Effects of glycyrrhizin, an active component of licorice roots, on Candida albicans infection in thermally injured mice.
Due to the generation of burn-associated CD8+ CD11b+ TCR gamma/delta+ type 2 T cells (burn-associated type 2 T cells), the susceptibility of thermally injured mice to infection with C. albicans has been shown to be increased by up to 50-fold when compared with normal mice. Glycyrrhizin (GR), an active component of licorice roots, reduced the susceptibility of thermally injured mice to C. albicans infection to levels observed in normal mice. Thermally injured mice inoculated with CD4+ T cells from GR-treated mice were also resistant to C. albicans infection. The following demonstrated that susceptibility to fungal infection was similar in thermally injured mice and normal mice inoculated with T6S cells (a clone of burn-associated type 2 T cells). This susceptibility of T6S mice (normal mice inoculated with T6S cells) was reversible by (i) administration of GR, (ii) inoculation of CD4+ T cells from GR-treated mice, and (iii) injection of a mixture of MoAbs targeted against type 2 cytokines (IL-4 and IL-10). After stimulation with anti-CD3 MoAb, splenic T cells from thermally injured and T6S mice, treated with GR or inoculated with CD4+ T cells from GR-treated mice, did not have type 2 cytokines in culture supernatants. They were present in splenic T cell cultures from thermally injured and T6S mice that were treated with saline or inoculated with naive T cells. These results suggest that GR, by inducing CD4+ T cells which suppress type 2 cytokines produced by burn-associated type 2 T cells, improves the resistance of thermally injured mice to C. albicans. An anti-type 2 T cell action of the CD4+ T cells derived from GR-treated mice was previously described. (+info)
Hepatitis C: epidemiology and review of complementary/alternative medicine treatments.
Hepatitis C is emerging as a serious worldwide problem. In the United States the current mortality figures may triple in the next ten years, rivaling HIV. The disease has a latency of 10-30 years and symptoms or signs may not appear until cirrhosis is evident. Adequate diagnosis, including liver biopsy, is essential in assessing the current stage of the viral infection and the need for treatment. Hepatitis C may manifest as hepatic fibrosis, cirrhosis, hepatocellular carcinoma, lichen planus, glomerulonephritis, mixed cryoglobulinemia, or porphyria. The hepatic damage is due both to the cytopathic effect of the virus and the inflammatory changes secondary to immune activation. The use of the botanical components glycyrrhizin, catechin, silymarin and phytosterols, and the antioxidants N-acetylcysteine and vitamin E are reviewed for their efficacy in treating chronic hepatitis and affecting liver damage. (+info)
Hydroxyprolylserine derivatives JBP923 and JBP485 exhibit the antihepatitis activities after gastrointestinal absorption in rats.
It has been a desire to develop orally effective therapeutic agents that restore the liver function in chronic injury. Here we demonstrated that trans-4-L-hydroxyprolyl-L-serine (JBP923) and cyclo-trans-4-L-hydroxyprolyl-L-serine (JBP485), which was previously isolated from hydrolysate of human placenta, exhibit potent antihepatitis activity after their oral administration. The increase in bilirubin concentration and activities of liver cytosolic enzymes in serum caused by alpha-naphthylisothiocyanate intoxication in rats were significantly countered both after i.v. and oral administration of these dipeptides, whereas glycyrrhizin, which has been used in the treatment of chronic hepatitis, is active only after its i.v. administration. Antihepatitis activity of dipeptides results, at least partially, from their direct effect on hepatocytes because glutamic-oxaloacetic transaminase and lactate dehydrogenase activities in the medium of hepatotoxin-exposed primary cultured hepatocytes were reduced by these compounds. When comparing the plasma concentration-time profile of JBP923 after its i.v., oral, and portal vein injection, it is suggested that JBP923 is almost completely absorbed from gastrointestinal lumen, and hepatic first-pass removal is minor. JBP923 inhibited the proton-dependent transport of glycylsarcosine in brush-border membrane vesicles, suggesting that peptide transport system(s) may recognize JBP923. Thus, these dipeptides are potent antihepatitis reagents that are still active after oral administration and may be useful for clinical applications. (+info)
Human cervical tissue metabolizes the tobacco-specific nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, via alpha-hydroxylation and carbonyl reduction pathways.
