[Hemophagocytic lymphohistiocytosis caused by hematogenous disseminated pulmonary tuberculosis: A case report].

Hemophagocytic lymphohistiocytosis (HLH) was a life-threatening syndrome due to the uncontrolled immune activation of cytotoxic T lymphocytes, natural killer (NK) cells, and macrophages. HLH is characterized by primary and secondary causes, the early diagnosis and treatment of patients are closely related to the prognosis and clinical outcome of patients. The clinical presentation is variable but mostly includes prolonged fever, splenomegaly, coagulopathy, hypertriglyceridemia, and hemophagocytosis, none of them is specific and particular for HLH. Tuberculosis (TB) infection is one of the causes of HLH. HLH caused by TB is very rare clinically, but it has a high mortality. For patients with fever of unknown origin, HLH-related clinical manifestations sometimes present before the final diagnosis of TB, and HLH is associated with the most significant mortality rate. This article is mainly about a 28-year-old patient with HLH who suffered from severe TB infection. The patient attended a hospital with a history of 2 months of prolonged fever, 10 days booger and subcutaneous hemorrhage in lower limbs. Before this, he was in good health and denied any history of tuberculosis exposure. Combined with relevant laboratory test results (such as splenomegaly, hemoglobin, platelet count, and hypertriglyceridemia) and clinical manifestations (e.g. fever), the patient was diagnosed with hemophagocytic lymphohistiocytosis, but the etiology of HLH remained to be determined. To confirm the etiology, the patient was asked about the relevant medical history (intermittent low back pain) and was performed chest CT scan, bone marrow biopsy, and fundus photography. Finally, he was diagnosed with hemophagocytic lymphohistiocytosis caused by hematogenous disseminated pulmonary tuberculosis. In response to this, intravenous methylprednisolone and anti-tuberculosis treatment (isoniazid, pyrazinamide, moxifloxacin, and amikacin) were administered to the patient. After more than a month of treatment, the patient recovered from HLH caused by severe TB infection. Therefore, this case suggests that we should be vigilant to the patient who admitted to the hospital with fever for unknown reasons, to diagnose HLH as early as possible and clarify its cause, then perform interventions and treatment, especially HLH secondary to tuberculosis. Also, cases of atypical TB and severe TB should be carefully monitored to achieve early diagnosis and early intervention.

Regulation of the expression of cyclooxygenases and production of prostaglandin I2 and E2 in human coronary artery endothelial cells by curcumin.

Curcumin regulates prostaglandin (PG) synthesis in a variety of cells. PGE2 and PGI2 are generated from arachidonic acid (AA) by cyclooxygenases 1 and 2 (COX-1 and COX-2) and the synthase (PGES and PGI2S) pathways. This study evaluates the in vitro effect of curcumin on the expression of COX-1, COX-2, PGI2S and microsomal PGES-1 (mPGES-1), and the production of PGE2 and PGI2 in human coronary artery endothelial cells (HCAEC). HCAEC monolayers were incubated with curcumin and the expression of mRNA, protein and the production of PGI2 and PGE2 were quantified. Incubation of HCAEC with curcumin led to a time and concentration-dependent increases in COX-2 mRNA with a small but significant decrease in COX-1 mRNA expression. Curcumin also stimulated the expression of PGI2S and mPGES-1 mRNA. Although curcumin stimulated COX-2, PGI2S and mPGES-1 gene expression, it failed to increase PGI2 or PGE2 production. Interestingly, supplementation of the culture medium with AA increased prostanoid production by both quiescent and curcumin-treated cells. However, in comparison to the quiescent cells, the prostanoid production by curcumin-treated cells was markedly enhanced as AA concentrations in the medium were increased, and the enhanced prostanoid production was blocked by the presence of COX-2 specific inhibitor. Taken together, these results suggest that curcumin regulates prostanoid homeostasis in HCAEC by modulating multiple steps including the expression of COX-1, COX-2, PGI2S and mPGES-1.

Molecular modelling study of the mechanism of high-potency inhibition of human catechol-O-methyltransferase by (-)-epigallocatechin-3-O-gallate.

