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In a study to investigate the relationship between the chemical structure and the differentiation-inducing activity of pentacyclic triterpenes, several lupane, oleanane, and ursane triterpenes were prepared and their effects on B16 2F2 melanoma cell differentiation and growth were examined. Eleven lupane triterpenes used in this study acted on the melanoma(More)
Cyclooxygenase-2 (COX-2), the rate-limiting enzyme in prostaglandin biosynthesis, plays a key role in inflammation and circulatory homeostasis. Peroxisome proliferator-activated receptors (PPARs) are ligand-dependent transcription factors belonging to the nuclear receptor superfamily and are involved in the control of COX-2 expression, and vice versa. Here,(More)
Lemongrass is a widely used herb as a food flavoring, as a perfume, and for its analgesic and anti-inflammatory purposes; however, the molecular mechanisms of these effects have not been elucidated. Previously, we identified carvacrol from the essential oil of thyme as a suppressor of cyclooxygenase (COX)-2, a key enzyme for prostaglandin synthesis, and(More)
The cytotoxicities of 11 lupane series triterpenes against 3 human leukemias, 2 melanomas, 2 neuroblastomas and normal fibroblast cells were examined. Lupane triterpenes with a carbonyl group at C-17 (7-11) showed inhibitory effects on leukemia, melanoma and neuroblastoma cell growth. Lup-28-al-20(29)-en-3-one (8) markedly inhibited the cell growth of 3(More)
Renin-binding protein (RnBP) is a highly specific renin inhibitor first isolated from porcine kidney. Our recent studies demonstrated that the human RnBP is the enzyme N-acetyl-D-glucosamine (GlcNAc) 2-epimerase [Takahashi, S. et al. (1999) J. Biochem. 125, 348-353]. We have developed a new assay method for GlcNAc 2-epimerase activity using a system of(More)
We examined the signaling mechanisms involved in the differentiation-inducing activity of lupeol toward B16 2F2 melanoma cells. alpha-Melanocyte stimulating hormone (alpha-MSH), forskolin and dibutyryl cAMP, which are believed to be cAMP-elevating agents and analogues, enhanced lupeol-induced B16 2F2 cell differentiation. However, H89, an inhibitor of(More)
Sialic acid is a major determinant of carbohydrate-receptor interactions in many systems pertinent to human health and disease. N-Acetylmannosamine (ManNAc) is the first committed intermediate in the sialic acid biosynthetic pathway; thus, the mechanisms that control intracellular ManNAc levels are important regulators of sialic acid production. UDP-GlcNAc(More)
The existence of human renin-binding protein (RnBP) in the kidney has been shown by the isolation and characterization of a complex of porcine renin-human RnBP [S. Takahashi et al. (1985) J. Biochem. 97, 671-677]. However, the properties of the free form of human RnBP had not been understood, because of the limitation of materials. In the present study, we(More)
Human prorenin was expressed in Escherichia coli as a fusion protein of thioredoxin. The chimeric protein, which accumulated insoluble inclusion bodies, was solubilized in 4 M guanidine-HCl and refolded by an arginine-detergent buffer system and by systematic dialysis. The refolded fusion prorenin was activated by trypsin. The antiserum against human kidney(More)
Lupeol induces the formation of dendrites in B16 2F2 melanoma cells. The remodeling of cytoskeletal components contributes to the dendricity of melanoma cells. We studied the effects of lupeol on the remodeling of cytoplasmic filaments in B16 2F2 cells. Western blotting revealed no change in the levels of actin and tubulin. Lupeol attenuated stress fiber(More)