We determined the ability of human epithelial cervical cells, human cervical microsomes and cytosol to metabolize 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). All preparations metabolized NNK by alpha-hydroxylation, demonstrated by the presence of 4-oxo-4-(3-pyridyl)butyric acid (keto acid), and by carbonyl reduction, illustrated by the formation of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL). Cervical cells metabolized NNK by the oxidative pathway to an extent comparable to that by the reductive pathway. In both human cervical cytosol and microsomes, the concentration of alpha-hydroxylation products ranged from undetectable to 10 times lower than those of NNAL. An apparent K(m) and V(max) of 7075 microM and 650 pmol/mg/min, respectively, were determined for the keto acid in one microsomal preparation. NNAL was formed in all preparations at the highest levels, ranging from 16.9 to 35.5 pmol/10(6) cells in incubations with ectocervical cells and 6.2 pmol/10(6) cells in incubations with endocervical cells. NNAL levels were 1.88-4.95 and 1.44-2.08 pmol/mg/min in human cervical microsomes and cytosolic fractions, respectively. An apparent K(m) of 739 microM and a V(max) of 1395 pmol/mg/min for NNAL formation were established in the same microsomal preparation used for the keto acid kinetics study. The stereochemistry of the NNAL formed in incubations of NNK with human cervical cells and subcellular fractions was determined by derivatization with (S)-(-)-methylbenzyl isocyanate. Human cervical cells and microsomes both formed the (R)-enantiomer of NNAL almost exclusively; incubations with human cervical cytosol resulted predominantly in the formation of the (S)-enantiomer. Substrates for 11 beta-hydroxysteroid dehydrogenase, cortisone, glycyrrhizic acid and metyrapone all inhibited the formation of NNAL in incubations with human cervical microsomes; the inhibition ranged from 16% to 80%. These studies illustrate that human cervical tissue can metabolize NNK by both oxidative and reductive pathways and that 11 beta-HSD may, in part, be responsible for the carbonyl reduction of NNK. (+info)
Hepatitis-associated aplastic anemia and transfusion-transmitted virus infection.
A 17-year-old man was admitted to our hospital because of severe acute hepatitis. Serologic studies were negative for A, B, C and G hepatitis viruses. Later, he was found to be positive for transfusion-transmitted virus (TTV) DNA. He was discharged after normalization of liver function tests. Four months after the onset of hepatitis, he was re-admitted because of pancytopenia. Bone marrow findings were consistent with aplastic anemia. The anemia responded to steroid therapy. In this case, TTV was probably involved in the development of aplastic anemia. (+info)
Aldosterone receptor antagonism normalizes vascular function in liquorice-induced hypertension.
