Synthesis and evaluation of butylphthalide-scutellarein hybrids as multifunctional agents for the treatment of Alzheimer's disease.

A series of butylphthalide and scutellarein hybrids 3-(alkyl/alkenyl) hydroxyphthalide derivatives were designed, synthesized and evaluated as multifunctional agents against Alzheimer's disease. In vitro bioactivity assays indicated that most of the compounds displayed excellent antioxidant activity and moderate to good inhibition activities of self-induced Aß1-42 aggregation. Among them, compound 7c was demonstrated as a potential and balanced multifunctional candidate displaying the best inhibitory effects on self- and Cu2+-induced Aß1-42 aggregation (90.2 % and 35.4 %, respectively) and moderate activity for disaggregation of Aß1-42 aggregation (42.5 %). In addition, 7c also displayed excellent antioxidant (2.42 Trolox equivalents), metal ions chelating, oxidative stress alleviation, neuroprotective and anti-neuroinflammatory activities. Furthermore, in vivo study demonstrated that 7c could ameliorate the learning and memory impairment induced by sodium nitrite and Aß1-42 in the step-down passive avoidance test. These balanced multifunctional profiles supporting compound 7c as a novel potential candidate for the treatment of AD.

Development of novel salicylic acid-donepezil-rivastigmine hybrids as multifunctional agents for the treatment of Alzheimer's disease.

Alzheimer's disease (AD) is a chronic, progressive brain degenerative disease that is common in the elderly. So far, there is no effective treatment. The multi-target-directed ligands (MTDLs) strategy has been recognised as the most promising approach due to the complexity of the pathogenesis of AD. Herein, novel salicylic acid-donepezil-rivastigmine hybrids were designed and synthesised. The bioactivity results exhibited that 5a was a reversible and selective eqBChE inhibitor (IC50 = 0.53 µM), and the docking provided the possible mechanism. Compound 5a also displayed potential anti-inflammatory effects and significant neuroprotective effect. Moreover, 5a exhibited favourable stabilities in artificial gastrointestinal solution and plasma. Finally, 5a demonstrated potential cognitive improvement in scopolamine-induced cognitive dysfunction. Hence, 5a was a potential multifunctional lead compound against AD.

Discovery of novel 5-(2-hydroxyphenyl)-2-phthalide-3(3H)-pyrazolones as balanced multifunctional agents against Alzheimer's disease.

Based on previous work, a series of novel 5-(2-hydroxyphenyl)-2-phthalide-3(3H)-pyrazolones derivatives were identified as potential multifunctional therapeutic agents for Alzheimer's disease. Biological evaluation exhibited that these derivatives had great performance against MAO-B, Aß1-42 aggregation, oxidative stress and metal ion dyshomeostasis. Among them, 10x was selected as the optimal agent for its excellent MAO-B inhibitory activity (IC50 = 0.41 µM, SI > 24.4), good antioxidant activity (1.16 Trolox equivalent) and anti-Aß aggregation activity (56.03% and 57.51% for inhibition of self- and Cu2+-induced Aß1-42 aggregation; 81.91% and 82.40% for disaggregation of self- and Cu2+-induced Aß1-42 fibrils at 25.0 µM). Besides, 10x also exhibited obvious metal-ion chelating ability, anti-neuroinflammation (NO, TNF-α), neuroprotective activity and BBB permeability. More importantly, in vivo behavioral assessment demonstrated 10x could remarkably improve the memory and cognitive impairment in Aß1-42 induced AD mice model. Overall, these test results indicated 10x could serve as a balanced multifunctional anti-AD agent and deserved further research.

Research progress in traditional Chinese medicine in the treatment of Alzheimer's disease and related dementias.

Alzheimer's disease (AD) is the world's leading cause of dementia and has become a huge economic burden on nations and families. However, the exact etiology of AD is still unknown, and there are no efficient medicines or methods to prevent the deterioration of cognition. Traditional Chinese medicine (TCM) has made important contributions in the battle against AD based on the characteristics of multiple targets of TCM. This study reviewed the treatment strategies and new discoveries of traditional Chinese medicine in current research, which may be beneficial to new drug researchers.

