Chikako Ishikawa

Inhibitory effects of docosahexaenoic acid on colon carcinoma 26 metastasis to the lung

Unsaturated fatty acids, including n-3 polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid (C22:6, DHA) and eicosapentaenoic acid (C20:5, EPA), and a series of n-6 PUFAs were investigated for their anti-tumour and antimetastatic effects in a subcutaneous (s.c.) implanted highly metastatic colon carcinoma 26 (Co 26Lu) model. EPA and DHA exerted significant inhibitory effects on tumour growth at the implantation site and significantly decreased the numbers of lung metastatic nodules. Oleic acid also significantly inhibited lung metastatic nodules. Treatment with arachidonic acid showed a tendency for reduction in colonization. However, treatment with high doses of fatty acids, especially linoleic acid, increased the numbers of lung metastatic nodules. DHA and EPA only inhibited lung colonizations when administered together with the tumour cells, suggesting that their incorporation is necessary for an influence to be exerted. Chromatography confirmed that contents of fatty acids in both tumour tissues and plasma were indeed affected by the treatments. Tumour cells pretreated with fatty acids in vivo, in particular DHA, also showed a low potential for lung colony formation when transferred to new hosts. Thus, DHA treatment exerted marked antimetastatic activity associated with pronounced change in the fatty acid component of tumour cells. The results indicate that uptake of DHA into tumour cells results in altered tumour cell membrane characteristics and a decreased ability to metastasize.

Inhibitory effects of oleic and docosahexaenoic acids on lung metastasis by colon-carcinoma-26 cells are associated with reduced matrix metalloproteinase-2 and -9 activities.

In order to determine the effects of single unsaturated fatty acids (UFAs) or combinations on establishment of lung metastatic colonies, UFAs were administered orally to CDF1 mice bearing s.c. implants of the highly metastatic colon carcinoma 26. Oleic acid (OA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) demonstrated significant inhibition. In the case of DHA, this inhibitory potential was markedly reduced by co‐administration of linoleic acid (LA) or EPA. Furthermore, while tumor cells treated with DHA showed a very low potential for lung colony formation when injected i.v., this again being partially reversed by co‐administration of EPA. UFAs were found to be well absorbed into tumor tissues after oral administration, causing marked changes in relative levels, the arachidonic acid (AA) content, in particular, being markedly decreased by treatment with DHA or EPA, but not with DHA plus EPA or with DHA plus LA. Investigation of the gelatinolytic activity of the 57‐kDa and 92‐kDa isoforms of type‐IV collagenase (MMP‐2 and MMP‐9, respectively) showed a clear reduction in the former by treatment with OA, while DHA, but not DHA plus LA or EPA, caused a decrease in the 92‐kDa isoform, which was well correlated with AA content in tumor tissues (r = 0.900, p < 0.001). These results suggest that inhibition of metastasis due to treatment with OA and DHA might be due to depressed type‐IV collagenase activity. Int. J. Cancer 73:607–612, 1997.

Colon cancer prevention with a small amount of dietary perilla oil high in alpha-linolenic acid in an animal model

Background. Epidemiologic and experimental studies suggest that dietary fish oil and vegetable oil high in ω‐3 polyunsaturated fatty acids (PUFAs) suppress the risk of colon cancer. The optimal amount to prevent colon carcinogenesis with perilla oil high in ω‐3 PUFA α‐linolenic acid in a 12% medium‐fat diet was investigated in female F344 rats. For comparison, safflower oil high in ω‐6 PUFA linoleic acid was used.

A frameshift variant of CYP2C8 was identified in a patient who suffered from rhabdomyolysis after administration of cerivastatin

AbstractA hypercholesterolemic patient medicated with cerivastatin for 22 days resulted in acute rhabdomyolysis. CYP2C8 and CYP3A4 are the major enzymes responsible for the metabolism of cerivastatin, and a transporter, OATP2, contributes to uptake of cerivastatin to the liver. In this study, the patients DNA was sequenced in order to identify a variant that would lead to the adverse effect of cerivastatin. Three nucleotide variants, 475delA, G874C, and T1551C, were found in the exons of CYP2C8. The patient was homozygous for 475delA variant that leads to frameshift and premature termination. Accordingly, the patient is most likely lacking the enzyme activity. The patients children were both heterozygous for the mutation. The patient had three nucleotide variants in exon 4 (A388G) and exon 5 (C571T and C597T) of OATP2 that were all heterozygous. No nucleotide variation in the exons of CYP3A4 was identified. To our knowledge, this is the first report showing that the adverse effect of cerivastatin might be caused by the genetic variant of CYP2C8.

