Formononetin

Virol J. 2015 Mar 1;12(1):35.

Formononetin inhibits enterovirus 71 replication by regulating COX- 2/PGE2 expression.[Pubmed: 25890183]

The activation of ERK, p38 and JNK signal cascade in host cells has been demonstrated to up-regulate of enterovirus 71 (EV71)-induced cyclooxygenase-2 (COX-2)/ prostaglandins E2 (PGE₂) expression which is essential for viral replication. So, we want to know whether a compound can inhibit EV71 infection by suppressing COX-2/PGE₂ expression.
METHODS AND RESULTS:
The antiviral effect of Formononetin was determined by cytopathic effect (CPE) assay and the time course assays. The influence of Formononetin for EV71 replication was determined by immunofluorescence assay, western blotting assay and qRT-PCR assay. The mechanism of the antiviral activity of Formononetin was determined by western blotting assay and ELISA assay. Formononetin could reduce EV71 RNA and protein synthesis in a dose-dependent manner. The time course assays showed that Formononetin displayed significant antiviral activity both before (24 or 12 h) and after (0-6 h) EV71 inoculation in SK-N-SH cells. Formononetin was also able to prevent EV71-induced cytopathic effect (CPE) and suppress the activation of ERK, p38 and JNK signal pathways. Furthermore, Formononetin could suppress the EV71-induced COX-2/PGE₂ expression. Also, Formononetin exhibited similar antiviral activities against other members of Picornaviridae including coxsackievirus B2 (CVB2), coxsackievirus B3 (CVB3) and coxsackievirus B6 (CVB6).
CONCLUSIONS:
Formononetin could inhibit EV71-induced COX-2 expression and PGE₂ production via MAPKs pathway including ERK, p38 and JNK. Formononetin exhibited antiviral activities against some members of Picornaviridae. These findings suggest that Formononetin could be a potential lead or supplement for the development of new anti-EV71 agents in the future.

Mol Carcinog. 2016 Mar;55(3):312-9.

Formononetin promotes proliferation that involves a feedback loop of microRNA-375 and estrogen receptor alpha in estrogen receptor-positive cells.[Pubmed: 25663261]

Formononetin is an O-methylated isoflavone that is isolated from the root of Astragalus membranaceus, and it has antitumorigenic effects. Our previous studies found that Formononetin triggered growth-inhibitory and apoptotic activities in MCF-7 breast cancer cells.
METHODS AND RESULTS:
To further investigate the potential effect of Formononetin in promoting cell proliferation in estrogen receptor (ER)-positive cells, we used in vivo and in vitro studies to elucidate the possible mechanism. ERα-positive cells (HUVEC, MCF-7) were treated with Formononetin. The CCK8 assay, Hoechst 33258, and flow cytometry were used to assess cell proliferation and apoptosis. mRNA levels of ERα, Bcl-2, and miR-375 were quantified using real-time polymerase chain reaction. ERα, p-Akt, and Bcl-2 expression was determined using Western blot. Compared with the control, low Formononetin concentrations (2-6 μM) stimulated ERα-positive cell proliferation (HUVEC, MCF-7). The more sensitive HUVEC cells were used to study the relevant signaling pathway. After treatment with Formononetin, ERα, miR-375, p-Akt, and Bcl-2 expression was significantly upregulated. The proliferative effect of Formononetin was also blocked by a miR-375 inhibitor or raloxifene pretreatment. Additionally, in the in vivo studies, uterine weight in ovariectomized mice treated with Formononetin increased significantly, but the weight dramatically decreased with raloxifene or miR-375 inhibitor pretreatment before Formononetin.
CONCLUSIONS:
This study demonstrated that Formononetin promoted ERα-positive cell proliferation through miR-375 activation and this mechanism is possibly involving in a miR-375 and ERα feedback loop.

J Nutr Biochem. 2010 Jul;21(7):613-20.

