10

ml, equivalent to 15 grams of Astragalus), and group II was

treated with a different concentrated PAP (10 ml, equivalent

to 5 grams of Astragalus). Both treatment groups received a

dose of 10 ml twice daily. The effectiveness was statistically

different between the groups with 82.76% and 47.37% in

Group I and II, respectively. The total effective rate was

65.22%. The average WBC count of group I was significant-

ly higher than that of group II with a significant rise of the

WBC counts in both groups after treatment (Weng XS,

1995).

Cardiovascular Effects

The effect of Astragalus membranaceus on left ventricular

function and oxygen free radicals was evaluated in 43

cardiac patients. All patients in the treatment group had

experienced their myocardial infarction within the past 36

hours. The herb demonstrated a strengthening of left

ventricular function and an effect of anti-oxygen free

radicals for a cardiotonic action. The herb decreased the ratio

of pre- ejection period/left ventricular ejection time, in-

creased the superoxide dismutase activity of red blood cells

and reduced lipid peroxidation content (Chen, 1995).

INDICATIONS AND USAGE

Unproven Uses: The herb has been used for respiratory

infections, immune depression, cancer, heart failure, viral

infections, liver disease and kidney disease. Astragalus has

also been used as a diuretic.

Chinese Medicine: The herb has been used alone and in

combination for liver fibrosis, acute viral myocarditis, heart

failure, small cell lung cancer, amenorrhea, and antiviral.

PRECAUTIONS AND ADVERSE REACTIONS

General: Caution should be taken with patients receiving

immunosuppressive therapy, such as transplant patients, or

patients with autoimmune diseases. Extracts of Astragalus

lusitanicus in animal models resulted in toxic excitatory

cardiac effects and respiratory depression, involving skeletal

muscle and neurological systems (Abdennebi, 1998).

Neurological Dysfunction: Due to the selenium content in

Astragalus, toxic doses may result in neurological dysfunc-

tion leading to paralysis (Panter, 1996).