Design, synthesis, and biological evaluation of novel donepezil-tacrine hybrids as multi-functional agents with low neurotoxicity against Alzheimer's disease

Research progress and perspectives of dual-target inhibitors

The occurrence and development of diseases are complex, and single-target drugs that affect only a single target or pathway often fail to achieve the expected therapeutic effect. The simultaneous effect on two key targets could not only increase patient tolerance but also accelerate disease remission. Dual-target inhibitors have already been studied the most intensively in the development of dual-target drugs. This article briefly introduces the function of drug therapy targets, and mainly summarizes the design strategies and research progress of dual-target inhibitors in neurodegenerative diseases, infectious diseases, metabolic diseases and cardiovascular diseases.

Antioxidants in anti-Alzheimer's disease drug discovery

Oxidative stress is widely recognized as a key contributor to the pathogenesis of Alzheimer's disease (AD). While not the sole factor, it is closely linked to critical pathological features, such as the formation of senile plaques and neurofibrillary tangles. The development of agents with antioxidant properties has become an area of growing interest in AD research. Between 2015 and 2024, several antioxidant-targeted drugs for AD progressed to clinical trials, with increasing attention to the evaluation of antioxidant properties during their development. Oxidative stress plays a pivotal role in linking various AD hypotheses, underscoring its importance in understanding the disease mechanisms. Despite this, comprehensive reviews addressing advancements in AD drug development from the perspective of antioxidant capacity remain limited, hindering the design of novel compounds. This review aims to explore the mechanistic relationship between oxidative stress and AD, summarize methods for assessing antioxidant capacity, and provide an overview of antioxidant compounds with anti-AD properties reported over the past decade. The goal is to offer strategies for identifying effective antioxidant-based therapies for AD and to deepen our understanding of the role of oxidative stress in AD pathology.

Development of novel melatonin-isatin hybrids as multifunctional agents for Alzheimer's disease

The development of multifunctional agents has been a heated area of research for AD treatment in recent years. In this work, a series of melatonin-isatin hybrids were designed, synthesized, and evaluated as multifunctional agents for treating AD. In vitro studies indicated that most of the synthesized compounds displayed moderate to good MAO-B inhibition activities and good antioxidant activities. In particular, compounds IM-5 and IM-10 exhibited the best inhibitory activities with IC50 value of 12.4 μM and 15.6 μM against MAO-B, and potent antioxidant activities with their ORAC-FL values of 4.6 and 5.2 at 5 μM, respectively. ThT assay revealed compounds IM-5 and IM-10 exhibited the optimal Aβ1-42 self-induced aggregation inhibitory activities with the inhibition ratio of 72.8% and 69.7% at 20 μM. In addition, compounds IM-5 and IM-10 exhibited low cytotoxicities and significant neuroprotective effects on Aβ1-42-induced and H2O2-induced SH-SY5Y cell injury. More importantly, compounds IM-5 and IM-10 could significantly ameliorate the memory impairment and cognition injury in scopolamine-induced mice. The SwissADME program was used to predict drug-like properties of compounds IM-5 and IM-10 which exhibited they had good pharmacokinetics and drug-likeness properties. Molecular docking study further manifested that compounds IM-5 and IM-10 showed high hMAO-B inhibitory potency. In summary, all above results revealed compounds IM-5 and IM-10 might be promising multifunctional agents for AD treatment.

Acetylcholinesterase inhibitory phloroglucinols from tropic Rhodomyrtus tomentosa

Four previously undescribed phloroglucinols, including three pairs of enantiomers, (±)-rhodotomentodimer F, (±)-rhodotomentodimer G, and (±)-rhodotomentomonomer E, and one phloroglucinol-sesquiterpene meroterpenoid, rhodotomentodione E, together with one previously reported congener, (±)-rhodomyrtosone A, were obtained from the leaves of Rhodomyrtus tomentosa. The structures including absolute configurations of previously undescribed isolates were elucidated by extensive spectroscopic analysis (HRESIMS and NMR), ECD calculations, and single-crystal X-ray diffraction. (±)-Rhodotomentodimer F is a rare phloroglucinol derivative conjugated by a β-triketone moiety and an unprecedented resorcinol unit via the formation of a rare bis-furan ring system, whereas (±)-rhodotomentomonomer E shares a rearranged pentacyclic scaffold. Pharmacologically, (±)-rhodotomentomonomer E showed the strongest human acetylcholinesterase (hAChE) inhibitory effect with an IC50 value of 1.04 ± 0.05 μM. Molecular formula studies revealed that hydrogen bonds formed between hAChE residues Glu202, Ser203, Ala204, Gly121, Gly122, Tyr337, and His447 and (±)-rhodotomentomonomer E played crucial roles in its observed activity. These findings indicated that the leaves of Rhodomyrtus tomentosa can supply a rich source of hAChE inhibitors. These inhibitors might potentially be utilized in the therapeutic strategy for Alzheimer's disease, offering promising candidates for further research and development.

