Background: Peripheral nervous system damages reverse as retrograde to alpha neuron cell bodies and cause spinal degeneration. The fact that herbs, due to their antioxidant properties, have an important role in viability and reproduction of neurons has led to the application of their extracts. Hence, this study was done to determine the neuro-protective effects of the hydroalcoholic extract of Nigella sativa on alpha-motoneurons degeneration after sciatic nerve injury in rats.

Materials and Methods: In this experimental study, 24 male Wistar rats with average bodyweight of 250-300gr were divided into four groups of six: Control, compression, A (compression+hydroalcoholic extract 50 mg/kg), and B (compression+hydroalcoholic extract 75 mg/kg). In compression and treatment groups, the right leg sciatic nerve was subjected to compression (30 seconds). In treatment groups, the extract was injected intraperitoneally two times after compression. After 28 days, lumbar segments of spinal cord, L2-L4, were sampled through perfusion method. After going through tissue passage stages, they were cut in serial sections (7µ) and stained with toluidine blue. Then the density of alpha motoneurons of the spinal cord ventral horn was measured by dissector method.

Results: Neuronal density showed a significant difference between the compression and control groups (p<0.05). Also, in treatment groups A and B, it had a significant increase compared to the compression group (p<0.05).

Conclusion: The results indicated that the hydroalcoholic extract of Nigella sativa has neuro-protective effects and the increase in neuronal density is relevant to the amount of extract used.

Abstract

Background: Retrograde transport to the alpha motoneurons causes spinal degeneration. The neurotrophic factor (NT3) increases the number of myelinated axons in the dorsal root, leads to differentiation and survival of sensory neurons, parasympathetic motoneurons and prevents cell death. Lavender is a plant in the family Lamiaceae which is reported to have antioxidant, antispasmodic, diuretic, anti-asthmatic, refrigerant, and antipyretic effects. This study examined NT3 gene expression changes after sciatic nerve compression in rats, in the presence of Lavandula officinalis extract. 

Materials and Methods: Lavender Soxhlet hydroalcoholic extraction was prepared. 36 male Wistar rats were randomly divided into 3 groups including control, compression and treatment (compression group + hydroalcoholic extract of Lavender injections 75mg/kg) groups. In controls the muscle was opened without damage to gain access to the sciatic nerve. In compression and treatment groups, the sciatic nerve (right leg) was compressed. The extract was injected intraperitoneally in two occasions. A biopsy was taken from the spinal cord segments L4-L6 on day 28, total RNA was extracted and cDNA was synthesized and NT3 gene expression changes were analyzed by ANOVA test by using SPSS software. 

Results: The results showed that NT3 gene expression had a significant reduction in compression group compared to the control group (p<0.001) and it had a significant increase in treatment group compared with the compression group (p<0.001).

Conclusion: A significant increase in gene expression shows that Lavandula officinalis hydroalcoholic extract improves nerve regeneration via NT3 gene expression.