Objective: Peripheral nerve injury (PNI) is an important global health problem. Nerve Growth Factor (NGF) plays crucial role in the survival, growth, and maintenance of various neurons in the mammalian nervous system, human included. Hericium erinaceus (HE), an edible and medicinal mushroom, has been extensively studied for its neuroprotective properties. In this study, the neuroprotective and neurotogenic effects of HE and NGF were compared on mouse PNI model by using a laser microdissection technique.
Methods: Neuronal cultures were prepared from dorsal root ganglia (DRG) of 6-8 week aged mice, pretreated them with phosphate-buffered saline (PBS), NGF, HE, or the combination of NGF and HE. To model axonal injury in vitro, axons were cut (axotomy) with a microscope-controlled laser beam. Axotomized neurons were imaged under the microscope. Axotomized neurons' survival ratios were calculated using the propidium iodide (PI), which is a red-fluorescent nuclear dye. Their axon lengths were measured using the AxioVision 4.8 software.
Results: Although both HE and NGF have neuroprotective and regenerative effects on axotomized peripheral sensory neurons, HE exhibits a higher neuroprotective activity compared to the NGF. The combination of HE and NGF maximizes axonal regeneration ability of axotomized neurons.
Conclusion: HE has capabilities of preventing the death of neurons and regenerating their axons in the experimental axonal injury model. Our findings provide experimental evidence that HE may serve as a neuroprotective and regenerative candidate for treating peripheral nerve injuries. Present study warrants further investigation of HE as a potential natural compound to remedy PNI.
Keywords: DRG neurons; NGF; axotomy; regeneration.