Formononetin, an isoflavone, relaxes rat isolated aorta through endothelium-dependent and endothelium-independent pathways.[Pubmed: 19570671 ]

We evaluated the vasorelaxation effects of Formononetin, an isoflavone/phytoestrogen found abundantly in Astragalus mongholicus Bunge, on rat isolated aorta and the underlying mechanisms involved.
METHODS AND RESULTS:
Cumulative administration of Formononetin, genistein, daidzein and biochanin A relaxed phenylephrine-preconstricted aorta. Formononetin and biochanin A caused a similar magnitude of relaxation whereas daidzein was least potent. Mechanical removal of endothelium, L-NAME (100 microM) and methylene blue (10 microM) suppressed Formononetin-induced relaxation. Formononetin increased endothelial nitric oxide (NO) synthase (eNOS), but not inducible NO synthase, activity with an up-regulation of eNOS mRNA and p-eNOS(Ser1177) protein expression. In endothelium-denuded preparations, Formononetin-induced vasorelaxation was significantly reduced by glibenclamide (3 microM) and iberiotoxin (100 nM), and a combination of glibenclamide (3 microM) plus iberiotoxin (100 nM) abolished the relaxation. In contrast, Formononetin-elicited endothelium-independent relaxation was not altered by ICI 182,780 (10 microM, an estrogen receptor (ER alpha/ER beta) antagonist) or mifepristone (10 microM, a progesterone receptor antagonist). In single aortic smooth muscle cells, Formononetin caused opening of iberiotoxin-sensitive Ca(2+)-activated K(+) (BK(Ca)) channels and glibenclamide-sensitive adenosine triphosphate (ATP)-dependent K(+) (K(ATP)) channels.
CONCLUSIONS:
Thus, our results suggest that Formononetin caused vascular relaxation via endothelium/NO-dependent mechanism and endothelium-independent mechanism which involves the activation of BK(Ca) and K(ATP) channels.

Cell Physiol Biochem. 2014;34(4):1351-8.

Formononetin promotes cell cycle arrest via downregulation of Akt/Cyclin D1/CDK4 in human prostate cancer cells.[Pubmed: 25301361]

Formononetin is an O-methylated isoflavone isolated from the root of Astragalus membranaceus. It has already been reported that Formononetin could inhibit cell proliferation and induce cell apoptosis in several cancers, including prostate cancer. This study aimed to further investigate whether cell cycle arrest is involved in Formononetin-mediated antitumor effect in human prostate cancer cells, along with the underlying molecular mechanism.
METHODS AND RESULTS:
Human prostate cancer cells PC-3 and DU145 were respectively treated with various concentrations of Formononetin. The inhibitory effect of Formononetin on proliferation of prostate cancer cells was determined using MTT assays and flow cytometry. Next, Formononetin-induced alterations in cyclin D1, CDK4 and Akt expression in PC-3 cells were detected by real-time PCR and western blot. Formononetin dose-dependently inhibited prostate cancer cell proliferation via the induction of cell cycle arrest at G0/G1 phase in vitro, which was more evident in PC-3 cells. Meanwhile, concomitant with reduced phosphorylation of Akt in PC-3 cells, Formononetin remarkably downregulated expression levels of cyclin D1 and CDK4 in a dose-dependent manner. More interestingly, in the in vivo studies, Formononetin showed a noticeable inhibition of tumor growth in recipient mice.
CONCLUSIONS:
Formononetin could exhibit inhibitory activity against human prostate cancer cells in vivo and in vitro, which is associated with G1 cell cycle arrest by inactivation of Akt/cyclin D1/CDK4. Therefore, Formononetin may be used as a candidate agent for clinical treatment of prostate cancer in the future.

Int J Clin Exp Pathol. 2014 Dec 1;7(12):8453-61.

Formononetin suppresses the proliferation of human non-small cell lung cancer through induction of cell cycle arrest and apoptosis.[Pubmed: 25674209]

