Flunarizine enhances functional recovery following sciatic nerve crush lesion in rats

Ameliorating potential of curcumin and its analogue in central nervous system disorders and related conditions: A review of molecular pathways

Curcumin, isolated from turmeric (Curcuma longa L.) is one of the broadly studied phytomolecule owing to its strong antioxidant and anti-inflammatory potential and has been considered a promising therapeutic candidate in a wide range of disorders. Considering, its low bioavailability, different curcumin analogs have been developed to afford desired pharmacokinetic profile and therapeutic outcome in varied pathological states. Several preclinical and clinical studies have indicated that curcumin ameliorates mitochondrial dysfunction, inflammation, oxidative stress apoptosis-mediated neural cell degeneration and could effectively be utilized in the treatment of different neurodegenerative diseases. Hence, in this review, we have summarized key findings of experimental and clinical studies conducted on curcumin and its analogues with special emphasis on molecular pathways, viz. NF-kB, Nrf2-ARE, glial activation, apoptosis, angiogenesis, SOCS/JAK/STAT, PI3K/Akt, ERK1/2 /MyD88 /p38 MAPK, JNK, iNOS/NO, and MMP pathways involved in imparting ameliorative effects in the therapy of neurodegenerative disorders and associated conditions.

Vasoactive agent buflomedil up-regulated expression of vascular endothelial growth factor in a rat model of sciatic nerve crush injury

Objectives:

To study the effect of Buflomedil on the morphological repair on crush injury of sciatic nerve and also the expression of vascular endothelial growth factor (VEGF).

Materials and Methods:

Rat sciatic nerves were crushed by pincers. All of the 400 Sprague Dawley rats were randomly divided into: Sham-operated; saline; saline + VEGF-antibody; Buflomedil; and Buflomedil + VEGF antibody groups. The expression of VEGF in dorsal root ganglia (DRGs), following crush injury to sciatic nerves, was studied by RT-PCR, immunohistochemistry. The effects of Buflomedil on expression of VEGF and repair of neural pathology were also evaluated.

Results:

VEGF mRNA was significantly increased in Buflomedil and Buflomedil + VEGF-antibody groups, compared with other groups. The number of VEGF-positive neurons was significantly increased in the Buflomedil and the saline groups. Besides, Buflomedil also caused less pathological changes in DRGs.

Conclusions:

The vasoactive agent Buflomedil may decrease the pathological lesion and improve the functional rehabilitation of peripheral nerves, which may correlate to upregulation of the expression of VEGF, following crush injury to the peripheral nerves.

Rosiglitazone ameliorates the histological parameters of the dorsal root ganglion and functional assessment after sciatic nerve injury in the rat

BACKGROUND

This study investigates the effects of rosiglitazone (a peroxisome proliferator-activated receptor-gamma) on the histological parameters of the dorsal root ganglion (DRG) and the recovery potential of the injured sciatic nerve in rats using stereological methods.

METHODS

The rats were divided into four groups including control, sham-operated, sciatic nerve crush (SNC), and SNC + rosiglitazone treatment (5 mg/kg body weight/day). The sciatic functional index (SFI) was used to evaluate functional recovery. The main DRG neurons were defined as either A cells (the larger cell with a central nucleolus in the nucleus and granulated cytoplasm) or B cells (the smaller cell with multiple peripherally located nucleoli and homogenous cytoplasm). Satellite cells (supporting) surround the neuron cell body.

RESULTS

The volume and surface of A and B cells decreased in the SNC group compared to the sham-operated group. In the SNC + rosiglitazone group, the volume of A and B cells decreased to a lesser extent, and was 30% and 48% higher in comparison with the SCN group. In the SNC + rosiglitazone rats the surface of the A and B cells decreased to a minor extent, and was 45% and 21% higher in comparison with the SNC animals. In rosiglitazone-treated rats the number of the A, B, and satellite cells decreased less, and was 38%, 34%, and 29% higher than in the SNC rats. The SFI score improved in SNC + rosiglitazone rats in comparison with non-treated animals.

CONCLUSION

Rosiglitazone has an ameliorative effect on the DRG and enhances the functional recovery after SNC in rats.

FK506 protects neurons following peripheral nerve injury via immunosuppression

In this study, we have evaluated neuroprotective effect of an immunosuppressant immunophilin ligand, FK506, in the sciatic nerve injury model in rats. FK506 was injected to the sciatic nerve transected 3-month-old female Wistar rats (2 mg/kg/day starting 1 day prior to sciatic nerve injury up to 7 day post operation). Equal number of sciatic nerve transected animals served as injured untreated controls. The contralateral side served as respective control. L4-L5 region of the spinal cord was removed on day 1, 3, 7, 14, 21, and 28, post operation and then processed for cryo-sectioning and paraffin sectioning. The cryocut sections were used for immunohistochemistry for localizing all microglia (using anti-Iba-1) and MHC-II expressing microglia (with OX-6). The physical dissector method was applied on Nissl stained paraffin sections for absolute motor neuron counting in the L4-L5 region of spinal cord. FK506 treated animals presented 88.7% neuronal survival while the injured alone had 79.12%, which is significantly less than the treated animals. FK506 caused early proliferation of microglia at 1 and 3 days post operation. FK506 also significantly restricted transformation of these cells in to phagocytes. Colocalization of activated microglia by anti-Iba-1 and OX-6 antibodies, confirms that the MHC-II expressing cells in injured spinal cord are none other than microglial cells and MHC-II expressing cells are significantly less in treated as compared to untreated injured animals. We propose that immunosuppression is one of the main mechanisms by which FK506 protects the central neurons following peripheral injury.