Using six different cultured cell models representing osteoblast, intestine, kidney and keratinocyte, we have demonstrated that 1α, 25-dihydroxyvitamin D3 (1α, 25(OH)2D3) is metabolized into 3-epi-1α, 25(OH)2D3 in vitamin D-target cells. Although differences existed in the amount of 3-epi-1α, 25(OH)2D3 formed with different cell types, it was apparent that 1α, 25(OH)2D3 was subjected to metabolism both through the C24-oxidation and 3-epimerization pathways. Time course and dose response studies showed that the production of 3-epi-1α, 25(OH)2D3 was enzymatic. It is interesting to note that this epimerization proceeded from 3β towards 3α unidirectionally, and this conversion was not inhibited by ketoconazole. These data suggest that cytochrome P450 related enzymes including the 24-hydroxylase would not affect this reaction. The biological activity of 3-epi-1α, 25(OH)2D3 was found to be lower than the native 1α, 25(OH)2D3 in suppressing of proliferation of HL-60 cells, while the affinity of 3-epi-1α, 25(OH)2D3 for vitamin D-binding protein was 2.5-fold higher than that of 1α, 25(OH)2D3. The results indicate that 3-epimerization may change the pharmacokinetics and catabolism of 1α, 25(OH)2D3 in vitamin D-target cells.
The addition of lipopolysaccharide (LPS) together with cycloheximide (CHX) induced apoptosis in a subline of a J774.1 macrophage-like cell line, JA-4, as judged by terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick and labeling (TUNEL)-staining and poly(adenosine 5'-diphosphate(ADP)-ribose) polymerase (PARP)-cleavage. Caspase activities were examined in these macrophages in vitro using fluorogenic substrates such as acetyl-DEVD-aminomethyl coumarine (Ac-DEVD-AMC, caspase-3-like), acetyl-YVAD-aminomethyl coumarine (Ac-YVAD-AMC, caspase-1-like), acetyl-VEID-aminomethyl coumarine(Ac-VEID-AMC, caspase-6-like), and carbobenzoxy-IETD-aminofluoro coumarine (Z-IETD-AFC; caspase-8-like). Kinetic studies revealed these caspase activities with different Km and Vmax values in extracts of apoptotic macrophages. In the course of apoptosis, caspase-3-like activity increased first at 75 min, simultaneously with the appearance of TUNEL staining and prior to PARP cleavage, and then caspase-6 and 8-like activities increased at 90 and 105 min, respectively. However, caspase-1-like activity did not change throughout the experiment. Furthermore, removal of LPS and CHX by extensive washing of the cells for 60 min completely abolished the apoptosis and the subsequent release of lactate dehydrogenase (LDH) during additional incubation until 4 h after LPS addition. However, washing of the cells after 75 min or later resulted in the progress of apoptosis and LDH release, which was coordinated with the elevation of caspase-3-like activity at 60 min and that of caspase-6 or 8-like activity at 90 min, but not with that of caspase-1-like activity. These results suggest that caspase-3-like activity represents the most apical caspase among these caspases in terms of the intiation of apoptosis in macrophages treated with LPS and CHX.In the present study, we also provide evidence on the relatively low specificities of a series of caspase inhibitors other than acetyl-DEVD-aldehyde (Ac-DEVD-CHO) which specifically inhibited the caspase-3-like activity.
Two metallothionein cDNAs (MT-A and MT-B) in the fresh-water fish crucian carp (Carassius cuvieri TEMMINCK et SCHLEGEL) were cloned. Sequence analysis of both cDNAs gave the structure of a coding region corresponding to 60 amino acid residues. The homology of their deduced amino acid sequences was completely conserved at the positions of the cysteine residue, but a significant difference existed in the size of their 3'-untrans-lated regions (130 base pairs for MT-A and 280 base pairs for MT-B). Direct amino acid sequencing of the MT-II isoform purified by HPLC was accomplished for up to 30 residues and its sequence was identical to that deduced from MT-B cDNA. This is the first case in vertebrates that N-terminal methionine in crucian carp MT-II was not blocked. By northern blot analysis, basal and cadmium chloride- or dexamethasone-induced MT-B (MT-II) mRNAs were detected time dependently after treatment. On the other hand, the expression of MT-A mRNA was extremely low. These results indicate that the MT isoform II in crucian carp is coded by the MT-B gene, and that the MT-B-dominant expression of mRNA in crucian carp may be due to the difference in the 3'-untranslated regions of MT mRNAs.
