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Hyperforin, an Anti-Inflammatory Constituent from St. John's Wort, Inhibits Microsomal Prostaglandin E(2) Synthase-1 and Suppresses Prostaglandin E(2) Formation in vivo.

Koeberle A, Rossi A, Bauer J, Dehm F, Verotta L, Northoff H, Sautebin L, Werz O - Front Pharmacol (2011)

Bottom Line: The acylphloroglucinol hyperforin (Hyp) from St. John's wort possesses anti-inflammatory and anti-carcinogenic properties which were ascribed among others to the inhibition of 5-lipoxygenase.Intraperitoneal (i.p.) administration of Hyp (4 mg kg(-1)) to rats impaired exudate volume and leukocyte numbers in carrageenan-induced pleurisy associated with reduced PGE(2) levels, and Hyp (given i.p.) inhibited carrageenan-induced mouse paw edema formation (ED(50) = 1 mg kg(-1)) being superior over indomethacin (ED(50) = 5 mg kg(-1)).We conclude that the suppression of PGE(2) biosynthesis in vitro and in vivo by acting on mPGES-1 critically contributes to the anti-inflammatory efficiency of Hyp.

View Article: PubMed Central - PubMed

Affiliation: Department for Pharmaceutical Analytics, Pharmaceutical Institute, University of Tübingen Tübingen, Germany.

ABSTRACT
The acylphloroglucinol hyperforin (Hyp) from St. John's wort possesses anti-inflammatory and anti-carcinogenic properties which were ascribed among others to the inhibition of 5-lipoxygenase. Here, we investigated whether Hyp also interferes with prostanoid generation in biological systems, particularly with key enzymes participating in prostaglandin (PG)E(2) biosynthesis, i.e., cyclooxygenases (COX)-1/2 and microsomal PGE(2) synthase (mPGES)-1 which play key roles in inflammation and tumorigenesis. Similar to the mPGES-1 inhibitors MK-886 and MD-52, Hyp significantly suppressed PGE(2) formation in whole blood assays starting at 0.03-1 μM, whereas the concomitant generation of COX-derived 12(S)-hydroxy-5-cis-8,10-trans-heptadecatrienoic acid, thromboxane B(2), and 6-keto PGF(1α) was not significantly suppressed up to 30 μM. In cell-free assays, Hyp efficiently blocked the conversion of PGH(2) to PGE(2) mediated by mPGES-1 (IC(50) = 1 μM), and isolated COX enzymes were not (COX-2) or hardly (COX-1) suppressed. Intraperitoneal (i.p.) administration of Hyp (4 mg kg(-1)) to rats impaired exudate volume and leukocyte numbers in carrageenan-induced pleurisy associated with reduced PGE(2) levels, and Hyp (given i.p.) inhibited carrageenan-induced mouse paw edema formation (ED(50) = 1 mg kg(-1)) being superior over indomethacin (ED(50) = 5 mg kg(-1)). We conclude that the suppression of PGE(2) biosynthesis in vitro and in vivo by acting on mPGES-1 critically contributes to the anti-inflammatory efficiency of Hyp.

No MeSH data available.


