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Curcumin inhibits glyoxalase 1: a possible link to its anti-inflammatory and anti-tumor activity.

Santel T, Pflug G, Hemdan NY, Schäfer A, Hollenbach M, Buchold M, Hintersdorf A, Lindner I, Otto A, Bigl M, Oerlecke I, Hutschenreuther A, Hutschenreuter A, Sack U, Huse K, Groth M, Birkemeyer C, Schellenberger W, Gebhardt R, Platzer M, Weiss T, Vijayalakshmi MA, Krüger M, Birkenmeier G - PLoS ONE (2008)

Bottom Line: Results of enzyme kinetics revealed that curcumin, compared to the polyphenols quercetin, myricetin, kaempferol, luteolin and rutin, elicited a stronger competitive inhibitory effect on Glo1 (K(i) = 5.1+/-1.4 microM).Moreover, whereas curcumin was found to hamper the growth of breast cancer (JIMT-1, MDA-MB-231), prostate cancer PC-3 and brain astrocytoma 1321N1 cells, no effect on growth or vitality of human primary hepatocytes was elucidated.The results described herein provide new insights into curcumin's biological activities as they indicate that inhibition of Glo1 by curcumin may result in non-tolerable levels of MGO and GSH, which, in turn, modulate various metabolic cellular pathways including depletion of cellular ATP and GSH content.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biochemistry, University of Leipzig, Leipzig, Germany.

ABSTRACT

Background: Glyoxalases (Glo1 and Glo2) are involved in the glycolytic pathway by detoxifying the reactive methylglyoxal (MGO) into D-lactate in a two-step reaction using glutathione (GSH) as cofactor. Inhibitors of glyoxalases are considered as anti-inflammatory and anti-carcinogenic agents. The recent finding that various polyphenols modulate Glo1 activity has prompted us to assess curcumin's potency as an Glo1 inhibitor.

Methodology/principal findings: Cultures of whole blood cells and tumor cell lines (PC-3, JIM-1, MDA-MD 231 and 1321N1) were set up to investigate the effect of selected polyphenols, including curcumin, on the LPS-induced cytokine production (cytometric bead-based array), cell proliferation (WST-1 assay), cytosolic Glo1 and Glo2 enzymatic activity, apoptosis/necrosis (annexin V-FITC/propidium iodide staining; flow cytometric analysis) as well as GSH and ATP content. Results of enzyme kinetics revealed that curcumin, compared to the polyphenols quercetin, myricetin, kaempferol, luteolin and rutin, elicited a stronger competitive inhibitory effect on Glo1 (K(i) = 5.1+/-1.4 microM). Applying a whole blood assay, IC(50) values of pro-inflammatory cytokine release (TNF-alpha, IL-6, IL-8, IL-1beta) were found to be positively correlated with the K(i)-values of the aforementioned polyphenols. Moreover, whereas curcumin was found to hamper the growth of breast cancer (JIMT-1, MDA-MB-231), prostate cancer PC-3 and brain astrocytoma 1321N1 cells, no effect on growth or vitality of human primary hepatocytes was elucidated. Curcumin decreased D-lactate release by tumor cells, another clue for inhibition of intracellular Glo1.

Conclusions/significance: The results described herein provide new insights into curcumin's biological activities as they indicate that inhibition of Glo1 by curcumin may result in non-tolerable levels of MGO and GSH, which, in turn, modulate various metabolic cellular pathways including depletion of cellular ATP and GSH content. This may account for curcumin's potency as an anti-inflammatory and anti-tumor agent. The findings support the use of curcumin as a potential therapeutic agent.

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Related in: MedlinePlus

Growth inhibition of different tumor cell lines by polyphenols.Tumor cells (5000 cells/well) were seeded (start) and cultured at 37°C/5% CO2 in the presence of increasing concentrations of curcumin or the flavonoids quercetin or myricetin. Following 24-h incubation, cell proliferation was evaluated using the WST-1 assay.
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pone-0003508-g003: Growth inhibition of different tumor cell lines by polyphenols.Tumor cells (5000 cells/well) were seeded (start) and cultured at 37°C/5% CO2 in the presence of increasing concentrations of curcumin or the flavonoids quercetin or myricetin. Following 24-h incubation, cell proliferation was evaluated using the WST-1 assay.

Mentions: It is known that inhibitors of Glo1, structurally related to GSH, have anti-proliferative properties [19]. To study the action of curcumin on cell growth, we incubated different tumor cells with increasing concentrations of curcumin for 24 h and measured changes in cell proliferation applying WST-1 assay (Fig. 3). Curcumin effectively inhibited the growth of different cancer cell lines derived from prostate cancer (PC-3), breast cancer (MDA-MB-231, JIMT-1), and brain astrocytoma (1321N1). Curcumin-treated cells manifested a dose-dependent reduction in cell proliferation (Fig. 3A). Obviously, the cellular activity of curcumin is biphasic. At low concentrations, it is stimulatory rather than inhibitory, especially in the range between 1 µM and 10 µM. This effect was observed predominantly in prostate and breast cancer cells and was absent in astrocytoma cells. However, strong anti-proliferative effects were observed at concentrations above 50 µM for all cancer cells tested. Not only did curcumin inhibit cell growth as seen for 1321N1, MDA-MB-231 and JIMT-1 cells, but it also exerted even a toxic effect at 100 µM on PC-3 cells. In this case, the normal cellular morphology got lost indicating necrotic cell death. Comparable to curcumin, both of quercetin and myricetin, which also inhibited Glo1 activity, were less anti-proliferative to 1321N1 cells. This indicates that the growth suppressing effect of the studied polyphenols may be related to the Ki-values for Glo1 inhibition as shown in figure 1.


