Astragalus membranaceus is no stranger to the world of herbal healing. This well-known plant has been referenced in Chinese medicinal writings over 2,000 years old, and is still commonly used today. In the world of Chinese medicine, it is said to nourish and replenish the Qi while helping the body adapt to stress by normalizing body processes (4, 6).
Its first appearance was in Shen Nong Ben Cao Jing, one of three foundational books of Chinese medicine, now translated to The Divine Farmer’s Materia Medica (6). It was valued for its ability to strengthen the primary energy of the body (the immune system), as well as the metabolic, respiratory, and eliminative functions in the body (6).
Today with a quick search, you’ll see statements of immune boosting, cardiovascular aid, blood glucose regulation, anti-aging, wound healing and many more; but how can one herb help accomplish all of those very different tasks?
A. membranaceus has over 200 isolated compounds, including polysaccharides, saponins, and flavonoids, which when isolated can work towards accomplishing these various functions within the body (6). A. membranaceus is a very well-studied and well-known herb for all of these reasons but has only more recently found its way into the mainstream skincare scene.
Simply put, the use of Astragalus membranaceus in a skincare formula can lead to decreased MMP-1 responsible for the breakdown of collagen, an increase in hyaluronic acid responsible for skin hydration, and decreased melanin production due to UV damage (4, 7). It has been also found to have wound healing properties by various parties (6, 11). All of these together lead to the overall anti-aging effect of this herb, and good reason to consider adding it to a skincare regimen.
One of the major active components extracted from Astragalus membranaceus is Astragaloside IV (AST), which has been found to decrease the rate of environmentally induced breakdown of collagen in the skin (1). What causes this environmental breakdown? One major factor is ultraviolet radiation.
As we know, UV can be very damaging to our skin. This UV radiation has been shown to impair vital signaling pathways necessary for healthy skin function, particularly the TGF-β/Smad signaling pathway. TGF-β (Transforming growth factor-β) is the primary regulator of collagen synthesis in the human skin, and smads are intracellular proteins that deliver DNA signals from TGF-β molecules to the cells to activate gene transcription (3). It has been reported that UV radiation impairs TGF-β/Smad signaling (1). This impairment is a major reason for the reduced collagen synthesis in human skin fibroblasts, which are responsible for the production of collagen and other fibers. This damage from this UV radiation then leads to the appearance of matrix metalloproteinases (MMPs) in skin cells which are responsible for the degradation of many extracellular matrix proteins. Collagenase-1, also known as MMP-1, is the specific MMP responsible for the breakdown of collagen (1,2,4).
Astragalus membranaceus, as previously mentioned, is comprised of saponins. Astragaloside IV (AST) is one of these saponins that has been shown to decrease MMP-1 activity caused by UV damage (1, 2, 6). When studying this effect, it was identified that MMP-1 expression was significantly lower in the AST group compared to the control, suggesting that AST is a significant inhibitor of UV-induced MMP-1 expression (1). This saponin inhibits UV-induced collagen-1 breakdown by stimulating the same TGF-β/Smad signaling pathway as well as suppressing MMP-1 expression (1). Skin collagen is constantly being broken down and created, as with all cells within our bodies, but as we age the breakdown tends to outperform the synthesis leading to the overall loss of collagen due to aging. A. membranaceus’ effect of suppressing this overactive MMP-1 helps to return skin to a more youthful and balanced function.
Not only can A. membranaceus decrease the breakdown of collagen, it has also been found to increase hyaluronic acid content within the skin. As many now know, hyaluronic acid is a naturally occurring substance in the skin that provides moisture and the full or plump appearance of youthful skin. Hyaluronic Acid (HA) is the key molecule for skin moisture due to its unique capacity to retain water (9). Unfortunately, as the human body ages, epidermal HA also decreases, resulting in a loss of moisture in the outer layer of our skin creating those visible signs of aging we all try to avoid.
To combat this, many topical products now contain HA. The problem is HA has a rather large molecular size, making it difficult to absorb into the skin on its own when applied topically (9). Some products incorporate penetration enhancing ingredients to help combat this, but it is still not the same as naturally occurring HA. Through a series of cell studies, A. Membranaceus has been found to increase the content of hyaluronic acid by increasing hyaluronan synthase-3 and hyaluronan synthase-2, the enzymes responsible for hyaluronic acid synthesis in the skin (7). This means A. membranaceus may have the ability to promote natural HA synthesis within the body leading to fuller more hydrated skin through the aging process.
As discussed previously, UV radiation can be extremely damaging to our skin. Not only can it damage collagen production pathways, it also creates unsightly dark patches due to an overproduction of melanin, the dark pigment in the skin. This melanin production is your skin’s attempt at protecting itself against this damaging UV exposure. This can lead to patches of pigmentation commonly known as “sun spots” or “age spots”. These spots are a result of UV related tyrosinase activity, the enzyme that accelerates melanin synthesis. Tyrosinase not only causes browning in human and animal skin but also the browning of some fruits and vegetables (3). Since many plants have this same browning enzyme, it makes sense that they would have a natural way to regulate the process.