Eubacterium sp. GLH possessing glycyrrhizin (GL) and glycyrrhetic acid mono-glucuronide (GAMG) β-D-glucuronidases, Ruminococcus sp. PO1-3 possessing GL and GAMG β-D-glucuronidases and 3β-hydroxysteroid dehydrogenase and these mixed bacteria were cultured in GAM medium with and without GL, GAMG or both. GL added to Eubacterium sp. GLH accelerated the peaks of enhanced GL β-D-glucuronidase activity and suppressed GAMG β-D-glucuronidase activity, and GAMG delayed the peaks of the enhanced growth with GL and GAMG β-D-glucuronidase activities. GL added to Ruminococcus sp. PO1-3 enhanced gradually the growth with GL and GAMG β-D-glucuronidase activities, and GAMG enhanced slowly GL β-D-glucuronidase activity and rapidly the growth with GAMG β-D-glucuronidase activity. The metabolite glycyrrhetic acid (GA) was produced by Eubacterium sp. GLH and Ruminococcus sp. PO1-3 in larger amounts and faster from GAMG than from GL.GL(1.0 mM) and 1.0 mM GAMG added to these mixed bacteria enhanced the growth with GL and GAMG β-D-glucuronidase activities and were metabolized almost completely to GA in culture of 2 d and 1 d, respectively. It was found that the metabolism of GAMG was faster than that of GL.GL with GAMG added to mixed Eubacterium sp. GLH and Ruminococcus sp. PO1-3 cultured for 0 and 1 d led to a lower level of these enzyme activities and the consumption of GAMG more quickly, not GL. Low GAMG β-D-glucuronidase had the ability to hydrolyze GAMG well.
The catalytic properties of rabbit heart acetohexamide reductase (RHAR) for naphthoquinones were examined. RHAR efficiently reduced 1, 4-naphthoquinone and juglone (5-hydroxy-1, 4-naphthoquinone), whereas it had little or no ability to reduce menadione (2-methyl-1, 4-naphthoquinone) or plumbagin (5-hydroxy-2-methyl-1, 4-naphthoquinone). The structural requirements for these four naphthoquinones and one acetohexamide analog, and the kinetic mechanism for the inhibition of acetohexamide reduction by juglone led us to conclude that the 2-methyl group of menadione and plumbagin prevents access of the substrates to the catalytic site of RHAR. Five of six peptides derived from RHAR showed 30-42% residue identities with regions in the amino acid sequence of mouse lung carbonyl reductase (MLCR) belonging to the short-chain dehydrogenase/reductase (SDR) family. The catalytically important residues (Arg-39, Ser-136, Tyr-149 and Lys-153) of MLCR were found in the peptide sequences of RHAR, despite the low residue identities between the two enzymes. RHAR is probably bast classified as a member of the SDR family similar to MLCR.
The influence of sesamol, an antioxidant in processed sesame oil, on oxidative modification of human erythrocyte membrane proteins was investigated. Human erythrocytes were incubated with sesamol at various concentrations up to 10 mM at 37°C for 1 h. The amounts of hemoglobin bound to the mambranes and detergent C12E8-insoluble membrane protein aggregates were increased as the concentration of sesamol increased. Western blot analysis indicated that aggregates of band 3 protein were increased by the treatment. Binding of anti-band 3 antibody to the erythrocytes was increased by the treatment. Isolated cell membranes were incubated with sesamol similarly. Aggregates of band 3 protein were also increased, indicating that the band 3 protein aggregation was little affected by hemoglobin bound to the membranes. Aggregation of band 3 protein in the treatment of isolated cell membranes was partially prevented when the treatment was couducted under anaerobic conditions, suggesting that augmentation of the protein aggregation by sesamol involved both oxygen-dependent and oxygen-independent pathways. Among phenolics, sesamol showed a distinctive feature to increase band 3 protein aggregation in erythrocyte membranes and to enhance anti-band 3 binding to erythrocytes.