The molecular mechanism of inhibition of human catechol-O-methyltransferase (COMT) by (-)-epigallocatechin-3-O-gallate (EGCG), which is a modest substrate of COMT but an ultra-potent inhibitor of this enzyme, was studied. EGCG has an IC(50) value of 70 nM for inhibiting human liver COMT-mediated O-methylation of 2-hydroxyestradiol, which was 210-760 times more potent than catechin, epigallocatechin and epicatechin. Kinetic analyses showed that EGCG had a strong component of non-competitive inhibition of the O-methylation of 2-hydroxyestradiol. Computational molecular modelling studies showed that the B- and D-rings of EGCG can bind tightly to the human COMT in four different modes (i.e. D-para-OH, D-meta-OH, B-para-OH, and B-meta-OH). The binding geometry of EGCG in these binding modes was found to be less than ideal to form perfect Mg(2+) coordination for the catalysis of its own methylation. It is concluded that the very tight binding interaction of EGCG with COMT makes it a potent non-competitive inhibitor, but its imperfect geometry makes it a poor substrate for methylation by this enzyme.

Human and animal spongiform encephalopathies are the result of chronic autoimmune attack in the CNS: a novel medical theory supported by overwhelming experimental evidence.

Spongiform encephalopathies, also called "prion diseases", are fatal degenerative diseases of the central nervous system which can occur in animals (such as the "mad cow disease" in cattle) and also in humans. This paper presents a novel medical theory concerning the pathogenic mechanisms for various human and animal spongiform encephalopathies. It is hypothesized that various forms of prion diseases are essentially autoimmune diseases, resulting from chronic autoimmune attack of the central nervous system. A key step in the pathogenic process leading towards the development of spongiform encephalopathies involves the production of specific autoimmune antibodies against the disease-causing prion protein (PrPsc) and possibly other immunogenic macromolecules present in the brain. As precisely explained in this paper, the autoimmune antibodies produced against PrPsc are responsible for the conversion of the normal cellular prion protein (PrPc) to PrPsc, for the accumulation of PrPsc in the brain and other peripheral tissues, and also for the initiation of an antibody-mediated chronic autoimmune attack of the central nervous system neurons, which would contribute to the development of characteristic pathological changes and clinical symptoms associated with spongiform encephalopathies. The validity and correctness of the proposed theory is supported by an overwhelming body of experimental observations that are scattered in the biomedical literature. In addition, the theory also offers practical new strategies for early diagnosis, treatment, and prevention of various human and animal prion diseases.

On the mechanism of homocysteine pathophysiology and pathogenesis: a unifying hypothesis.

Studies have shown that hyperhomocysteinemia is an important and independent risk factor for a variety of human cardiovascular diseases. In this paper, a unifying hypothesis is proposed which suggests that hyperhomocysteinemia may exert its pathogenic effects largely through metabolic accumulation of S-adenosyl-L-homocysteine, a strong noncompetitive inhibitor of the catechol-O-methyltransferase (COMT)-mediated methylation metabolism of various catechol substrates (such as catecholamines and catechol estrogens). In the case of endogenous catecholamines in peripheral tissues, inhibition of their methylation by S-adenosyl-L-homocysteine will result in elevation of blood or tissue levels of catecholamines, and consequently, over-stimulation of the cardiovascular system's functions. Moreover, because the vasculature is constantly exposed to high levels of endogenous catecholamines (due to high levels of circulating neurohormone epinephrine plus rich innervation with sympathetic nerve terminals), vascular endothelial cells would incur chronic cumulative damage caused by the large amounts of the oxidative products (catechol quinones/semiquinones and oxyradicals) generated from endogenous catecholamines. This mechanistic explanation for the vascular toxicity of hyperhomocysteinemia is supported by many experimental findings, and it also fully agrees with the known protective effects of folate, vitamins B6 and B12 in hyperhomocysteinemic patients. In addition, based on the predictable effects of hyperhomocysteinemia on the methylation of catecholamines in the central nervous system as well as on the methylation of catechol estrogens in estrogen target organs, it is also suggested that hyperhomocysteinemia is an important risk factor for the development of neurodegerative disorders (Parkinson's and Alzheimer's diseases) and estrogen-induced hormonal cancers. More studies are warranted to test these intriguing ideas.

Preferential growth stimulation of mammary glands over uterine endometrium in female rats by a naturally occurring estradiol-17beta-fatty acid ester.

