Comment on "Berberine and its emerging benefits in psychiatric conditions especially Alzheimer's disease"

Evaluation of the size effect of hydrophobic ring substitution on 9-O position of berberine on DNA binding

The interaction of deoxyribonucleic acid (DNA) with medicinally significant small molecules has long piqued the interest of researchers because its applications are directly related to the discovery of new classes of drugs. Keeping this in mind, here we report berberine derivatives and their interaction with calf thymus DNA (CT-DNA). In this report we discussed on the structural perspectives and thermodynamic characteristics of the interaction of four 9-O-substituted berberines (BRDR1 to BRDR4) with CT-DNA. The binding affinity of BRDR-DNA complexes increased with increasing the cycloalkane ring size of the substitution except BRDR2. The binding constant value obtained from UV-Visible spectral analysis was 1.12 × 106 for BRDR1, 0.37 × 106 for BRDR2, 1.72 × 106 for BRDR3 and 3.20 × 106 for BRDR4. Ferrocyanide quenching experiments revealed unequivocally that the analogues except BRDR2 had a partly intercalative binding to DNA. From the ITC experiment it was found that the bindings of BRDR1, BRDR3 and BRDR4 to DNA was favoured by negative enthalpy and positive entropy while BRDR2 was driven by positive enthalpy and positive entropy. In all cases the hydrophobic interaction plays a crucial role. Thus, the complete multispectroscopic and thermodynamic binding studies may be useful for new drug design and development.Communicated by Ramaswamy H. Sarma.

Boosting the autophagy-lysosomal pathway by phytochemicals: A potential therapeutic strategy against Alzheimer's disease

The lysosome is a membrane-enclosed organelle in eukaryotic cells, which has basic pattern recognition for nutrient-dependent signal transduction. In Alzheimer's disease, the already declining autophagy-lysosomal function is exacerbated by an increased need for clearance of damaged proteins and organelles in aged cells. Recent evidence suggests that numerous diseases are linked to impaired autophagy upstream of lysosomes. In this way, a comprehensive survey on the pathophysiology of the disease seems necessary. Hence, in the first section of this review, we will discuss the ultimate findings in lysosomal signaling functions and how they affect cellular metabolism and trafficking under neurodegenerative conditions, specifically Alzheimer's disease. In the second section, we focus on how natural products and their derivatives are involved in the regulation of inflammation and lysosomal dysfunction pathways, including how these should be considered a crucial target for Alzheimer's disease therapeutics.

Berberine regulates neurite outgrowth through AMPK-dependent pathways by lowering energy status

As a widely used anti-bacterial agent and a metabolic inhibitor as well as AMP-activated protein kinase (AMPK) activator, berberine (BBR) has been shown to cross the blood-brain barrier. Its efficacy has been investigated in various disease models of the central nervous system. Neurite outgrowth is critical for nervous system development and is a highly energy-dependent process regulated by AMPK-related pathways. In the present study, we aimed to investigate the effects of BBR on AMPK activation and neurite outgrowth in neurons. The neurite outgrowth of primary rat cortical neurons at different stages of polarization was monitored after exposure of BBR. Intracellular energy level, AMPK activation and polarity-related pathways were also inspected. The results showed that BBR suppressed neurite outgrowth and affected cytoskeleton stability in the early stages of neuronal polarization, which was mediated by lowered energy status and AMPK activation. Liver kinase B1 and PI3K-Akt-GSK3β signaling pathways were also involved. In addition, mitochondrial dysfunction and endoplasmic reticulum stress contributed to the lowered energy status induced by BBR. This study highlighted the knowledge of the complex activities of BBR in neurons and corroborated the significance of energy status during the neuronal polarization.

Metabolic profiling analysis of berberine, palmatine, jatrorrhizine, coptisine and epiberberine in zebrafish by ultra-high performance liquid chromatography coupled with LTQ Orbitrap mass spectrometer

1. Zebrafish has been used in metabolic study of drugs as a powerful tool in recent years. In this study, we make a feasible metabolism investigation of five protoberberine alkaloids (PBAs) applied in zebrafish model for the first time, including berberine (BBR), palmatine (PAL), jatrorrhizine (JAT), coptisine (COP) and epiberberine (EBBR). 2. After exposure for 24 hours, 19 metabolites were identified by LTQ Orbitrap mass spectrometer, including 9 phase I metabolites and 10 phase II metabolites. Demethylation, hydroxylation, sulfation and glucuronidation were the major metabolic transformation of PBAs in zebrafish, which were similar to mammals. Compared with reported literatures, BBR and JAT showed high consistency between human and zebrafish in metabolic pathways. 3. To our knowledge, this is the first time to study in vivo metabolism of COP, which provides useful information to other researchers. 4. This study indicated that zebrafish model is feasible and reasonable to predict the metabolism of PBAs. It showed great potential for developing a novel and rapid method for predicting the metabolism of trace compounds of botanical drugs, with the advantages of lower cost, higher performance and easier set up.