Related in: MedlinePlus

Effects of hyperforin on the activity of mPGES-1. (A) Concentration–response curves for Hyp, octahydro-hyperforin, the acylphloroglucinol core, and humulone. (B) Chemical structures of octahydro-hyperforin, the acylphloroglucinol core, and humulone. (C) Concentration–response curves for a St. John's wort extract. (A,C) For studies of mPGES-1 inhibition, microsomal preparations of IL-1β-stimulated A549 cells were pre-incubated with vehicle (DMSO) or the test compounds at the indicated concentrations for 15 min at 4°C, and the reaction was started with 20 μM PGH2. After 1 min at 4°C, the reaction was terminated using a stop solution containing FeCl2 and 11β-PGE2 (1 nmol) as internal standard. The 100% values in the individual experiments are in the range of 3–4 μg ml−1 PGE2. Data are given as mean ± SE, n = 3–4. (D) Reversibility of mPGES-1 inhibition by Hyp. Microsomal preparations of IL-1β-stimulated A549 cells were pre-incubated with 3 μM inhibitor for 15 min at 4°C. An aliquot was diluted 10-fold to obtain an inhibitor concentration of 0.3 μM. For comparison, microsomal preparations were pre-incubated for 15 min with 0.3 μM Hyp or with vehicle (DMSO), and then, 20 μM PGH2 was added (no dilution). Then, all samples were incubated for 1 min on ice, and PGE2 formation was analyzed as described by RP-HPLC. Data are given as mean ± SE, n = 3–4, **p < 0.01 vs. vehicle (0.1% DMSO) control, ANOVA + Tukey HSD post hoc tests.
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Figure 4: Effects of hyperforin on the activity of mPGES-1. (A) Concentration–response curves for Hyp, octahydro-hyperforin, the acylphloroglucinol core, and humulone. (B) Chemical structures of octahydro-hyperforin, the acylphloroglucinol core, and humulone. (C) Concentration–response curves for a St. John's wort extract. (A,C) For studies of mPGES-1 inhibition, microsomal preparations of IL-1β-stimulated A549 cells were pre-incubated with vehicle (DMSO) or the test compounds at the indicated concentrations for 15 min at 4°C, and the reaction was started with 20 μM PGH2. After 1 min at 4°C, the reaction was terminated using a stop solution containing FeCl2 and 11β-PGE2 (1 nmol) as internal standard. The 100% values in the individual experiments are in the range of 3–4 μg ml−1 PGE2. Data are given as mean ± SE, n = 3–4. (D) Reversibility of mPGES-1 inhibition by Hyp. Microsomal preparations of IL-1β-stimulated A549 cells were pre-incubated with 3 μM inhibitor for 15 min at 4°C. An aliquot was diluted 10-fold to obtain an inhibitor concentration of 0.3 μM. For comparison, microsomal preparations were pre-incubated for 15 min with 0.3 μM Hyp or with vehicle (DMSO), and then, 20 μM PGH2 was added (no dilution). Then, all samples were incubated for 1 min on ice, and PGE2 formation was analyzed as described by RP-HPLC. Data are given as mean ± SE, n = 3–4, **p < 0.01 vs. vehicle (0.1% DMSO) control, ANOVA + Tukey HSD post hoc tests.

Mentions: Because Hyp potently inhibited PGE2 formation in whole blood from AA but failed to block COX-2, inhibition of PGE2 synthesis downstream of COX-2 (i.e., interference with PGE2 synthases) appeared reasonable. mPGES-1 is the major PGE2 synthase under pathological conditions related to inflammation and cancer (Samuelsson et al., 2007), and its expression is strongly increased in blood upon LPS treatment, primarily contributing to PGE2 formation in blood (Mosca et al., 2007). To assess the effects of Hyp on mPGES-1 activity, microsomal preparations of IL-1β-stimulated A549 cells, a rich source of mPGES-1 (Jakobsson et al., 1999), were used. Microsomes were pre-incubated with Hyp for 15 min, and then, PGE2 formation was initiated by addition of 20 μM PGH2 as substrate for mPGES-1. MK-886, used as reference compound, concentration-dependently inhibited PGE2 formation with an IC50 of 2.1 μM (data not shown), which is in agreement with the literature (Koeberle et al., 2008). As shown in Figure 4A, Hyp concentration-dependently suppressed PGE2 formation with an IC50 of 1 μM, and at 10 μM, 85 ± 2% inhibition was evident. Decreasing the PGH2 concentration to 1 μM did not significantly alter the potency of Hyp (data not shown). Interestingly, octahydro-hyperforin was equally effective, whereas the acylphloroglucinol core or the closely related polyprenylated acylphloroglucinol humulone (Figure 4B) failed to significantly inhibit PGE2 formation up to 10 μM (Figure 4A). These data suggest that defined structural arrangements are required for Hyp's inhibitory effect on mPGES-1. Finally, also an ethanolic extract (60% ethanol, v v−1) of St. John's wort proved to be efficient in suppressing PGE2 formation with an ED50 = 4 μg ml−1 (Figure 4C).


