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Evolution of availability of curcumin inside poly-lactic-co-glycolic acid nanoparticles: impact on antioxidant and antinitrosant properties.

Betbeder D, Lipka E, Howsam M, Carpentier R - Int J Nanomedicine (2015)

Bottom Line: Acellular assays showed that the antioxidant effect of curcumin was greater when loaded in PLGA nanoparticles.Furthermore, we observed that light decreased, though heat restored, antioxidant activity of PLGA-encapsulated curcumin, probably by modulating the accessibility of curcumin to reactive oxygen species, an observation supported by results from quenching experiments.These results highlight the importance of understanding effects of nanoparticle maturation on an encapsulated drug's activity.

View Article: PubMed Central - PubMed

Affiliation: U995-LIRIC, Inserm (Institut National de la Recherche Médicale), Lille, France ; U995-LIRIC, CHRU de Lille, Lille, France ; U995-LIRIC, Faculté de Médecine, Université de Lille, Lille, France ; Faculté des Sciences du Sport, Université d'Artois, Arras, France.

ABSTRACT

Purpose: Curcumin exhibits antioxidant properties potentially beneficial for human health; however, its use in clinical applications is limited by its poor solubility and relative instability. Nanoparticles exhibit interesting features for the efficient distribution and delivery of curcumin into cells, and could also increase curcumin stability in biological systems. There is a paucity of information regarding the evolution of the antioxidant properties of nanoparticle-encapsulated curcumin.

Method: We described a simple method of curcumin encapsulation in poly-lactic-co-glycolic acid (PLGA) nanoparticles without the use of detergent. We assessed, in epithelial cells and in an acellular model, the evolution of direct antioxidant and antinitrosant properties of free versus PLGA-encapsulated curcumin after storage under different conditions (light vs darkness, 4°C vs 25°C vs 37°C).

Results: In epithelial cells, endocytosis and efflux pump inhibitors showed that the increased antioxidant activity of PLGA-encapsulated curcumin relied on bypassing the efflux pump system. Acellular assays showed that the antioxidant effect of curcumin was greater when loaded in PLGA nanoparticles. Furthermore, we observed that light decreased, though heat restored, antioxidant activity of PLGA-encapsulated curcumin, probably by modulating the accessibility of curcumin to reactive oxygen species, an observation supported by results from quenching experiments. Moreover, we demonstrated a direct antinitrosant activity of curcumin, enhanced by PLGA encapsulation, which was increased by light exposure.

Conclusion: These results suggest that the antioxidant and antinitrosant activities of encapsulated curcumin are light sensitive and that nanoparticle modifications over time and with temperature may facilitate curcumin contact with reactive oxygen species. These results highlight the importance of understanding effects of nanoparticle maturation on an encapsulated drug's activity.

No MeSH data available.


Related in: MedlinePlus

NP-formulated curcumin is more potent antioxidant that free curcumin.Notes: (A) A549 cells were loaded with H2DCF-DA then treated with TBHP and free (from 0 to 20 µM) or encapsulated (0.4 µM) curcumin. Fluorescence of H2DCF-DA was measured to quantify ROS induction. (B) A549 cells were treated as in (A). Various amounts of curcumin (by varying the load of curcumin into PLGA-NP) or various amounts of PLGA-NP (with the same of concentration of curcumin) were used to determine and compare the antioxidant activity of free and NP-formulated curcumin. Theoretical drug loading is indicated and results are expressed in mean ± SEM.Abbreviations: Cur-NP, curcumin-loaded PLGA-based NP; NP, nanoparticles; H2DCF-DA, 2′,7′-dichlorodihydrofluorescein diacetate; TBHP, tert-butyl hydroperoxide; PLGA, poly-lactic-co-glycolic acid; SEM, standard error of the mean; ROS, reactive oxygen species; wt, weight.
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f1-ijn-10-5355: NP-formulated curcumin is more potent antioxidant that free curcumin.Notes: (A) A549 cells were loaded with H2DCF-DA then treated with TBHP and free (from 0 to 20 µM) or encapsulated (0.4 µM) curcumin. Fluorescence of H2DCF-DA was measured to quantify ROS induction. (B) A549 cells were treated as in (A). Various amounts of curcumin (by varying the load of curcumin into PLGA-NP) or various amounts of PLGA-NP (with the same of concentration of curcumin) were used to determine and compare the antioxidant activity of free and NP-formulated curcumin. Theoretical drug loading is indicated and results are expressed in mean ± SEM.Abbreviations: Cur-NP, curcumin-loaded PLGA-based NP; NP, nanoparticles; H2DCF-DA, 2′,7′-dichlorodihydrofluorescein diacetate; TBHP, tert-butyl hydroperoxide; PLGA, poly-lactic-co-glycolic acid; SEM, standard error of the mean; ROS, reactive oxygen species; wt, weight.