We hypothesize that the endogenously present lipoidal estrogen fatty acid esters may have a stronger mitogenic action in the fat-rich mammary tissues than in the uterus. To test this hypothesis, we compared the activity of estradiol-17beta-stearate (E(2)-17beta-S) with that of estradiol-17beta (E(2)) in stimulating the growth of mammary glandular cells versus the growth of uterine endometrial cells in ovariectomized female Sprague Dawley rats. Experimentally, an estimated 0.5 or 5 nmol of E(2)-17beta-S or E(2) was released daily to ovariectomized female rats through an Alzet pump implanted under the back skin of the animal for 10 or 23 days. The growth-stimulatory effect of E(2)-17beta-S and E(2) on mammary glandular cells was determined according to 5-bromo-2'-deoxyuridine labeling indices, and their effect on the uterus was determined by measuring both the 5-bromo-2'-deoxyuridine labeling index and the uterine wet weight. Our results showed that chronic treatment of ovariectomized female rats with 0.5 or 5 nmol/day E(2)-17beta-S for 10 or 23 days had a stronger stimulatory effect on mammary glandular cell proliferation than treatment with equimolar doses of E(2). In the uterus, however, E(2) was more active in stimulating the proliferation of uterine endometrial cells than E(2)-17beta-S at equimolar doses. Our results demonstrated, for the first time, that a naturally occurring estradiol-17beta-fatty acid ester has a differential, strong mitogenic effect in the fat-rich mammary tissues, and this effect was not observed with E(2). It is tempting to suggest that the fatty acid esters of the endogenous estrogens and their bioactive metabolites (e.g., 4-hydroxyestradiol and 16alpha-hydroxyestrone) may be of unique importance for stimulating cell growth and possibly also for inducing tumor formation in the fat-rich mammary tissues as compared with the uterus. More studies are warranted to test these ideas.

Characterization of the NADPH-dependent metabolism of 17beta-estradiol to multiple metabolites by human liver microsomes and selectively expressed human cytochrome P450 3A4 and 3A5.

We characterized the NADPH-dependent metabolism of 17beta-estradiol (E2) by liver microsomes from 21 male and 12 female human subjects. A large number of radioactive estrogen metabolite peaks were detected following incubations of [3H]E2 with male or female human liver microsomes in the presence of NADPH. The structures of 18 hydroxylated or keto estrogen metabolites formed by these microsomes were identified by gas chromatography/mass spectrometry analysis. 2-Hydroxylation (the formation of 2-OH-E2 and 2-OH-E1) was the dominant metabolic pathway with all human liver microsomes tested. The average ratio of 4-OH-E2 to 2-OH-E2 formation was approximately 1:6. A new monohydroxylated E2 metabolite (chemical structure unidentified) was found to be one of the major metabolites formed by human liver microsomes of both genders. 6beta-OH-E2 and 16beta-OH-E2 were also formed in significant quantities, but products of estrogen 16alpha-hydroxylation (16alpha-OH-E2 + 16alpha-OH-E1) were quantitatively minor metabolites. In addition, many other estrogen metabolites such as 6-keto-E2, 6alpha-OH-E2, 7alpha-OH-E2, 12beta-OH-E2, 15alpha-OH-E2, 15beta-OH-E2, 16beta-OH-E1, and 16-keto-E2 were also formed in relatively small quantities. The overall profiles for the E2 metabolites formed by male and female human liver microsomes were similar, and their average rates were not significantly different. The activity of testosterone 6beta-hydroxylation (a selective probe for CYP3A4/5 activity) strongly correlated with the rate of formation of 2-OH-E2, 4-OH-E2, and several other hydroxyestrogen metabolites by both male and female liver microsomes. The dominant role of hepatic CYP3A4 and CYP3A5 in the formation of these hydroxyestrogen metabolites was further confirmed by incubations of selectively expressed human CYP3A4 or CYP3A5 with [3H]E2 and NADPH.

PPARalpha-dependent induction of liver microsomal esterification of estradiol and testosterone by a prototypical peroxisome proliferator.