Chemical, physicochemical and spectrophotometric properties of crystalline chlorophyll-protein complexes from Lepidium virginicum L.

Two kinds of water-soluble chlorophyll-protein complexes were prepared from leaves of Lepidium virginicum L., one (CP661) from the plant cultivated in a green house from seeds collected near Mono Lake, CA, and the other (CP-663) from a plant collected at Narashino, Chiba, Japan, by ammonium sulfate fractionation followed by column chromatography on DEAE-cellulose and Sephacryl S-200. The chlorophyll . proteins were further purified by crystallization. CP661 has absorption peaks at 661, 468, 439, 419, 380, 339 and 272 nm. CP663 had absorption peaks at 663, 469, 438, 419, 379, 338 and 272 nm. Estimated molecular weights were 78 000 for CP661 and 80 000 for CP663 by gel filtration chromatography and 83 000 for CP661 and 107 000 for CP663 by an equilibrium sedimentation method. 1 mol chlorophyll . protein contained 4 mol chlorophyll a and b with ratios of 1.0 in CP661 and 1.6 to 1.9 in CP663, but no carotenoids. These characters are different from those of chlorophyll-protein complexes which are prepared from the thylakoid membranes of chloroplasts with detergents.

Incorporation of exogenous docosahexaenoic acid into various bacterial phospholipids

Incorporation of exogenous docosahexaenoic acid (DHA) into bacterial phospholipids was examined as a method for DHA-linked phospholipid production. The cultivation of 23 bacterial strains in medium with DHA showed that an eicosapentaenoic acid-producing bacteriumShewanella sp. strain SCRC-2738 (strain SCRC-2738),Bacillus subtilis W23,B. cereus, an Antarctic marine bacterium strain S-7 (strain S-7), photosynthesis bacterium (PSB)Rhodopseudomonas capsulatus utilized for the production of larval marine fish,Pseudomonas aeruginosa, Staphylococcus aureus, Serratia marcescens andEscherichia coli K12 all incorporated DHA into their polar lipids. The polar lipids of the strain SCRC-2738, strain S-7, PSB andE. coli K12 were identified to be phospholipids. DHA was localized at thesn-2 position in the phospholipids of the four strains. Incorporation of exogenous DHA into their phospholipids produced an increase in saturated fatty acids and a decrease in monounsaturated fatty acids exceptE. coli K12. The strain SCRC-2738 incorporated the largest amount of DHA into their phospholipids among the tested bacterial strains in this study: DHA was 16% of the total fatty acids in the phosphatidylethanolamine (PE) and 29% in the phosphatidylglycerol (PG). In the PSB, incorporated DHA was 12% of the total fatty acids in the PE, 10% in the PG and phosophatidylcholine so that the PSB was nutritionally fortified.

Lipid and fatty acid compositions of a novel docosahexaenoic acid- producing marine bacterium

An unidentified bacterial strain, SCRC-21406, isolated from the intestine of a marine fish, Glossanodon semifasciatus, produced docosahexaenoic acid at 23% (mol/mol) [=28% (w/w)] of total fatty acids in a medium containing 0.5% (wt/vol) peptone and 0.1% (wt/vol) yeast extract at 12°C under atmospheric pressure. The cell yield was 0.43 g/L. The major lipids of the strain were phosphatidylethanolamine and phophatidylglycerol. Docosahexaenoic acid was localized at the sn-2 positions of both phospholipids. The amounts of polyunsaturated fatty acids other than docosahexaenoic acid were extremely small [<3% (mol/mol)]. Monousaturated fatty acids of the cis-7, cis-9 and cis-11 types were detected.