The vertebrate olfactory system receives and discriminates a great variety of odorants. Many lines of evidence suggest that individual olfactory neuron expresses a single type or limited types of the olfactory receptor genes. However, the mechanism of selection of a single gene in the olfactory receptor family remains unclear. In the present study, we utilized zebrafish to identify the promoter element of the olfactory receptor genes in their 5'-upstream regions. First, we isolated a number of zebrafish olfactory receptor genes. These olfactory receptor genes were specifically expressed in the olfactory tissue as visualized by whole mount in situ hybridization analysis. Time of onset of the expression of each receptor clone varied from 24 h to 48 h postfertilization. Then, we injected various constructs containing the 5'-upstream regions of the olfactory receptor genes connected to β-galactosidase reporter gene into fertilized zebrafish embryos. Constructs from two independent olfactory receptor genes exerted β-galactosidase (promoter) activity that is specifically upregulated in the olfactory tissue. Use of either longer or deleted constructs of these two genes diminished the promoter activity in the olfactory tissue. From these results we discuss the mechanism of the transcription of the olfactory receptor genes in the olfactory neurons.
The effects of the angiotensin II type 1 receptor antagonist YM358 on blood pressure were compared to those of the angiotensin converting enzyme inhibitor enalapril in one-kidney, one-clip renal hypertensive rats(1K1C RHR), two-kidney, one-clip renal hypertensive rats (2K1C RHR) and normotensive rats (NTR). Additionally, the local drug actions in peripheral tissues were investigated using isolated mesenteric arteries from these rats. In 2K1C RHR, YM358 and enalapril produced a long-lasting hypotensive effect in a dose-dependent manner. In 1K1C RHR, YM358 (30 mg/kg) also produced an antihypertensive effect, whereas enalapril (30 mg/kg)had no effect. Administration of YM358, but not enalapril, to 1K1C RHR, 2K1C RHR and NTR did not affect heart rate. In isolated mesenteric arteries from 1K1C RHR and 2K1C RHR, angiotensin II (Ang II), angiotensin I (Ang I) and tetradecapeptide (TDP), a physiologically active renin substrate, produced concentration-dependent vasoconstriction. YM358 (10-7 M) inhibited the vasoconstricting responses to Ang II, Ang I and TDP in isolated mesenteric arteries. In contrast, enalaprilat (10-7M), an active metabolite of enalapril, did not completely inhibit the response to Ang I and TDP. These results indicate that YM358 has higher efficary than enalapril for the treatment of hypertension.
The pharamacological profile of a novel selective vasopressin V2 receptor antagonist, VP-343(N-[4-[[(2S, 3aR)-2-hydroxy-2, 3, 3a, 4-tetrahydropyrrolo[1, 2-a]quinoxalin-5(1H)-yl]carbonyl]Phenyl]-4'-methyl[1, 1'-biphenyl]-2-carboxamide) was characterized in several in vitro and in vivo rat models. The IC50 values of VP-343 for vasopressin V1A and V2 receptors were 110 and 0.77 nM, respectively. VP-343 inhibited dose-dependently the pressor response to exogenous arginine vasopressin (AVP; 30 mU/kg, i.v.) in pithed rats, with an ID50 value of 0.57 mg/kg(i.v.). VP-343 induced strong aquaresis in normal saline-loaded conscious rats. Antidiuretic activities of VP-343 have not been detected in AVP deficient Bratteleboro rats, showing its lack AVP V2 agonistic activity. During repeated administration for 21 d (3 mg/kg, p.o.) and after recovery, the aquaretic action VP-343 still remained. In the aged (17 month) saline-loaded conscious rats study, VP-343 (3 mg/kg, p.o.) exhibited remarkable diuretic action. In a single dose oral toxicity study in mice, VP-343 did not produce any clinical signs and mortality at any of the tested doses.The results indicate that VP-343 is a potent, orally active selective V2 receptor antagonist, suggesting that it can be expected to be useful as an aquaretic drug.