Enhancement of the functionality of attenuating acute lung injury by a microemulsion formulation with volatile oil of Angelicae Sinensis Radix and Ligusticum Chuanxiong Rhizoma encapsulated.

Acute lung injury (ALI), a clinical syndrome of acute respiratory failure due to acute lung inflammation, remains a substantial public health problem in the worldwide. Ligusticum Chuanxiong Rhizoma and Angelicae Sinensis Radix was herb-pair of the traditional Chinese medicine. Modern pharmacological studies have shown that volatile oil extracted from Chuanxiong Rhizome and Angelicae Sinensis Radix is identified as an important active ingredient, which has good antipyretic, analgesic and anti-inflammatory effects. However, whether their volatile oil combination (CA-VO), has effects on the prevention and treatment of ALI has not been reported yet. Due to poor water solubility and low oral bioavailability of CA-VO, CA -VO-loaded microemulsion (CA-VO-ME) was formulated to enhance its oral bioavailability. The physical properties of CA-VO-ME were characterized. The pharmacokinetic parameters and the effect on ALI were evaluated. The particle size, polydispersity index, zeta potential, and encapsulation efficiency of CA-VO-ME were 20.19 ± 0.08 nm, 0.091 ± 0.01, 36.33 ± 4.29%, and 93.75%, respectively. CA-VO-ME had a greater bioavailability (214%) than CA-VO. CA-VO-ME reduced the lipopolysaccharide (LPS)-induced increase in levels of nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1ß (IL-1ß), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) in vitro and/or in vivo. Moreover, CA-VO-ME treatment notably decreased the lung index, ameliorated histopathological changes and prolonged the survival of ALI mice. By comparison, CA-VO-ME exerted a better effect on ALI than CA-VO, suggesting that CA-VO-ME is a promising drug for the treatment of ALI.

Novel donepezil-chalcone-rivastigmine hybrids as potential multifunctional anti-Alzheimer's agents: Design, synthesis, in vitro biological evaluation, in vivo and in silico studies.

Alzheimer's disease (AD) is a chronic, progressive brain neurodegenerative disorder. Up to now, there is no effective drug to halt or reverse the progress of AD. Given the complex pathogenesis of AD, the multi-target-directed ligands (MTDLs) strategy is considered as the promising therapy. Herein, a series of novel donepezil-chalone-rivastigmine hybrids was rationally designed and synthesized by fusing donepezil, chalone and rivastigmine. The in vitro bioactivity results displayed that compound 10c was a reversible huAChE (IC50 = 0.87 µM) and huBuChE (IC50 = 3.3 µM) inhibitor. It also presented significant anti-inflammation effects by suppressing the level of IL-6 and TNF-α production, and significantly inhibited self-mediated Aß1-42 aggregation (60.6%) and huAChE-mediated induced Aß1-40 aggregation (46.2%). In addition, 10c showed significant neuroprotective effect on Aß1-42-induced PC12 cell injury and activated UPS pathway in HT22 cells to degrade tau and amyloid precursor protein (APP). Furthermore, compound 10c presented good stabilty in artificial gastrointestinal fluids and liver microsomes in vitro. The pharmacokinetic study showed that compound 10c was rapidly absorbed in rats and distributed in rat brain after intragastric administration. The PET-CT imaging demonstrated that [11C]10c could quickly enter the brain and washed out gradually in vivo. Further, compound 10c at a dose of 5 mg/kg improved scopolamine-induced memory impairment, deserving further investigations.

Development of naringenin-O-alkylamine derivatives as multifunctional agents for the treatment of Alzheimer's disease.