Fatty acyl-coenzyme A:estradiol acyltransferase in liver microsomes catalyzes the formation of estradiol fatty acid esters. These estrogen esters are extremely lipophilic and have prolonged hormonal activity because they are slowly metabolized and slowly release estradiol. Our previous studies showed that treatment of female rats with clofibrate or gemfibrozil (peroxisome proliferators commonly used as hypolipidemic drugs) markedly stimulated the liver microsomal esterification of estradiol. Although clofibrate administration is a potent inducer of liver microsomal fatty acyl-coenzyme A:estradiol acyltransferase in rats, it is a poor inducer in mice. In contrast to these observations, Wy-14,643 (an exceptionally potent prototypical peroxisome proliferator) is a strong inducer of fatty acyl-coenzyme A:estradiol acyltransferase in mice. To explore the role of PPARalpha in the induction of fatty acyl-coenzyme A:estradiol acyltransferase and fatty acyl-coenzyme A:testosterone acyltransferase activities by peroxisome proliferators, we fed 0.1% Wy-14,643 to female wild-type and PPARalpha null mice for 11 d. The liver microsomal acyl-coenzyme A:estradiol acyltransferase and acyl-coenzyme A:testosterone acyltransferase activities were increased 4- to 5-fold in wild-type mice fed Wy-14,643, but no increase was observed in null mice. These results demonstrate that induction of acyl-coenzyme A:estradiol acyltransferase and acyl-coenzyme A:testosterone acyltransferase activities by a prototypical peroxisome proliferator is dependent on PPARalpha.

Stimulatory effect of clofibrate on the action of estradiol in the mammary gland but not in the uterus of rats.

Treatment of ovariectomized rats with dietary clofibrate caused a manyfold increase in the liver microsomal esterification of estradiol with fatty acids. The stimulatory effect of clofibrate administration on fatty acid esterification of estradiol by liver microsomes was paralleled in vivo by enhanced estradiol-induced increases in the formation of lobules in the mammary gland and by increased incorporation of bromodeoxyuridine into these lobules. In contrast to the stimulatory effect of clofibrate administration on the action of estradiol in the mammary gland, clofibrate administration had no effect on the uterotropic action of estradiol. These results indicate that clofibrate administration has a selective stimulatory effect on the hormonal action of estradiol in the mammary gland but not in the uterus.

Stimulatory effect of clofibrate and gemfibrozil administration on the formation of fatty acid esters of estradiol by rat liver microsomes.

Fatty acyl-coenzyme A (CoA):estradiol acyltransferase in liver microsomes catalyzes the formation of estradiol fatty acid esters. These esters are lipophilic and have prolonged hormonal activity because they are slowly metabolized and because they slowly release estradiol. In the present study, we have shown that treatment of rats with clofibrate or gemfibrozil (peroxisome proliferators that are commonly used hypolipidemic drugs) markedly stimulate the liver microsomal esterification of estradiol. Administration of 0.15, 0.30, 0.45, or 0.60% clofibrate in an AIN-76A diet to female rats for 4 weeks stimulated fatty acyl-CoA:estradiol acyltransferase activity per milligram of microsomal protein by 4-, 8-, 14- and 16-fold, respectively, when estradiol was incubated with liver microsomes and a fatty acyl-CoA. Additional studies showed that incubation of (3)H-labeled estradiol with liver microsomes, ATP, and coenzyme A resulted in the formation of multiple fatty acid esters of estradiol from endogenous fatty acids in liver microsomes, and the formation of these esters was stimulated manyfold by pretreatment of rats with clofibrate. This study provides the first demonstration of a stimulatory effect of an environmental agent on the esterification of an estrogen.

Rapid conversion of tea catechins to monomethylated products by rat liver cytosolic catechol-O-methyltransferase.

1. The metabolic O-methylation of several catechol-containing tea polyphenols by rat liver cytosolic catechol-O-methyltransferase (COMT) has been studied. 2. When (-)-epicatechin was used as substrate, its O-merthylation showed dependence on incubation time, cytosolic protein concentration, incubation pH and concentration of S-adenosyl-L-methionine. The O-methylation of increasing concentrations of (-)-epicatechin followed typical Michaelis-Menten kinetics, and the apparent Km and Vmax were 51 microM and 2882 pmol mg protein(-1) min(-1), respectively, at pH 7.4, and were 17 microM and 2093 pmol mg protein(-1) min(-1), respectively, at pH 10.0. 3. Under optimized conditions for in vitro O-methylation, (-)-epicatechin, (+)-epicatechin and (-)-epigallocatechin were rapidly O-methylated by rat liver cytosol. In comparison, (-)-epicatechin gallate and (-)-epigallocatechin gallate vere O-methylated at significantly lower rates under the same reaction conditions. catalysed O-methylation of (-)-epicatechin and (-)-epigallocatechin was inhibited in a concentration-dependent manner by S-adenosyl-L-homocysteine, a demethylated product of S-adenosyl-L-methionine. The IC50 was approximately 10 microM. 5. In summary, the results showed that several catechol-containing tea polyphenols were rapidly O-methylated by rat liver cytosolic COMT. These observations raise the possibility that some of the biological effects of tea polyphenols may be exerted by their O-methylated products or may result from their potential inhibition of the COMT-catalysed O-methylation of endogenous catecholamines and catechol oestrogens.

