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Antioxidant biomarkers from Vanda coerulea stems reduce irradiated HaCaT PGE-2 production as a result of COX-2 inhibition.

Simmler C, Antheaume C, Lobstein A - PLoS ONE (2010)

Bottom Line: Dihydro-phenanthropyran (1) and dihydro-phenanthrene (2) displayed the best DPPH/(•)OH radical scavenging activities as well as HaCaT intracellular antioxidant properties (using DCFH-DA probe: IC(50) 8.8 µM and 9.4 µM, respectively) compared to bibenzyle (3) (IC(50) 20.6 µM).Major antioxidant stilbenoids (1-3) from Vanda coerulea stems displayed an inhibition of UV(B)-induced COX-2 expression.Imbricatin (1) and methoxycoelonin (2) were also able to inhibit COX-2 activity in a concentration-dependent manner thereby reducing PGE-2 production from irradiated HaCaT cells.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Pharmacy, University of Strasbourg, Illkirch, France. charlotte.simmler@pharma.u-strasbg.fr

ABSTRACT

Background: In our investigations towards the isolation of potentially biologically active constituents from Orchidaceae, we carried out phytochemical and biological analyses of Vanda species. A preliminary biological screening revealed that Vanda coerulea (Griff. ex. Lindl) crude hydro-alcoholic stem extract displayed the best DPPH /(•)OH radical scavenging activity and in vitro inhibition of type 2 prostaglandin (PGE-2) release from UV(B) (60 mJ/cm(2)) irradiated HaCaT keratinocytes.

Principal findings: Bio-guided fractionation and phytochemical analysis led to the isolation of five stilbenoids: imbricatin (1) methoxycoelonin (2) gigantol (3) flavidin (4) and coelonin (5). Stilbenoids (1-3) were the most concentrated in crude hydro-alcoholic stem extract and were considered as Vanda coerulea stem biomarkers. Dihydro-phenanthropyran (1) and dihydro-phenanthrene (2) displayed the best DPPH/(•)OH radical scavenging activities as well as HaCaT intracellular antioxidant properties (using DCFH-DA probe: IC(50) 8.8 µM and 9.4 µM, respectively) compared to bibenzyle (3) (IC(50) 20.6 µM). In turn, the latter showed a constant inhibition of PGE-2 production, stronger than stilbenoids (1) and (2) (IC(50) 12.2 µM and 19.3 µM, respectively). Western blot analysis revealed that stilbenoids (1-3) inhibited COX-2 expression at 23 µM. Interestingly, stilbenoids (1) and (2) but not (3) were able to inhibit human recombinant COX-2 activity.

Conclusions: Major antioxidant stilbenoids (1-3) from Vanda coerulea stems displayed an inhibition of UV(B)-induced COX-2 expression. Imbricatin (1) and methoxycoelonin (2) were also able to inhibit COX-2 activity in a concentration-dependent manner thereby reducing PGE-2 production from irradiated HaCaT cells. Our studies suggest that stilbenoids (1-3) could be potentially used for skin protection against the damage caused by UV(B) exposure.

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Radical scavenging activities of stilbenoids 1–5 on DPPH and OH radicals.Results are expressed as IC50 (mean ± sd) of stilbenoids determined on DPPH and •OH radicals scavenging. IC50: concentration causing half-maximal neutralization of radical DPPH or •OH. Quercetin was used as standard reference. IC50 values were compared to those obtained with the standard reference. Statistical significance (*) was set at p<0.05.
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pone-0013713-g002: Radical scavenging activities of stilbenoids 1–5 on DPPH and OH radicals.Results are expressed as IC50 (mean ± sd) of stilbenoids determined on DPPH and •OH radicals scavenging. IC50: concentration causing half-maximal neutralization of radical DPPH or •OH. Quercetin was used as standard reference. IC50 values were compared to those obtained with the standard reference. Statistical significance (*) was set at p<0.05.

Mentions: Among all the ROS produced, •OH radicals are among the most aggressive forms implied in cellular oxidative stress [1]–[2]. Our results revealed that dihydro-phenanthropyrans (1, 4) and dihydro-phenanthrenes (2, 5) displayed better •OH but also DPPH radicals scavenging properties than bibenzyle (3). Activities of imbricatin (1) and methoxycoelonin (2) were quite similar to the standard quercetin on •OH radical scavenging activities, while flavidin (4) and coelonin (5) were globally less active. (Figure 2, Table 1).