Curcumin inhibits glyoxalase 1: a possible link to its anti-inflammatory and anti-tumor activity.

Santel T, Pflug G, Hemdan NY, Schäfer A, Hollenbach M, Buchold M, Hintersdorf A, Lindner I, Otto A, Bigl M, Oerlecke I, Hutschenreuther A, Hutschenreuter A, Sack U, Huse K, Groth M, Birkemeyer C, Schellenberger W, Gebhardt R, Platzer M, Weiss T, Vijayalakshmi MA, Krüger M, Birkenmeier G - PLoS ONE (2008)

Growth inhibition of different tumor cell lines by polyphenols.Tumor cells (5000 cells/well) were seeded (start) and cultured at 37°C/5% CO2 in the presence of increasing concentrations of curcumin or the flavonoids quercetin or myricetin. Following 24-h incubation, cell proliferation was evaluated using the WST-1 assay.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2567432&req=5

pone-0003508-g003: Growth inhibition of different tumor cell lines by polyphenols.Tumor cells (5000 cells/well) were seeded (start) and cultured at 37°C/5% CO2 in the presence of increasing concentrations of curcumin or the flavonoids quercetin or myricetin. Following 24-h incubation, cell proliferation was evaluated using the WST-1 assay.
Mentions: It is known that inhibitors of Glo1, structurally related to GSH, have anti-proliferative properties [19]. To study the action of curcumin on cell growth, we incubated different tumor cells with increasing concentrations of curcumin for 24 h and measured changes in cell proliferation applying WST-1 assay (Fig. 3). Curcumin effectively inhibited the growth of different cancer cell lines derived from prostate cancer (PC-3), breast cancer (MDA-MB-231, JIMT-1), and brain astrocytoma (1321N1). Curcumin-treated cells manifested a dose-dependent reduction in cell proliferation (Fig. 3A). Obviously, the cellular activity of curcumin is biphasic. At low concentrations, it is stimulatory rather than inhibitory, especially in the range between 1 µM and 10 µM. This effect was observed predominantly in prostate and breast cancer cells and was absent in astrocytoma cells. However, strong anti-proliferative effects were observed at concentrations above 50 µM for all cancer cells tested. Not only did curcumin inhibit cell growth as seen for 1321N1, MDA-MB-231 and JIMT-1 cells, but it also exerted even a toxic effect at 100 µM on PC-3 cells. In this case, the normal cellular morphology got lost indicating necrotic cell death. Comparable to curcumin, both of quercetin and myricetin, which also inhibited Glo1 activity, were less anti-proliferative to 1321N1 cells. This indicates that the growth suppressing effect of the studied polyphenols may be related to the Ki-values for Glo1 inhibition as shown in figure 1.

Bottom Line: Results of enzyme kinetics revealed that curcumin, compared to the polyphenols quercetin, myricetin, kaempferol, luteolin and rutin, elicited a stronger competitive inhibitory effect on Glo1 (K(i) = 5.1+/-1.4 microM).Moreover, whereas curcumin was found to hamper the growth of breast cancer (JIMT-1, MDA-MB-231), prostate cancer PC-3 and brain astrocytoma 1321N1 cells, no effect on growth or vitality of human primary hepatocytes was elucidated.The results described herein provide new insights into curcumin's biological activities as they indicate that inhibition of Glo1 by curcumin may result in non-tolerable levels of MGO and GSH, which, in turn, modulate various metabolic cellular pathways including depletion of cellular ATP and GSH content.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biochemistry, University of Leipzig, Leipzig, Germany.

ABSTRACT

Background: Glyoxalases (Glo1 and Glo2) are involved in the glycolytic pathway by detoxifying the reactive methylglyoxal (MGO) into D-lactate in a two-step reaction using glutathione (GSH) as cofactor. Inhibitors of glyoxalases are considered as anti-inflammatory and anti-carcinogenic agents. The recent finding that various polyphenols modulate Glo1 activity has prompted us to assess curcumin's potency as an Glo1 inhibitor.

Methodology/principal findings: Cultures of whole blood cells and tumor cell lines (PC-3, JIM-1, MDA-MD 231 and 1321N1) were set up to investigate the effect of selected polyphenols, including curcumin, on the LPS-induced cytokine production (cytometric bead-based array), cell proliferation (WST-1 assay), cytosolic Glo1 and Glo2 enzymatic activity, apoptosis/necrosis (annexin V-FITC/propidium iodide staining; flow cytometric analysis) as well as GSH and ATP content. Results of enzyme kinetics revealed that curcumin, compared to the polyphenols quercetin, myricetin, kaempferol, luteolin and rutin, elicited a stronger competitive inhibitory effect on Glo1 (K(i) = 5.1+/-1.4 microM). Applying a whole blood assay, IC(50) values of pro-inflammatory cytokine release (TNF-alpha, IL-6, IL-8, IL-1beta) were found to be positively correlated with the K(i)-values of the aforementioned polyphenols. Moreover, whereas curcumin was found to hamper the growth of breast cancer (JIMT-1, MDA-MB-231), prostate cancer PC-3 and brain astrocytoma 1321N1 cells, no effect on growth or vitality of human primary hepatocytes was elucidated. Curcumin decreased D-lactate release by tumor cells, another clue for inhibition of intracellular Glo1.

Conclusions/significance: The results described herein provide new insights into curcumin's biological activities as they indicate that inhibition of Glo1 by curcumin may result in non-tolerable levels of MGO and GSH, which, in turn, modulate various metabolic cellular pathways including depletion of cellular ATP and GSH content. This may account for curcumin's potency as an anti-inflammatory and anti-tumor agent. The findings support the use of curcumin as a potential therapeutic agent.

Show MeSH
Related in: MedlinePlus