Anti-Aging Properties - Cycloastragenol (CAG) is an aglycone of astragaloside IV. It was first identified when screening Astragalus membranaceus extracts for active ingredients with antiaging properties. The present study demonstrates that CAG stimulates telomerase activity and cell proliferation in human neonatal keratinocytes. In particular, CAG promotes scratch wound closure of human neonatal keratinocyte monolayers in vitro. The distinct telomerase-activating property of CAG prompted evaluation of its potential application in the treatment of neurological disorders. Accordingly, CAG induced telomerase activity and cAMP response element binding (CREB) activation in PC12 cells and primary neurons. Blockade of CREB expression in neuronal cells by RNA interference reduced basal telomerase activity, and CAG was no longer efficacious in increasing telomerase activity. (Article)
Depression Remedy - CAG treatment not only induced the expression of bcl2, a CREB-regulated gene, but also the expression of telomerase reverse transcriptase in primary cortical neurons. Interestingly, oral administration of CAG for 7 days attenuated depression-like behavior in experimental mice. In conclusion, CAG stimulates telomerase activity in human neonatal keratinocytes and rat neuronal cells, and induces CREB activation followed by tert and bcl2 expression. Furthermore, CAG may have a novel therapeutic role in depression. (Article)
Diabetes Prevention - Because advanced glycation end product (AGE) inhibitors such as pyridoxamine significantly inhibit the development of retinopathy and neuropathy in the streptozotocin-induced diabetic rat, treatment with AGE inhibitors is believed to be a potential strategy for the prevention of lifestyle-related diseases such as diabetic complications. A crude extract of Astragali Radix (AR; roots of Astragalus membranaceus) inhibits the formation of Nε-(carboxymethyl)lysine (CML) and pentosidine during the incubation of bovine serum albumin with ribose. In the present study, compounds were isolated from AR that prevented CML and pentosidine formation. Astragalosides significantly inhibited the formation of both CML and pentosidine, and astragaloside V had the strongest inhibitory effect among all if the isolated compounds. These data suggest that AR and astragalosides may be a potentially useful strategy for the prevention of clinical diabetic complications by inhibiting AGEs. (Article)
Anti- Cancer - Owing to a dramatic increase in average life expectancy and the Family Planning program of the 1970s - 1990s, China is rapidly becoming an aging society. Therefore, the investigation of healthspan-extending drugs becomes more urgent. Astragalus membranaceus (Huangqi) is a major medicinal herb that has been commonly used in many herbal formulations in the practice of traditional Chinese medicine (TCM) to treat a wide variety of diseases and body disorders, or marketed as life-prolonging extracts for human use in China, for more than 2000 years. The major components of Astragalus membranaceus are polysaccharides, flavonoids, and saponins. Pharmacological research indicates that the extract component of Astragalus membranaceus can increase telomerase activity, and has antioxidant, anti-inflammatory, immunoregulatory, anticancer, hypolipidemic, antihyperglycemic, hepatoprotective, expectorant, and diuretic effects. A proprietary extract of the dried root of Astragalus membranaceus, called TA-65, was associated with a signi