Antioxidant biomarkers from Vanda coerulea stems reduce irradiated HaCaT PGE-2 production as a result of COX-2 inhibition.

Simmler C, Antheaume C, Lobstein A - PLoS ONE (2010)

Radical scavenging activities of stilbenoids 1–5 on DPPH and OH radicals.Results are expressed as IC50 (mean ± sd) of stilbenoids determined on DPPH and •OH radicals scavenging. IC50: concentration causing half-maximal neutralization of radical DPPH or •OH. Quercetin was used as standard reference. IC50 values were compared to those obtained with the standard reference. Statistical significance (*) was set at p<0.05.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2965657&req=5

pone-0013713-g002: Radical scavenging activities of stilbenoids 1–5 on DPPH and OH radicals.Results are expressed as IC50 (mean ± sd) of stilbenoids determined on DPPH and •OH radicals scavenging. IC50: concentration causing half-maximal neutralization of radical DPPH or •OH. Quercetin was used as standard reference. IC50 values were compared to those obtained with the standard reference. Statistical significance (*) was set at p<0.05.
Mentions: Among all the ROS produced, •OH radicals are among the most aggressive forms implied in cellular oxidative stress [1]–[2]. Our results revealed that dihydro-phenanthropyrans (1, 4) and dihydro-phenanthrenes (2, 5) displayed better •OH but also DPPH radicals scavenging properties than bibenzyle (3). Activities of imbricatin (1) and methoxycoelonin (2) were quite similar to the standard quercetin on •OH radical scavenging activities, while flavidin (4) and coelonin (5) were globally less active. (Figure 2, Table 1).

Bottom Line: Dihydro-phenanthropyran (1) and dihydro-phenanthrene (2) displayed the best DPPH/(•)OH radical scavenging activities as well as HaCaT intracellular antioxidant properties (using DCFH-DA probe: IC(50) 8.8 µM and 9.4 µM, respectively) compared to bibenzyle (3) (IC(50) 20.6 µM).Major antioxidant stilbenoids (1-3) from Vanda coerulea stems displayed an inhibition of UV(B)-induced COX-2 expression.Imbricatin (1) and methoxycoelonin (2) were also able to inhibit COX-2 activity in a concentration-dependent manner thereby reducing PGE-2 production from irradiated HaCaT cells.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Pharmacy, University of Strasbourg, Illkirch, France. charlotte.simmler@pharma.u-strasbg.fr

ABSTRACT

Background: In our investigations towards the isolation of potentially biologically active constituents from Orchidaceae, we carried out phytochemical and biological analyses of Vanda species. A preliminary biological screening revealed that Vanda coerulea (Griff. ex. Lindl) crude hydro-alcoholic stem extract displayed the best DPPH /(•)OH radical scavenging activity and in vitro inhibition of type 2 prostaglandin (PGE-2) release from UV(B) (60 mJ/cm(2)) irradiated HaCaT keratinocytes.

Principal findings: Bio-guided fractionation and phytochemical analysis led to the isolation of five stilbenoids: imbricatin (1) methoxycoelonin (2) gigantol (3) flavidin (4) and coelonin (5). Stilbenoids (1-3) were the most concentrated in crude hydro-alcoholic stem extract and were considered as Vanda coerulea stem biomarkers. Dihydro-phenanthropyran (1) and dihydro-phenanthrene (2) displayed the best DPPH/(•)OH radical scavenging activities as well as HaCaT intracellular antioxidant properties (using DCFH-DA probe: IC(50) 8.8 µM and 9.4 µM, respectively) compared to bibenzyle (3) (IC(50) 20.6 µM). In turn, the latter showed a constant inhibition of PGE-2 production, stronger than stilbenoids (1) and (2) (IC(50) 12.2 µM and 19.3 µM, respectively). Western blot analysis revealed that stilbenoids (1-3) inhibited COX-2 expression at 23 µM. Interestingly, stilbenoids (1) and (2) but not (3) were able to inhibit human recombinant COX-2 activity.

Conclusions: Major antioxidant stilbenoids (1-3) from Vanda coerulea stems displayed an inhibition of UV(B)-induced COX-2 expression. Imbricatin (1) and methoxycoelonin (2) were also able to inhibit COX-2 activity in a concentration-dependent manner thereby reducing PGE-2 production from irradiated HaCaT cells. Our studies suggest that stilbenoids (1-3) could be potentially used for skin protection against the damage caused by UV(B) exposure.

Show MeSH
Related in: MedlinePlus