Imine stilbene analog ameliorate isoproterenol-induced cardiac hypertrophy and hydrogen peroxide-induced apoptosis.

Cardiac hypertrophy is an adaptive response to stress, in order to maintain proper cardiac function. However, sustained stress leads to pathological hypertrophy accompanied by maladaptive responses and ultimately heart failure. At the cellular level, cardiomyocyte hypertrophy is characterized by an increase in myocyte size, reactivation of the fetal gene markers, disassembly of the sarcomere and transcriptional remodelling which are regulated by heart-specific transcription factors like MEF2, GATA4 and immediate early genes like c-jun and c-fos.2. It has been explored and established that the hypertrophic process is associated by oxidative stress and mediated by pathways involving several terminal stress kinases like P38, JNK and ERK1/2. Stilbenoids are bioactive polyphenols and earlier studies have shown that imine stilbene exert cardioprotective and anti aging effects by acting as modulators of Sirt1. The present study was aimed at designing and synthesizing a series of imine stilbene analogs and investigate its anti hypertrophic effects and regulatory mechanism in cardiac hypertrophy and apoptosis. Interestingly one of the analog, compound 3e (10 µM) alleviated isoproterenol (ISO, 25 µM) induced hypertrophy in rat cardiomyocyte (H9c2) cells by showing a marked decrease in the myocyte size. Further, compound 3e also restored the cardiac function by activating the metabolic stress sensor, AMPK. Moreover, molecular docking studies showed stable binding between compound 3e and GSK3ß suggesting that compound 3e may directly regulate GSK3ß activity and ameliorate ISO-induced cardiac hypertrophy. In agreement with this, compound 3e also modulated the crosstalk of all the hypertrophy inducing terminal Kinases by bringing down the expression to near control conditions. The compound also relieved H2O2 (100 µM) mediated ROS and normalized abnormal mitochondrial oxygen demand in hypertrophic conditions indicating the possibility of the compound to show promise in playing a role in cardiac hypertrophy.

Evolvement of nutraceutical onion plants engineered for resveratrol biosynthetic pathway.

KEY MESSAGE: Genetically engineered onion expressing codon-optimized VvSTS1 gene accumulated stilbenes and extended life span in yeast and can serve as potential nutraceutical. Resveratrol (RV) is a natural polyphenolic compound found in certain plant species including grapes. RV is well known for its nutraceutical properties and to assuage several disease conditions. Onion is the second most consumed vegetable worldwide and contains large quantities of precursor molecules, malonyl-CoA and para-coumaroyl-CoA that are needed for RV biosynthesis. The present study reports the development of nutraceutical onion by engineering RV biosynthetic pathway. A codon-optimized grapevine synthetic stilbene synthase gene (VvSTS1) was synthesized using native grapevine sequence. Six-week-old healthy yellowish compact nodular calli were co-cultivated with Agrobacterium tumefaciens harbouring pCAMBIA1300-hpt II-CaMV35S-VvSTS1-nos. PCR analysis revealed the presence of VvSTS1 and hpt II genes in putative transgenics. Southern blot analysis confirmed the integration of VvSTS1 gene and independent nature of transformants. LC-ESI-HRMS analysis revealed the accumulation of variable quantities of RV (24.98-50.18 µg/g FW) and its glycosylated form polydatin (33.6-67.15 µg/g FW) in both leaves and bulbs, respectively, indicating the successful engineering of RV biosynthetic pathway into onion. The transgenic onion bulb extracts extended the life span in haploid yeast. The transgenic onion accumulating RV and polydatin, developed for the first of its kind, may serve as a potential nutraceutical resource.

Molecular docking analysis of imine stilbene analogs and evaluation of their anti-aging activity using yeast and mammalian cell models.

The NAD+-dependent histone deacetylase SIRT1 was shown to be associated with aging and longevity. A stilbene, resveratrol (RV) was shown to exert anti-aging activity by stimulating the SIRT1 activity. However, the utility of RV is limited by its low bioavailability and structural instability. It is thus envisaged to test imine stilbene (IMS) analogs of RV for their potential anti-aging activity. In the present study, molecular docking analysis of five IMS analogs (3a, 3b, 3c, 3d and 3e) against the SIRT1 protein has been carried out. All the five IMS analogs displayed enhanced binding affinity towards SIRT1; three out of five IMS analogs (3a, 3 b, 3e) showed significantly higher affinity with lower binding energies (-9.58, -9.54, and -9.82 kcal mol-1) than RV (-8.11 kcal mol-1). Further, experimental validation of anti-aging activity was performed by measuring the chronological life span in vitro using yeast and cellular replicative senescence (CRS) in mammalian cell line models. All IMS analogs extended the chronological life span in yeast as compared to untreated cells as well as RV treated cells. Enhanced anti-aging activity was also observed in an analogous mammalian cell line model upon treatment with either RV or IMS analogs. The results thus suggest that most of the IMS analogs tested may serve as potent drug lead molecules with anti-aging activity.

Synthesis of Novel Imine Stilbene Analogs Exhibiting Potent Anticancer Activity.

BACKGROUND: Resveratrol (RV) and its analogues Aza-stilbenes were found effective in exhibiting anticancer activity. OBJECTIVE: The present study mainly focused on the green synthesis of novel imine stilbene analogues and evaluation of their anticancer activity besides their influence on hypoxia-induced gene expression in cancer cells. METHOD: Novel imine stilbenes, differing in number and/or position of hydroxyl and methoxy functional groups, have been synthesized using green chemistry mediated condensation reaction between aldehydes and amines in the ethanolic extract of Psoralea corylifolia hairy roots and tested for their anticancer potential. RESULTS: Ethanol containing 1% hairy root extract facilitated instant reaction and yielded more than 99% product( s). MTT assay on HeLa cells treated with imine stilbene analogues revealed an increase in the inhibition of cell proliferation as compared to RV. Treatment of nontumor HEK293 cells with these compounds disclosed minimal toxicity implying the selective advantage of these compounds for cervical cancer therapy. Scratch assay on HeLa cells displayed inhibition of directional cell motility by these analogues and compound 3e [4-((E)-(4- hydroxyphenylimino)methyl)-2-methoxyphenol] recorded maximum inhibition. In reporter assay, as compared to untreated N-(2-Methoxy-2-oxoacetyl) glycine methyl ester (DMOG) induced cells, hypoxia response element- directed transcriptional activity has been significantly reduced in DMOG induced cells treated with imine stilbene analogues. CONCLUSION: Overall results indicated that four of the five imine stilbene analogues exhibited enhanced anticancer activity than that of the RV. As such, the novel synthetic compounds 3d, 3e and 3b endowed with potent anticancer activity than RV can serve as drug lead molecules.