Receptor for advanced glycation end products (RAGE) is a receptor of the immunoglobulin super family that plays various important roles under physiological and pathological conditions. Compelling evidence suggests that RAGE acts as both an inflammatory intermediary and a critical inducer of oxidative stress, underlying RAGE-induced Alzheimer-like pathophysiological changes that drive the process of Alzheimer's disease (AD). A critical role of RAGE in AD includes beta-amyloid (Aβ) production and accumulation, the formation of neurofibrillary tangles, failure of synaptic transmission, and neuronal degeneration. The steady-state level of Aβ depends on the balance between production and clearance. RAGE plays an important role in the Aβ clearance. RAGE acts as an important transporter via regulating influx of circulating Aβ into brain, whereas the efflux of brain-derived Aβ into the circulation via BBB is implemented by LRP1. RAGE could be an important contributor to Aβ generation via enhancing the activity of β- and/or γ-secretases and activating inflammatory response and oxidative stress. However, sRAGE-Aβ interactions could inhibit Aβ neurotoxicity and promote Aβ clearance from brain. Meanwhile, RAGE could be a promoting factor for the synaptic dysfunction and neuronal circuit dysfunction which are both the material structure of cognition, and the physiological and pathological basis of cognition. In addition, RAGE could be a trigger for the pathogenesis of Aβ and tau hyper-phosphorylation which both participate in the process of cognitive impairment. Preclinical and clinical studies have supported that RAGE inhibitors could be useful in the treatment of AD. Thus, an effective measure to inhibit RAGE may be a novel drug target in AD.

Cerebral small vessel disease (CSVD) is a group of pathological processes with multifarious etiology and pathogenesis that are involved into the small arteries, arterioles, venules, and capillaries of the brain. CSVD mainly contains lacunar infarct or lacunar stroke, leukoaraiosis, Binswanger’s disease, and cerebral microbleeds. CSVD is an important cerebral microvascular pathogenesis as it is the cause of 20% of strokes worldwide and the most common cause of cognitive impairment and dementia, including vascular dementia and Alzheimer’s disease (AD). It has been well identified that CSVD contributes to the occurrence of AD. It seems that the treatment and prevention for cerebrovascular diseases with statins have such a role in the same function for AD. So far, there is no strong evidence-based medicine to support the idea, although increasing basic studies supported the fact that the treatment and prevention for cerebrovascular diseases will benefit AD. Furthermore, there is still lack of evidence in clinical application involved in specific drugs to benefit both AD and CSVD.

Berberine, an important protoberberine isoquinoline alkaloid, has several pharmacological activities, including antimicrobial, glucose- and cholesterol-lowering, antitumoral, and immunomodulatory properties. Substantial studies suggest that berberine may be beneficial to Alzheimer’s disease (AD) by limiting the pathogenesis of extracellular amyloid plaques and intracellular neurofibrillary tangles. Increasing evidence has indicated that berberine exerts a protective role in atherosclerosis related to lipid- and glucose-lowering properties, implicating that berberine has the potential to inhibit these risk factors for AD. This review also attempts to discuss the pharmacological basis through which berberine may retard oxidative stress and neuroinflammation to exhibit its protective role in AD. Accordingly, berberine might be considered a potential therapeutic approach to prevent or delay the process of AD. However, more detailed investigations along with a safety assessment of berberine are warranted to clarify the role of berberine in limiting these risk factors and AD-related pathologies.

BBR attenuated cognitive deficits and limited hyperphosphorylation of tau via inhibiting the activation of NF-κB signaling pathway, and by retarding oxidative stress and neuro-inflammation.

BBR inhibits the activity of β/γ-secretases, enhances α-secretases, and lowers the Aβ level in the hippocampus of AD mice, and improves Alzheimer's-like cognitive impairment.