Mentions: Cells were treated with free curcumin (from 0 to 20 µM) or Cur-NP, then ROS were induced after 30 minutes with TBHP treatment. Increasing doses of free curcumin lowered the ROS induction in a dose-dependent manner. Cur-NP (containing 0.4 µM of curcumin) showed a similar antioxidant effect to that of 4 µM of free curcumin as soon as TBHP was added (Figure 1A). This was not dependent on the PLGA-NP themselves which did not show any antioxidant or pro-oxidant activity (Figure S1). To determine the effect of the curcumin:NP ratio on antioxidant activity, dose–response curves of free and NP-encapsulated curcumin were obtained using two approaches: either with a fixed amount of PLGA-NP that encapsulated increasing doses of curcumin, or with a fixed dose of curcumin encapsulated in increasing amounts of PLGA-NP. This was done in order to discriminate between the antioxidant properties of curcumin observed when using NP highly concentrated in curcumin from those observed when using NP weakly concentrated in curcumin. A gradual increase of antioxidant activity was observed when the amount of free curcumin was increased. Increasing amounts of Cur-NP also exhibited a proportional antioxidant activity (Figure 1B). Interestingly, the dose of 4 µM of free curcumin had comparable antioxidant activity to 0.4 µM of Cur-NP, meaning that encapsulation into PLGA-NP led to a tenfold increase in antioxidant activity. For 2 µM and 4 µM of curcumin in Cur-NP, a 20- to 50-fold increase over the values for free curcumin was observed.


Evolution of availability of curcumin inside poly-lactic-co-glycolic acid nanoparticles: impact on antioxidant and antinitrosant properties.

Betbeder D, Lipka E, Howsam M, Carpentier R - Int J Nanomedicine (2015)

NP-formulated curcumin is more potent antioxidant that free curcumin.Notes: (A) A549 cells were loaded with H2DCF-DA then treated with TBHP and free (from 0 to 20 µM) or encapsulated (0.4 µM) curcumin. Fluorescence of H2DCF-DA was measured to quantify ROS induction. (B) A549 cells were treated as in (A). Various amounts of curcumin (by varying the load of curcumin into PLGA-NP) or various amounts of PLGA-NP (with the same of concentration of curcumin) were used to determine and compare the antioxidant activity of free and NP-formulated curcumin. Theoretical drug loading is indicated and results are expressed in mean ± SEM.Abbreviations: Cur-NP, curcumin-loaded PLGA-based NP; NP, nanoparticles; H2DCF-DA, 2′,7′-dichlorodihydrofluorescein diacetate; TBHP, tert-butyl hydroperoxide; PLGA, poly-lactic-co-glycolic acid; SEM, standard error of the mean; ROS, reactive oxygen species; wt, weight.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4554401&req=5

