M.B. Katan

Wageningen University, Wageningen, Provincie Gelderland, Netherlands

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Publications (16)10.11 Total impact

  • Article: Absorption, distribution, and biliary excretion of cafestol, a potent cholesterol-elevating compound in unfiltered coffees, in mice.
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    ABSTRACT: Cafestol is a diterpene present in unfiltered coffees. It is the most potent cholesterol-elevating compound present in the human diet. However, the precise mechanisms underlying this effect are still unclear. In contrast, cafestol is also known as a hepatoprotective compound, which is likely to be related to the induction of glutathione biosynthesis and conjugation. In the present study, we investigated whole-body distribution, biliary excretion, and portal bioavailability of cafestol in mice. First, dissection was used to study distribution. Five hours after an oral dose with (3)H-labeled cafestol, most activity was found in small intestine, liver, and bile. These results were confirmed by quantitative whole-body autoradiography in a time course study, which also showed elimination of all radioactivity within 48 h after administration. Next, radiolabeled cafestol was dosed intravenously to bile duct-cannulated mice. Five hours after the dose 20% of the radioactivity was found in bile. Bile contained several metabolites but no parent compound. After intestinal administration of radioactive cafestol to portal vein-cannulated mice, cafestol was shown to be rapidly absorbed into the portal vein as the parent compound, a glucuronide, and an unidentified metabolite. From the presence of a glucuronide in bile that can be deconjugated by a bacterial enzyme and the prolonged absorption of parent compound from the gastrointestinal tract, we hypothesized that cafestol undergoes enterohepatic cycling. Together with our earlier observation that epoxidation of the furan ring occurs in liver, these findings merit further research on the process of accumulation of this coffee ingredient in liver and intestinal tract.
    Drug metabolism and disposition: the biological fate of chemicals 04/2010; 38(4):635-40. · 3.74 Impact Factor
  • Article: [Negligible amounts of cholesterol-raising diterpenes in coffee made with coffee pads in comparison with unfiltered coffee].
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    ABSTRACT: To determine the amounts of the serum-cholesterol raising diterpenes cafestol and kahweol in coffee made with coffee pads and the Senseo coffee machine as opposed to filtered and unfiltered coffee. Observational. In five cities in the Netherlands coffee was purchased in three major supermarkets resulting in a total of 30 samples of coffee pads. The levels of cafestol and kahweol were determined by gas chromatography. As controls, the diterpene levels in filtered and unfiltered coffee were also measured. Coffee prepared using coffee pads contained on average 0.76 mg/l cafestol (95% CI: 0.69-0.82) and 0.85 mg/l kahweol (95% CI: 0.77-0.94). Filtered coffee contained 0.76 mg/l cafestol (95% CI: 0.63-0.88) and 0.81 mg/l kahweol (95% CI: 0.63-0.99). Unfiltered coffee contained 72.5 mg/l cafestol (95% CI: 48.5-96.4) and 71.5 mg/l kahweol (95% CI: 45.0-98.1). Coffee prepared using coffee pads and the Senseo coffee machine contained minute levels of diterpenes comparable to those of filtered coffee. Its effect on serum-cholesterol levels is therefore likely to be negligible.
    Nederlands tijdschrift voor geneeskunde 01/2007; 150(52):2873-5.
  • Article: Cafestol increases serum cholesterol levels in apolipoprotein E*3-Leiden transgenic mice by suppression of bile acid synthesis.