Hyperforin, an Anti-Inflammatory Constituent from St. John's Wort, Inhibits Microsomal Prostaglandin E(2) Synthase-1 and Suppresses Prostaglandin E(2) Formation in vivo.

Koeberle A, Rossi A, Bauer J, Dehm F, Verotta L, Northoff H, Sautebin L, Werz O - Front Pharmacol (2011)

Effects of hyperforin on the activity of mPGES-1. (A) Concentration–response curves for Hyp, octahydro-hyperforin, the acylphloroglucinol core, and humulone. (B) Chemical structures of octahydro-hyperforin, the acylphloroglucinol core, and humulone. (C) Concentration–response curves for a St. John's wort extract. (A,C) For studies of mPGES-1 inhibition, microsomal preparations of IL-1β-stimulated A549 cells were pre-incubated with vehicle (DMSO) or the test compounds at the indicated concentrations for 15 min at 4°C, and the reaction was started with 20 μM PGH2. After 1 min at 4°C, the reaction was terminated using a stop solution containing FeCl2 and 11β-PGE2 (1 nmol) as internal standard. The 100% values in the individual experiments are in the range of 3–4 μg ml−1 PGE2. Data are given as mean ± SE, n = 3–4. (D) Reversibility of mPGES-1 inhibition by Hyp. Microsomal preparations of IL-1β-stimulated A549 cells were pre-incubated with 3 μM inhibitor for 15 min at 4°C. An aliquot was diluted 10-fold to obtain an inhibitor concentration of 0.3 μM. For comparison, microsomal preparations were pre-incubated for 15 min with 0.3 μM Hyp or with vehicle (DMSO), and then, 20 μM PGH2 was added (no dilution). Then, all samples were incubated for 1 min on ice, and PGE2 formation was analyzed as described by RP-HPLC. Data are given as mean ± SE, n = 3–4, **p < 0.01 vs. vehicle (0.1% DMSO) control, ANOVA + Tukey HSD post hoc tests.
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Related In: Results  -  Collection

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Figure 4: Effects of hyperforin on the activity of mPGES-1. (A) Concentration–response curves for Hyp, octahydro-hyperforin, the acylphloroglucinol core, and humulone. (B) Chemical structures of octahydro-hyperforin, the acylphloroglucinol core, and humulone. (C) Concentration–response curves for a St. John's wort extract. (A,C) For studies of mPGES-1 inhibition, microsomal preparations of IL-1β-stimulated A549 cells were pre-incubated with vehicle (DMSO) or the test compounds at the indicated concentrations for 15 min at 4°C, and the reaction was started with 20 μM PGH2. After 1 min at 4°C, the reaction was terminated using a stop solution containing FeCl2 and 11β-PGE2 (1 nmol) as internal standard. The 100% values in the individual experiments are in the range of 3–4 μg ml−1 PGE2. Data are given as mean ± SE, n = 3–4. (D) Reversibility of mPGES-1 inhibition by Hyp. Microsomal preparations of IL-1β-stimulated A549 cells were pre-incubated with 3 μM inhibitor for 15 min at 4°C. An aliquot was diluted 10-fold to obtain an inhibitor concentration of 0.3 μM. For comparison, microsomal preparations were pre-incubated for 15 min with 0.3 μM Hyp or with vehicle (DMSO), and then, 20 μM PGH2 was added (no dilution). Then, all samples were incubated for 1 min on ice, and PGE2 formation was analyzed as described by RP-HPLC. Data are given as mean ± SE, n = 3–4, **p < 0.01 vs. vehicle (0.1% DMSO) control, ANOVA + Tukey HSD post hoc tests.
Mentions: Because Hyp potently inhibited PGE2 formation in whole blood from AA but failed to block COX-2, inhibition of PGE2 synthesis downstream of COX-2 (i.e., interference with PGE2 synthases) appeared reasonable. mPGES-1 is the major PGE2 synthase under pathological conditions related to inflammation and cancer (Samuelsson et al., 2007), and its expression is strongly increased in blood upon LPS treatment, primarily contributing to PGE2 formation in blood (Mosca et al., 2007). To assess the effects of Hyp on mPGES-1 activity, microsomal preparations of IL-1β-stimulated A549 cells, a rich source of mPGES-1 (Jakobsson et al., 1999), were used. Microsomes were pre-incubated with Hyp for 15 min, and then, PGE2 formation was initiated by addition of 20 μM PGH2 as substrate for mPGES-1. MK-886, used as reference compound, concentration-dependently inhibited PGE2 formation with an IC50 of 2.1 μM (data not shown), which is in agreement with the literature (Koeberle et al., 2008). As shown in Figure 4A, Hyp concentration-dependently suppressed PGE2 formation with an IC50 of 1 μM, and at 10 μM, 85 ± 2% inhibition was evident. Decreasing the PGH2 concentration to 1 μM did not significantly alter the potency of Hyp (data not shown). Interestingly, octahydro-hyperforin was equally effective, whereas the acylphloroglucinol core or the closely related polyprenylated acylphloroglucinol humulone (Figure 4B) failed to significantly inhibit PGE2 formation up to 10 μM (Figure 4A). These data suggest that defined structural arrangements are required for Hyp's inhibitory effect on mPGES-1. Finally, also an ethanolic extract (60% ethanol, v v−1) of St. John's wort proved to be efficient in suppressing PGE2 formation with an ED50 = 4 μg ml−1 (Figure 4C).