Organotropic chemopreventive effects of n-3 unsaturated fatty acids in a rat multi-organ carcinogenesis model

Organotropic chemopreventive effects of n‐3 unsaturated fatty acids were studied using a multi‐organ carcinogenesis model in male rats. Rats were treated with diethylnitrosamine (DEN), N‐methyl‐N‐nitrosourea (MNU), N‐butyl‐N‐4‐hydroxybutylnitrosamine (BBN), 1,2‐dimethylhydrazine (DMH) and dihydroxy‐di‐n‐propylnitrosamine (DHPN) during the first 7 weeks, and then given unsaturated fatty acid (UFAs), docosahexaenoic acid (n‐3, C22:6) (DHA), eicosapentaenoic acid (n‐3, C20:5) (EPA), linoleic acid (n‐6, C18:2) (LA) or oleic acid (n‐9, C18:1) (OA) at a dose of 1.0 ml/rat, 3 tunes a week by gavage for the consecutive 30 weeks. All rats were fed a low LA basal diet throughout the experiment and a calorie‐restricted basal diet during the period of UFAs feeding administration. DHA significantly reduced tumor size and numbers in the large intestine as compared to OA treatment. Furthermore, DHA showed a tendency to inhibit carcinogenesis in the small intestine and lung. EPA also showed a tendency to inhibit intestinal carcinogenesis. On the other hand, LA showed a tendency to inhibit lung carcinogenesis, but to promote large intestinal carcinogenesis. However these UFAs did not influence preneoplastic and neoplastic lesion development in the liver, kidney, and urinary bladder. Levels of the administered fatty acids were clearly increased in the serum and organs. In contrast, arachidonic acid (AA) levels in the large and small intestines and liver were markedly decreased by treatment with DHA and EPA. Decreased levels of AA in the large intestine correlated well with tumor incidence, although the number of glutathione S‐transferase‐positive (GST‐P+) foci showed an inverse correlation with AA levels. The data thus provide evidence that an organotropism exists with regard to the influence of UFAs on carcinogenesis, which correlates with reduction of tissue AA levels in the target organs.

The amino acid sequence of adzuki bean proteinase inhibitor I

1. Introduction Proteins inhibiting the activity of proteinases are widely distributed in plant and animal tissues, and they are especially rich in leguminous seeds [ 11. Knowledge of the amino acid sequences of these proteinase inhibitors is important for studies on their structure- function relationships and molecular evolution. As for legume inhibitors, the amino acid sequences of Bowman-Birk soybean inhibitor [2] and two addi- tional soybean inhibitors [3] have been determined completely, and those of lima bean inhibitors IV and IV’ [4] and garden bean inhibitors II and II’ [S] nearly completely. These results show that these legume inhibitors are a family of low molecular weight proteins composed of about 70-80 amino acid residues and are double-headed, i.e., consisting of two domains each having a proteinase reactive site. Here, we report the amino acid sequence of adzuki bean proteinase inhibitor I, one of the major proteinase inhibitors isolated from adzuki bean (Phase&s

Clearance rates of cerivastatin metabolites in a patient with cerivastatin‐induced rhabdomyolysis

We report on a patient who developed acute rhabdomyolysis after taking cerivastatin. A 74‐year‐old hypercholestrerolaemic woman taking cerivastatin (0·15 mg/day) for 22 days complained of general muscle weakness and muscle pain. Her serum creatinine phosphokinase level was 19 190 IU/L. Serum myoglobin was over 3000 ng/mL. Serum concentration of cerivastatin at 6 h after taking the last dose (0·15 mg) was 8062·5 ng/L, which was almost 5·7 times higher than that of normal persons. The serum concentration of cerivastatin showed that the half‐life of cerivastatin in this patient was 22·4 h, compared with 2·4 h for normal controls. Cerivastatin is catabolized by cytochrome P450, 3A4 and 2C8 to M‐1, and by 2C8 to M‐23. The ratio of M‐23 to M‐1 in her serum was much lower than that of control persons (0·64 vs. 2·08). She had previously taken simvastatin which is metabolized by CYP3A4, without any sign and symptoms of rhabdomyolysis. These results suggest that the slowed clearance of cerivastatin in this patient might have been compounded by cytochrome P450, 2C8 dysfunction.