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    ABSTRACT: Cafestol, a diterpene present in unfiltered coffee, potently increases serum cholesterol levels in humans. So far, no suitable animal model has been found to study the biochemical background of this effect. We determined the effect of cafestol on serum cholesterol and triglycerides in different mouse strains and subsequently studied its mechanism of action in apolipoprotein (apo) E*3-Leiden transgenic mice. ApoE*3-Leiden, heterozygous low density lipoprotein-receptor (LDLR+/-) knockout, or wild-type (WT) C57BL/6 mice were fed a high- (0.05% wt/wt) or a low- (0.01% wt/wt) cafestol diet or a placebo diet for 8 weeks. Standardized to energy intake, these amounts are equal to 40, 8, or 0 cups of unfiltered coffee per 10 MJ per day in humans. In apoE*3-Leiden mice, serum cholesterol was statistically significantly increased by 33% on the low- and by 61% on the high-cafestol diet. In LDLR+/- and WT mice, the increases were 20% and 24%, respectively, on the low-cafestol diet and 55% and 46%, respectively, on the high-cafestol diet. These increases were mainly due to a rise in very low density lipoprotein (VLDL) and intermediate density lipoprotein cholesterol in all 3 mouse strains. To investigate the mechanism of this effect, apoE*3-Leiden mice were fed a high-cafestol or a placebo diet for 3 weeks. Cafestol suppressed enzyme activity and mRNA levels of cholesterol 7alpha-hydroxylase by 57% and 58%, respectively. mRNA levels of enzymes involved in the alternate pathway of bile acid synthesis, ie, sterol 27-hydroxylase and oxysterol 7alpha-hydroxylase, were reduced by 32% and 48%, respectively. The total fecal bile acid output was decreased by 41%. Cafestol did not affect hepatic free and esterified cholesterol, but it decreased LDLR mRNA levels by 37%. The VLDL apoB and triglyceride production rates, as measured after Triton injection, were 2-fold decreased by cafestol, indicating that the number of particles secreted had declined and that there was no change in the amount of triglycerides present in the VLDL particle during cafestol treatment. However, the VLDL particles contained a 4-times higher amount of cholesteryl esters, resulting in a net 2-fold increased secretion of cholesteryl esters. The decrease in triglyceride production was the result of a reduction in hepatic triglyceride content by 52%. In conclusion, cafestol increases serum cholesterol levels in apoE*3-Leiden mice by suppression of the major regulatory enzymes in the bile acid synthesis pathways, leading to decreased LDLR mRNA levels and increased secretion of hepatic cholesterol esters. We suggest that suppression of bile acid synthesis may provide an explanation for the cholesterol-raising effect of cafestol in humans.
    Arteriosclerosis Thrombosis and Vascular Biology 07/2000; 20(6):1551-6. · 6.37 Impact Factor
  • Article: Cafestol increases serum cholesterol levels in apolipoprotein E*3Leiden transgenic mice by suppression of bile acid synthesis
    [show abstract] [hide abstract]
    ABSTRACT: Cafestol, a diterpene present in unfiltered coffee, potently increases serum cholesterol levels in humans. So far, no suitable animal model has been found to study the biochemical background of this effect. We determined the effect of cafestol on serum cholesterol and triglycerides in different mouse strains and subsequently studied its mechanism of action in apolipoprotein (apo) E*3-Leiden transgenic mice. ApoE*3-Leiden, heterozygous low density lipoprotein–receptor (LDLR /-) knockout, or wild-type (WT) C57BL/6 mice were fed a high- (0.05 t/wt) or a low- (0.01 t/wt) cafestol diet or a placebo diet for 8 weeks. Standardized to energy intake, these amounts are equal to 40, 8, or 0 cups of unfiltered coffee per 10 MJ per day in humans. In apoE*3-Leiden mice, serum cholesterol was statistically significantly increased by 33␘n the low- and by 61␘n the high-cafestol diet. In LDLR /- and WT mice, the increases were 20nd 24°respectively, on the low-cafestol diet and 55nd 46°respectively, on the high-cafestol diet. These increases were mainly due to a rise in very low density lipoprotein (VLDL) and intermediate density lipoprotein cholesterol in all 3 mouse strains. To investigate the mechanism of this effect, apoE*3-Leiden mice were fed a high-cafestol or a placebo diet for 3 weeks. Cafestol suppressed enzyme activity and mRNA levels of cholesterol 7-hydroxylase by 57nd 58°respectively. mRNA levels of enzymes involved in the alternate pathway of bile acid synthesis, ie, sterol 27-hydroxylase and oxysterol 7-hydroxylase, were reduced by 32nd 48°respectively. The total fecal bile acid output was decreased by 41ÐCafestol did not affect hepatic free and esterified cholesterol, but it decreased LDLR mRNA levels by 37ÐThe VLDL apoB and triglyceride production rates, as measured after Triton injection, were 2-fold decreased by cafestol, indicating that the number of particles secreted had declined and that there was no change in the amount of triglycerides present in the VLDL particle during cafestol treatment. However, the VLDL particles contained a 4-times higher amount of cholesteryl esters, resulting in a net 2-fold increased secretion of cholesteryl esters. The decrease in triglyceride production was the result of a reduction in hepatic triglyceride content by 52ÐIn conclusion, cafestol increases serum cholesterol levels in apoE*3-Leiden mice by suppression of the major regulatory enzymes in the bile acid synthesis pathways, leading to decreased LDLR mRNA levels and increased secretion of hepatic cholesterol esters. We suggest that suppression of bile acid synthesis may provide an explanation for the cholesterol-raising effect of cafestol in humans.