Methyl 2-nitroimidazole-1-acetohydroxamate (KIN-804) is a 2-nitroimidazole derivative containing a hydroxamate side chain designed to enhance the radiosensitization response of hypoxic cells. The possible sensitization of tumor tissue by KIN-804 can be evaluated through investigation of the levels of the free radical scavengers; namely, glutathione (GSH) and its complex enzyme system including glutathione reductase (GR) and glutathione peroxidase (GSH-Px), as well as glucose-6-phosphate dehydrogenase (G-6-PD). Female albino mice were inoculated with Ehrlich carcinoma in the thigh. Administration of KIN-804 (i.p. 80 mg/kg body weight) was carried out 20 min before localized irradiation of 10 Gy. The data revealed that KIN-804 administration, followed or not by gamma irradiation, resulted in a significant decrease in GSH content in tumor tissues associated with inhibition in GR and G-6-PD activities. Blood GSH-Px was enhanced in tumor inoculated mice and the administration of KIN-804 returned it to the normal value. These changes were more noticeable in tumor bearing mice exposed to both KIN-804 and irradiation.
In order to decrease toxicity and/or increase radiosensitizing activity, a new 2-nitroimidazole derivative, methyl 2-nitroimidazole-1-acetohydroxamate (KIN-804), was synthesized to solve the problem of tumor hypoxia. Evaluation of the efficiency of KIN-804 was carried out through studying the antioxidant enzyme system : The superoxide dismutase (SOD), catalase and lipid peroxide levels provide a rough index of the balance between free radical generation and scavenging. Female albino mice were inoculated with Ehrlish ascites carcinoma (EAC) in the thigh. The administration of KIN-804 (i.p. 80 mg/kg body weight) was carried out 20 min before localizad irradiation of 10 Gy. In general, the data revealed that KIN-804 administration, followed or not by gamma irradiation, exerted significant inhibition of SOD and catalase activities accompanied by a significant increase in lipid peroxide level in tumor-bearing mice.
Moutan Cortex (root cortex of Paeonia suffruticosa ANDREWS) and Paeoniae Radix (root of Paeonia lactiflora PALLAS) are crude drugs used in many traditional prescriptions and have constituents in common. We studied the effects of extracts of these crude drugs and their constituents on oxidative DNA damage caused by phenylhydroquinone (PHQ), a major metabolite of o-phenylphenol. Both drugs suppressed the cleavage of pUC18 DNA induced by PHQ, and scavenged the superoxide and hydroxy radical generated by the chemical. They also inhibited the oxidative DNA cleavage by tert-butylhydroquinone (TBHQ), one of the major metabolites of butylated hydroxyanisole. When constituents were examined with the same system, galloylpaeoniflorin and 1, 2, 3, 4, 6-penta-O-galloyl-β-D-glucose (PGG) were found to be the most potent inhibitors of the DNA cleavage. These constituents had oxygen radical scavenging activity. Paeonol also attenuated the DNA cleavage. Paeoniflorin and albiflorin had relatively small inhibitory effects on DNA cleavage. However, catechin enhanced the PHQ-induced DNA cleavage. The suppression of oxidative DNA damage by Moutan Cortex and Paeoniae Radix might be attributable to the additive effects of galloylpaeoniflorin, PGG and other constituents.
Astrocytes have a function in the uptake of excitatory neurotransmitter L-glutamate via the glutamate transporter. To evaluate the L-glutamate clearance capacity of atrocytes, we developed a colorimetric method for the determination of L-glutamate concentration and measured changes in extracellular L-glutamate concentration in rat cortical astrocyte cultures. When L-glutamate (50-200 μM) was added to astrocyte cultures and incubated for 1-8 h, the extracellular L-glutamate concentration declined with time. When L-glutamate was mixed with astrocyte culture supernatants only, no significant change in L-glutamate concentration was observed, ruling out the possibility that L-glutamate is spontaneously or enzymatically degraded in the extracellular space. Alternatively, the time-dependent decline of extracellular L-glutamate concentration was blocked by the presence of glutamate uptake inhibitors, indicating that the glutamate uptake system of astrocytes plays a major role in the clearance of extracellular L-glutamate.
Dermal application of propranolol (PRL) induced formation of erythema and edema, and pseudoeosinophil infiltration in epidermis and dermis at the application site in guinea pigs. We investigated the production of prostaglandin E2 (PCE2) and leukotriene B4 (LTB4) at the application site of PRL and the role of these inflammatory chemical mediators in the occurrence of the skin reactions. PGE2 was found to be produced at the application site slightly after the accumulation of PRL released from the adhesive bandage in the patch test, and the amount of PGE2 increased continuously, with a peak value obtained at 24 h after application. The time-course changes resembled those of Δa* value, the index of erythema formation determined by colorimetric measurement, and edema formation. The production of PGE2 by dermal application of PRL was suppressed by local pretreatment with dexamethasone or indomethacin. However, no notable production of LTB4 was observed at the application site of PRL.
