Myrcene Consumption and Restrain Stress: An In Vivo Comparative Study on an Alzheimer’s Disease Model and In Vitro Investigation on Abeta Fibrils

Alzheimer's disease (AD) is a neurodegenerative disease characterized by amyloid plaques and neuronal death. Natural therapies have always attracted attention against AD. Herein, Myrcene, as a natural monoterpene, was applied to examine its protective and therapeutic effects on a rat model of AD along with short-term restraint stress. In order to create Alzheimer’s rat model, bilateral injection of Amyloid β1–42 was performed into rats’ hippocampus. Both therapeutic (post-AD induction) and preventive effects of Myrcene consumption (100 mg/kg) were investigated on the antioxidant and behavioral parameters as well as neurogenesis and brain amyloid plaque formation. Meanwhile, the effects of restraint stress was observed. Moreover, the effect of Myrcene (100 µM) was observed on Aβ1–42 fibrils in vitro. Alzheimer’s-induced group showed impairment in the memory and antioxidant parameters along with amyloid plaque formation and loss of neuronal cells. Administration of Myrcene, in both treatment and protective modes increased neurogenesis, reduced amyloid plaques, and improved antioxidant parameters as well as memory even during applying restraint stress. Therefore, Myrcene showed capability of improving AD signs in vivo as well as direct anti-fibril effect in vitro and therefore could be considered as neuroprotective agent.