Both cyclooxygenase and lipoxygenase inhibitor partially restore the anorexia by interleukin-1 beta.

Since the peripheral prostaglandin synthetizing system may at least partly involved in the anorexia that follows central interleukin-1 beta (IL-1) administration, this study was undertaken to investigate the effect of ibuprofen (ip), selective cyclooxygenase blocker and AA 861, selective lipoxygenase inhibitor, on changes of food and water intake by a single injection of IL-1 (2 micrograms/rat, ip). We demonstrated that food and water intake were suppressed by peripheral administration of IL-1. Throughout the entire observation periods, suppressed food intake was partially restored to control levels by ibuprofen, while water intake completely restored. In addition, no significant differences about water/food intake were observed in the IL-1 + ibuprofen-treated groups, respectively. In the next experiment, IL-1 induced anorexia was also partially restored to the control level following pretreatment with AA 861. These results may suggest that other mechanism including lipoxygenase blocker besides prostaglandin production may be involved in IL-1 induced anorexia.     

A cAMP-dependent protein kinase inhibitor modulates the blocking action of ATP and 5-hydroxydecanoate on the ATP-sensitive K+ channel.

We studied the blocking mechanism of 5-hydroxydecanoate, a novel antiarrhythmic agent, on the ATP-sensitive K+ channel in the single ventricular myocytes using the inside-out patch clamp technique. The channel activity in response to 5-hydroxydecanoate varied with each membrane patch corresponding to the sensitivity to ATP. In this condition the exogenous application of cAMP or cAMP-dependent protein kinase (PKA) obviously recovered the ATP-sensitive K+ channel activity after channel deactivation. By contrast, in membrane patches exhibited low sensitivity to ATP, endogenous cAMP-dependent protein kinase inhibitor (PKI) depressed the channel activity and restored the inhibitory action of 5-hydroxydecanoate and ATP on the channel. These results suggest that PKA-PKI system is involved in the regulatory mechanism of gating activity of the ATP-sensitive K+ channel and the blocking action of 5-hydroxydecanoate and ATP appears to be exerted by potentiating the inhibitory action of PKI on the channel.     

Anticlastogenic effect of flavonoids against mutagen-induced micronuclei in mice.

14 flavonoids, including flavone and flavonol derivatives, were tested for their anticlastogenic effect against induction of micronuclei by benzo[a]pyrene in polychromatic erythrocytes of mice. When each flavonoid was administered orally, together with intraperitoneally administered benzo[a]pyrene, most flavonol derivatives showed an anticlastogenic effect. The data suggest that the 2,3-double bond and 3,5,7-hydroxyl groups in the flavonoid molecules may be essential to produce anticlastogenic effects against benzo[a]pyrene. Galangin, one of the active compounds, and (-)-epicatechin, a weak one, were administered to mice in order to compare their anticlastogenic effect against 3 different kinds of carcinogens: ethyl methanesulfonate, 7,12-dimethylbenz[a]anthracene, and adriamycin. Galangin showed a stronger anticlastogenic effect than (-)-epicatechin against ethyl methanesulfonate and 7,12-dimethylbenz[a]anthracene. However, there was no significant effect against adriamycin-induced micronuclei by both compounds. Our study indicates that most flavonoids are anticlastogenic agents. Their anticlastogenic effects are apparently independent of their own clastogenic activities. Furthermore, their anticlastogenic activities do not apply universally to all types of genotoxic chemicals.     

Appearance of new lipoxygenases in soybean cotyledons after germination and evidence for expression of a major new lipoxygenase gene

The appearance and subsequent disappearance of lipoxygenase activity at pH 6.8 in germinated cotyledons of soybean (Glycine max [L.]) was shown using a variant soybean cultivar (Kanto 101) that lacks the two lipoxygenase isozymes, L-2 and L-3, that are present in dry seeds of a normal soybean cultivar (Enrei). Three new lipoxygenases, designated lipoxygenase L-4, L-5, and L-6, were purified using anionic or cationic ion exchange chromatography. The major lipoxygenase in 5-day-old cotyledons of the variant soybean was lipoxygenase L-4. Lipoxygenases L-5 and L-6 preferentially produced 13(S)-hydroperoxy-9(Z), 11(E)-octadecadienoic acid (13S-HPOD) as a reaction product of linoleic acid, whereas lipoxygenase L-4 produced both 13S-HPOD and 9(S)-hydroperoxy-10(E), 12(Z)-octadecadienoic acid. All three isozymes have pH optima of 6.5, no activity at pH 9.0, and preferred linolenic acid to linoleic acid as a substrate. Partial amino acid sequencing of lipoxygenase L-4 showed that this isozyme shares amino acid sequence homology with lipoxygenases L-1, L-2, and L-3 but is not identical to any of them. This indicates that a new lipoxygenase, L-4, is expressed in cotyledons.     

Two flavonol glycosides from Vancouveria hexandra.

In addition to two known glycosides, ikarisoside F and epimedin A, two new glycosides of a flavonol with a gamma, gamma-dimethylallyl group were isolated from the underground and the aerial parts of Vancouveria hexandra. The structures were determined to be des-O-methylanhydroicaritin 3,7-diglucoside and anhydroicaritin 3-glucosyl (1----3)rhamnoside-7-glucoside by means of spectral analysis.     

Oleanane glycosides from Glycyrrhiza yunnanensis roots.

From the roots of Glycyrrhiza yunnanensis, collected in Yunnan, China, six new oleanane-type triterpene glycosides named yunganosides A1, B1, C1, D1, E2 and F2 were isolated together with hypaphorine. The structures of these glycosides were established by spectroscopic and chemical means.     

Flavonol glycoside production in callus cultures of Epimedium diphyllum.

Callus cultures of Epimedium diphyllum produced a large amount of epimedoside A in addition to a small amount of diphylloside B, ikarisoside C, epimedoside E, diglycosides of des-O-methylanhydroicaritin (8-gamma, gamma-dimethylallylkaempfero). Icariin, epimedins A-C, which are glycosides of anhydroicaritin, were also produced in the callus cultures. Contents of the flavonol glycosides in callus tissue were higher than those of mother plants, but the composition of each flavonol glycoside mixture in the callus cultures was different from that of the original plants. The time-course experiments showed that an inverse relationship existed between cell growth and flavonol glycoside production. Effects of hormonal factors on cell growth and flavonol glycoside production indicated that 2,4-dichlorophenoxyacetic acid was needed for the production of flavonol glycosides.     

L-lactate production from xylose employingLactococcus lactis IO-1

Summary The growth, substrate utilisation and L-lactate production ofLactococcus lactis IO-1 were examined on xylose, and glucose and xylose media. The yield of lactate on xylose was 0.47 g lactate/g xylose at an initial xylose concentration of 51.2 g/l and the _max was 0.72 h^–1. Xylose cultures were more susceptible to lactate inhibition than were glucose cultures but showed similar kinetic behaviour. The organism was capable of complete sugar utilisation when grown on a mixture of 20 g/l xylose and 20 g/l glucose and synthesised 0.66 g lactate/g sugar.