    Arteriosclerosis Thrombosis and Vascular Biology - ARTERIOSCLER THROMB VASC BIOL. 01/2000;
  • Article: Verwaarloosbare hoeveelheden cholesterolverhogende diterpenen in koffie gezet met de koffiepadzetmethode bij vergelijking met ongefilterde kookkoffie=Negligible amounts of cholesterol-raising diterpenes in coffee made with coffee pads in comparison with unfiltered coffee
    [show abstract] [hide abstract]
    ABSTRACT: To determine the amounts of the serum-cholesterol raising diterpenes cafestol and kahweol in coffee made with coffee pads and the Senseo coffee machine as opposed to filtered and unfiltered coffee. DESIGN: Observational. METHOD: In five cities in the Netherlands coffee was purchased in three major supermarkets resulting in a total of 30 samples of coffee pads. The levels of cafestol and kahweol were determined by gas chromatography. As controls, the diterpene levels in filtered and unfiltered coffee were also measured. RESULTS: Coffee prepared using coffee pads contained on average 0.76 mg/l cafestol (95% CI: 0.69-0.82) and 0.85 mg/l kahweol (95% CI: 0.77-0.94). Filtered coffee contained 0.76 mg/l cafestol (95% CI: 0.63-0.88) and 0.81 mg/l kahweol (95% CI: 0.63-0.99). Unfiltered coffee contained 72.5 mg/l cafestol (95% CI: 48.5-96.4) and 71.5 mg/l kahweol (95% CI: 45.0-98.1). CONCLUSION: Coffee prepared using coffee pads and the Senseo coffee machine contained minute levels of diterpenes comparable to those of filtered coffee. Its effect on serum-cholesterol levels is therefore likely to be negligible
    Nederlands Tijdschrift voor Geneeskunde 150 (2006) 52.
  • Article: The Cholesterol-Raising Factor from Coffee Beans, Cafestol, as an Agonist Ligand for the Farnesoid and Pregnane X Receptors
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    ABSTRACT: Cafestol, a diterpene present in unfiltered coffee brews such as Scandinavian boiled, Turkish, and cafetière coffee, is the most potent cholesterol-elevating compound known in the human diet. Several genes involved in cholesterol homeostasis have previously been shown to be targets of cafestol, including cholesterol 7-hydroxylase (CYP7A1), the rate-limiting enzyme in bile acid biosynthesis. We have examined the mechanism by which cafestol elevates serum lipid levels. Changes in several lipid parameters were observed in cafestol-treated APOE3Leiden mice, including a significant increase in serum triglyceride levels. Microarray analysis of these mice identified alterations in hepatic expression of genes involved in lipid metabolism and detoxification, many of which are regulated by the nuclear hormone receptors farnesoid X receptor (FXR) and pregnane X receptor (PXR). Further studies demonstrate that cafestol is an agonist ligand for FXR and PXR, and that cafestol down-regulates expression of the bile acid homeostatic genes CYP7A1, sterol 12-hydroxylase, and Na+-taurocholate cotransporting polypeptide in the liver of wild-type but not FXR null mice. Cafestol did not affect genes known to be up-regulated by FXR in the liver of wild-type mice, but did increase expression of the positive FXR-target genes intestinal bile acid-binding protein and fibroblast growth factor 15 (FGF15) in the intestine. Because FGF15 has recently been shown to function in an enterohepatic regulatory pathway to repress liver expression of bile acid homeostatic genes, its direct induction in the gut may account for indirect effects of cafestol on liver gene expression. PXR-dependent gene regulation of cytochrome P450 3A11 and other targets by cafestol was also only seen in the intestine. Using a double FXR/PXR knockout mouse model, we found that both receptors contribute to the cafestol-dependent induction of intestinal FGF15 gene expression. In conclusion, cafestol acts as an agonist ligand for both FXR and PXR, and this may contribute to its impact on cholesterol homeostasis.