Neutrophil is accumulated by chemoattractants at inflammatory sites. In order to find a new substance to regulate the chemotaxis of neutrophil, we examined the effects of purified tannins and related compounds (33 species). Among those studied, sanguiin H-11, purified from the plant Sanguisorba officinalis, was the most potent inhibitor of rat cytokine induced neutrophil chemoattractant-1 (CINC-1, a counterpart of human GRO(melanoma growth-stimulating activity)) dependent chemotaxis in rat neutrophils. Sanguiin H-11 inhibited platelet-activating factor- and N-formylmethionyl-leucyl-phenylalanine-dependent chemotaxis of neutrophil in addition to CINC-1-dependent reactions. Sanguiin H-11 also inhibited chemokinesis of neutrophil, but did not drastically affect the increase of intracellular free [Ca2+] level or degranulation monitored by the secretion of elastase, following chemoattractant stimulation. These results indicated that sanguiin H-11 is a potent inhibitor of chemoattractant-dependent and independent neutrophil movement.
The induction of micronucleated liver cells (MN-liver cell) was examined with halogenated and hydroxylated quinolines using partially hepatectomized mice. Among the chloroquinolines, 8-chloroquinoline demonstrated a significantly higher level of induction than the control. All the fluorinated derivatives examined, except for 6-fluoroquinoline, induced significantly higher levels, and there were no appreciable differences in MN-liver cell induction among the fluorinated quinolines, regardless of their mutagenic potencies in the Ames test. Of the hydroxylated quinolines examined, 2- and 4-isomers, which are not mutagenic, induced MN-liver cells to the same extent as a mutagenic isomer, 8-hydroxyquinoline. It seems that clastogenicity was not satisfactorily correlated with mutagenicity in the Ames test as far as this class of compounds is concerned.
Fenretinide, N-(4-Hydroxyphenyl)retinamide (4-HPR), is a cencer chemopreventive and antiproliferative agent whose mechanism of action is unknown. 4-HPR is a potent inducer of apoptosis in HL60 human leukemia cells which generates intracellular reactive oxygen species. The structural similarity of retinoic acid (RA), 4-HPR, and α-tocopherol (vitamin E) led us to investigate whether 4-HPR exhibits antioxidant activity. It was found that 4-HPR scavenged α, α-diphenyl-β-picrylhydrazyl (DPPH) radicals in a 1 : 1 ratio in contrast to vitamin E, where a 1 : 2 ratio relative to DPPH radicals was observed. In addition, linoleic acid peroxidation initiated by hydroxyl radaicals was decreased by 4-HPR to the same extent as by vitamin E. Furthermore, lipid peroxidation in rat liver microsomes was reduced by 4-HPR to a greater extent than by vitamin E. Based on these results, 4-HPR appears to be an effective antioxidant that may have clinical utility for diseases treated with vitamin E.
The current study reports several post-translational modifications of αB-crystallin in normal human lenses. The isoforms of post-translational modified αB-crystallin were isolated from the normal human lenses of >70-age group by ion exchange chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The isoform modifications were determined in detail by fast atom bombardment mass spectroscopy and amino acid sequence analysis. As the criterion of non-modified αB-crystallin, αB-crystallin from 1-d-old infant lenses were used. The modifications found in this study involve oxidation of the N-terminal methionine-1 residue, phosphorylation of the serine-59 residue, and truncation of four amino acids from the C-terminal position of the crystallin. The oxidation of methionine-1 was found in the early stage of human life in 1-d-old lens, although other modification of αB-crystallin were usually only found in old lenses (>70-age group).
