Objective: To explore the effects of different concentration of catalpol on the cell survival and axonal growth of cortical neurons cultured in vitro from 24 h newly born rat.
Method: Primary cultured cortical neurons from 24 h newly born rat were dissociated and cultured. The different concentration of catalpol and 1 mg mL(-1) citicoline were added to the culture plates for 48 h, and the final of catalpol concentration were 0.25, 0.5, 1, 2.5, 5 mg mL(-1), respectively. The cortical neuron was identified by NF-200 antigen and its survival activity detected by MTT assay. The axonal growth of cultured cortical neuron were observed by inverted microscopy with micrometer.
Result: Immunocytochemistry demonstrated more than 95% of the primary cultured cortical neurons were positive for NF-200 antigen, which indicated the cultured cells were neurons. Neurons survived growing on the concentration of 0.25, 0.5, 1, 2.5, 5 mg mL(-1). Compared with blank and 1 mg mL(-1) citicoline group,neurons survival rates were not statistical significant difference. However, it demonstrated that catalpol significantly promoted axonal growth from 1-5 mg mL(-1) (P <0.05). Interestedly, compared with the dose of 2.5 mg mL(-1), axonal growth was shorter at the dose of 5 mg mL(-1), and 2.5 mg mL(-1) catalpol showed the strongest promotion effect.
Conclusion: The catalpol can enhance cortical neuron axonal growth, but not promote cortical neuron survival.