    Molecular endocrinology 21 (2007) 7.
  • Article: Coffee Oil Consumption Increases Plasma Levels of 7alpha-Hydroxy-4-cholesten-3-one in Humans
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    ABSTRACT: Unfiltered coffee brews such as French press and espresso contain a lipid from coffee beans named cafestol that raises serum cholesterol in humans. Cafestol decreases the expression and activity of cholesterol 7-hydroxylase, the rate-limiting enzyme in the classical pathway of bile acid synthesis, in cultured rat hepatocytes and livers of APOE3Leiden mice. Inhibition of bile acid synthesis has been suggested to be responsible for the cholesterol-raising effect of cafestol. Therefore, we assessed whether cafestol decreases the activity of cholesterol 7-hydroxylase in humans. Because liver biopsies were not feasible, we measured plasma levels of 7-hydroxy-4-cholesten-3-one, a marker for the activity of cholesterol 7-hydroxylase in the liver. Plasma 7-hydroxy-4-cholesten-3-one was measured in 2 separate periods in which healthy volunteers consumed coffee oil containing cafestol (69 mg/d) for 5 wk. Plasma levels of 7-hydroxy-4-cholesten-3-one increased by 47 ± 13% (mean ± SEM, n = 38, P = 0.001) in the first period and by 23 ± 10% (n = 31, P = 0.03) in the second treatment period. Serum cholesterol was raised by 23 ± 2% (P < 0.001) in the first period and by 18 ± 2% (P < 0.001) in the second period. We corrected individual 7-hydroxy-4-cholesten-3-one levels for serum cholesterol levels, because coffee oil increases serum cholesterol and 7-hydroxy-4-cholesten-3-one is probably present in the lipoprotein fraction of serum. After correction, the increase in 7-hydroxy-4-cholesten-3-one was 24 ± 11% (P = 0.04) in the first period and there was no effect in period 2. Our study showed that coffee oil did not decrease, and actually increased, plasma levels of 7-hydroxy-4-cholesten-3-one in humans in 2 separate treatment periods. Therefore, this study does not support the hypothesis that cafestol decreases bile acid synthesis in humans
    Journal of Nutrition 135 (2005).
  • Article: CYP7A1 A-278C polymorphism affects the response of plasma lipids after dietary cholesterol and cafestol interventions in humans.
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    ABSTRACT: The response of plasma lipids to dietary cholesterol and fat varies among individuals. Variations in genes involved in cholesterol metabolism can be important in these interindividual differences. The rate-limiting enzyme in the conversion of cholesterol into bile acids is cholesterol 7-hydroxylase (CYP7A1). We investigated the effect of the A278-C promoter polymorphism in the CYP7A1 gene on responses of plasma lipids to an increased intake in dietary cholesterol (742 ± 114 mg/d), cafestol (57 ± 6 mg/d), saturated fat [change of 8¿9 energy percent/d (en%/d)] and trans fat (change of 10¿11 en%/d) in 496 normolipidemic subjects. These responses were measured in 26 previously published dietary trials. After adjustment for the apolipoprotein E genotype effect, AA-subjects consuming a cholesterol-rich diet had a smaller increase in plasma HDL cholesterol than CC-subjects (0.00 ± 0.02 vs. 0.17 ± 0.04 mmol/L; P < 0.001). Upon intake of cafestol, AA-subjects had a smaller increase in plasma total cholesterol than CC-subjects (0.69 ± 0.10 vs. 1.01 ± 0.10 mmol/L; P = 0.028). No effects of the polymorphism were found in the saturated and trans fat interventions. In conclusion, the CYP7A1 polymorphism has a small but significant effect on the increase in plasma HDL cholesterol and plasma total cholesterol after an increased intake of dietary cholesterol and cafestol, respectively
    Journal of Nutrition 134 (2004) 9.
