Study on the role and mechanism of Tan IIA in Alzheimer's disease based on CREB-BDNF-TrkB pathway

BDNF/proBDNF Interplay in the Mediation of Neuronal Apoptotic Mechanisms in Neurodegenerative Diseases

The neurotrophic system includes neurotrophins, such as brain-derived neurotrophic factor (BDNF) and its precursor proBDNF, which play conflicting roles in neuronal survival and apoptosis, with their balance having a significant impact on neurodegenerative outcomes. While BDNF is widely acknowledged as a potent neurotrophin that promotes neuronal survival and differentiation, its precursor, proBDNF, has the opposite effect, promoting apoptosis and neuronal death. This review highlights the new and unique aspects of BDNF/proBDNF interaction in the modulation of neuronal apoptotic pathways in neurodegenerative disorders. It systematically discusses the cross-talk in apoptotic signaling at the molecular level, whereby BDNF activates survival pathways such as PI3K/Akt and MAPK/ERK, whereas proBDNF activates p75NTR and sortilin to induce neuronal apoptosis via JNK, RhoA, NFkB, and Rac-GTPase pathways such as caspase activation and mitochondrial injury. Moreover, this review emphasizes the factors that affect the balance between proBDNF and BDNF levels within the context of neurodegeneration, including proteolytic processing, the expression of TrkB and p75NTR receptors, and extrinsic gene transcription regulators. Cellular injury, stress, or signaling pathway alterations can disrupt the balance of BDNF/proBDNF, which may be involved in apoptotic-related neurodegenerative diseases like Alzheimer's, Parkinson's, and Huntington's diseases. This review provides a comprehensive framework for targeting neurotrophin signaling in the development of innovative therapies for neuronal survival and managing apoptotic-related neurodegenerative disorders, addressing the mechanistic complexity and clinical feasibility of BDNF/proBDNF interaction.

The effect of tanshinones on cognitive impairments in animal models of Alzheimer's disease: a systematic review and meta-analysis

Background

Alzheimer's disease (AD) is an age-related neurological illness that poses a significant hazard to human health. A fat-soluble compound called tanshinones was isolated from Danshen, a traditional Chinese herb. Recent years have seen reports of clinical trials examining the effects of tanshinones on cognitive impairment among individuals with AD, as well as the publication of pertinent basic research. Tanshinones are not yet commonly utilized in the therapeutic treatment of AD, and the effectiveness of tanshinones as a treatment program for AD is not yet adequately supported by evidence. To assess the impact of tanshinones on cognitive impairment in experimental rodent models of AD, we carried out a systematic review in this work.

Method

All relevant studies on the usage of tanshinones in AD model animals published in PubMed, Cochrane Library, Web of Science, EMBASE, Chinese Biomedicine Database, and China National Knowledge Infrastructure before 8 September 2024, were systematically retrieved. To assess the methodological quality, the CAMARADES checklist was used. Meta-analysis was calculated and graphed in the Stata 14.0 software. For each outcome in every study, the standard mean difference (SMD) and the 95% confidence interval (CI) of each effect size were calculated.

Results

Fourteen studies were included in this study. Compared with the AD model group without tanshinones intervention, tanshinones significantly reduced the number of escape latency [SMD = -2.082, 95% CI = (-2.481, -1.683), p < 0.001]. Tanshinones also increased the times of platform crossing [SMD = 1.464, 95% CI = (1.183, 1.744), p < 0.001] and time in target quadrants [SMD = 2.703, 95% CI = (2.132, 3.275), p < 0.001].

Conclusion

Tanshinones are thought to have positive effects on cognitive impairment in rodent models of AD, according to the findings of this study. However, the level of quality of the included research may have an impact on the accuracy of positive outcomes. Thus, more high-quality randomized controlled animal studies are required to guide future scientific and clinical research.

Systematic Review Registration

identifier CRD42024557980.

Ginsenosides Rg1, Rb1 and rare ginsenosides: Promising candidate agents for Parkinson's disease and Alzheimer's disease and network pharmacology analysis

Ginseng has been commonly used as a traditional Chinese medicine in Asian countries for thousands of years. Ginsenosides are the main pharmacologically active ingredients isolated from ginseng and have neuroprotective effects in the treatment of neurodegenerative disorders, such as Parkinson's disease (PD) and Alzheimer's disease (AD). To summarise and investigate the protective roles of ginsenosides and their underlying mechanisms in PD and AD, we used ''Ginsenoside", ''Parkinson's disease", ''Alzheimer's disease", ''anti-inflammatory", ''antioxidant", and ''apoptosis" as keywords to search and extract relevant literature information from scientific databases such as Elsevier, PubMed, and Google Scholar databases. In particular, we used network pharmacology to identify the potential targets of ginsenosides Rg1 and Rb1 in PD and AD. By analysing the existing research advances and network pharmacology results, we found that the neuroprotective effects of ginsenosides, primarily mediated through anti-inflammation, anti-apoptosis and anti-oxidative stress, etc, may be associated with the PI3K/Akt, BDNF/TrkB, MAPKs, NF-κB, Nrf2 and Wnt/β-catenin signalling pathways. This review systematically summarises the different roles and mechanisms of ginsenosides Rg1, Rb1, and rare ginsenosides in PD and AD and provides new strategies for the treatment of neurodegenerative disorders. Network pharmacology provides a new research paradigm for the treatment of PD and AD using Rg1 and Rb1.