Astragalus membranaceus is a herb considered particularly important in modern nutraceutical and traditional Chinese medicine from which it comes. Historically it has always been used in a wide variety of mixtures of herbs and "natural" remedies, including one of the most famous such as the Dang-gui buxue tang, which is Astragalus membranaceus combined with Angelicae Sinensis.

Astragalus membranaceus has been studied for its cardioprotective, anti-inflammatory and antiaging effects. 

Although the integration of Astragalus membranaceus has been shown to reduce the physical complications resulting from the natural biological processes of ageing, there are currently no scientific studies with uniform results showing that this effect is derived from a single factor but probably the effect on the reduction of pathological factors induced by ageing processes, should be sought in all elements that act positively.

The flavonoid content of Astragalus membranaceus can also contribute to its cardioprotective effects: given its polysaccharide content, it protects the heart because it is a powerful anti-inflammatory agent able, among other things, to reduce cholesterol levels.

The main mechanism of Astragalus membranaceus is the result of its active ingredients. The main component is Astragaloside IV, which was extracted, isolated and patented under the name of TA-65 and marketed as a longevity agent. Unfortunately, Stragaloside IV has low bioavailability, which means it has limited circulation in the body after ingestion, remaining in the body only at low concentrations.

Despite these low concentrations of Stragaloside IV, the same provides equally cardioprotective effects.
Astragalus membranaceus can also be integrated via a root extract.
The main bioactive compound in Astragalus membranaceus is Astragaloside IV, which can be integrated by itself. The standard dose for Astragaloside IV is 5-10mg.

As mentioned above, there are many positive effects on health: we try to summarize them briefly following the most recent scientific studies.

Longevity

This protective effect on mitochondria was observed during the evaluation in diabetic mice, where the administration of astragalus at 700 mg /kg per day was able to preserve the mitochondrial structure. (1) Mitochondrial membranes may be damaged by lipid peroxidation (2) which is known to increase with age, (3) astragalus polysaccharides exert dose-inhibitionlipid peroxidation dependent on a concentration of 2 mg / L and may inhibit up to 90% lipid peroxidation in hepatic mitochondria and 78% in neurons at a concentration of 32 mg / L. (4)

Neuroprotection

An extract of Astragalus taken orally at 10-40mg/kg body weight was able to mitigate the pro-Alzheimer effects of the drug Desamethasone, a synthetic glucocorticoid with dose-dependent actions similar to cortisol. (5) This extract was also able to preserve the neuronal structure of the hippocampus and reduce adverse changes in caspase-3 and caspase-9, and suggests that the astragalus could protect against neurodegeneration due to stress. (6)

These effects of stress protection were previously noted with higher doses of regular astragalus extract and suggesting an adaptogenic effect. (7)
It has been noted that the anti-inflammatory effects of astragalus at doses of 40-80 mg /kg body weight in rats are able to suppress the increase in THF-α and IL-1β associated with cerebral ischemia/reperfusion injury. (8) This, may lead to less neuronal death and nerve damage. (9)

It is not known which ingredients contribute to these effects but, despite the limited absorption of Astragaloside IV, it may be an active component. By itself, it can reduce damage associated with ischemia/recurrence (10) and general neuroprotection. (11)

Blood pressure

At least one study in the man who used oral administration noted a decrease in blood pressure associated with ingestion of astragalus (1,050 mg a day), but was confused with Coptis Chinensis (630 mg a day) and Lonicera Japonic (2,520 mg a day). (12) A study of rats using a Shichimotsukokato (SKT) formula of Astragalus Membranaceus and 6 other herbs found blood pressure reductions in rats subject to nephrectomy by preventing the "downregulation" of a key anti-hypertensive enzyme,(13) and another study using 100-200 mg/kg of a related Astragalus plant (Complanatus) found that the flavonoid content (similar in profile to Membranaceus) was able to reduce 17% after oral administration (14) blood pressure.