[Enhancement of fermentative glycerol yield with heat shock treatment].

A heat shock treatment was studied in glycerol fermentation of osmotolerant yeast Candida krusei. The experiment results showed that the optimal temperature and duration time for heat shock is 45 degrees C and 30 min respectively, and the optimal start time of the treatment is at the mid term in exponential growth stage. With such treatment, glycerol yield was enhanced greatly, while no significant effects on both cell growth and glucose consumption were observed.

Strong inhibition of estrone-3-sulfatase activity by pregnenolone 16alpha-carbonitrile but not by several analogs lacking a 16alpha-nitrile group.

In recent years, development of potent inhibitors for estrogen sulfatases has become an actively pursued strategy for chemoprevention and/or chemotherapy of estrogen-dependent human breast cancers. We report here our findings that pregnenolone 16alpha-carbonitrile (PCN) is a potent inhibitor of estrone-3-sulfatase activity of rats and also humans. PCN inhibited in a concentration-dependent manner the desulfation of estrone-3-sulfate catalyzed by liver microsomal and nuclear fractions of female Sprague-Dawley rats. The inhibition of estrone-3-sulfatase activity in these two subcellular fractions showed a biphasic pattern, with a highly sensitive phase seen at 78 nM to 1.25 microm of PCN followed by a markedly less-sensitive phase at > 2.5 microm of PCN. Interestingly, several of PCN's structural analogs without a 16alpha-nitrile group showed little or no inhibitory effect on rat liver microsomal E(1)-3-sulfatase activity. Double-reciprocal analysis showed that the inhibition of rat liver microsomal E(1)-3-sulfatase activity by PCN was essentially competitive in nature. When microsomes from six human term placentas were tested for their E(1)-3-sulfatase activity, PCN showed a similar biphasic inhibition of placental E(1)-3-sulfatase. Likewise, several of its structural analogs showed little or no inhibitory effect on placental E(1)-3-sulfatase activity. Computational analysis of the D-ring structure of PCN and other structurally similar analogs used in the study suggests that the potent sulfatase-inhibiting activity of PCN may be partly due to its unique steric orientation and size of the 16alpha-nitrile group. This knowledge may be useful for the rational design of more potent steroidal inhibitors of E(1)-3-sulfatase by introducing an additional nitrile group to their C16alpha-position.

O-Methylation of tea polyphenols catalyzed by human placental cytosolic catechol-O-methyltransferase.

In the present study, we evaluated the metabolic O-methylation of several catechol-containing tea polyphenols by human placental catechol-O-methyltransferase (COMT). (-)-Epicatechin, (+)-epicatechin, and (-)-epigallocatechin were good substrates for metabolic O-methylation by placental cytosolic COMT (150-500 pmol/mg of protein/min), but (-)-epicatechin gallate and (-)-epigallocatechin gallate were O-methylated at much lower rates (<50 pmol/mg of protein/min). When (-)-epicatechin was used as substrate, its O-methylation by human placental COMT showed dependence on incubation time, cytosolic protein concentration, incubation pH, and concentration of S-adenosyl-L-methionine (the methyl donor). Analysis of cytosolic COMT from six human term placentas showed that the O-methylation of increasing concentrations of (-)-epicatechin or (-)-epigallocatechin follows typical Michaelis-Menten kinetics, with K(m) and V(max) values of 2.2 to 8.2 microM and 132 to 495 pmol/mg of protein/min for (-)-epicatechin and 3.9 to 6.7 microM and 152 to 310 pmol/mg of protein/min for (-)-epigallocatechin, respectively. Additional analysis revealed that COMT-catalyzed O-methylation of (-)-epicatechin and (-)-epigallocatechin was strongly inhibited in a concentration-dependent manner by S-adenosyl-L-homocysteine (IC(50) = 3.2-5.7 microM), a demethylated product of S-adenosyl-L-methionine. This inhibition by S-adenosyl-L-homocysteine follows a mixed (competitive plus noncompetitive) mechanism of enzyme inhibition. In summary, several catechol-containing tea polyphenols are rapidly O-methylated by human placental cytosolic COMT. This metabolic O-methylation is subject to strong inhibitory regulation by S-adenosyl-L-homocysteine, which is formed in large quantities during the O-methylation of tea polyphenols.

