[Antagonism mechanism of gingerols against inflammatory effect of toxic raphides from Pinella pedatisecta].

This study was to investigate the mechanism of gingerols antagonizing the inflammatory effect of toxic raphides from Pinella pedatisecta. Mice peritonitis models induced by toxic raphides from P. pedatisecta were applied to observe the effect of gingerols on inflammatory mediators PGE2 in the exudates of abdominal inflammation in mice; rats peritoneal macrophage in vitro culture models were adopted to study the anti-inflammatory effects of gingerol against toxic raphides, with TNF-α and IL-1ß in supernatant as indexes. Scanning electron microscopy was used to observe the changes in surface morphology of macrophages treated by raphides and gingerols. Macrophages-neutrophils co-cultured models were used to study the antagonism of gingerols against the effect of toxic raphides' stimulation on neutrophils migration. Results showed that gingerols could significantly inhibit the production of PGE2 in the exudates of abdominal inflammation induced by toxic raphides from P. pedatisecta in mice. Gingerols could significantly inhibit the toxic raphides from P. pedatisecta to induce the release of inflammatory factors, with certain dose dependence. Scanning electron microscopy showed that gingerols could significantly inhibit phagocytosis of macrophages, cytomembrane injury, and neutrophils migration induced by toxic raphides from P. pedatisecta. The results showed that the antagonism mechanism of gingerols against the toxic raphides from P. pedatisecta may be associated with inhibiting the pro-inflammatory toxicity including macrophage activation, inflammatory factors release, and neutrophils migration.

Involvement of calcineurin in the signal transduction of PBAN in the silkworm, Bombyx mori (Lepidoptera).

In several moth species sex pheromone production in the pheromone gland is regulated by a neurohormone, pheromone biosynthesis activating neuropeptide (PBAN). In Bombyx mori it is suggested that PBAN, after binding to the cell-surface receptor, primarily activates a plasma membrane receptor-activated Ca2+ channel to increase cytosolic levels of Ca2+, and Ca2+/calmodulin complex directly or indirectly activates a phosphoprotein phosphatase, which in turn elicits activation of acyl CoA reductase (the key enzyme under PBAN control) through dephosphorylation, resulting in pheromone (bombykol) production. The effect of cyclosporin A (CsA) and FK 506, specific inhibitors of calcineurin (phosphoprotein phosphatase 2B) was studied on the sex pheromone production, in B. mori. The in vitro experiments showed that both chemicals exerted a dose-dependent inhibitory action when they were co-incubated with TKYFSPRL amide (Hez-PBAN fragment peptide). Practically, no difference was detected between the two chemicals in the tested doses (0.025-1250 microM). When effects of CsA or FK 506 were studied on cell-free production of bombykol by using microsomal fraction no inhibition was detected. Since microsomal fraction contains the acyl CoA synthetase, the rate-limiting acyl CoA reductase and the precursor, bombykol is produced if supplied with CoA, ATP and NADPH. Thus, the inhibitory action of CsA and FK506 under in vitro conditions should occur before the step of acyl group reduction and the effect is likely to be attributable to the inhibition of calcineurin in the signal transduction cascade mechanism of PBAN, in B. mori. The existence of calcineurin in the pheromone gland by using Western blot analysis is also demonstrated.

[Mechanism of cis-8-dodecenyl acetate suppression of male Laspeyresia pomonella codling moth responses to the sex attractant trans-8,10-dodecadienol]. / O mekhanizme podavleniia tsis-8-dodetsenilatsetatom reaktsii na polovoi attraktant trans-8,10-dodekadienol u samtsov iablonnoi plodozhorki Laspeyresia pomonella.

In field experiments, studies have been made on sex attractiopn of males in the moth L. pomonella. Cis-8-dodecenyl acetate (DDA) was confirmed to be a potent inhibitor of male attraction to the traps baited with virgin females or to a synthetic sex attractant (sex pheromone) trans-8,10-dodecadienol (DDD). DDA also slightly reduced the mating activity under laboratory conditions. The inhibitory effect of DDA on male sex attraction was studied by means of electroantennogram technique. Male antennae were stimulated by DDD and DDA either separately or in combination, DDA vapours being superimposed on the constant DDD background. DDD evoked always negative (excitatory) EAGs, but DDA elicited complex EAGs including both negative and positive (excitatory) EAGs, but DDA elicited complex EAGs including both negative and positive waves. Experiments with double stimulation showed that DDD and DDA produce excitation in different groups of the olfactory receptor cells. Besides, DDA was found to inhibit the EAG evoked by DDD. This inhibition is presumably due to hyperpolarization of the DDD-sensitive cells. Both physiological effects may be involved into inhibition of behavioural reactions in males. The inhibitory mechanism based on competition between DDA and DDD molecules for common receptor sites, seems to be lessprobable.

Cardiotonic action of [8]-gingerol, an activator of the Ca++-pumping adenosine triphosphatase of sarcoplasmic reticulum, in guinea pig atrial muscle.

[8]-Gingerol (gingerol), a component of ginger, produced a concentration-dependent positive inotropic effect on guinea pig isolated left atria at concentrations of 1 X 10(-6) to 3 X 10(-5) M. Gingerol also exhibited positive inotropic and chronotropic effects on guinea pig right atria. The gingerol-induced inotropic effect was abolished by ryanodine, but was little affected by propranolol, chlorpheniramine, cimetidine, tetrodotoxin, diltiazem or reserpine. The time to peak tension and relaxation time within a single contraction were shortened by gingerol (1 X 10(-5) M) as well as isoproterenol, whereas they were prolonged by BAY K 8644. In guinea pig isolated atrial cells, gingerol (3 X 10(-6) M) caused an increase in the degree and the rate of longitudinal contractions. In guinea pig left atria, gingerol (1 X 10(-6) to 3 X 10(-5) M) gave little influence on the action potential, although it increased the contractile force of the atria. The whole-cell patch-clamp experiments showed that the slow inward current was little affected by gingerol (1 X 10(-6) to 3 X 10(-5) M) in voltage-clamped guinea pig cardiac myocytes. The measurement of extravesicular Ca++ concentration using a Ca++ electrode indicated that gingerol (3 X 10(-6) to 3 X 10(-5) M) accelerated the Ca++ uptake of fragmented sarcoplasmic reticulum (SR) prepared from canine cardiac muscle in a concentration-dependent manner.(ABSTRACT TRUNCATED AT 250 WORDS)