Triterpenoids isolated from Zizyphus jujuba inhibit foam cell formation in macrophages

Because foam cell formation in macrophages is believed to play an essential role in the progression of early atherosclerotic lesions in vivo, prevention of foam cell formation is considered to be one of the major targets for the treatment of atherosclerosis. The present study examined the inhibitory effect of 50 crude plant extracts on foam cell formation. Among those crude extracts, Zizyphi Fructus (ZF) and Zizyphi Semen (ZS) extracts significantly inhibited the foam cell formation induced by acetylated LDL. Furthermore, triterpenoids such as oleanonic acid, pomolic acid, and pomonic acid were the major active compounds, and triterpenoids containing a carboxylic acid at C-28 play an important role in the inhibitory effect on foam cell formation in human macrophages. These data suggest that triterpenoids in Zizyphus jujuba , the plant source of ZF and ZS, may therefore be useful for the prevention of atherosclerosis.     

Characteristics and classification of an unirrigated anthropogenic-alluvial soil found in the Kumamoto Plain

In Japan anthropogenic-alluvial soils excluding irrigated rice soils are lagging for behind other genetic soil types in pedological investigations. Although there are some investigations of anthropogenic-alluvial soils used for mulberry plantations, orchards, vegetable gardens, and seeding beds for trees, the main object of these investigations is not pedological. Kanno et al. (1) reported that unirrigated anthropogenic-alluvial soils used for vegetable growing in the Chikugo Plain resemble the “Alochthonous brown warp soil” defined by Kubiena (2). First of all, it is of great importance to accumulate general data for unirrigated anthropogenic-alluvial soils and to develop the classification principles for them. Classification problems will be settled in accordance with the accumulated data. This paper deals with characteristics of an unirrigated anthorpogenic-alluvial soil found in the Kumamoto Plain and with classification principles for it. These principles have almost never been described for a pedological standpoint in Japan.     

Allantoin production and its utilization in relation to nodule formation in soybeans

A remarkable accumulation and utilization of allantoin are observed in soybean plant bearing modules (Glycine max variety A62-1). To study ita physiological role, changes in activities and distribution of the enzymes concerning the purine catabolism (i.e., xanthine oxidase, uricase, allantoinase and allantoicase) were measured during development.

Uricase activity was found in the radicles in the early stage of seedling development, and no difference of the enzyme activity was detected between the radicles of the nodulating variety (A62-) and non-nodulating variety (A62-2). On maturation the activity disappeared rapidly in radicles and appeared in leaves, pods and nodules. The activity in nodules was much higher than that in the leaves and the pods throughout the culture period.

Xanthine oxidase activity was found in the radicles and nodules.

Allantoinase activity was present in all regions of both varieties, and the specific activity in the nodules Was 2-10 times that in other regions.

Allantoicase activity was detected in the leaves, but not in the nodules.

The distribution of these enzymes suggested that allantoin is formed in the nodules and utilized mainly in the leaves after translocation.

Changes in the allantoin concentration and in the activities of uricase and allantoicase were studied in non-nodulating soybean (A62-2) grown in a culture solution containing various nitrogenous compounds. The allantoin concentration in the leaves increased as the plants were cultured in the solution containing 100 ppm of nitrate-N, urea-N or allantoin-N, whereas no uricase activity in the root was detected. The specific activity of uricase decreased in the process of plant development in all cultures. Allantoicase activity increased in the roots and leaves when the plants were cultured in this solution containing 100 ppm of urea-N or allantoin-N, indicating that allantoin is utilized easily in the soybean plants.

Intracellular localization of uricase in the nodules was studied by the method of linear sucrose density gradient centrifugation. The uricase activity was associated with the bacteroids, density 1.25.

The uricase activity peak was coincident with the peak of fonnic dehydrogenase activity (bacteria type), and not with peaks of catalase activity, cytochrome oxidase activity and absorbance at 280 nm. This evidence together with the observation by electron microscopy suggested that at uricase is associated with bacteroids.     