After a review of several medicinal herbs, it was found that Astragalus membranaceus shows some tyrosinase inhibitory activity (3). Not only does this mean A. membranaceus could help to correct dark spots due to UV exposure, but tyrosinase inhibitors have also become an important aspect of hyperpigmentation products. Hyperpigmentation is also due to an overproduction of melanin in certain areas of the skin.The active compound isolated from A. membranaceus, calycosin, could be used as a natural depigmentation agent for people with hyperpigmentation (3). The major factor being calycosin, isolated from the roots of Astragalus membranaceus, decreasing melanin production through regulation of tyrosinase enzymes leading to an evening of skin tone appearance (3). This helps to reverse damage and discoloration due to UV exposure as well as a potential treatment for hyperpigmentation issues.
The wound healing capabilities of this herb stem from its polysaccharide content. One of these (APS2-1) had a particular effect in this process. When studying cell cultures during the replication cycle of healing skin, this polysaccharide was found capable of promoting reepithelialization, revascularization, and cytokine secretion (8,10,11). These steps include the final phase of healing where epithelial cells return to resurface the wound and complete the sealing process of the affected area, the restoration of the blood circulation to the area, and vital cell signaling of the TGF-β1 pathway (8,10,11). This is accomplished by downregulating cyclin D1, a protein required for progression through the G1 phase of the cell cycle, where RNA is produced and the cell ensures everything is set and ready for DNA to be duplicated in the next phase (S phase).
As a result, it shortens the G1/S stage and accelerates cell proliferation in the wound area to accelerate the healing process (11). Essentially the main mechanism of action for the wound healing function of APS2-1 is related to the reduction of the inflammatory response, promotion of cell cycle progression, and the secretion of cytokines that stimulate this pathway, to begin with, and aid in the anti-inflammatory effect (5, 11).
All of these together seem to paint the picture of a powerful anti-aging herb. By improving the skin’s own healing ability, it can recover from trauma more efficiently, with decreased collagen breakdown and increased hyaluronic acid, the skin will be stronger and retain more moisture. Add this to the pigmentation element, that would make for more even, moist, strong skin. This plant as a whole has a generally positive effect on health, but when the specific compounds are isolated, it can work wonders for the skin.
1. Chen, B., Li, R., Yan, N., Chen, G., Qian, W., Jiang, H., . . . Bi, Z. (2015). Astragaloside IV controls collagen reduction in photoaging skin by improving transforming growth factor-β/Smad signaling suppression and inhibiting matrix metalloproteinase-1. Molecular Medicine Reports,11(5), 3344-3348. doi:10.3892/mmr.2015.3212
2. Curnow, A., & Owen, S. J. (2016). An Evaluation of Root Phytochemicals Derived from Althea officinalis (Marshmallow) and Astragalus membranaceus as Potential Natural Components of UV Protecting Dermatological Formulations. Oxidative Medicine and Cellular Longevity, 2016, 1-9. doi:10.1155/2016/7053897
3. Gene Family: SMAD family (SMAD). (n.d.). Retrieved from https://www.genenames.org/cgi-bin/genefamilies/set/750
4. Hong, M. J., Ko, E. B., Park, S. K., & Chang, M. S. (2012). Inhibitory effect of Astragalus membranaceus root on matrix metalloproteinase-1 collagenase expression and procollagen destruction in ultraviolet B-irradiated human dermal fibroblasts by suppressing nuclear factor kappa-B activity. Journal of Pharmacy and Pharmacology,65(1), 142-148. doi:10.1111/j.2042-7158.2012.01570.x
5. Kim, B., Oh, I., Kim, J., Jeon, J., Jeon, B., Shin, J., & Kim, T. (2014). Anti-inflammatory activity of compounds isolated from Astragalus sinicus L. in cytokine-induced keratinocytes and skin. Experimental & Molecular Medicine,46(3). doi:10.1038/emm.2013.157
6. Kim, J. H., Kim, M. R., Lee, E. S., & Lee, C. H. (2009). Inhibitory Effects of Calycosin Isolated from the Root of Astragalus membranaceus on Melanin Biosynthesis. Biological & Pharmaceutical Bulletin,32(2), 264-268. doi:10.1248/bpb.32.264
7. Liu, P., Zhao, H., & Luo, Y. (2017). Anti-Aging Implications of Astragalus Membranaceus (Huangqi): A Well-Known Chinese Tonic. Aging and Disease,8(6), 868. doi:10.14336/ad.2017.0816
8. Mukherjee, P. K., Maity, N., Nema, N. K., & Sarkar, B. K. (2011). Bioactive compounds from natural resources against skin aging. Phytomedicine,19(1), 64-73. doi:10.1016/j.phymed.2011.10.003
9. Papakonstantinou, E., Roth, M., & Karakiulakis, G. (2012). Hyaluronic acid: A key molecule in skin aging. Dermato-Endocrinology,4(3), 253-258. doi:10.4161/derm.21923
10. Wound Care Tips for the Proliferation Phase of Healing. (2015, December 21). Retrieved from https://www.advancedtissue.com/wound-care-tips-for-the-proliferation-phase-of-wound-healing/
11. Zhao, B., Zhang, X., Han, W., Cheng, J., & Qin, Y. (2017). Wound healing effect of an Astragalus membranaceus polysaccharide and its mechanism. Molecular Medicine Reports,15(6), 4077-4083. doi:10.3892/mmr.2017.6488