A cDNA clone (GgCAS1) encoding cycloartenol synthase (CAS) has been isolated from Glycyrrhiza glabra(licorice) by cross-hybridization with that of Pisum sativum CAS as a probe. The deduced amino acid sequence of GgCAS1 exhibits 89%, 83% and 81% identity to those of Pisum sativum, Panax ginseng and Arabidopsis thaliana CASs, respectively. CAS activity has been detected in the homogenate of the yeast transformed with the expression vector containing the open reading frame of GgCAS1. Southerbn blot analysis suggested that at least two CAS genes exist in the licorice genome. In Northern blot analysis, the strong signal for CAS mRNA is detected in the cultured licorice cells of all growth phases, but no significant increase of GAS mRNA expression was observed in the cells treated with the 3-hydroxy-3-methylglutaryl-CoA reductase inhibitor, pravastatin.
A computer program is described for maximum likelihood estimation within the gamma or normal distribution which can be used to estimate pharmacokinetic parameters. Pharmacokinetic analysis using this proposed program was investigated by the Monte Carlo method. The assumed pharmacokinetic models were a one-compartment intravenous model and an oral model. The simulated drug concentrations were generated using a 10% S.D. based on the gamma or normal distribution. The gamma or normal distribution was adopted as the probability density function (p.d.f.) to estimate model parameters. The Powell method was used to maximize the logarithmic likelihood. There were no differences in the estimated parameters in terms of statistical and frequency distributions between the gamma and normal distributions using the generated data and the p.d.f. distributions.However, the number of failures to calculate the parameters using the p.d.f. with the normal distribution was more than five times that using the gamma distribution. This result suggests that it may be necessary to evaluate the validity of results computed using the maximum likelihood estimation based on a normal distribution as a data error distribution and p.d.f.
The antifibrotic effect of the methanol extract from Polygonum aviculare (PA), Artemisia capillaris (AC) and an aqueous solution of biphenyl dimethyl dicarboxylate (DDB) on liver fibrosis were studied. Liver fibrosis was induced by a bile duct ligation and scission (BDL/S) operation, duration of 4 weeks in rats. In BDL/S rats, the levels of aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), total bilirubin in serum and hydroxyproline content in liver dramatically increased. The PA treatment in BDL/S rawts reduced the serum AST, ALT and ALP levels significantly (p<0.01). Liver hydroxyproline content in PA treated BDL/S group was also reduced to 40% that of BDL/S control group (p<0.01). The morphological characteristics of fibrotic liver, which appeared in BDL/S control group were improved in the PA treated BDL/S group. But neither AC nor DDB treatment improved any parameters in fibrotic rats induced by BDL/S. These results indicate that PA has an antifibrotic effect on fibrotic rats induced by BDL/S.
A new method to assay the activity of aldose reductase (AR) and aldehyde reductase (AHR) by high-performance liquid chromatography is described. The separation of AR and AHR from tissue extracts using an anionexchange column was followed by chromatographic measurement of the activity in the elute. AR and AHR activity were expressed as the area under the peak obtained by post-coumn spectrophotometric detection of the decrease of coenzyme (NADPH) in each enzyme reaction. In the enzyme preparation from rat or human tissues obtained by this method, two active peaks were identified as AR and AHR. The conrrelation coefficient between the injection volume of the enzyme preparation from each tissue and each peak area was 0.998 or greater. In addition, the within-day preservation rate of AR or AHR activity from each tissue was over 95%.In a comparative study of fidarestat with other AR inhibitors using this method, it was confirmed that the inhibitory effect of fidarestat on AR activity from each rat tissue was more potent than that produced by sorbinil and equipotent to that of epalrestat and zenarestat. Fidarestat was also found to inhibit AR activity more potently than AHR activity in human erythrocytes. Therefore, this method is applicable to studies of the selective inhibition of AR or AHR by test compounds.
Schizophyllan (SPG, Sonifilan) is a soluble (1→3)-β-D-glucan, used as a biological response modifier (BRM)with radiation therapy for cancer treatment in Japan. The mechanism of SPG mediated antitumor activity is thought to be via immune stimulation, which includes cytokine production, hematopoietic response, and so on. In this paper, we found that the activity of SPG was quite long-lived and an overdose significantly failed to display the antitumor activity. To demonstrate the mechanism several parameters were examined using a high dose of SPG administration as follow : i) the effect on vascular permeability in vivo, ii) the priming effect on tumor necrosis factor (TNF-α) production in vivo, iii) the effect on macrophage adherence to plastic plate in vivo, and iv) anti-Sarcoma 180 antibody production in vito. It was evident that vascular permeability and anti-Sarcoma 180 antibody production remained unchanged, but TNF-α production and adherence to a plastic plate was significantly reduced by a high dose of SPG. These facts strongly suggested that modulation of the cytokine syntheses and the leukocyte traffic would be the causative mechanisms of the failure of antitumor activity by an overdose of SPG.