Bottom Line: The acylphloroglucinol hyperforin (Hyp) from St. John's wort possesses anti-inflammatory and anti-carcinogenic properties which were ascribed among others to the inhibition of 5-lipoxygenase.Intraperitoneal (i.p.) administration of Hyp (4 mg kg(-1)) to rats impaired exudate volume and leukocyte numbers in carrageenan-induced pleurisy associated with reduced PGE(2) levels, and Hyp (given i.p.) inhibited carrageenan-induced mouse paw edema formation (ED(50) = 1 mg kg(-1)) being superior over indomethacin (ED(50) = 5 mg kg(-1)).We conclude that the suppression of PGE(2) biosynthesis in vitro and in vivo by acting on mPGES-1 critically contributes to the anti-inflammatory efficiency of Hyp.

View Article: PubMed Central - PubMed

Affiliation: Department for Pharmaceutical Analytics, Pharmaceutical Institute, University of Tübingen Tübingen, Germany.

ABSTRACT
The acylphloroglucinol hyperforin (Hyp) from St. John's wort possesses anti-inflammatory and anti-carcinogenic properties which were ascribed among others to the inhibition of 5-lipoxygenase. Here, we investigated whether Hyp also interferes with prostanoid generation in biological systems, particularly with key enzymes participating in prostaglandin (PG)E(2) biosynthesis, i.e., cyclooxygenases (COX)-1/2 and microsomal PGE(2) synthase (mPGES)-1 which play key roles in inflammation and tumorigenesis. Similar to the mPGES-1 inhibitors MK-886 and MD-52, Hyp significantly suppressed PGE(2) formation in whole blood assays starting at 0.03-1 μM, whereas the concomitant generation of COX-derived 12(S)-hydroxy-5-cis-8,10-trans-heptadecatrienoic acid, thromboxane B(2), and 6-keto PGF(1α) was not significantly suppressed up to 30 μM. In cell-free assays, Hyp efficiently blocked the conversion of PGH(2) to PGE(2) mediated by mPGES-1 (IC(50) = 1 μM), and isolated COX enzymes were not (COX-2) or hardly (COX-1) suppressed. Intraperitoneal (i.p.) administration of Hyp (4 mg kg(-1)) to rats impaired exudate volume and leukocyte numbers in carrageenan-induced pleurisy associated with reduced PGE(2) levels, and Hyp (given i.p.) inhibited carrageenan-induced mouse paw edema formation (ED(50) = 1 mg kg(-1)) being superior over indomethacin (ED(50) = 5 mg kg(-1)). We conclude that the suppression of PGE(2) biosynthesis in vitro and in vivo by acting on mPGES-1 critically contributes to the anti-inflammatory efficiency of Hyp.

No MeSH data available.


Related in: MedlinePlus