Current pharmacophore based approaches for the development of new anti-Alzheimer's agents

Amyloid beta peptide (Aβ) and hyperphosphorylated neuronal tau proteins accumulate in neurofibrillary tangles in Alzheimer's disease (AD), a chronic neurodegenerative illness. Chronic inflammation in the brain, which promotes disease progression, is another feature of the Alzheimer's disease pathogenesis. Approximately 60-70 % of dementia cases are caused by AD. The development of effective therapies for the treatment of AD is urgently needed given the severity of the condition and its rapidly rising prevalence. Cholinesterase inhibitors, beta-amyloid (A-beta), tau inhibitors, and many other medications are currently used as preventive medicine for AD. These medications can temporarily suppress dementia symptoms but cannot halt or reverse the disease's progression. Many international pharmaceutical companies have tried numerous times to develop an amyloid clearing medication based on the amyloid hypothesis, but without success. Therefore, the amyloid theory may not be entirely plausible. This review mainly covers the recent and important reported pharmacophores as the starting point to discuss already known targets like tau, butyrylcholinesterase, amyloid beta, and acetylcholinesterase and covers the literature between years 2019-2024.

Lathyrane and premyrsinane Euphorbia diterpenes against Alzheimer's disease: Bioinspired synthesis, anti-cholinesterase and neuroprotection bioactivity

The first systematic acylated diversification of naturally scarce premyrsinane diterpenes, together with their biosynthetic precursors lathyrane diterpene were carried out. Two new series of premyrsinane derivates (1a-32a) and lathyrane derivates (1-32) were synthesized from the naturally abundant lathyrane diterpene Euphorbia factor L3 through a bioinspired approach. The cholinesterase inhibitory and neuroprotective activities of these diterpenes were investigated to explore potential anti-Alzheimer's disease (AD) bioactive lead compounds. In general, the lathyrane diterpenes showed the better acetylcholinesterase (AChE) inhibitory activity than that of premyrsinanes. The lathyrane derivative 17 bearing a 3-dimethylaminobenzoyl moiety showed the best AChE inhibition effect with the IC50 value of 7.1 μM. Molecular docking demonstrated that 17 could bond with AChE well (-8 kal/mol). On the other hand, premyrsinanes showed a better neuroprotection profile against H2O2-induced injury in SH-SY5Y cells. Among them, the premyrsinane diterpene 16a had significant neuroprotective effect with the cell viability rate of 113.5 % at 12.5 μM (the model group with 51.2 %). The immunofluorescence, western blot and reactive oxygen species (ROS) analysis were conducted to demonstrate the mechanism of 16a. Furthermore, a preliminary SAR analysis of the two categories of diterpenes was performed to provide the insights for anti-AD drug development.

Potentials and future perspectives of multi-target drugs in cancer treatment: the next generation anti-cancer agents

Cancer is a major public health problem worldwide with more than an estimated 19.3 million new cases in 2020. The occurrence rises dramatically with age, and the overall risk accumulation is combined with the tendency for cellular repair mechanisms to be less effective in older individuals. Conventional cancer treatments, such as radiotherapy, surgery, and chemotherapy, have been used for decades to combat cancer. However, the emergence of novel fields of cancer research has led to the exploration of innovative treatment approaches focused on immunotherapy, epigenetic therapy, targeted therapy, multi-omics, and also multi-target therapy. The hypothesis was based on that drugs designed to act against individual targets cannot usually battle multigenic diseases like cancer. Multi-target therapies, either in combination or sequential order, have been recommended to combat acquired and intrinsic resistance to anti-cancer treatments. Several studies focused on multi-targeting treatments due to their advantages include; overcoming clonal heterogeneity, lower risk of multi-drug resistance (MDR), decreased drug toxicity, and thereby lower side effects. In this study, we'll discuss about multi-target drugs, their benefits in improving cancer treatments, and recent advances in the field of multi-targeted drugs. Also, we will study the research that performed clinical trials using multi-target therapeutic agents for cancer treatment.