Molecular Analysis of Clerodendrum formicarum Effects in Painful Diabetic Neuropathy in Rat

The pathophysiology of diabetic neuropathic pain is due to primarily metabolic and vascular fac- tors. There is an increase in sorbitol and fructose, glycated end products, reactive oxygen species and activation of protein kinase C in the diabetic state. All these factors lead to direct damage to the nerves. Taking effective clinical management of neuropathic pain is based on a pharmacologi- cal treatment that has shown their limits and many side effects. The hypothesis of central sensiti- zation inhibited by Clerodendrum formicarum, an African pharmacopoeia plant used to treat headaches, arthritis, epilepsy and chronic pain could act on astrocytes and microglial cells. The objective of this work is to study the effect of Clerodendrum formicarum (100, 150 and 200 mg/kg body weight) on astrocytes and microglial cells in a model of diabetic neuropathic pain induced by alloxan monohydrate (150 mg/kg). We noted a suppression of mechanical allodynia and me- chanical hyperalgesia respectively by the Von Frey filaments test and the pressure test on the paw by the Clerodendrum formicarum extracts (ECF) at different doses from 2 h at the first injection of the ECF. After 5 days of treatment, we expressed by Western Blot bands of different proteins and by quantitative RT-PCR, we determined inhibition of the expression of GFAP, CD11b and isoforms 1 and 2 of cyclooxygenase. These results suggest that ECF inhibits the activation of astrocytes, mi- croglial cells and cyclooxygenase signaling pathway.