Cytological characteristics of microconidia of <Emphasis Type="Italic">Magnaporthe oryzae</Emphasis>

The inner cellular structure of microconidia of Magnaporthe oryzae was examined using fluorescent probes and electron microscopic techniques. The volume of the nucleus relative to the cell was significantly larger in microconidia than in macroconidia or vegetative hyphae, similar to observations for spermatia of other fungi. Selective fluorescent staining revealed that cytosolic RNA was less abundant in microconidia than in macroconidia and germ tubes, suggesting that general metabolic activity in microconidia is low. Consistently, GFP expression driven by the TrpC promoter was highly active during the formation of phialides and microconidia but gradually decreased as the microconidia matured. Such data suggest that microconidia are in a quiescent or dormant state.     

Morphological and molecular characterization of <Emphasis Type="Italic">Oidium</Emphasis> subgenus <Emphasis Type="Italic">Reticuloidium</Emphasis> (powdery mildew) newly occurred on cucumber in Japan

In 2002, a powdery mildew with catenate conidia lacking fibrosin bodies was found on cucumber in a greenhouse in Kanagawa Prefecture, Japan. Morphological observation revealed that the fungus belongs to Oidium subgenus Reticuloidium, anamorph of the genus Golovinomyces. Molecular phylogenetic analyses of the nucleotide sequences of the rDNA ITS regions and D1/D2 domains of the 28S rDNA indicated that the fungus belongs to the clade of G. orontii with other Golovinomyces fungi from a wide range of host plants, suggesting that the fungus was newly transported from abroad. Because there has been no prior report of cucumber powdery mildew caused by Reticuloidium, further research on the physiology, epidemiology, control and resistant cucumber varieties is required.     

杉木采样时间及DNA提取方法的研究

从材料中提取ＤＮＡ时,必须因材而异,杉木材料中含有较多的酚类等粘性物质。对杉木的采样时期及其 ＤＮＡ提取方法进行的研究表明：５月份采取杉木新芽 ３ ｇ,用 ＣＴＡＢ洗净法可以获得浓度和纯度最高的ＤＮＡ。     

Inhibitory effect of 2,4-dibromophenol and 2,4,6-tribromophenol on larval survival and metamorphosis of the sea urchin <Emphasis Type="Italic">Strongylocentrotus nudus</Emphasis>

ABSTRACT:   As a possible factor leading to the low recruitment level of sea urchins in kelp forests, the inhibitory effect of 2,4-dibromophenol (DBP) and 2,4,6-tribromophenol (TBP) released from the large perennial brown algae Ecklonia kurome and Eisenia bicyclis on survival and metamorphosis of eight-armed larvae of the sea urchin Strongylocentrotus nudus was examined. The percentage of larvae that underwent metamorphosis in filtered sea water after 1 h exposure to one-half dilution of saturated dibromomethane solution (∼60 ppm) as a chemical inducer reached approximately 100% after 1 h, while that in filtered sea water containing 1 ppm TBP was reduced to 73%. This was further reduced to less than 40% in the presence of 10 and 20 ppm TBP after 2 h. In filtered sea water containing 1 and 10 ppm DBP, the proportion of metamorphosed larvae was reduced markedly to 43 and 5% after 2 h, respectively. All larvae exposed to 50 ppm TBP and to 20 and 50 ppm DBP died after 1 h. These findings suggest that DBP is more toxic than TBP for sea urchin larvae, strongly inhibiting their metamorphosis.     

Seasonality of serum levels of vitellogenin in male Japanese whiting, Sillago japonica, reared under natural temperature and photoperiod

ABSTRACT:   Because blood vitellogenin (Vg) has been considered a biomarker for environmental estrogens, the basal levels of Vg and 17β-estradiol (E₂) were determined in male Japanese whiting reared under natural conditions. Serum levels of Vg and E₂ were measured and gonadal development was assessed by gonadosomatic index (GSI) and histological observation in 8–10 male fish at monthly intervals throughout the annual reproductive cycle. Serum E₂ was <60 pg/mL throughout the study period. In contrast, serum Vg exhibited seasonal changes: serum levels of Vg gradually increased from April to May (mean 63 ± 13 ng/mL and 124 ± 48 ng/mL in April and May, respectively), and then reached a peak value (mean 352 ± 68 ng/mL) in June. Thereafter, serum Vg gradually decreased, reaching undetectable levels (<50 ng/mL) in October. Serum levels of Vg tended to increase in the male fish in which the GSI was >1%. Histological observation revealed that testes in such male fish were in active spermatogenesis and then all of the testes of male fish in which serum Vg decreased to ND levels were regressed. These results suggest that Vg productive potency (sensitivity to estrogens) may increase in the spermatogenic stage, resulting in production of Vg in response to very low levels of natural or xenobiotic estrogens.     

