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Evalution of in vitro effect of flavonoids on human low-density lipoprotein carbamylation.

Ghaffari MA, Shanaki M - Iran J Pharm Res (2010)

Bottom Line: The results of this study showed that a number of flavonoids including rutin, catechin, morin, myricetin, kaempferol, taxifolin, luteolin, naringin and quercetin decreased LDL carbamylation in a dose dependent manner.Also, it was demonstrated that these nutrients decreased electrophoretic mobility of carbamylated LDL.Based on the results obtained in this study, it is suggested that flavonoids are able to inhibit LDL carbamylation (probably by scavenging cyanate ions) and thus, may have a role in ameliorating atherosclerotic risk of patients with kidney failure.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry, Faculty of Medicine, Ahwaz Jundishapour University of Medical Sciences, Ahwaz, Iran.

ABSTRACT
The non-enzymatic carbamylation of low density lipoprotein (LDL) is a naturally occurring chemical modification of apolipoprotein B as a result of condensation between lysine residues and cyanate derived from urea. Carbamylated LDL is poorly recognized by LDL receptors and initiates different processes that can be considered proatherogenic. Thus, LDL carbamylation may contribute to the increased risk of atherosclerosis in patients with kidney failure. The objective of this study was to investigate in vitro effects of flavonoids on LDL carbamylation. LDL was isolated from plasma using ultracentrifuge technique with a single step discontinuous gradient. Then, cyanate was added to LDL and LDL carbamylation level was estimated in absence and presence of flavonoids by a colorimetric method at 530 nm. The results of this study showed that a number of flavonoids including rutin, catechin, morin, myricetin, kaempferol, taxifolin, luteolin, naringin and quercetin decreased LDL carbamylation in a dose dependent manner. Also, it was demonstrated that these nutrients decreased electrophoretic mobility of carbamylated LDL. Based on the results obtained in this study, it is suggested that flavonoids are able to inhibit LDL carbamylation (probably by scavenging cyanate ions) and thus, may have a role in ameliorating atherosclerotic risk of patients with kidney failure.

No MeSH data available.


Related in: MedlinePlus

(A) Electrophoresis analysis of carbamylated LDL in absence (Lane 1) and presence of 40 μmol/L concentration of rutin (Lane 2), catechin (Lane 3), morin (Lane 4), myricetin (Lane 5), kaempferol (Lane 6), taxifolin (lane 7), luteolin (Lane 8), naringin (Lane 9) and quercetin (Lane 10) on 5% polyacrylamide gel. (B) The Comparison of the flow rate of carbamylated LDL (cLDL) in absence and presence of flavonoids (40 μmol/L) on 5% polyacrylamide gel
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Figure 6: (A) Electrophoresis analysis of carbamylated LDL in absence (Lane 1) and presence of 40 μmol/L concentration of rutin (Lane 2), catechin (Lane 3), morin (Lane 4), myricetin (Lane 5), kaempferol (Lane 6), taxifolin (lane 7), luteolin (Lane 8), naringin (Lane 9) and quercetin (Lane 10) on 5% polyacrylamide gel. (B) The Comparison of the flow rate of carbamylated LDL (cLDL) in absence and presence of flavonoids (40 μmol/L) on 5% polyacrylamide gel

Mentions: A series of experiments were performed to examine the influence of flavonoidson LDL carbamylation process. Rutin, one of the flavonoids tested, was incubated at concentration of 0 to 40 μmol/L with LDL (0.6 mg protein/mL) and cyanate (20 μmol/L) at 35°C for 4 h. The extent of LDL carbamylation in the absence (as control) and/or presence of rutin were estimated as nmol homocitrolline per mg LDL protein (Figure 3). The same procedure was repeated to investigate the effect of other flavonoids. Figure 3 shows the inhibitory effect of 9 flavonoids (5 flavonols (kaempferol, morin, rutin, myricetin, quercetin), 1 flavonone (naringin),, 1 flavone (luteolin), 1 flavanol (catechin) and 1 flavanolol (taxifolin)) on LDL carbamylation. The results presented in Figure 3 showed that these flavonoids, compared to the controls, decrease significantly the LDL carbamylation in a dose-dependent manner. In this study, all flavonoids in comparison to the control (without flavonoids) were shown a significant inhibition of LDL carbamylation as shown by the ANOVA test, P < 0.001. According to these study, 40 μmol/L concentrations of rutin, catechin, morin, myricetin, kaempferol, taxifolin, luteolin, naringin and quercetin are able to reduce LDL carbamylation approximately by 69%, 67%, 65%, 63%, 61%, 60%, 58%, 57% and 55%, respectively (Figure 4). We also investigated electrophoretic mobility of 20 μmol/L cyanate treated LDL on polyacrylamide gel (Figure 5). Figure 5 shows that carbamylation increased anodic migration (flow rate) of LDL when compared to native LDL. The comparison of electrophoretic mobility of carbamylated LDL in presence of flavonoids (40 μmol/L) showed a decrease in anodic migration and/or flow rate of this LDL isoform (Figure 6). These observations suggest that flavonoids above can decrease LDL carbamylation in presence of cyanate.


