Calycosin

Calycosin, a major isoflavonoid isolated from Radix Astragal, induces angiogenesis in human umbilical vein endothelial cell cultures (HUVEC) in vitro and zebrafish embryos in vivo via the up-regulation of vascular endothelial growth factor (VEGF), VEGFR1 and VEGFR2 mRNA expression;it acts similar to other selective estrogen receptor modulators (SERMs) to promote angiogenesis via activation of MAPK with the involvement of ERK1/2 and ER. , such as raloxifene and tamoxifen, by displaying selective potency and affinity to estrogen receptors ERa and ERb.^[1]

Calycosin has neuroprotective effects in cerebral ischemia/reperfusion rats, and the molecular mechanisms may correlate with the positive feedback between ER-α and miR-375, along with the regulation of downstream targets.^[2]

Calycosin inhibits growth and induce apoptosis in ER-positive breast cancer cells, which is mediated by ER-α-induced inhibition of IGF-1R, along with the selective regulation of MAPK and phosphatidylinositol 3-kinase (PI3K)/Akt pathways.^[3]

Calycosin can promote proliferation of estrogen receptor-positive cells via estrogen receptors and ERK1/2 activation in vitro and in vivo.^[4]

Calycosin can reduce advanced glycation end products-induced macrophage migration and adhesion to endothelial cells and relieve the local inflammation; furthermore, this effect is via estrogen receptor-ERK1/2–NF-κB pathway.^[5]

Calycosin is a vasorelaxant, its action is endothelium-independent and is unrelated to intracellular Ca(2+) release; it is also a noncompetitive Ca(2+) channel blocker, the effect of it on Ca(2+) channel blockade may be different from that of dihydropyridines. ^[6]