Neurotrophic activity of the seaweed Kappaphycus alvarezii in primary hippocampal neurons

Abstract

Brain aging could be one cause of neurodegenerative diseases that may affects memory, thinking, and social abilities. Age-associated neurodegenerative disorders could be treated using neurotrophic agents to support neurodevelopment and protect mature neurons from atrophy. I have screened Indonesian seaweeds for their neuritogenic activity in the fetal rat hippocampal neurons in vitro. The primary culture of hippocampal neurons was incubated with the addition of seaweed ethanolic extract. At indicated time, cultures were fixed and stained to visualize the neuronal morphology. Morphometric analysis was performed using ImageJ software. Among 34 seaweed species, ethanol extract of Kappaphycus alvarezii (EKA) has shown potent neuritogenic activities. The EKA showed neuritogenic activity in a dose-dependent manner with an optimal dose of 1 µg mL-1. On the optimal dose, EKA significantly accelerated the maturation of neuronal cells (p<0.05) based on the stage of neurodevelopment and number of processes. The axonal development and dendrites complexity were increased significantly with the present of EKA in the medium of neuron culture. Ethyl acetate fraction of K. alvarezii methanolic extract showed the highest activity in neurites outgrowth. These results indicate that K. alvarezii would be one promising candidate for neurotrophic agents.