چکیده (انگلیسی):

Objective: To investigate whether Hainan papayas has protective effects in an Ab40-
induced primary neuron injury model and elucidate the underlying molecular mechanism.
Methods: Cultured primary neurons from the dorsal root ganglia (DRG) of Sprague–
Dawley (SD) rats were treated with 20 mMAb40 peptide, 100 mg/L Hainan papaya water
extract, peptide plus extract, or culture medium for 24 h. Cell viability was measured by
MTT assay, and neuronal apoptosis was evaluated by DAPI staining. ERK signaling
pathway-associated molecule activation and changes in Bax expression were analyzed by
Western blotting and immunofluorescence.
Results: A cell viability rate of (44.11 ± 6.59)% in the Ab40 group was rescued to
(79.13 ± 6.64)% by adding different concentrations of the extract. DAPI showed pyknotic
nuclei in 39.5% of Ab40-treated cells; the fraction dropped to 17.4% in the 100 mg/L
extract group. ERK phosphorylation was observed in the Ab40 group but was ameliorated
by pretreatment with 100 mg/L extract. Hainan papaya water extract also prevented
Ab40-induced phosphorylation of MEK, RSK1 and CREB associated with ERK
signaling and downregulated Bax expression in the neurons.
Conclusion: The results suggest that Hainan papaya water extract has protective effects
on neurons; the mechanism may be related to suppression of ERK signaling activation.