Reserpine Inhibit the JB6 P+ Cell Transformation Through Epigenetic Reactivation of Nrf2-Mediated Anti-oxidative Stress Pathway

Abstract

Abstract. Nuclear factor erythroid-2 related factor 2 (Nrf2) is a crucial transcription factor that regulates the expression of defensive antioxidants and detoxification enzymes in cells. In a previous study, we showed that expression of the Nrf2 gene is regulated by an epigenetic modification. Rauvolfia verticillata, a traditional Chinese herbal medicine widely used in China, possesses anticancer and antioxidant effects. In this study, we investigated how Nrf2 is epigenetically regulated by reserpine, the main active component in R. verticillata, in mouse skin epidermal JB6 P+ cells. Reserpine induced ARE (antioxidant response element)-luciferase activity in HepG2-C8 cells. Accordingly, in JB6 P+ cells, it upregulated the mRNA and protein levels of Nrf2 and its downstream target genes heme oxygenase-1 (HO-1) and NAD(P)H:quinone oxidoreductase 1 (NQO1), while it only increased the protein level of UDP-glucuronosyltransferase 1A1 (UGT1A1). Furthermore, reserpine decreased the TPA (12-O-tetradecanoylphorbol-13-acetate)-induced colony formation of JB6 cells in a dosedependent manner. DNA sequencing and methylated DNA immunoprecipitation further demonstrated the demethylation effect of reserpine on the first 15 CpGs of the Nrf2 promoter in JB6 P+ cells. Reserpine also reduced the mRNA and protein expression of DNMT1 (DNA methyltransferase 1), DNMT3a (DNA methyltransferases 3a), and DNMT3b (DNA methyltransferases 3b). Moreover, reserpine induced Nrf2 expression via an epigenetic pathway in skin epidermal JB6 P+ cells, enhancing the protective antioxidant activity and decreasing TPA-induced cell transformation. These results suggest that reserpine exhibits a cancer preventive effect by reactivating Nrf2 and inducing the expression of target genes involved in cellular protection, potentially providing new insight into the chemoprevention of skin cancer using reserpine.

Targeting Protein Quality Control Mechanisms by Natural Products to Promote Healthy Ageing

“…Chronic administration (30 μΜ) of reserpine to C. elegans increased its lifespan by 31%, provided stress tolerance and delayed age-related decline in the mobility of the worm [ 91 ]. These results are further supported by another study, which suggests that reserpine exerted cancer-preventive properties by reactivating Nrf2 and inducing the expression of cytoprotective genes [ 128 ]. Although the use of reserpine as an anti-ageing factor is rather promising, according to Drugs.com (Drugs Information Database) the clinical use of reserpine as anti-psychotic and anti-hypertensive drug (0.1–0.5 mg orally daily) revealed numerous side-effects, such as respiratory, psychiatric and cardiovascular complications.…”

Taxifolin Activates the Nrf2 Anti-Oxidative Stress Pathway in Mouse Skin Epidermal JB6 P+ Cells through Epigenetic Modifications

“…Radix Angelicae sinensis extract and Z-ligustlide significantly reduced the level of methylation of the first five CpGs that lead to an increase in Nrf2 expression [ 42 ]. Some compounds might alter DNA demethylation and epigenetically enhance Nrf2 expression in JB6 P+ cells, including apigenin [ 43 ] and reserpine [ 44 ]. These reported indicated that some chempreventive compounds could activate the silenced Nrf2 gene via DNA demethylation.…”

The Role of Natural Products in Targeting Cardiovascular Diseases via Nrf2 Pathway: Novel Molecular Mechanisms and Therapeutic Approaches

“…Studies have demonstrated that DNA demethylation and histone (de)acetylation can trigger or increase Nrf2 expression. Natural compounds derived from plants (such as sulforaphane, corosolic acid, taxifolin, reserpine, quercetin, Z-ligustilide and curcumin) and marine constituents (fucoxanthin) have been shown to activate Nrf2 signaling through epigenetic regulation ( Khor et al, 2011 ; Su et al, 2013 ; Liu et al, 2015 ; Hong et al, 2016 ; Muta et al, 2016 ; Kuang et al, 2017 ; Jie et al, 2018 ; Yang et al, 2018c ; Zhao F. et al, 2018 ). Quercetin, a natural flavonoid, significantly inhibited nickel-induced inflammation in mouse liver by decreasing Nrf2 DNA methylation and inhibiting the p38 MAPK signaling pathway ( Liu et al, 2015 ).…”