Although the flavonoid component of the astragalus appears to be suspect, (15) injections of Astragaloside IV have also been shown to reduce blood pressure in hypertensive rats to 0.5-2 mg /kg body weight. (16)

Skin quality

After oral administration of astragalus in atopic dermatitis at the oral dose of 100 mg/kg body weight is able to suppress skin reactions in response to 2,4-dinitrofluorobenzne, a chemical used to induce dermatitis and was more effective than cortisone used for deterpencil reduction (17)

Observing the mechanisms of function, the astragalus has not been able to inhibit the increase of the Ige (whose elevated levels are a distinctive sign of atopic dermatitis) nor the increase of IL-4 (aids in the conversion of Igm in Ige)but it seemed to suppress the inflammation anyway. (17)
The mechanisms can be partly explained by the suppression of IFN-y, of which Astragalus and cortisone drug were equal power. (17)

Through its ability to inhibit Mmps, especially MMP1, the astragalus can be able to protect the skin from UV-induced photoaging.

Bibliography

1. Mao XQ, et al. Hypoglycemic effect of polysaccharide enriched extract of Astragalus membranaceus in diet induced insulin resistant C57BL/6J mice and its potential mechanism. Phytomedicine. (2009)
2. Paradies G, et al. Age-dependent decline in the cytochrome c oxidase activity in rat heart mitochondria: role of cardiolipin. FEBS Lett. (1997)

3. Spiteller G. Lipid peroxidation in aging and age-dependent diseases. Exp Gerontol. (2001)
4. Li XT, et al. Mitochondrial Protection and Anti-aging Activity of Astragalus Polysaccharides and Their Potential Mechanism. Int J Mol Sci. (2012)
5. Li WZ, et al. Protective effect of extract of Astragalus on learning and memory impairments and neurons' apoptosis induced by glucocorticoids in 12-month-old male mice. Anat Rec (Hoboken). (2011)
6. Park HJ, et al. The Effects of Astragalus Membranaceus on Repeated Restraint Stress-induced Biochemical and Behavioral Responses. Korean J Physiol Pharmacol. (2009)
7. Effect of extract of astragalus on inflammatory factor and apoptosis after focal cerebral ischemia/reperfusion injury in rats.
8. Huang XP, et al. Astragalus extract alleviates nerve injury after cerebral ischemia by improving energy metabolism and inhibiting apoptosis. Biol Pharm Bull. (2012)
9. Qu YZ, et al. Astragaloside IV attenuates cerebral ischemia-reperfusion-induced increase in permeability of the blood-brain barrier in rats. Eur J Pharmacol. (2009)
10. Luo Y, et al. Astragaloside IV protects against ischemic brain injury in a murine model of transient focal ischemia. Neurosci Lett. (2004)
11. Chan WS, et al. Neuroprotective effects of Astragaloside IV in 6-hydroxydopamine-treated primary nigral cell culture. Neurochem Int. (2009)
12. Zhang N, et al. Astragaloside IV improves metabolic syndrome and endothelium dysfunction in fructose-fed rats. Molecules. (2011)
13. Chao M, et al. Improving insulin resistance with traditional Chinese medicine in type 2 diabetic patients. Endocrine. (2009)
14. Bai F, et al. Anti-hypertensive effects of shichimotsukokato in 5/6 nephrectomized Wistar rats mediated by the DDAH-ADMA-NO pathway. J Nat Med. (2012)
15. Li JX, et al. Antihypertensive effect of total flavonoid fraction of Astragalus complanatus in hypertensive rats. Chin J Physiol. (2005)
16. Zheng KY, et al. Flavonoids from Radix Astragali induce the expression of erythropoietin in cultured cells: a signaling mediated via the accumulation of hypoxia-inducible factor-1α. J Agric Food Chem. (2011)
17. Lee SJ, et al. Oral administration of Astragalus membranaceus inhibits the development of DNFB-induced dermatitis in NC/Nga mice. Biol Pharm Bull. (2007)