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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

Effect of curcumin on glutathione (GSH) level of 1321 N1 and JIMT-1 cells.Astrocytoma 1321N1 (A) and JIMT-1 (B) cells were cultured for 24 h at 37°C and 5% CO2 in the absence or presence of curcumin. Cells were harvested and GSH concentration was determined in the cytosolic extract. Data represent the mean±S.D. of independent experiments (n = 6).
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pone-0003508-g007: Effect of curcumin on glutathione (GSH) level of 1321 N1 and JIMT-1 cells.Astrocytoma 1321N1 (A) and JIMT-1 (B) cells were cultured for 24 h at 37°C and 5% CO2 in the absence or presence of curcumin. Cells were harvested and GSH concentration was determined in the cytosolic extract. Data represent the mean±S.D. of independent experiments (n = 6).

Mentions: As shown in figure 7, curcumin-treated 1321N1 and JIMT-1 cells revealed decreased GSH levels. GSH was diminished by approximately 20% in cells treated with 50 µM curcumin, a concentration which yields approximately 30% inhibition of cell proliferation as presented in figure 3. This may be linked to the increasingly formed hemithioacetal that might trap GSH. This trapping can be magnified in case of a low Glo2 activity, an enzyme that hydrolyzes the S-lactoylglutathione, the end product of Glo1, to release D-lactate and to regenerate GSH. Therefore, we measured the Glo2 activity in cytosolic cell extracts (Table 1). The results demonstrated between 10- and 70-fold decrease in specific activity of Glo2 compared to Glo1 in different tumor cell lines. Thus, the low expression of Glo2 is suggested to impair the regeneration of GSH. Obviously, this could add additional effects to the GSH depletion.


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)

Effect of curcumin on glutathione (GSH) level of 1321 N1 and JIMT-1 cells.Astrocytoma 1321N1 (A) and JIMT-1 (B) cells were cultured for 24 h at 37°C and 5% CO2 in the absence or presence of curcumin. Cells were harvested and GSH concentration was determined in the cytosolic extract. Data represent the mean±S.D. of independent experiments (n = 6).
© Copyright Policy
Related In: Results  -  Collection

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

pone-0003508-g007: Effect of curcumin on glutathione (GSH) level of 1321 N1 and JIMT-1 cells.Astrocytoma 1321N1 (A) and JIMT-1 (B) cells were cultured for 24 h at 37°C and 5% CO2 in the absence or presence of curcumin. Cells were harvested and GSH concentration was determined in the cytosolic extract. Data represent the mean±S.D. of independent experiments (n = 6).
Mentions: As shown in figure 7, curcumin-treated 1321N1 and JIMT-1 cells revealed decreased GSH levels. GSH was diminished by approximately 20% in cells treated with 50 µM curcumin, a concentration which yields approximately 30% inhibition of cell proliferation as presented in figure 3. This may be linked to the increasingly formed hemithioacetal that might trap GSH. This trapping can be magnified in case of a low Glo2 activity, an enzyme that hydrolyzes the S-lactoylglutathione, the end product of Glo1, to release D-lactate and to regenerate GSH. Therefore, we measured the Glo2 activity in cytosolic cell extracts (Table 1). The results demonstrated between 10- and 70-fold decrease in specific activity of Glo2 compared to Glo1 in different tumor cell lines. Thus, the low expression of Glo2 is suggested to impair the regeneration of GSH. Obviously, this could add additional effects to the GSH depletion.

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