Inhibitory effect of isoprothiolane on metabolism of a phosphoramidate by isolates of Pyricularia oryzae cav. in relation to fungicide sensitivity

The inhibitory effect of isoprothiolane(diisopropyl 1,3-dithiolan-2-ylidenemalonate), a fungicide for rice blast control, on the metabolism of dibutyl N-methyl-N-phenylphosphoramidate (BPA) by 20 isolates of Pyricularia oryzae was examined in relation to sensitivity of the isolates to the reference fungicide IBP(S-benzyl diisopropylphosphorothiolate). The isolates were divided into five groups based on the modes of BPA metabolism and the inhibition of BPA metabolism by isoprothiolane. Every isolate in groups I and II, which was either a field isolate or a stock culture, decomposed BPA rapidly and produced both hydroxylated and N-demethylated BPA as metabolites. BPA decomposition by these isolates was strongly inhibited by isoprothiolane, resulting in the decreased production of both metabolites in group I and of the hydroxylated metabolite in group II. These isolates were almost equally sensitive to isoprothiolane. Isolates in groups III, IV, and V were all obtained from selection of the fungus mutants found growing on media containing isoprothiolane. Isolates in group III, derived by plating large numbers of conidia, did not decompose BPA to any extent. Mutants of groups IV and V were obtained from fast-growing sectors on agar containing isoprothiolane. Both these groups decomposed BPA, but isolates belonging to group IV produced copious amount of N-demethylated BPA whereas isolates in group V did not. BPA metabolism by these in vitro mutants in groups III, IV, and V was not inhibited by isoprothiolane. Thus, the inhibitory effect of isoprothiolane on BPA metabolism was correlated with sensitivity of an isolate to isoprothiolane. The inhibitory effect of IBP on BPA metabolism was not always correlated with the sensitivity of an isolate to IBP.     

Reducing effect of dietary anacardic acid on body fat pads in rats

We have previously shown that anacardic acid has an uncoupling effect on oxidative phosphorylation in rat liver mitochondria using succinate as a substrate (Toyomizu et al. 2000). In the present study, in order to clarify whether or not anacardic acid could be used advantageously as a special feed/food supplement to reduce fat deposition through the uncoupling action, two sets of experiments were conducted to determine quantitatively the effect of dietary anacardic acid (0.1% w/w) supplementation. More specifically, effects on growth, feed efficiency, fattening, and levels of several constituents of blood serum in rats fed normal and low protein–high carbohydrate (CHO) diets were examined. There were no significant differences in bodyweight gain, feed consumption and feed efficiency among the experimental groups. For the total fat pad content, including inguinal and epididymal fat, significant interaction was shown between both treatments: dietary anacardic acid at 0.1% w/w significantly decreased the total fat pad content in rats fed the CHO diet, but not in rats fed the normal diet. Weights of heart, spleen and brown adipose tissue were not affected by either the dietary treatment or anacardic acid, while both liver and kidney weights decreased with feeding of anacardic acid at 0.1% w/w, but were not affected by the CHO diet. Anacardic acid supplementation in the diet had no effect on serum glutamic oxaloacetic transaminase, alkaline phosphatase or lactate dehydrogenase levels, suggesting that the dysfunction of liver or kidney may not be induced by dietary anacardic acid. The results of the present study reveal a unique function of anacardic acid in that, for dietary conditions enhancing body fat deposition, that is consumption of a diet high in carbohydrates, dietary anacardic acid has the potential to decrease body fat deposition. A possible mechanism for differences observed in anacardic acid‐induced regulation of body fat pad content between rats fed the normal and CHO diets, based on uncoupling action of anacardic acid on the mitochondrial oxidative phosphorylation, is discussed.