A novel hypothesis for the mechanism of action of P-glycoprotein as a multidrug transporter.

For years, P-glycoprotein (P-gp) has been purported to be a membrane transporter capable of selectively transporting many (but not all) lipophilic anticancer drugs with diverse chemical structures. Because the alleged functions of P-gp provide a straightforward, near-perfect explanation for the molecular mechanism of multidrug resistance associated with P-gp overexpression. However, the exact molecular mechanism for P-gp's purported function has never been clearly understood since its initial discovery some 20 yr ago. In this paper, I develop a novel working hypothesis regarding the mechanism of P-gp's action and suggest that P-gp is an energy-dependent efflux pump only for certain conjugated metabolites (probably sulfates) of the lipophilic anticancer drugs but not for the parent compounds, as was always claimed. According to this hypothesis, P-gp overexpression in most cases is not the "culprit" but instead an "accomplice" in P-gp-associated multidrug resistance. The culprit is probably the enhanced function of the metabolizing enzymes for the lipophilic anticancer drugs. This hypothesis also predicts that one of the important physiological functions of P-gp is to be part of an intracellular machinery (together with the phase I and II metabolizing enzymes) for the metabolism, detoxification, and disposition of lipophilic endogenous chemicals as well as xenobiotics, including cytotoxic anticancer drugs. There exists a considerable body of circumstantial evidence in the literature that lends strong support to this mechanistic hypothesis of P-gp's action as well as to the predicted physiological functions of P-gp. It will be of considerable interest to examine this novel hypothesis experimentally.

Dietary administration of an extract from rosemary leaves enhances the liver microsomal metabolism of endogenous estrogens and decreases their uterotropic action in CD-1 mice.

We evaluated the effects of a methanol extract from the leaves of the plant Rosmarinus officinalis L. (rosemary) on the metabolism and action of estradiol and estrone. Treatment of female CD-1 mice with 2% rosemary in AIN-76A diet for 3 weeks increased the liver microsomal 2-hydroxylation of estradiol and estrone by approximately 150%, increased their 6-hydroxylation by approximately 30% and inhibited the 16alpha-hydroxylation of estradiol by approximately 50%. Treatment of female CD-1 mice with 2% rosemary diet for 3 weeks also stimulated the liver microsomal glucuronidation of estradiol and estrone by 54-67% and 37-56%, respectively. In additional studies, feeding 2% rosemary diet to ovariectomized CD-1 mice for 3 weeks inhibited the uterotropic action of estradiol and estrone by 35-50% compared with animals fed a control diet. The results of this study showed that feeding female mice a 2% rosemary diet increased the liver microsomal oxidation and glucuronidation of estradiol and estrone and inhibited their uterotropic action.

Effect of dietary curcumin and dibenzoylmethane on formation of 7,12-dimethylbenz[a]anthracene-induced mammary tumors and lymphomas/leukemias in Sencar mice.

Female Sencar mice (6 weeks old) were administered 1 mg of 7,12-dimethylbenz[a]anthracene (DMBA) by oral gavage once a week for 5 weeks. At 20 weeks after the first dose of DMBA, 68% of mice developed mammary tumors (the average 1.08 tumors per mouse) and 45% had lymphomas/leukemias. Feeding 1% dibenzoylmethane (DBM) in AIN 76A diet, starting at 2 weeks before the first dose of DMBA and continuing until the end of the experiment, inhibited both the multiplicity and incidence of DMBA-induced mammary tumor by 97%. The incidence of lymphomas/leukemias was completely inhibited by 1% DBM diet. In contrast, feeding 2% curcumin diet had little or no effect on the incidence of mammary tumors, and the incidence of lymphomas/leukemias was reduced by 53%.

Clinical and biologic activity of an estrogenic herbal combination (PC-SPES) in prostate cancer.