The enzyme 11beta-hydroxysteroid dehydrogenase (11beta-HSD2) provides mineralocorticoid receptor specificity for aldosterone by metabolizing glucocorticoids to their receptor-inactive 11-dehydro derivatives. The present study investigated the effects of the aldosterone receptor antagonists spironolactone and eplerenone on endothelial function in liquorice-induced hypertension. Glycyrrhizic acid (GA), a recognized inhibitor of 11beta-HSD2, was supplemented to the drinking water (3 g/L) of Wistar-Kyoto rats over a period of 21 days. From days 8 to 21, spironolactone (5.8+/-0.6 mg. kg(-1). d(-1)), eplerenone (182+/-13 mg. kg(-1). d(-1)), or placebo was added to the chow (n=7 animals per group). Endothelium-dependent or -independent vascular function was assessed as the relaxation of preconstricted aortic rings to acetylcholine or sodium nitroprusside, respectively. In addition, aortic endothelial nitric oxide synthase (eNOS) protein content, nitrate tissue levels, and endothelin-1 (ET-1) protein levels were determined. GA increased systolic blood pressure from 142+/-8 to 185+/-9 mm Hg (P<0.01). In the GA group, endothelium-dependent relaxation was impaired compared with that in controls (73+/-6% versus 99+/-5%), whereas endothelium-independent relaxation remained unchanged. In the aortas of 11beta-HSD2-deficient rats, eNOS protein content and nitrate tissue levels decreased (1114+/-128 versus 518+/-77 microgram/g protein, P<0.05). In contrast, aortic ET-1 protein levels were enhanced by GA (308+/-38 versus 497+/-47 pg/mg tissue, P<0.05). Both spironolactone and eplerenone normalized blood pressure in animals on GA (142+/-9 and 143+/-9 mm Hg, respectively, versus 189+/-8 mm Hg in the placebo group; P<0.01), restored endothelium-dependent relaxation (96+/-3% and 97+/-3%, respectively, P<0.01 versus placebo), blunted the decrease in vascular eNOS protein content and nitrate tissue levels, and normalized vascular ET-1 levels. This is the first study to demonstrate that aldosterone receptor antagonism normalizes blood pressure, prevents upregulation of vascular ET-1, restores NO-mediated endothelial dysfunction, and thus, may advance as a novel and specific therapeutic approach in 11beta-HSD2-deficient hypertension. (+info)
Inhibition of concanavalin A-induced mice hepatitis by coumarin derivatives.
The effects of coumarin derivatives, osthole, imperatorin, Pd-Ia, Pd-II and Pd-III, on mice concanavalin A (Con A) (0.2 mg/mouse, i.v.)-induced hepatitis were studied. At the dose of 200 mg/kg (i.p.), these coumarins inhibited more than 90% of the Con A-induced elevation of plasma alanine aminotransferase activity, but glycyrrhizin (200 mg/kg, i.p.) caused only 45% inhibition. At the dose of 100 mg/kg (i.p.), osthole produced the strongest inhibition among these coumarins. The inhibitory activity of osthole is lost when its 7-methoxy group is replaced by a 7-hydroxy group to form osthenol. The present results showed that coumarin derivatives inhibited Con A-induced hepatitis, with osthole being the most inhibitory. (+info)
Inhibition of gap-junctional communication induces the trans-differentiation of osteoblasts to an adipocytic phenotype in vitro.
Osteoblasts and adipocytes are thought to differentiate from a common stromal progenitor cell. These two phenotypically mature cell types show a high degree of plasticity, which can be observed when cells are grown under specific culture conditions. Gap junctions are abundant among osteoblastic cells in vivo and in vitro, whereas they are down-regulated during adipogenesis. Gap junctional communication (GJC) modulates the expression of genes associated with the mature osteoblastic phenotype. Inhibition of GJC utilizing 18-alpha-glycyrrhetinic acid (AGRA) blocks the maturation of pre-osteoblastic cells in vitro. Moreover, cytoplasmic lipid droplets are detectable at the end of the culture period, suggesting that GJC inhibition may favor an adipocytic phenotype. We used several human osteoblastic cell lines, as well as bone-derived primary osteoblastic cells, to show that confluent cultures of human osteoblastic cells grown under osteogenic conditions developed an adipocytic phenotype after 3 days of complete inhibition of GJC using AGRA or oleamide, two dissimilar nontoxic reversible inhibitors. Development of an adipogenic phenotype was confirmed by the accumulation of triglyceride droplets and the increase in mRNA expression of the adipocytic markers peroxisome proliferator-activated receptor gamma2 and lipoprotein lipase. Glycyrrhizic acid, a noninhibitory AGRA analog, or alpha-bromopalmitate, a nondegradable fatty acid, had no effect. Modulation of skeletal GJC may represent a new pharmacological target by which inhibition of marrow adipogenesis can take place with the parallel enhancement of osteoblastogenesis, thus providing a novel therapeutic approach to the treatment of human age-related osteopenic diseases and postmenopausal osteoporosis. (+info)