Neuroprotection of SAK3 on scopolamine-induced cholinergic dysfunction in human neuroblastoma SH-SY5Y cells

Paeoniflorin inhibits pyruvate dehydrogenase kinase 3 and promotes BDNF activity by modulating neuronal activity and TNF-α

Metabolic dysregulation causes diseases like diabetes and cancer, making PDKs attractive targets. However, a thorough investigation into the unique roles played by the different members of the PDK family, especially PDK3, about memory loss and related diseases like Alzheimer's disease (AD) is still lacking. The current study investigates PF's potential to reduce PDK3-associated toxicity in neurodegenerative illnesses, including AD. The association between PF and PDK3 presents a significant opportunity for medication development and AD therapy approaches. PF efficiently suppresses PDK3 activity, as demonstrated by molecular docking and biophysical characterization, providing an in-depth understanding of their molecular interactions. PF significantly inhibited PDK3 in a concentration-dependent manner with an IC50 value of 4.88 µM. Considering this, the current investigation also explores the biological component of PF, which exhibits potential in treating AD and is primarily associated with neuroprotection. In the present study, a 3-hour pre-treatment of PF was administered at varying concentrations (4, 6, and 8 µM) in response to the 24-hour SCP (2 mM)-mediated toxicity. Based on the results of in silico and biophysical characterization, it is concluded that PF inhibits the PDK3 activity. Additionally, it can enhance cell viability, suppress ROS expression, impede apoptosis, and downregulate TNF-α expression. When combined, these actions help to prevent neuronal death in an in vitro model of SCP. PF strengthens the memory marker, which is confirmed through BDNF expression. This study found that all results were more effective at lower and moderate doses of PF. Our research indicates that PF boosts memory, decelerates the progression of oxidative stress, and could potentially serve as a dose-dependent treatment for AD.

Protective effects of enzymatically digested velvet antler polypeptides on mitochondria in primary astrocytes

Traditionally, velvet antler (VA) has been used as a medicine or dietary supplement in East Asia. It contains biologically active compounds that exert anti-inflammatory, anti-fatigue, anti-aging, and anticancer effects. Although demand for VA has increased globally, its supply and consumption are limited due to the low recovery of its bioactive compounds from traditional decoctions. Therefore, alternative extraction methods are required to enrich the active compounds and enhance their biological efficacy. The extract has been reported to protect against neuropathological conditions in brain cells and suppress oxidative stress and neuroinflammation-crucial for the initiation or progression of neurodegenerative diseases. Therefore, VA is a potential therapeutic agent for neurodegenerative diseases. However, the beneficial effects of VA on astrocytes, which are the predominant glial cells in the brain, remain unclear. In the present study, we investigated the protective effects of enzymatically digested VA extract (YC-1101) on the mitochondria in astrocytes, which are essential organelles regulating oxidative stress. Proteomic and metabolomic results using liquid chromatography-mass spectrometry (LC-MS/MS) identified enriched bioactive ingredients in YC-1101 compared to hot water extract of VA. YC-1101 displayed significant protective effects against mitochondrial stressors in astrocytes compared with other health functional ingredients. Altogether, our results showed improved bioactive efficacy of YC-1101 and its protective role against mitochondrial stressors in astrocytes.

Comparison of Malondialdehyde, Acetylcholinesterase, and Apoptosis-Related Markers in the Cortex and Hippocampus of Cognitively Dysfunctional Mice Induced by Scopolamine

Objectives: Until now, many researchers have conducted evaluations on hippocampi for analyses of cognitive dysfunction models using scopolamine. However, depending on the purposes of these analyses, there are differences in the experimental results for the hippocampi and cortexes. Therefore, this study intends to compare various analyses of cognitive dysfunction after scopolamine administration with each other in hippocampi and cortexes. Methods: Scopolamine was administered at three dosages in mice: 0.5, 1, and 3 mg/kg. And this study evaluates the differences in cognitive function and the expression of malondialdehyde (MDA), acetylcholinesterase (AChE), and brain-derived neurotrophic factor (BDNF) in mice's hippocampi and cortexes based on scopolamine dosages. Results: The Morris water maze test was conducted between 1 and 3 h after scopolamine injection to assess its duration. A significant decrease in behavioral ability was evaluated at 1 h, and we observed a similar recovery to the normal group at 3 h. And the Morris water maze escape latency showed differences depending on scopolamine concentration. While the escape waiting time in the control group and scop 0.5 administration group remained similar to that seen before administration, the administration of scop 1 and 3 increased it. In the experimental group administered scop 1 and 3, cerebral MDA levels in the cerebral cortex significantly increased. In the hippocampus, the MDA level in the scopolamine-administered groups slightly increased compared to the cortex. A Western blotting assay shows that Bax and Bcl-xl showed a tendency to increase or decrease depending on the concentration, but BDNF increased in scop 0.5, and scop 1 and 3 did not show a significant decrease compared to the control at the cerebral cortex. In the hippocampus, BDNF showed a concentration-dependent decrease in expression. Conclusions: This study's findings indicate that chemical analyses for MDA and AChE can be performed in the cerebral cortex, while the hippocampus is better suited for protein analysis of apoptosis and BDNF.