Evalution of in vitro effect of flavonoids on human low-density lipoprotein carbamylation.

Ghaffari MA, Shanaki M - Iran J Pharm Res (2010)

(A) Electrophoresis analysis of carbamylated LDL in absence (Lane 1) and presence of 40 μmol/L concentration of rutin (Lane 2), catechin (Lane 3), morin (Lane 4), myricetin (Lane 5), kaempferol (Lane 6), taxifolin (lane 7), luteolin (Lane 8), naringin (Lane 9) and quercetin (Lane 10) on 5% polyacrylamide gel. (B) The Comparison of the flow rate of carbamylated LDL (cLDL) in absence and presence of flavonoids (40 μmol/L) on 5% polyacrylamide gel
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC3869556&req=5

Figure 6: (A) Electrophoresis analysis of carbamylated LDL in absence (Lane 1) and presence of 40 μmol/L concentration of rutin (Lane 2), catechin (Lane 3), morin (Lane 4), myricetin (Lane 5), kaempferol (Lane 6), taxifolin (lane 7), luteolin (Lane 8), naringin (Lane 9) and quercetin (Lane 10) on 5% polyacrylamide gel. (B) The Comparison of the flow rate of carbamylated LDL (cLDL) in absence and presence of flavonoids (40 μmol/L) on 5% polyacrylamide gel
Mentions: A series of experiments were performed to examine the influence of flavonoidson LDL carbamylation process. Rutin, one of the flavonoids tested, was incubated at concentration of 0 to 40 μmol/L with LDL (0.6 mg protein/mL) and cyanate (20 μmol/L) at 35°C for 4 h. The extent of LDL carbamylation in the absence (as control) and/or presence of rutin were estimated as nmol homocitrolline per mg LDL protein (Figure 3). The same procedure was repeated to investigate the effect of other flavonoids. Figure 3 shows the inhibitory effect of 9 flavonoids (5 flavonols (kaempferol, morin, rutin, myricetin, quercetin), 1 flavonone (naringin),, 1 flavone (luteolin), 1 flavanol (catechin) and 1 flavanolol (taxifolin)) on LDL carbamylation. The results presented in Figure 3 showed that these flavonoids, compared to the controls, decrease significantly the LDL carbamylation in a dose-dependent manner. In this study, all flavonoids in comparison to the control (without flavonoids) were shown a significant inhibition of LDL carbamylation as shown by the ANOVA test, P < 0.001. According to these study, 40 μmol/L concentrations of rutin, catechin, morin, myricetin, kaempferol, taxifolin, luteolin, naringin and quercetin are able to reduce LDL carbamylation approximately by 69%, 67%, 65%, 63%, 61%, 60%, 58%, 57% and 55%, respectively (Figure 4). We also investigated electrophoretic mobility of 20 μmol/L cyanate treated LDL on polyacrylamide gel (Figure 5). Figure 5 shows that carbamylation increased anodic migration (flow rate) of LDL when compared to native LDL. The comparison of electrophoretic mobility of carbamylated LDL in presence of flavonoids (40 μmol/L) showed a decrease in anodic migration and/or flow rate of this LDL isoform (Figure 6). These observations suggest that flavonoids above can decrease LDL carbamylation in presence of cyanate.

Bottom Line: The results of this study showed that a number of flavonoids including rutin, catechin, morin, myricetin, kaempferol, taxifolin, luteolin, naringin and quercetin decreased LDL carbamylation in a dose dependent manner.Also, it was demonstrated that these nutrients decreased electrophoretic mobility of carbamylated LDL.Based on the results obtained in this study, it is suggested that flavonoids are able to inhibit LDL carbamylation (probably by scavenging cyanate ions) and thus, may have a role in ameliorating atherosclerotic risk of patients with kidney failure.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry, Faculty of Medicine, Ahwaz Jundishapour University of Medical Sciences, Ahwaz, Iran.

ABSTRACT
The non-enzymatic carbamylation of low density lipoprotein (LDL) is a naturally occurring chemical modification of apolipoprotein B as a result of condensation between lysine residues and cyanate derived from urea. Carbamylated LDL is poorly recognized by LDL receptors and initiates different processes that can be considered proatherogenic. Thus, LDL carbamylation may contribute to the increased risk of atherosclerosis in patients with kidney failure. The objective of this study was to investigate in vitro effects of flavonoids on LDL carbamylation. LDL was isolated from plasma using ultracentrifuge technique with a single step discontinuous gradient. Then, cyanate was added to LDL and LDL carbamylation level was estimated in absence and presence of flavonoids by a colorimetric method at 530 nm. The results of this study showed that a number of flavonoids including rutin, catechin, morin, myricetin, kaempferol, taxifolin, luteolin, naringin and quercetin decreased LDL carbamylation in a dose dependent manner. Also, it was demonstrated that these nutrients decreased electrophoretic mobility of carbamylated LDL. Based on the results obtained in this study, it is suggested that flavonoids are able to inhibit LDL carbamylation (probably by scavenging cyanate ions) and thus, may have a role in ameliorating atherosclerotic risk of patients with kidney failure.

No MeSH data available.


Related in: MedlinePlus