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Metformin, the first medication that is often prescribed for the treatment of type 2 diabetes mellitus, was recently found to be neuroprotective. To study the mechanism underlying the neuroprotective effect of metformin, we pretreated primary spinal cord neurons with 50 [micro]M or 100 [micro]M metformin for 2 h prior to treatment with hydrogen peroxide ([H.sub.2][O.sub.2]) for up to 48 h. Our results showed that [H.sub.2][O.sub.2] increased the expression of purinergic receptor P2X7 (P2X7R) in spinal cord neurons, which promoted the downstream pro-inflammatory cytokines release and oxidative stress. We found that metformin could reverse these pro-inflammatory and pro-oxidative effects of [H.sub.2][O.sub.2]. Besides, P2X7R knockdown by siRNA suppressed [H.sub.2][O.sub.2]-induced pro-inflammatory cytokine release and oxidative stress response. In conclusion, our results show that metformin can alleviate [H.sub.2][O.sub.2]-induced inflammation and oxidative stress via modulating the P2X7R signaling pathway. Key words: metformin, inflammation, oxidative stress, spinal cord neurons. Recemment, on a montre que la metformine, le medicament contre le diabete sucre de type 2 souvent prescrit en premier, a des effets neuroprotecteurs. En vue d'etudier le mode d'action sous-jacent des effets neuroprotecteurs de la metformine, nous avons mis des neurones de moelle epiniere primaires en presence de peroxyde d'hydrogene ([H.sub.2][O.sub.2]) pendant jusqu'a 48 heures apres les avoir exposes a de la metformine a 50 ou a 100 [micro]M pendant 2 heures. Nos resultats ont montre que le [H.sub.2][O.sub.2] entrainait une augmentation de l'expression du recepteur purinergique de P2X7 (P2X7R) dans les neurones de moelle epiniere, ce qui favorisait la liberation de cytokines proinflammatoires en aval et le stress oxydatif. Nous avons observe que la metformine pouvait inverser ces effets proinflammatoires et pro-oxydatifs du [H.sub.2][O.sub.2]. Par ailleurs, la repression (<< knockdown >>) des P2X7R par siRNA permettait d'inhiber completement la liberation de cytokines proinflammatoires et la reaction de stress oxydatif engendrees par le [H.sub.2][O.sub.2]. En conclusion, nos resultats montrent que la metformine peut attenuer l'inflammation et le stress oxydatif engendres par le [H.sub.2][O.sub.2] par l'intermediaire de la modulation de la voie de signalisation des P2X7R. [Traduit par la Redaction] Mots-cles: metformine, inflammation, stress oxydatif, neurones de moelle epiniere., Introduction Spinal cord injury (SCI) is one of the devastating injuries that are commonly caused by trauma or conditions such as infection and tumor. The World Health Organization (WHO) estimates [...]

Various types of complications arising from intravenous indwelling needles have become a challenge in clinical care. It is urgent to seek a simple and cost-effective method for prevention and treatment of phlebitis. We investigated the roles of mirabilite in preventing and treating phlebitis caused by intravenous indwelling needles and provide guidance for prevention and treatment of mechanical phlebitis caused by intravenous indwelling needles. A total of 57 healthy congeneric big-eared New Zealand rabbits were randomly divided into 3 groups: blank control, indwelling needle, and group with external application of mirabilite. The ear vein of each rabbit was punctured with an intravenous indwelling needle. The ear vein specimens were taken at 3, 5, and 7 days after indwelling. The hematoxylin and eosin stained pathological tissue sections of the ear veins of the rabbits in each group were observed. The expression levels of IL-1 and IL-6, and tumour necrosis factor-α (TNF-α) in the vascular tissue of the ear veins of the rabbits in each group were detected with the immunofluorescence method. In the blank control group, there was no inflammatory cellular infiltration and no proliferation of fibrous tissue around the vascular wall. With the increase of the indwelling time, proliferation of fibrous tissue in vascular wall, increased inflammatory cellular infiltration and organized thrombus in the vascular tissue occurred in the ear veins of the rabbits in the indwelling needle group and group with external application of mirabilite. Compared with the indwelling needle group, the group with external application of mirabilite had significantly decreased fibrous tissue in the vascular wall and significantly decreased inflammatory cellular infiltration. At the same point in indwelling time, the expression levels of IL-1, IL-6, and TNF-α in the indwelling needle and group with external application of mirabilite were significantly higher than that in the blank control group (P<0.05). The expression levels of IL-1, IL-6, and TNF-α in the group with external application of mirabilite were lower than that in the indwelling needle group (P<0.05). The expression levels of IL-1, IL-6, and TNF-α are positively correlated with the indwelling time within the same group at different points in time. In conclusion, external application of mirabilite can significantly decrease infiltration of venous inflammatory cells of the rabbit ear margin, proliferation of fibrous tissue and thrombosis in the vascular wall, significant decrease the expression levels of IL-1, IL-6, and TNF-α in the mechanical phlebitis caused by intravenous indwelling needles, and decrease the inflammatory responses of the ear veins of rabbits. [ABSTRACT FROM AUTHOR]