BACKGROUND: Herbal mixtures are popular alternatives to demonstrated therapies. PC-SPES, a commercially available combination of eight herbs, is used as a nonestrogenic treatment for cancer of the prostate. Since other herbal medicines have estrogenic effects in vitro, we tested the estrogenic activity of PC-SPES in yeast and mice and in men with prostate cancer. METHODS: We measured the estrogenic activity of PC-SPES with transcriptional-activation assays in yeast and a biologic assay in mice. We assessed the clinical activity of PC-SPES in eight patients with hormone-sensitive prostate cancer by measuring serum prostate-specific antigen and testosterone concentrations during and after treatment. RESULTS: In complementary yeast assays, a 1:200 dilution of an ethanol extract of PC-SPES had estrogenic activity similar to that of 1 nM estradiol, and in ovariectomized CD-1 mice, the herbal mixture increased uterine weights substantially. In six of six men with prostate cancer, PC-SPES decreased serum testosterone concentrations (P<0.05), and in eight of eight patients it decreased serum concentrations of prostate-specific antigen. All eight patients had breast tenderness and loss of libido, and one had venous thrombosis. High-performance liquid chromatography, gas chromatography, and mass spectrometry showed that PC-SPES contains estrogenic organic compounds that are distinct from diethylstilbestrol, estrone, and estradiol. CONCLUSIONS: PC-SPES has potent estrogenic activity. The use of this unregulated mixture of herbs may confound the results of standard or experimental therapies and may produce clinically significant adverse effects.

Is 2-methoxyestradiol an endogenous estrogen metabolite that inhibits mammary carcinogenesis?

Catechol estrogens (2- or 4-hydroxyestradiol and 2- or 4-hydroxyestrone) are chemically reactive estrogen metabolites that are O-methylated to less polar monomethyl ethers by catechol-O-methyltransferase, an enzyme present in many tissues such as the liver, kidney, brain, placenta, uterus, and mammary gland. In the present report, we review recent studies on the antitumorigenic and antiangiogenic effects of exogenously administered 2-methoxyestradiol in vitro and in vivo. We also discuss data that suggest that endogenous formation of 2-methoxyestradiol (and its 2-hydroxyestradiol precursor) may have a protective effect on estrogen-induced cancers in target organs. Although the molecular mechanism of action of 2-methoxyestradiol is not clear, we suggest that some unique effects of 2-methoxyestradiol may be mediated by a specific intracellular effector or receptor that is refractory to the parent hormone, estradiol. Additional research is needed to identify factors that regulate the metabolic formation and disposition of 2-methoxyestradiol in liver and in target cells and to evaluate the effects of modulating 2-methoxyestradiol formation on estrogen-induced carcinogenesis.

Effects of tea polyphenols and flavonoids on liver microsomal glucuronidation of estradiol and estrone.

Administration of 0.5 or 1% lyophilized green tea (5 or 10 mg tea solids per ml, respectively) as the sole source of drinking fluid to female Long-Evans rats for 18 days stimulated liver microsomal glucuronidation of estrone, estradiol and 4-nitrophenol by 30-37%, 15-27% and 26-60%, respectively. Oral administration of 0.5% lyophilized green tea to female CD-1 mice for 18 days stimulated liver microsomal glucuronidation of estrone, estradiol and 4-nitrophenol by 33-37%, 12-22% and 172-191%, respectively. The in vitro addition of a green tea polyphenol mixture, a black tea polyphenol mixture or (-)-epigallocatechin gallate inhibited rat liver microsomal glucuronidation of estrone and estradiol in a concentration-dependent manner and their IC50 values for inhibition of estrogen metabolism were approximately 12.5, 50 and 10 microg/ml, respectively. Enzyme kinetic analysis indicates that the inhibition of estrone glucuronidation by 10 microM (-)-epigallocatechin gallate was competitive while inhibition by 50 microM (-)-epigallocatechin gallate was noncompetitive. Similarly, several flavonoids (naringenin, hesperetin, kaempferol, quercetin, rutin, flavone, alpha-naphthoflavone and beta-naphthoflavone) also inhibited rat liver microsomal glucuronidation of estrone and estradiol to varying degrees. Naringenin and hesperetin displayed the strongest inhibitory effects (IC50 value of approximately 25 microM). These two hydroxylated flavonoids had a competitive mechanism of enzyme inhibition for estrone glucuronidation at a 10 microM inhibitor concentration and a predominantly noncompetitive mechanism of inhibition at a 50 microM inhibitor concentration.