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The Oxidative State of LDL is the Major Determinant of Anti/Prooxidant Effect of Coffee on Cu Catalysed Peroxidation.

Carru C, Pasciu V, Sotgia S, Zinellu A, Nicoli MC, Deiana L, Tadolini B, Sanna B, Masala B, Pintus G - Open Biochem J (2011)

Bottom Line: When the relative effects of different coffee concentrations were plotted against the lag time (LT) of control LDL (C-LDL), the apparently random experimental data arranged in sensible patterns: by increasing the LT the antioxidant activity of coffee decreased progressively to become prooxidant.The dependence of coffee effect on the LT of C-LDL was influenced by LDL but not by metal catalyst concentration.These novel findings point to the oxidative state of LDL as a major parameter controlling the anti/prooxidant effect of coffee and suggest the LT of C-LDL as a potent analytical tool to express experimental data when studying the action exerted by a compound on LDL oxidation.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43/B, 07100 Sassari, Italy.

ABSTRACT
Antioxidants exert contrasting effect on low density lipoprotein (LDL) oxidation catalysed by metals, acting as pro-oxidants under select in vitro conditions. Through our study on the effect of coffee on LDL oxidation, we identified the parameters governing this phenomenon, contributing to the comprehension of its mechanism and discovering significant implications for correct alimentary recommendations. By measuring conjugated diene formation, we have analysed the quantitative and qualitative effects exerted by an extract of roasted coffee on LDL oxidation triggered by copper sulphate. When the relative effects of different coffee concentrations were plotted against the lag time (LT) of control LDL (C-LDL), the apparently random experimental data arranged in sensible patterns: by increasing the LT the antioxidant activity of coffee decreased progressively to become prooxidant. The critical LT, at which coffee switches from antioxidant to prooxidant, increased by increasing coffee concentration. Also the contrasting results obtained following a delayed addition of coffee to the assay, arranged in a simple pattern when referred to the LT of C-LDL: the prooxidant effect decreased to become antioxidant as the LT of C-LDL increased. The dependence of coffee effect on the LT of C-LDL was influenced by LDL but not by metal catalyst concentration. These novel findings point to the oxidative state of LDL as a major parameter controlling the anti/prooxidant effect of coffee and suggest the LT of C-LDL as a potent analytical tool to express experimental data when studying the action exerted by a compound on LDL oxidation.

No MeSH data available.


Related in: MedlinePlus

Part of the data reported in Table 3 and in Tables 1 and 4 are presented. The length of the lag time obtained in the presence of coffee expressed as percentage of the lag time of control LDL was reported as a function of the lag time of control LDL. LDL (80 µg cholesterol) from different donors was incubated with 1 µM copper sulphate in the absence or presence of 1 µg coffee. Coffee was added either just before (▀) or 10 min after (▲) copper sulphate addition. LDL oxidation was followed by monitoring the change of the conjugated diene absorbance at 234 nm.
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Figure 4: Part of the data reported in Table 3 and in Tables 1 and 4 are presented. The length of the lag time obtained in the presence of coffee expressed as percentage of the lag time of control LDL was reported as a function of the lag time of control LDL. LDL (80 µg cholesterol) from different donors was incubated with 1 µM copper sulphate in the absence or presence of 1 µg coffee. Coffee was added either just before (▀) or 10 min after (▲) copper sulphate addition. LDL oxidation was followed by monitoring the change of the conjugated diene absorbance at 234 nm.

Mentions: Although the quantitative antioxidant effects of coffee appear to differ when assayed in the presence of the two copper concentrations (Table 2), no substantial difference was observed when the relative coffee effects were expressed as a function of C-LDL LT (Fig. 3). We also studied the influence of the time of coffee addition on LDL oxidation triggered by copper. In the experiments presented (Fig. 4), 1 µg coffee, when added before copper addition, exerted mostly an antioxidant effect, although it quantitatively differed depending on the LT of C-LDL: as previously observed, the shorter the lag time the stronger the antioxidant effect. However, if coffee addition was delayed 10 min, the results obtained drastically changed but, once again, they depended on the LT of C-LDL. Coffee exerted a prooxidant effect whose intensity decreased to become antioxidant by increasing the LT of C-LDL (Table 3 and Fig. 4).