Of a series of synthetic alkyl 2-(acylthio)benzoate (1-20), all the derivatives except for n-butyl 2-butyrylthiobenzoate (18) and n-butyl 2-n-valerylthiobenzoate (20) showed clear phytogrowth-inhibitory activity. All the compounds tested except for methyl 2-butyrylthiobenzoate (3) exhibited cytotoxic activity on mouse splenic T cells. Strong phytogrowth-inhibition and cytotoxic activity were found with 1, 6, 11 and 16 with an acetylthio group at C-2, suggesting that the acetyl group seems to play an important role in both activities of alkyl 2-(acylthio)benzoates. Among them, methyl 2-acetylthiobenzoate (1) was the strongest inhibitor. On the other hand, potent inhibition of prolyl endopeptidase was exhibited by 2, 7, 12 and 17 with a propionylthio group at C-2. These findings imply that a propionyl group might be useful for increasing the inhibitory activity against on prolyl endopeptidase.
The bromine atoms of the title compound, 5, 7-dibromo-2-methyl-8-hydroxyquinoline were replaced by the requisite amino compound to afford 6 amino derivatives viz : bis(diethylamino)-, bis(dibutylamino)-, bis(dicyclohexylamino)-, dipyrolidino-, dipiperidino- and dipiperazino derivatives. The antimicrobial activity of these compounds were investigated against selected Gram positive (Staphylococcus aureus and Bacillus subtilis), Gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and yeast (Candida albicans). All the compounds showed significant activity against the test microorganisms, from 5-30 times compared to the title compound. It was observed that all derivatives were more effective against Gram positive bacteria. No correlation has been established between the minimum inhibitory (MIC) concentrations of the derivatives and the structural modifications.
The ability of certain chemicals to mimic the effects of natural steroid hormones and their potential to disrupt the delicate balance of the endocrine system in animals has attracted much interest in recent years.Alkylphenolic chemicals have been reported to be weakly estrogenic. Estrogen receptor (ER) binding is primarily the result of interaction of the receptor with both a phenolic residue, and a hydrophobic pharmacophore. We have prepared and screened various phenols having a bulky 4-alkyl group, which may interact hydrophobically with the receptor, for estrogenic activity by using a previously described reporter gene assay employing COS-1 cells transfected with rat ERα-expression plasmid and an appropriate reporter plasmid. Some of the tested compounds, such as 4-(1-adamantyl)phenol and 4-cycloalkylphenols, exhibited much more potent activity than the typical estrogenic alkylphenol, 4-tert-octylphenol.
Four steroidal alkaloids, epipachysamines B (1) and E (2), pachystermine A (3) and pachysamine E (4), were isolated as cytotoxic principles from the MeOH extract of the stems of Pachysandra terminalis SIEB. et ZUCC. (Buxaceae). These alkaloids showed cytotoxic activity against P388 and P388/ADR leukemia cells in vitro. Three of the alkaloids (1-3) were previously isolated from this plant material, and this is the first report of their cytotoxic activity. Pachysamine E (4) is a new alkaloid.
The present study provides the first evidence that stilbene oxide and styrene oxide are reductively metabolized to the corresponding olefins in rats. When cis- or trans-stilbene oxide was given orally to rats, both cis- and trans-stilbene were isolated from the urine and feces. Styrene was also isolated from the urine and feces of rats given styrene oxide. These metabolites were identified unequivocally by UV and mass spectral comparison with authentic samples, and on the basis of their TLC and HPLC behavior. However, these olefins were not detected in the urine or faces of antibiotics-treated rats dosed with cis- or trans-stilbene oxide. Cecal contents of the untreated rats exhibited olefin oxide reductase activities toward cis- and trans-stilbene oxides under anaerobic conditions. The results suggest that intestinal bacteria play an important role in the reduction of olefin oxides to the corresponding olefins in the animal body.