Simple detection method of powerful antiradical compounds in the raw extract of plants and its application for the identification of antiradical plant constituents

A simple detection method for a powerful radical scavenging compound in a mixture containing a large variety of compounds, such as the raw extract of edible plants, was developed using 1,1-diphenyl-2-picrylhydrazyl (DPPH) as the radical reagent. The method was established on the basis of the features of the typical chain-breaking antioxidation reaction mechanism, which suggests that the radical scavenging antioxidant should be converted to other stable nonradical compounds during the reaction. This method requires only a simple HPLC instrument, and the disappearance or decrease in the peak intensity, which is induced by the addition of DPPH. This change is monitored by the HPLC to detect the powerful radical scavenger from the complex mixture. The method was applied to the detection and identification of the most powerful antiradical compound in the extracts of three antioxidatively active plant extracts (Psidium guajava, Citrus depressa, and Hypericum chinense). The radical scavenging efficiency of a newly identified compound from H. chinense was also compared with that of Trolox and catechin using the method.     

In vitro effects of insulin on glucose and lipid metabolism in rat embryos

Glucose is utilized for oxidation and synthesis of various lipids in cultured rat embryos. The present experiment examined the effect of insulin on the incorporation of glucose into lipid fractions in rat embryos in vitro . Embryos at the 2-cell, 8-cell and blastocyst stages were incubated for 5 h in hamster embryo culture medium (HECM)-1 containing ¹⁴C-glucose and 170 nmol/L insulin, or in HECM-1 containing only ¹⁴C-glucose, and the oxidation of glucose in these embryos was examined. In addition, the total lipids of blastocysts were separated by thin layer chromatography and the radioactivity of the separated lipid fractions was measured. Oxidation of glucose was significantly increased after insulin treatment compared with that without insulin treatment in 8-cell embryos and blastocysts ( P  < 0.05), but not in 2-cell embryos. Incorporation of glucose into lipids in blastocysts was significantly lowered by insulin treatment compared with that without insulin treatment ( P  < 0.05). Most of the radioactivity was recovered from triacylglycerols of blastocysts and the remaining radioactivity was found in other neutral lipids and phospholipids. We conclude that insulin accelerates the utilization for oxidation of glucose and inhibits the storage of triacylglycerols in rat blastocysts.     

Changes in Plasma Progesterone Levels in the Caudal Vena Cava and the Jugular Vein and Luteinizing Hormone Secretion Pattern After Feeding in Lactating and Non-lactating Dairy Cows

The present study was designed to assess progesterone profiles at the secreted (caudal vena cava) and circulating levels (jugular vein) and luteinizing hormone (LH) secretion pattern in lactating and non-lactating cows with reference to feeding. Four lactating and four non-lactating cycling Holstein cows were examined. Blood samples were collected simultaneously from the caudal vena cava (via a catheter inserted from the coccygeal vein) and the jugular vein every 15 min for 12 h (0500–1700 h) during the functional luteal phase. Cows were fed 50% of the daily diet 6 h after the start of blood sampling. During the 12-h sampling period, mean progesterone concentrations in the caudal vena cava did not differ between lactating and non-lactating cows (49.0 ± 2.9 and 53.3 ± 3.7 ng/ml; mean ± SE), whereas mean progesterone concentrations in the jugular vein in lactating cows were higher than those in non-lactating cows (6.4 ± 0.1 and 5.6 ± 0.1 ng/ml, P < 0.001). Lactating cows had a higher frequency of LH pulses than non-lactating cows (7.0 ± 0.7 and 4.3 ± 0.9 pulses/12 h, P<0.05). The influence of feeding was not observed on LH profiles but was observed on progesterone profiles in both veins. Progesterone concentrations in the caudal vena cava increased after feeding in both groups. Progesterone concentrations in the jugular vein decreased after feeding in lactating cows but not in non-lactating cows. These results indicate the difference in feeding-related changes in progesterone dynamics between lactating and non-lactating cows.     

Molecular cloning, nucleotide sequence and characteristics of a xylanase gene (xynA) from Ruminococcus albus 7

A 2.6-kb DNA fragment encoding a xylanase gene ( xyn A) was cloned from the rumen hemicellulolytic bacterium Ruminococcus albus 7. The deduced primary structure of the protein (XynA) was divided into a signal peptide region and 3 domains. Domain A was identified as a family 11 (G) catalytic domain, but one amino acid residue was replaced by another in an active site signature 1 of family 11. Domain B is a stabilizing domain for the catalytic domains of families 10 and 11. Deletion of domain B reduced stability of the xylanase at high temperature and at high and low pH. Domain B may be useful for protein engineering of xylanase. Domain C has sequence similarity to deacetylases and NodB proteins.     

Effects of brief exposure of male pheromone on multiple-unit activity at close proximity to kisspeptin neurons in the goat arcuate nucleus

Exposure of females to the male pheromone induces pulsatile release of gonadotropin-releasing hormone (GnRH) in goats. Recently, kisspeptin neurons in the arcuate nucleus (ARC) have been suggested to represent the proximate source of the GnRH pulse generator. In this study, we examined the effects of the pheromone on multiple-unit activity (MUA) in female goats fitted with recording electrodes aimed at the ARC kisspeptin neurons. In all eight goats, periodic bursts in MUA (MUA volleys), which were considered to be electrophysiological manifestations of the GnRH pulse generator, were observed. The mean intervolley interval (T) during the control period was calculated in each goat that was then exposed to the male pheromone for 1 sec at timings of 1/4 T, 1/2 T or 3/4 T after one regularly occurring MUA volley. An instantaneous rise in MUA was observed immediately after the exposure regardless of timing. Exposure at a timing of 3/4 T resulted in an MUA volley within 60 sec following the instantaneous rise in all goats. In contrast, an MUA volley was induced in only 2 goats by exposure at 1/2 T, while exposure at 1/4 T failed to induce an MUA volley in any goats. These results suggest that transmission of the pheromone signal to the ARC, represented by an instantaneous rise, activates the GnRH pulse generator. Moreover, the timing-dependent pheromone action in inducing an MUA volley indicates that the GnRH pulse generator has a refractory period for the pheromone signal after the burst.     