The Oxidative State of LDL is the Major Determinant of Anti/Prooxidant Effect of Coffee on Cu Catalysed Peroxidation.

Carru C, Pasciu V, Sotgia S, Zinellu A, Nicoli MC, Deiana L, Tadolini B, Sanna B, Masala B, Pintus G - Open Biochem J (2011)

Part of the data reported in Table 3 and in Tables 1 and 4 are presented. The length of the lag time obtained in the presence of coffee expressed as percentage of the lag time of control LDL was reported as a function of the lag time of control LDL. LDL (80 µg cholesterol) from different donors was incubated with 1 µM copper sulphate in the absence or presence of 1 µg coffee. Coffee was added either just before (▀) or 10 min after (▲) copper sulphate addition. LDL oxidation was followed by monitoring the change of the conjugated diene absorbance at 234 nm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3104561&req=5

Figure 4: Part of the data reported in Table 3 and in Tables 1 and 4 are presented. The length of the lag time obtained in the presence of coffee expressed as percentage of the lag time of control LDL was reported as a function of the lag time of control LDL. LDL (80 µg cholesterol) from different donors was incubated with 1 µM copper sulphate in the absence or presence of 1 µg coffee. Coffee was added either just before (▀) or 10 min after (▲) copper sulphate addition. LDL oxidation was followed by monitoring the change of the conjugated diene absorbance at 234 nm.
Mentions: Although the quantitative antioxidant effects of coffee appear to differ when assayed in the presence of the two copper concentrations (Table 2), no substantial difference was observed when the relative coffee effects were expressed as a function of C-LDL LT (Fig. 3). We also studied the influence of the time of coffee addition on LDL oxidation triggered by copper. In the experiments presented (Fig. 4), 1 µg coffee, when added before copper addition, exerted mostly an antioxidant effect, although it quantitatively differed depending on the LT of C-LDL: as previously observed, the shorter the lag time the stronger the antioxidant effect. However, if coffee addition was delayed 10 min, the results obtained drastically changed but, once again, they depended on the LT of C-LDL. Coffee exerted a prooxidant effect whose intensity decreased to become antioxidant by increasing the LT of C-LDL (Table 3 and Fig. 4).

Bottom Line: When the relative effects of different coffee concentrations were plotted against the lag time (LT) of control LDL (C-LDL), the apparently random experimental data arranged in sensible patterns: by increasing the LT the antioxidant activity of coffee decreased progressively to become prooxidant.The dependence of coffee effect on the LT of C-LDL was influenced by LDL but not by metal catalyst concentration.These novel findings point to the oxidative state of LDL as a major parameter controlling the anti/prooxidant effect of coffee and suggest the LT of C-LDL as a potent analytical tool to express experimental data when studying the action exerted by a compound on LDL oxidation.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43/B, 07100 Sassari, Italy.

ABSTRACT
Antioxidants exert contrasting effect on low density lipoprotein (LDL) oxidation catalysed by metals, acting as pro-oxidants under select in vitro conditions. Through our study on the effect of coffee on LDL oxidation, we identified the parameters governing this phenomenon, contributing to the comprehension of its mechanism and discovering significant implications for correct alimentary recommendations. By measuring conjugated diene formation, we have analysed the quantitative and qualitative effects exerted by an extract of roasted coffee on LDL oxidation triggered by copper sulphate. When the relative effects of different coffee concentrations were plotted against the lag time (LT) of control LDL (C-LDL), the apparently random experimental data arranged in sensible patterns: by increasing the LT the antioxidant activity of coffee decreased progressively to become prooxidant. The critical LT, at which coffee switches from antioxidant to prooxidant, increased by increasing coffee concentration. Also the contrasting results obtained following a delayed addition of coffee to the assay, arranged in a simple pattern when referred to the LT of C-LDL: the prooxidant effect decreased to become antioxidant as the LT of C-LDL increased. The dependence of coffee effect on the LT of C-LDL was influenced by LDL but not by metal catalyst concentration. These novel findings point to the oxidative state of LDL as a major parameter controlling the anti/prooxidant effect of coffee and suggest the LT of C-LDL as a potent analytical tool to express experimental data when studying the action exerted by a compound on LDL oxidation.

No MeSH data available.


Related in: MedlinePlus