  • Article: Cafestol, the cholesterol-raising factor from coffee beans, is a ligand for the farnesoid X receptor
  • Article: Subjects with the AA genotype of the A278-C polymorphism in the cholesterol 7a hydroxylase gene display a lower response to a dietary challenge with cholesterol or cafestol than CC homozygotes
    Atherosclerosis Supplements 3 (2002) 2. - ISSN 0021-9150.
  • Article: The coffee diterpene cafestol decreases bile acid synthesis by down-regulation of cholesterol 7 alpha-hydroxylase in apolipoprotein E*3-Leiden mice
    Atherosclerosis 144 (1999).
  • Article: Cafestol, the cholesterol-raising factor in boiled coffee, increases serum cholesterol levels in apolipoprotein E*3-Leiden transgenic mice by suppression of bile acid synthesis
    Hepatology 30 (1999) 4.
  • Article: Cafestol, the cholesterol-raising factor in boiled coffee, increases serum cholesterol levels in apolipoprotein E*3-leiden transgenic mice by suppression of bile acid synthesis
    Circulation 100 (1999) 18.
  • Article: Cafestol increases serum cholesterol levels in apolipoprotein E*3-Leiden transgenic mice by suppression of bile acid synthesis
    [show abstract] [hide abstract]
    ABSTRACT: Cafestol, a diterpene present in unfiltered coffee, potently increases serum cholesterol levels in humans. So far, no suitable animal model has been found to study the biochemical background of this effect. We determined the effect of cafestol on serum cholesterol and triglycerides in different mouse strains and subsequently studied its mechanism of action in apolipoprotein (apo) E*3-Leiden transgenic mice. ApoE*3-Leiden, heterozygous low density lipoprotein–receptor (LDLR /-) knockout, or wild-type (WT) C57BL/6 mice were fed a high- (0.05 t/wt) or a low- (0.01 t/wt) cafestol diet or a placebo diet for 8 weeks. Standardized to energy intake, these amounts are equal to 40, 8, or 0 cups of unfiltered coffee per 10 MJ per day in humans. In apoE*3-Leiden mice, serum cholesterol was statistically significantly increased by 33␘n the low- and by 61␘n the high-cafestol diet. In LDLR /- and WT mice, the increases were 20nd 24°respectively, on the low-cafestol diet and 55nd 46°respectively, on the high-cafestol diet. These increases were mainly due to a rise in very low density lipoprotein (VLDL) and intermediate density lipoprotein cholesterol in all 3 mouse strains. To investigate the mechanism of this effect, apoE*3-Leiden mice were fed a high-cafestol or a placebo diet for 3 weeks. Cafestol suppressed enzyme activity and mRNA levels of cholesterol 7-hydroxylase by 57nd 58°respectively. mRNA levels of enzymes involved in the alternate pathway of bile acid synthesis, ie, sterol 27-hydroxylase and oxysterol 7-hydroxylase, were reduced by 32nd 48°respectively. The total fecal bile acid output was decreased by 41ÐCafestol did not affect hepatic free and esterified cholesterol, but it decreased LDLR mRNA levels by 37ÐThe VLDL apoB and triglyceride production rates, as measured after Triton injection, were 2-fold decreased by cafestol, indicating that the number of particles secreted had declined and that there was no change in the amount of triglycerides present in the VLDL particle during cafestol treatment. However, the VLDL particles contained a 4-times higher amount of cholesteryl esters, resulting in a net 2-fold increased secretion of cholesteryl esters. The decrease in triglyceride production was the result of a reduction in hepatic triglyceride content by 52ÐIn conclusion, cafestol increases serum cholesterol levels in apoE*3-Leiden mice by suppression of the major regulatory enzymes in the bile acid synthesis pathways, leading to decreased LDLR mRNA levels and increased secretion of hepatic cholesterol esters. We suggest that suppression of bile acid synthesis may provide an explanation for the cholesterol-raising effect of cafestol in humans.
