Systemic and Local Peripheral Injections of Vitamin B12 Suppressed Orofacial Nociception Induced by Formalin in Rats

Abstract

Vitamin B12 has many biological functions including antinociceptive property. This study was designed to investigate the effects of local peripheral (into upper lip) and systemic injection of vitamin B12 and diclofenac on the orofacial pain. Orofacial pain was induced by subcutaneous injection 50 µL of a diluted formalin solution (1.5%) in the right upper lip. The time spent face rubbing performed with ipsilateral forepaw was measured in 3 min blocks for a period of 45 min. Formalin produced a biphasic pattern (early phase: 0-3 min and second phase: 15-33 min) of pain response. Systemic (1, 2 and 4 mg/kg) and local peripheral (2.5, 5 and 10 µg/rat) injections of vitamin B12 significantly attenuated the second phase of formalin-induced pain. The same results were obtained from systemic (2 and 4 mg/kg) and local peripheral (100 and 200 µg/rat) injections of diclofenac. Systemic co-administrations of vitamin B12 and diclofenac increased vitamin B12-induced antinociception. Local co-administrations of vitamin B12 and diclofenac enhanced antinociception induced by diclofenac. The obtained results indicated that vitamin B12 and diclofenac produced powerful suppressing effects on orofacial inflammatory pain. Co-treatments with vitamin B12 and diclofenac produced more antinociceptive effects. Inhibition of cyclooxygenase (COX) pathway may be involved in antinociception induced by vitamin B12.

Effect of Vitamin B12 on Functional Recovery and Histopathologic Changes of Tibial Nerve-Crushed Rats

“…Considering these facts that vitamin B 12 defi ciency can lead to COX-2 expression [ 13 ] , diclofenac is an inhibitor of COX-1 and COX-2 pathways [ 38 ] , and celecoxib is a selective COX-2 inhibitor [ 45 , 46 ] , it seems that nerve regeneration promoting eff ect induced by co-administration of vitamin B 12 , diclofenac and celecoxib observed in the present study might be associated to inhibitory eff ects of them on COX pathways. However, the Wallerian degeneration reducing eff ects of vitamin B 12 , diclofenac and celecoxib observed in the present study may confi rm proposed mechanisms of action of vitamin B 12 [ 12 ] , NSDAIDs and COXIBs [ 5 , 43 ] on peripheral nerve degeneration and regeneration processes. In conclusion, the results of the present study showed that tibial nerve crush injury produced Wallerian degeneration and subsequent impairment of motor function of hind legs.…”

Dietary vitamin B12 regulates chemosensory receptor gene expression via the MEF2 transcription factor in Caenorhabditis elegans

“…Since chemoreceptor genes expressed in a specific chemosensory neuron type are generally linked to a common chemical response determined by the identity of the neuron in C. elegans , with a few exceptions in which neurons switch their preference towards odors (Tsunozaki et al 2008), it is probable that the srh-234 chemoreceptor may detect aversive chemical stimuli perceived by ADL. Interestingly, vitamin B12 in mammals has anti-nociceptive properties (Erfanparast et al 2014), and the activity of certain olfactory receptors in tissues other than neurons can respond to propionate (Pluznick et al 2013), which is a metabolic byproduct produced by gut bacteria in mammals (Morrison and Preston 2016). It is therefore tempting to speculate that vitamin B12 obtained through ingestion alters ADL-mediated nociceptive responses by changing the expression of individual chemoreceptor genes such as srh-234 .…”

The Neuro-protective Role of Vitamin B12 in Diazinon Poisoned Male Wistar Rats: Histopathological and Biochemical Evaluation

“…The current study was performed on 24 adult male Wistar rats weighing 200-250 grams at animals laboratory house of veterinary medicine college at University of Basrah, the animals were divided to 4 equal groups: group I was served as normal control; the group II was orally given 1/10 LD 50 (3.8mg/ kg.bw) of diazinon daily for 30 days according to Ahmed and Alwan [5]. ; the group III was orally given 1/10 LD 50 (3.8mg/kg.bw) of diazinon, and a systemic (I.M route) of (4 mg/kg) injections of vitamin B 12 daily for 30 days according to [11]; the group IV was administered only a systemic (I.M route) of (4 mg/kg) injections of vitamin B 12 daily for 30 days.…”