Formononetin is a novel herbal isoflavonoid isolated from Astragalus membranaceus and possesses antitumorigenic properties.
METHODS AND RESULTS:
In the present study, we investigated the anti-proliferative effects of Formononetin on human non-small cell lung cancer (NSCLC), and further elucidated the molecular mechanism underlying the anti-tumor property. MTT assay showed that Formononetin treatment significantly inhibited the proliferation of two NSCLC cell lines including A549 and NCI-H23 in a time- and dose-dependent manner. Flow cytometric analysis demonstrated that Formononetin induced G1-phase cell cycle arrest and promoted cell apoptosis in NSCLC cells. On the molecular level, we observed that exposure to Formononetin altered the expression levels of cell cycle arrest-associated proteins p21, cyclin A and cyclin D1. Meanwhile, the apoptosis-related proteins cleaved caspase-3, bax and bcl-2 were also changed following treatment with Formononetin. In addition, the expression level of p53 was dose-dependently upregulated after administration with Formononetin. We also found that Formononetin treatment increased the phosphorylation of p53 at Ser15 and Ser20 and enhances its transcriptional activity in a dose-dependent manner.
CONCLUSIONS:
Collectively, these results demonstrated that Formononetin might be a potential chemopreventive drug for lung cancer therapy through induction of cell cycle arrest and apoptosis in NSCLC cells.

Eur Rev Med Pharmacol Sci. 2014;18(15):2191-7.

Formononetin attenuates hydrogen peroxide (H2O2)-induced apoptosis and NF-κB activation in RGC-5 cells.[Pubmed: 25070826]

Diabetic retinopathy is a common diabetic eye disease caused by changes in retinal ganglion cells (RGCs). Several studies suggest that the oxidative stress plays a role in the pathogenesis of diabetic retinopathy in adults. Formononetin is a flavone with powerful antioxidant properties that exists naturally in various plants and Chinese medicine. In the present study, an attempt has been made to investigate the antioxidative effects of Formononetin on H2O2-induced apoptosis of RGC-5 cells.
METHODS AND RESULTS:
Exposure of retinal ganglion cells (RGCs) to the indicated concentrations of Formononetin and H2O2 for 24 h, analyzed by MTT assay. Cells were stained with Annexin V-FITC and PI, analyzed by flow cytometry. And the level of superoxide anions, malondialdehyde (MDA, a marker of lipid peroxidation), 8-hydroxy-2-deoxyguanosine (8-OHdG, indicator of oxidative DNA damage) and MnSOD (manganese superoxide dismutase) activity were measured by kits. Formononetin reduced hydrogen peroxide (H2O2)-induced apoptosis and improved the levels or activity of indicators of oxidative stress. Formononetin also inhibited the activation of nuclear factor-kappaB (NF-κB), which is a significant transcription factor for RGC-5 apoptosis.
CONCLUSIONS:
Formononetin may be developed as a antioxidant drug to treat diabetic retinopathy.

Menopause. 2012 Aug;19(8):856-63.

Formononetin reverses established osteopenia in adult ovariectomized rats.[Pubmed: 22781783]

Formononetin (Formo) prevents ovariectomy (Ovx)-induced bone loss in rats. However, there are no reports on the curative effects of Formo. The objective of this study was to investigate the ability of Formo in restoring trabecular microarchitecture and promoting new bone formation in osteopenic rats.
METHODS AND RESULTS:
Adult Sprague-Dawley rats were ovariectomized and left for 90 days for osteopenia to develop. After 90 days, Formo (10.0 mg kg d) was given orally for the next 12 weeks to Ovx rats in a therapeutic protocol. Sham-operated, Ovx + vehicle, and Ovx + parathyroid hormone (PTH) groups served as controls. Trabecular microarchitecture, osteoid formation, bone turnover/resorption markers, and bone osteoprotegerin-to-receptor activator for nuclear κB ligand ratio were studied. One-way analysis of variance was used to test significance of effects. Formo treatment significantly restored the lost trabecular microarchitecture in the femurs and tibia of osteopenic Ovx rats and promoted new bone formation. Formo was devoid of any uterine estrogenicity. Serum levels of type I collagen N-terminal propeptide, which is a reliable marker of bone formation, were increased in Ovx rats treated with Formo compared with Ovx + vehicle group, and the levels were comparable with those in the sham group. Formo prevented the Ovx-induced increase in bone turnover markers, including serum osteocalcin and urinary type I collagen degradation product. Furthermore, Formo-treated Ovx rats had an increased bone osteoprotegerin-to-receptor activator for nuclear κB ligand ratio compared with the Ovx + vehicle group.
CONCLUSIONS:
Daily oral administration of Formo for 12 weeks has a substantial anabolic effect, thus raising the possibility of its use in postmenopausal osteoporosis.