Vasculitic peripheral neuropathy induced by ischemia-reperfusion in the rat femoral artery involves activation of proinflammatory signaling pathway in the sciatic nerve

The Effect of Lutein on Ischemia-reperfusion-induced Vasculitic Neuropathic Pain and Neuropathy in Rats

BACKGROUND/AIM

Neuropathic pain and neuropathy is commonly seen after ischemia-reperfusion injuries. Our aim was to evaluate the effect of lutein on ischemia-reperfusion (I/R)-induced vasculitic neuropathic pain and neuropathy in rats.

MATERIALS AND METHODS

An hour before anesthesia, 6 Albino Wistar male rats with I/R were orally administered with 1 mg/kg lutein (LIR group). Two groups of 6 such rats who underwent surgery were provided with 0.5 ml distilled water (as solvent) either via oral administration (SIR group) or by gavage (sham group or SG). One hour following the administration, the later femoral arteries of the LIR and SIR rats were closed using a sterile silk thread and ischemia was induced in the sciatic nerve for 4 h, followed by reperfusion for 24 h. The femoral artery of the SG group was not closed with suture. Next, 1 mg/kg lutein was re-administered only to the LIR group for 1 h, followed by measurement of the paw pain thresholds by the Basile Algesimeter. The levels of malondialdehyde (MDA), total glutathione (tGSH), nuclear factor-kB (NF-κB), and tumor necrosis factor-alpha (TNF-α) in the sciatic nerve tissues were measured, and the tissues were histopathologically examined.

RESULTS

We found that the MDA, NF-κB, and TNF-α levels were higher and the tGSH level was lower in the SIR group relative to those in the LIR group, and the differences were statistically significant. Significant histopathological damage was noted in the SIR group, whereas the LIR group demonstrated protection from oxidative damage.

CONCLUSION

Lutein is potentially useful in the treatment of I/R-related neuropathy and neuropathic pain.

Resveratrol alleviates nuclear factor-κB-mediated neuroinflammation in vasculitic peripheral neuropathy induced by ischaemia-reperfusion via suppressing endoplasmic reticulum stress

Vasculitic peripheral neuropathy (VPN) arises from an inflammatory obstruction in the blood vessels supplying peripheral nerves and subsequent ischaemic insults, which exhibits the clinical features of neuropathic pain and impaired peripheral nerve function. VPN induced by ischaemia-reperfusion (IR) has been reported to involve nuclear factor-κB (NF-κB)-mediated neuroinflammation. Recent studies have suggested that endoplasmic reticulum (ER) stress has been implicated in the development of peripheral neuropathies. Resveratrol possesses a potent anti-inflammatory capacity. We hypothesized that resveratrol may exert a protective effect against VPN through modulating the interrelated ER stress and NF-κB pathways. Male Sprague-Dawley rats were allocated into five groups: sham, sham + resveratrol 40 mg/kg (R40), IR, IR + R20 and IR + R40. VPN was induced by occluding the right femoral artery for 4 hours followed by reperfusion. Our data have shown that VPN induced by IR led to hind paw mechanical allodynia, heat hyperalgaesia, and impaired motor nerve conduction velocity (MNCV). With resveratrol intervention, the behavioural parameters were improved in a dose-dependent manner and the MNCV levels were increased as well. The molecular data revealed that VPN induced by IR significantly increased the expression of NF-κB as well as the ER stress sensor proteins, protein kinase RNA-like endoplasmic reticulum kinase, inositol-requiring enzyme 1 and activating transcription factor 6 in the sciatic nerves. More importantly, resveratrol significantly attenuated the expression of NF-κB and the ER stress sensor proteins after IR. In conclusion, resveratrol alleviates VPN induced by IR. The mechanisms may involve modulating NF-κB-mediated neuroinflammation via suppressing ER stress.