    Arteriosclerosis Thrombosis and Vascular Biology 20 (2000).
  • Article: The role of epoxidation and electrophile-responsive element-regulated gene transcription in the potentially beneficial and harmful effects of the coffee components cafestol and kahweol
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    ABSTRACT: Cafestol and kahweol are diterpene compounds present in unfiltered coffees. Cafestol is known as the most potent cholesterol-raising agent that may be present in the human diet. Remarkably, the mechanisms behind this effect have only been partly resolved so far. Even less is known about the metabolic fate of cafestol and kahweol. From the structure of cafestol, carrying a furan moiety, we hypothesized that epoxidation may not only be an important biotransformation route but that this also plays a role in its effects found. In bile duct-cannulated mice, dosed with cafestol, we were able to demonstrate the presence of epoxy-glutathione (GSH) conjugates, GSH conjugates and glucuronide conjugates. In addition, it was shown that cafestol was able to induce an electrophile-responsive element (EpRE). Using a murine hepatoma cell line with a luciferase reporter gene under control of an EpRE from the human NQO1 regulatory region, we also found that metabolic activation by CYP450 enzymes is needed for EpRE induction. Furthermore, raising intracellular GSH resulted in a decrease in EpRE-mediated gene induction, whereas lowering intracellular GSH levels increased EpRE-mediated gene induction. In conclusion, evidence suggests that cafestol induces EpRE, apparently via a bioactivation process that possibly involves epoxidation of the furan ring. The epoxides themselves appear subject to conjugation with GSH. The effects on EpRE can also explain the induction of GSH which seems to be involved in the reported beneficial effects of cafestol, for example, when administered with aflatoxin B1 or other toxic or carcinogenic compounds
    Journal of Nutritional Biochemistry 21 (2010) 8.
  • Article: Absorption, distribution and biliary excretion of cafestol, a potent cholesterol elevating compound in unfiltered coffees in mice
    [show abstract] [hide abstract]
    ABSTRACT: Cafestol is a diterpene present in unfiltered coffees. It is the most potent cholesterol-elevating compound present in the human diet. However, the precise mechanisms underlying this effect are still unclear. In contrast, cafestol is also known as a hepatoprotective compound which is likely to be related to the induction of glutathione biosynthesis and conjugation. In the present study we investigated whole body distribution, biliary excretion and portal bioavailability of cafestol in mice. First, dissection was used to study distribution. Five hours after an oral dose with 3H labeled cafestol, most activity was found in small intestine, liver and bile. These results were confirmed by quantitative whole body autoradiography in a time course study which also showed elimination of all radioactivity within 48 hours after administration. Next, radiolabeled cafestol was dosed i.v. to bile duct cannulated mice. Five hours post dose 20% of the radioactivity was found in bile. Bile contained several metabolites but no parent compound. After intestinal administration of radioactive cafestol to portal vein cannulated mice, cafestol was shown to be rapidly absorbed into the portal vein as parent compound, a glucuronide and an unidentified metabolite. From the presence of a glucuronide in bile that can be deconjugated by a bacterial enzyme and the prolonged absorption of parent compound from the GI tract we hypothesize that cafestol undergoes enterohepatic cycling. Together with our earlier observation that epoxidation of the furan ring occurs in liver these findings merit further research on the process of accumulation of this coffee ingredient in liver and intestinal tract
    Drug Metabolism and Disposition 38 (2010) 4.