Peroxidase secretion in rat submandibular glands induced by PGE2: role of cAMP and nitric oxide

Modulatory Effect of an Urera Aurantiaca Extract on Immune and Tumoral Cells During Inflammation

There is a well known link between inflammation and cancer during initiation, propagation and metastasis. Urera aurantiaca (UA) Wedd. (Urticaceae) is a medicinal plant used in traditional medicine to treat inflammatory processes with proven in vivo antiinflammatory and antinociceptive effects. The effects of a methanolic extract (UA) and a purified fraction (PF) on the proliferation of normal and tumoral lymphocytes under the effect of prostaglandin E₂ (PGE₂ ) and on nitric oxide production by lipopolysaccharide-stimulated macrophages was evaluated. Both UA and PF stimulated normal lymphocytes but, in presence of PGE_2, a modulatory effect was observed. The normal lymphocyte proliferation induced by PGE₂ was driven by pathways involving both PKC and H₂ O₂ . In macrophages, UA and PF did not modify cell viability and abrogated the synthesis of nitric oxide induced by lipopolysaccharide. In tumoral lymphocytes, the UA exerted a biphasic effect: at low concentrations it increased cell proliferation, while at high concentrations, it displayed an antiproliferative effect. UA and PF were capable of reverting the proliferative action of PGE₂ . The tumoral cell proliferation induced by PGE₂ is related to PKC, ERK 1/2 and MAP Kinase P38 pathways. The observed effects could be attributed to polyphenols, flavonoids and tannins. This work demonstrates the modulatory effects of the UA on different cell types during inflammatory conditions, which reinforces its antiinflammatory action. Copyright © 2016 John Wiley & Sons, Ltd.

The activity of lysosomal exoglycosidases in serum of alcohol-dependent men supplemented with borage oil enriched with vitamin E

The aim of this study was to determine the activity of the lysosomal exoglycosidases: alpha-mannosidase (MAN), alpha-fucosidase (FUC), and beta-glucuronidase (GLUCUR) in serum of alcohol-dependent men supplemented and not supplemented with borage oil enriched with vitamin E. Serum was collected from eight social drinkers and 16 alcohol-dependent men after a drinking period. The activity of exoglycosidases and the concentration of protein in serum were determined. The increase in specific activity of MAN and GLUCUR was significant in serum of alcohol-dependent men both not supplemented and supplemented with borage oil enriched with vitamin E, in comparison with the specific activity in serum of social drinkers. In serum of alcohol-dependent men treated with borage oil enriched with vitamin E, specific activity of MAN and GLUCUR fluctuated in comparison with alcohol-dependent men not supplemented. Specific activity of FUC in serum of alcohol-dependent men both not supplemented and supplemented with borage oil enriched with vitamin E showed a tendency to increase, in comparison with social drinkers. Specific activity of FUC had a tendency to decrease in serum of alcohol-dependent men supplemented with borage oil enriched with vitamin E, in comparison with alcohol-dependent men not supplemented. Thus, supplementation of alcohol-dependent men after a long-lasting drinking period with borage oil and vitamin E did not change the rate of catabolism of the oligosaccharide chains of glycoconjugates, as evaluated by serum activity of exoglycosidases.

Effect of caffeine on the secretion of peroxidase in rat submandibular gland: a study of its mechanism of action

OBJECTIVE

In this work, we analysed the mechanism of action of caffeine on peroxidase secretion in the female rat submandibular gland. The signaling molecules cAMP and nitric oxide were monitored as potential mediators.

DESIGN

The salivary gland peroxidase secretion of female albino Wistar rats was assessed by a spectroscopic method.

RESULTS

Caffeine was found to exert an increase on peroxidase secretion in a concentration-response manner: the peroxidase secretion stimulation index (SI) (secreted peroxidase from treated/secreted peroxidase from basal) for caffeine 10 microg/ml: 2.2+/-0.18 (P<0.05); caffeine 100 microg/ml alone: 3+/-0.18 (P<0.01); +LNMMA (LN monomethyl arginine): 1+/-0.1 (P<0.05); caffeine 1000 microg/ml alone: 5+/-0.35 (P<0.01); +LNMMA: 2+/-0.2 (P<0.05). These results were associated with an increase in cAMP and total nitrites production. Total nitrites, SI caffeine 100 microg/ml alone: 2.8+/-0.2 (P<0.01); +LNMMA: 1+/-0.08 (P<0.05); caffeine 1000 microg/ml alone: 4.8+/-0.3 (P<0.01); +LNMMA: 2.3+/-0.18 (P<0.05).

CONCLUSION

It could thus be concluded that cAMP and NO are involved in the mechanism of action displayed by caffeine. This is the first report on the mechanism of action of caffeine on peroxidase secretion.

Nitric oxide (NO) increase at fertilization in sea urchin eggs upregulates fertilization envelope hardening

Previous studies indicate that the nitric oxide (NO) increase at fertilization in sea urchin eggs is Ca(2+)-dependent and attributed to the late Ca(2+) rise. However, its role in fertilization still remains unclear. Simultaneous measurements of the activation current, by a single electrode voltage clamp, and NO, using the NO indicator DAF-FM, showed that the NO increase occurred at the time of peak current (t(p)) which corresponds to peak [Ca(2+)](i), suggesting that NO is not related to any other ionic changes besides [Ca(2+)](i). We measured O(2) consumption by a polarographic method to examine whether NO regulated a respiratory burst for protection as reported in other biological systems. Our results suggested NO increased O(2) consumption. The fluorescence of reduced pyridine nucleotides, NAD(P)H was measured in controls and when the NO increase was eliminated by PTIO, a NO scavenger. Surprisingly, PTIO decreased the rate of the fluorescence change and the late phase of increase in NAD(P)H was eliminated. PTIO also suppressed the production of H(2)O(2) and caused weak and high fertilization envelope (FE). Our results suggest that NO increase upregulates NAD(P)H and H(2)O(2) production and consolidates FE hardening by H(2)O(2).