Classic Prescription, Kai-Xin-San, Ameliorates Alzheimer's Disease as an Effective Multitarget Treatment: From Neurotransmitter to Protein Signaling Pathway

Alzheimer's disease (AD) is a widespread neurodegenerative disease caused by complicated disease-causing factors. Unsatisfactorily, curative effects of approved anti-AD drugs were not good enough due to their actions on single-target, which led to desperate requirements for more effective drug therapies involved in multiple pathomechanisms of AD. The anti-AD effect with multiple action targets of Kai-Xin-San (KXS), a classic prescription initially recorded in Bei Ji Qian Jin Yao Fang and applied in the treatment of dementia for thousands of years, was deciphered with modern biological methods in our study. Aβ (25-35) and D-gal-induced AD rats and Aβ (25-35)-induced PC12 cells were applied to establish AD models. KXS could significantly improve cognition impairment by decreasing neurotransmitter loss and enhancing the expression of PI3K/Akt. For the first time, KXS was confirmed to improve the expression of PI3K/Akt by neurotransmitter 5-HT. Thereinto, PI3K/Akt could further inhibit Tau hyperphosphorylation as well as the apoptosis induced by oxidative stress and neuroinflammation. Moreover, all above-mentioned effects were verified and blocked by PI3K inhibitor, LY294002, in Aβ (25-35)-induced PC12 cells, suggesting the precise regulative role of KXS in the PI3K/Akt pathway. The utilization and mechanism elaboration of KXS have been proposed and dissected in the combination of animal, molecular, and protein strategies. Our results demonstrated that KXS could ameliorate AD by regulating neurotransmitter and PI3K/Akt signal pathway as an effective multitarget treatment so that the potential value of this classic prescription could be explored from a novel perspective.