Modulation of DNA intercalation by resveratrol and genistein

Abstract

Time correlated Single Photon Counting study (TCSPC) was performed for the first time to evaluate the effect of resveratrol (RES) and genistein (GEN) at 10-100 microM and 10-150 microM respectively, in modulating the DNA conformation and the variation induced due to intercalation by the dyes, ethidium bromide (EtBr) and acridine orange (AO). It is demonstrated using UV-absorption and fluorescence spectroscopy that RES and GEN, at 50 microM and 100 microM respectively can bind to DNA resulting in significant de-intercalation of the dyes, preventing their further intercalation within DNA. Hyperchromicity with red/blue shifts in DNA when bound to dyes was reduced upon addition of RES and GEN. DNA-dependent fluorescence of EtBr and AO was quenched in the presence of RES by 87.97% and 79.13% respectively, while similar quenching effect was observed for these when interacted with GEN (85.52% and 83.85%). It is found from TCSPC analysis that the higher lifetime component or constituent of intercalated dyes (tau(2), A (2)) decreased with the subsequent increase in smaller component or constituent of free dye (tau(1), A (1)) after the interaction of drugs with the intercalated DNA. Thus these findings signify that RES and GEN can play an important role in modulating DNA intercalation, leading to the reduction in DNA-directed toxicity.

Spectral Investigation of Preferential Solvation of Acridine in DMSO: Pr-OH Mixture

“…Therefore in the ground state of the fluorophore, self-association of propanol molecules is facilitated in the propanol-rich region whereas PrOH-DMSO interaction becomes more probable in the DMSO-rich region resulting in synergism. Similar behavior of acridine molecule has been reported in a binary mixture of N,Ndimethylformamide (DMF) and ethanol where the solute is solvated by the more polar DMF than ethanol (Usha et al, 2006). Yet unlike the present scenario, no synergism is observed due to stronger interactions between the solute and the solvent species thereby suppressing the possibility of interactions between the two solvents.…”

“…Moreover they are used as stains in biological processes for their capability of intercalation with nucleic acids (Usha et al, 2006;Wainwright, 2001Gasiorowski et al, 2001Bray et al, 2002). DMSO is a polar aprotic solvent with a hydrogen bond acceptor ability β of 0.76 and zero hydrogen bond donor ability.…”

Electrochemical and spectroscopic characterization of the interaction between DNA and Cu(II)–naringin complex

“…Association studies reported with DNA involving flavonols such as morin [3], quercitin [4], kaempferide and luteolin [5] revealed that the predominant interaction mode is intercalative. Some works obtained with resveratrol and genistein [6,7] have confirmed that their structural configuration, possessing a planar aromatic system, is suitable to insert between base-pairs in a helix. Most flavonoids have a common phenyl-benzopyrone skeleton, which differ with respect to the hydroxyl and methoxy groups (Fig.…”

Study of curcumin and genistein interactions with human serum albumin

“…It is known to antagonize human melanoma cell growth at G2/M transition [6] and found to inhibit H 2 O 2 /Cu(II) mediated DNA strand breaks acting as a direct scavenger of reactive oxygen species with the OH group at C-4 position responsible for its antioxidant activity [7]. Genisten intercalation into DNA and RNA duplexes is known [8][9][10] and the effects of genistein on activation of protein phosphatases is well investigated [11].…”