Design, Synthesis, and Pharmacological Evaluation of Embelin-Aryl/alkyl Amine Hybrids as Orally Bioavailable Blood-Brain Barrier Permeable Multitargeted Agents with Therapeutic Potential in Alzheimer's Disease: Discovery of SB-1448

The complex and multifaceted nature of Alzheimer's disease has brought about a pressing demand to develop ligands targeting multiple pathways to combat its outrageous prevalence. Embelin is a major secondary metabolite of Embelia ribes Burm f., one of the oldest herbs in Indian traditional medicine. It is a micromolar inhibitor of cholinesterases (ChEs) and β-site amyloid precursor protein cleaving enzyme 1 (BACE-1) with poor absorption, distribution, metabolism, and excretion (ADME) properties. Herein, we synthesize a series of embelin-aryl/alkyl amine hybrids to improve its physicochemical properties and therapeutic potency against targeted enzymes. The most active derivative, 9j (SB-1448), inhibits human acetylcholinesterase (hAChE), human butyrylcholinesterase (hBChE), and human BACE-1 (hBACE-1) with IC₅₀ values of 0.15, 1.6, and 0.6 μM, respectively. It inhibits both ChEs noncompetitively with k_i values of 0.21 and 1.3 μM, respectively. It is orally bioavailable, crosses blood-brain barrier (BBB), inhibits Aβ self-aggregation, possesses good ADME properties, and protects neuronal cells from scopolamine-induced cell death. The oral administration of 9j at 30 mg/kg attenuates the scopolamine-induced cognitive impairments in C57BL/6J mice.

Euonymus alatus Twig Extract Protects against Scopolamine-Induced Changes in Brain and Brain-Derived Cells via Cholinergic and BDNF Pathways

In the current study, the therapeutic and preventive effects of Euonymus alatus (EA) twig extract were investigated in a mouse model of cognitive deficit and B35 cells. Twig extract 1 was extracted with 70% ethanol and later twig extract 2 was extracted through liquid-liquid extraction with 70% ethanol and hexane. EA twig 2 (300 mg/kg) along with the standard drug donepezil (5 mg/kg) were orally administered to the mice for 34 days. Scopolamine was given intraperitoneally for 7 days. Administration of EA twig extract 2 significantly improved the passive avoidance test (PAT) in mice. EA twigs extract also restored the scopolamine-reduced brain-derived neurotrophic factor (BDNF)/extracellular regulated kinase (ERK)/cyclic AMP responsive element binding protein (CREB) signaling in B35 cells and the mouse hippocampus. In addition, EA twig extract significantly inhibited the acetylcholine esterase (AChE) activity in B35 cells in a dose-dependent manner. Chromatography and ESI MS analysis of EA twig extract revealed the presence of flavonoids; epicatechin, taxifolin, aromadendrin, and naringenin with catechin being the most abundant. These flavonoids exerted protective effects alone and had the possibility of synergistic effects in combination. Our work unmasks the ameliorating effect of EA twig extract 2 on scopolamine-associated cognitive impairments through the restoration of cholinergic systems and the BDNF/ERK/CREB pathway.

The investigation of the T-type calcium channel enhancer SAK3 in an animal model of TAF1 intellectual disability syndrome

T-type calcium channels, in the central nervous system, are involved in the pathogenesis of many neurodegenerative diseases, including TAF1 intellectual disability syndrome (TAF1 ID syndrome). Here, we evaluated the efficacy of a novel T-type Ca2+ channel enhancer, SAK3 (ethyl 8'-methyl-2', 4-dioxo-2-(piperidin-1-yl)-2'H-spiro [cyclopentane-1, 3'-imidazo [1, 2-a] pyridine]-2-ene-3-carboxylate) in an animal model of TAF1 ID syndrome. At post-natal day 3, rat pups were subjected to intracerebroventricular (ICV) injection of either gRNA-control or gRNA-TAF1 CRISPR/Cas9 viruses. At post-natal day 21 animals were given SAK3 (0.25 mg/kg, p.o.) or vehicle up to post-natal day 35 (i.e. 14 days). Rats were subjected to behavioral, morphological, electrophysiological, and molecular studies. Oral administration of SAK3 (0.25 mg/kg, p.o.) significantly rescued the behavior abnormalities in beam walking test and open field test caused by TAF1 gene editing. We observed an increase in calbindin-positive Purkinje cells and GFAP-positive astrocytes as well as a decrease in IBA1-positive microglia cells in SAK3-treated animals. In addition, SAK3 protected the Purkinje and granule cells from apoptosis induced by TAF-1 gene editing. SAK3 also restored the excitatory post synaptic current (sEPSCs) in TAF1 edited Purkinje cells. Finally, SAK3 normalized the BDNF/AKT signaling axis in TAF1 edited animals. Altogether, these observations suggest that SAK3 could be a novel therapeutic agent for TAF1 ID syndrome.