f1-ijn-10-5355: NP-formulated curcumin is more potent antioxidant that free curcumin.Notes: (A) A549 cells were loaded with H2DCF-DA then treated with TBHP and free (from 0 to 20 µM) or encapsulated (0.4 µM) curcumin. Fluorescence of H2DCF-DA was measured to quantify ROS induction. (B) A549 cells were treated as in (A). Various amounts of curcumin (by varying the load of curcumin into PLGA-NP) or various amounts of PLGA-NP (with the same of concentration of curcumin) were used to determine and compare the antioxidant activity of free and NP-formulated curcumin. Theoretical drug loading is indicated and results are expressed in mean ± SEM.Abbreviations: Cur-NP, curcumin-loaded PLGA-based NP; NP, nanoparticles; H2DCF-DA, 2′,7′-dichlorodihydrofluorescein diacetate; TBHP, tert-butyl hydroperoxide; PLGA, poly-lactic-co-glycolic acid; SEM, standard error of the mean; ROS, reactive oxygen species; wt, weight.
Mentions: Cells were treated with free curcumin (from 0 to 20 µM) or Cur-NP, then ROS were induced after 30 minutes with TBHP treatment. Increasing doses of free curcumin lowered the ROS induction in a dose-dependent manner. Cur-NP (containing 0.4 µM of curcumin) showed a similar antioxidant effect to that of 4 µM of free curcumin as soon as TBHP was added (Figure 1A). This was not dependent on the PLGA-NP themselves which did not show any antioxidant or pro-oxidant activity (Figure S1). To determine the effect of the curcumin:NP ratio on antioxidant activity, dose–response curves of free and NP-encapsulated curcumin were obtained using two approaches: either with a fixed amount of PLGA-NP that encapsulated increasing doses of curcumin, or with a fixed dose of curcumin encapsulated in increasing amounts of PLGA-NP. This was done in order to discriminate between the antioxidant properties of curcumin observed when using NP highly concentrated in curcumin from those observed when using NP weakly concentrated in curcumin. A gradual increase of antioxidant activity was observed when the amount of free curcumin was increased. Increasing amounts of Cur-NP also exhibited a proportional antioxidant activity (Figure 1B). Interestingly, the dose of 4 µM of free curcumin had comparable antioxidant activity to 0.4 µM of Cur-NP, meaning that encapsulation into PLGA-NP led to a tenfold increase in antioxidant activity. For 2 µM and 4 µM of curcumin in Cur-NP, a 20- to 50-fold increase over the values for free curcumin was observed.

Bottom Line: Acellular assays showed that the antioxidant effect of curcumin was greater when loaded in PLGA nanoparticles.Furthermore, we observed that light decreased, though heat restored, antioxidant activity of PLGA-encapsulated curcumin, probably by modulating the accessibility of curcumin to reactive oxygen species, an observation supported by results from quenching experiments.These results highlight the importance of understanding effects of nanoparticle maturation on an encapsulated drug's activity.

View Article: PubMed Central - PubMed

Affiliation: U995-LIRIC, Inserm (Institut National de la Recherche Médicale), Lille, France ; U995-LIRIC, CHRU de Lille, Lille, France ; U995-LIRIC, Faculté de Médecine, Université de Lille, Lille, France ; Faculté des Sciences du Sport, Université d'Artois, Arras, France.

ABSTRACT

Purpose: Curcumin exhibits antioxidant properties potentially beneficial for human health; however, its use in clinical applications is limited by its poor solubility and relative instability. Nanoparticles exhibit interesting features for the efficient distribution and delivery of curcumin into cells, and could also increase curcumin stability in biological systems. There is a paucity of information regarding the evolution of the antioxidant properties of nanoparticle-encapsulated curcumin.

Method: We described a simple method of curcumin encapsulation in poly-lactic-co-glycolic acid (PLGA) nanoparticles without the use of detergent. We assessed, in epithelial cells and in an acellular model, the evolution of direct antioxidant and antinitrosant properties of free versus PLGA-encapsulated curcumin after storage under different conditions (light vs darkness, 4°C vs 25°C vs 37°C).

Results: In epithelial cells, endocytosis and efflux pump inhibitors showed that the increased antioxidant activity of PLGA-encapsulated curcumin relied on bypassing the efflux pump system. Acellular assays showed that the antioxidant effect of curcumin was greater when loaded in PLGA nanoparticles. Furthermore, we observed that light decreased, though heat restored, antioxidant activity of PLGA-encapsulated curcumin, probably by modulating the accessibility of curcumin to reactive oxygen species, an observation supported by results from quenching experiments. Moreover, we demonstrated a direct antinitrosant activity of curcumin, enhanced by PLGA encapsulation, which was increased by light exposure.

Conclusion: These results suggest that the antioxidant and antinitrosant activities of encapsulated curcumin are light sensitive and that nanoparticle modifications over time and with temperature may facilitate curcumin contact with reactive oxygen species. These results highlight the importance of understanding effects of nanoparticle maturation on an encapsulated drug's activity.

No MeSH data available.


Related in: MedlinePlus