Bioactive polyphenol antioxidants protect oral fibroblasts from ROS-inducing agents.
BACKGROUND
Oxidative damage to soft oral tissues may result from exposure to the chemicals or biochemicals found in teeth-whitening products, dental restorations, tobacco, and alcohol. Our working hypothesis is that oral tissues are susceptible to the toxic effects of stressors such as hydrogen peroxide (H(2)O(2)), ethanol (EtOH) and nicotine (Nic), which decrease cell viability/DNA synthesis and elevate reactive oxygen species (ROS). In this study, we investigated specific polyphenols and turmeric derivative antioxidants (AO) in combinations that counteracted the effects of these stressors on cultured oral fibroblast proliferation and ROS production.


METHODS
Oral fibroblasts were exposed to stressors for 30 min and then treated with 10(-5) M of bioactive AO mixtures [resveratrol, ferulic acid and tetrahydrocurcuminoid (RFT), phloretin, ferulic acid and resveratrol (PFR), phloretin, ferulic acid and tetrahydrocurcuminoid (PFT)] for 24 h. Cell viability and DNA synthesis were monitored using incorporated 3-[4,5-dimethylthiazol-2-yl]-5-[3-carboxymethoxyphenyl]-2-[4-sulphophenyl]-2H-tetrazolium (MTS) and 5-bromo-2-deoxyuridine (BrdU) assays, respectively. Total ROS was measured with dichlorodihydrofluorescein diacetate (H(2)DCFDA).


RESULTS
Incubation of oral fibroblasts in the stressors for 30 min resulted in a dose-dependent decrease of DNA synthesis and number of viable cells, and an increased total ROS activity. AO treatment counteracted the insults by restoring DNA synthesis levels and cell viability, and decreasing the total ROS activity.


CONCLUSIONS
The AO combinations of RFT, PFR and PFT protected the oral fibroblasts from the detrimental effects of H(2)O(2), EtOH and Nic by decreasing total ROS and increasing cell viability and DNA synthesis.
Department of Biomedical Sciences, Texas A&M Health Science Center, Baylor College of Dentistry, Dallas, United States.
Symone M
SM
San Miguel
Lynne A
LA
Opperman
Edward P
EP
Allen
Jan
J
Zielinski
Kathy K H
KK
Svoboda
D000704:Analysis of Variance; D000975:Antioxidants / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D030024:Curcuma; D005347:Fibroblasts / Q000187:drug effects*; D005881:Gingiva / Q000166:cytology / Q000187:drug effects; D006801:Humans; D010936:Plant Extracts / Q000494:pharmacology; D059808:Polyphenols / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000494:pharmacology*; D013194:Staining and Labeling
D000975:Antioxidants; D010936:Plant Extracts; D059808:Polyphenols; D017382:Reactive Oxygen Species; C012596:turmeric extract