5α-Epoxyalantolactone from Inula macrophylla attenuates cognitive deficits in scopolamine-induced Alzheimer's disease mice model.

Alzheimer's disease (AD) is a complex neurodegenerative condition. 5α-epoxyalantolactone (5α-EAL), a eudesmane-type sesquiterpene isolated from the herb of Inula macrophylla, has various pharmacological effects. This work supposed to investigate the improved impact of 5α-EAL on cognitive impairment. 5α-EAL inhibited the generation of nitric oxide (NO) in BV-2 cells stimulated with lipopolysaccharide (LPS) with an EC50 of 6.2 µM. 5α-EAL significantly reduced the production of prostaglandin E2 (PGE2) and tumor necrosis factor-α (TNF-α), while also inhibiting the production of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) proteins. The ability of 5α-EAL to penetrate the blood-brain barrier (BBB) was confirmed via a parallel artificial membrane permeation assay. Scopolamine (SCOP)-induced AD mice model was employed to assess the improved impacts of 5α-EAL on cognitive impairment in vivo. After the mice were pretreated with 5α-EAL (10 and 30 mg/kg per day, i.p.) for 21 days, the behavioral experiments indicated that the administration of the 5α-EAL could alleviate the cognitive and memory impairments. 5α-EAL significantly reduced the AChE activity in the brain of SCOP-induced AD mice. In summary, these findings highlight the beneficial effects of the natural product 5α-EAL as a potential bioactive compound for attenuating cognitive deficits in AD due to its pharmacological profile.

A new neuroprotective candidate TJ1 targeting amyloidogenesis in 5xFAD Alzheimer's disease mice.

As one of the main pathmechanisms of Alzheimer's disease (AD), amyloid-ß (Aß) is widely considered to be the prime target for the development of AD therapy. Recently, imidazolylacetophenone oxime ethers or esters (IOEs) have shown neuroprotective effects against neuronal cells damage, suggesting their potential use in the prevention and treatment of AD. Thirty IOEs compounds from our lab in-house library were constructed and screened for the inhibitory effects on Aß42-induced cytotoxicity. Among them, TJ1, as a new IOEs hit, preliminarily showed the effect on inhibiting Aß42-induced cytotoxicity. Furthermore, the inhibitory effects of TJ1 on Aß42 aggregation were tested by ThT assays and TEM. The neuroprotective effects of TJ1 were evaluated in Aß42-stimulated SH-SY5Y cells, LPS-stimulated BV-2 cells, and H2O2- and RSL3-stimulated PC12 cells. The cognitive improvement of TJ1 was assessed in 5xFAD (C57BL/6J) transgenic mouse. These results showed that TJ1 had strong neuroprotective effects and high blood-brain barrier (BBB) permeability without obvious cytotoxicity. TJ1 impeded the self-accumulation process of Aß42 by acting on Aß oligomerization and fibrilization. Besides, TJ1 reversed Aß-, H2O2- and RSL3-induced neuronal cell damage and decreased neuroinflammation. In 5xFAD mice, TJ1 improved cognitive impairment, increased GSH level, reduced the level of Aß42 and Aß plaques, and attenuated the glia reactivation and inflammatory response in the brain,. Taken together, our results demonstrate that TJ1 improves cognitive impairments as a new neuroprotective candidate via targeting amyloidogenesis, which suggests the potential of TJ1 as a treatment for AD.

Herpotrichone A Exerts Neuroprotective Effects by Relieving Ferroptosis.

Inhibition of oxidative stress and ferroptosis is currently considered to be a promising therapeutic approach for neurodegenerative diseases. Herpotrichones, a class of compounds derived from insect symbionts, have shown potential for neuroprotective activity with low toxicity. However, the specific mechanisms through which herpotrichones exert their neuroprotective effects remain to be fully elucidated. In this study, the natural [4 + 2] adducts herpotrichone A (He-A) and its new analogues were isolated from the isopod-associated fungus Herpotrichia sp. SF09 and exhibited significantly protective effects in H2O2-, 6-OHDA-, and RSL3-stimulated PC12 cells and LPS-stimulated BV-2 cells. Moreover, He-A was able to relieve ferroptotic cell death in RSL3-stimulated PC12 cells and 6-OHDA-induced zebrafish larvae. Interestingly, He-A can activate antioxidant elements and modulate the SLC7A11 pathway without capturing oxidic free radical and chelating iron. These findings highlight He-A as a novel hit that protects against ferroptosis-like neuronal damage in the treatment of neurodegenerative diseases.

Design, synthesis, and biological evaluation of imidazolylacetophenone oxime derivatives as novel brain-penetrant agents for Alzheimer's disease treatment.

Alzheimer's disease (AD, also known as dementia) has become a serious global health problem along with population aging, and neuroinflammation is the underlying cause of cognitive impairment in the brain. Nowadays, the development of multitarget anti-AD drugs is considered to be one effective approach. Imidazolylacetophenone oxime ethers or esters (IOEs) were multifunctional agents with neuroinflammation inhibition, metal chelation, antioxidant and neuroprotection properties against Alzheimer's disease. In this study, IOEs derivatives 1-8 were obtained by structural modifications of the oxime and imidazole groups, and the SARs showed that (Z)-oxime ether (derivative 2) had stronger anti-neuroinflammatory and neuroprotective ability than (E)-congener. Then, IOEs derivatives 9-30 were synthesized based on target-directed ligands and activity-based groups hybridization strategy. In vitro anti-AD activity screening revealed that some derivatives exhibited potentially multifunctional effects, among which derivative 28 exhibited the strongest inhibitory activity on NO production with EC50 value of 0.49 µM, and had neuroprotective effects on 6-OHDA-induced cell damage and RSL3-induced ferroptosis. The anti-neuroinflammatory mechanism showed that 28 could inhibit the release of pro-inflammatory factors PGE2 and TNF-α, down-regulate the expression of iNOS and COX-2 proteins, and promote the polarization of BV-2 cells from pro-inflammatory M1 phenotype to anti-inflammatory M2 phenotype. In addition, 28 can dose-dependently inhibit acetylcholinesterase (AChE) and Aß42 aggregation. Moreover, the selected nuclide [18F]-labeled 28 was synthesized to explore its biodistribution by micro-PET/CT, of which 28 can penetrate the blood-brain barrier (BBB). These results shed light on the potential of 28 as a new multifunctional candidate for AD treatment.