Urinary free metanephrines measurement in dogs with adrenal gland diseases using a new simple liquid chromatography tandem mass spectrometry method

Measurement of urinary metanephrines in spot samples is used for the diagnosis of canine pheochromocytoma (PC). We describe a simple analytical method based on liquid chromatography tandem mass spectrometry (LC-MS/MS) for measuring free metanephrine (MN) and normetanephrine (NMN) in spot urine samples. Using the developed method, we evaluated the stability of urinary free-MN and free-NMN at various storing conditions. In addition, we assessed the feasibility of urinary free-MN and -NMN measurement for diagnosing PC. Urine samples were mixed with stable isotope internal standards and thereafter purified by ultrafiltration. The purified samples were analyzed by LC-MS/MS in the multiple reaction monitoring mode after separation on a multimode octa decyl silyl column. The coefficient of variation of free-MN and -NMN measurement was 7.6% and 5.5%, respectively. The linearity range was 0.5–10 µg/l for both analytes. Degradation was less than 10% for both analytes under any of the storage conditions. The median free-NMN ratio to creatinine of 9 PC dogs (595, range 144–47,961) was significantly higher (P<0.05) than that of 13 dogs with hypercortisolism (125, range 52–224) or 15 healthy dogs (85, range 50–117). The developed method is simple and may not require acidification of spot urine. The results of this preliminary retrospective study suggest that the measurement of urinary free metanephrines is a promising tool for diagnosing canine PC.     

Gelation of low salt soluble proteins from scallop adductor muscle in relation to its freshness

ABSTRACT: The low salt extract from scallop striated adductor muscle contained extra proteins in addition to sarcoplasmic proteins and was turned into a gel upon standing or immediately by the addition of Ca²⁺. The amount of extra protein, which was composed of a large amount of actin and a small amount of myosin, decreased with a decrease in adenosine triphosphate (ATP) content in the muscle during storage at 5°C. Actin was easily extracted from scallop myofibrils in low salt solution with ATP at 1 mM or above. Furthermore, ATP was required to induce the gelation of the low salt extract. A visual observation of the gelation of low salt extract is therefore a simple and easy method to inspect prerigor state of scallop adductor muscle.     

Recovery mechanism of the antioxidant activity from carnosic acid quinone,an oxidized sage and rosemary antioxidant

A solution of carnosic acid quinone, which is a radical chain-termination product having no antioxidant activity in the antioxidant reaction of carnosic acid, recovers potent antioxidant activity upon standing. The HPLC analysis of an aged solution of carnosic acid quinone revealed that several antioxidants are produced in the solution. From the time-course and quantitative analyses of the formation of the products and their structural analysis, an antioxidant mechanism from carnosic acid quinone is proposed that includes a redox reaction of carnosic acid quinone in addition to the isomerization to lactone derivatives. In the first stage of antioxidation, carnosic acid, the reduction product from carnosic acid quinone, contributes to the potent antioxidant activity of the solution. This proposed mechanism can explain one of the reasons for the strong antioxidant activity of the extract of the popular herbs sage and rosemary.     

Changes in the ovary and the peripheral concentrations of sex hormones after the aspiration of follicular fluid from the spontaneous follicular cysts of dairy cows

The aim of the present study was to clarify the ovarian and hormonal dynamics after the aspiration of follicular fluid in cows with follicular cysts. Follicular fluid was aspirated from the follicular cysts and follicles that were fated to become cystic follicles and other coexisting normal follicles, respectively, in lactating cows (n = 3). After the aspiration procedure, new follicles developed and reached a diameter of 25 mm without ovulation within 13–19 days. The plasma concentrations of inhibin decreased and follicle-stimulating hormone increased rapidly after the aspiration procedure, and subsequently increased and decreased, respectively, as a new follicle grew. No luteal structures developed after the aspiration procedure, and the animals’ plasma progesterone levels remained low. The present study indicates that the cystic follicles are never luteinized by the aspiration of follicular fluid, and consequently, new follicular cysts are observed to repeatedly develop.     

Phenotypic variation in root development of 162 soybean accessions under hypoxia condition at the seedling stage

Soybean is often damaged by hypoxia caused by waterlogging at the seedling stage. Hypoxia severely inhibits root development and retards plant growth. We aimed to clarify phenotypic variation in root development under hypoxia condition at the seedling stage using diverse soybean accessions. Root development in 162 accessions was evaluated in hydroponic culture. Substantial changes under hypoxia were investigated by means of WinRHIZO analysis before and after the treatment. We found significant phenotypic variation in hypoxia tolerance in root among the 162 accessions. A principal components analysis indicated an association between hypoxia tolerance and the country of origin. We found three new accessions which have a high ability to develop roots under hypoxia (Kokubu 7, Maetsue zairai 90B, and Yahagi). Root development in selected accessions was also evaluated in soil culture. Root development levels in hydroponic and soil culture were significantly correlated. These results will provide important information on waterlogging damage in regions where waterlogging occurs. The three accessions with hypoxia-tolerant roots might be useful for genetic improvement of waterlogging tolerance of modern soybean varieties.