In this study, a series of naringenin-O-alkylamine derivatives were designed and obtained by introducing an alkylamine fragment into the naringenin skeleton. The in vitro biological activity results revealed that compounds 5f and 7k showed good antioxidant activity with ORAC values of 2.3eq and 1.2eq, respectively. Compounds 5f and 7k were reversible and excellent huAChE inhibitors with IC50 values of 0.91 µM and 0.57 µM, respectively. Moreover, compounds 5f and 7k could inhibit self-induced Aß1-42 aggregation with 62.1% and 43.8% inhibition rate, respectively, and significantly inhibited huAChE-Aß1-40 aggregation with 51.7% and 43.4% inhibition rate, respectively. In addition, compounds 5f and 7k were selective metal chelators and remarkably inhibited Cu2+-induced Aß1-42 aggregation with 73.5% and 68.7% inhibition rates, respectively. Furthermore, compounds 5f and 7k could cross the blood-brain barrier in vitro and displayed good neuroprotective effects and anti-inflammatory properties. Further investigation showed that compound 5f did not show obvious hepatotoxicity and displayed a good hepatoprotective effect by its antioxidant activity. The in vivo study displayed that compound 5f significantly improved scopolamine-induced mice memory impairment. Therefore, compound 5f was a potential multifunctional candidate for the treatment of AD.

Development of novel 2-aminoalkyl-6-(2-hydroxyphenyl)pyridazin-3(2H)-one derivatives as balanced multifunctional agents against Alzheimer's disease.

Based on multitarget-directed ligands approach, through two rounds of screening, a series of 2-aminoalkyl-6-(2-hydroxyphenyl)pyridazin-3(2H)-one derivatives were designed, synthesized and evaluated as innovative multifunctional agents against Alzheimer's disease. In vitro biological assays indicated that most of the hybrids were endowed with great AChE inhibitory activity, excellent antioxidant activity and moderate Aß1-42 aggregation inhibition. Taken both efficacy and balance into account, 12a was identified as the optimal multifunctional ligand with significant inhibition of AChE (EeAChE, IC50 = 0.20 µM; HuAChE, IC50 = 37.02 nM) and anti-Aß activity (IC50 = 1.92 µM for self-induced Aß1-42 aggregation; IC50 = 1.80 µM for disaggregation of Aß1-42 fibrils; IC50 = 2.18 µM for Cu2+-induced Aß1-42 aggregation; IC50 = 1.17 µM for disaggregation of Cu2+-induced Aß1-42 fibrils; 81.7% for HuAChE-induced Aß1-40 aggregation). Moreover, it was equipped with the potential to serve as antioxidant (3.03 Trolox equivalents), metals chelator and anti-neuroinflammation agent for synergetic treatment. Finally, in vivo study demonstrated that 12a, with suitable BBB permeability (log BB = -0.61), could efficaciously ameliorate cognitive dysfunction on scopolamine-treated mice by regulating cholinergic system and oxidative stress simultaneously. Altogether, these results highlight the potential of 12a as an innovative balanced multifunctional candidate for Alzheimer's disease treatment.

6-Benzyloxyphthalides as selective and reversible monoamine oxidase B inhibitors with antioxidant and anti-neuroinflammatory activities for Parkinson's disease treatment.

A series of 6-benzyloxyphthalides were designed and synthesized as potent monoamine oxidase B inhibitors with antioxidant and anti-neuroinflammatory activities. The representative compounds 8f and 14a exhibited excellent selective MAO-B inhibition activity (IC50 = 1.33 nM, SI = 865; IC50 = 0.02 nM, SI = 40250, respectively) and moderate antioxidant activity (0.34 and 0.36 Trolox equivalent, respectively). Further studies showed that they were competitive and quasi-reversible MAO-B inhibitors. In cellular experiments, they could significantly decrease the production of NO and TNF-α in LPS-stimulated BV-2 cells to perform their in vitro anti-neuroinflammatory activities. Moreover, BBB permeability study and the predicted physicochemical properties indicated they were suitable for the CNS. Finally, in in vivo acute and subacute MPTP-induced mice model of PD, 8f and 14a could significantly improve most behavioral disorders, restore the DA content and decrease the MDA content in the mice striatum, exhibiting better anti-PD effects than clinically used safinamide. Hence, compounds 8f and 14a are identified in our studies as prospective prototype in the research of innovative multifunctional drugs for Parkinson's disease treatment.

Design, synthesis and evaluation of cinnamic acid hybrids as multi-target-directed agents for the treatment of Alzheimer's disease.

Herein, combining 1,2,3,4-tetrahydroisoquinoline and benzylpiperidine groups into cinnamic acid derivatives, a series of novel cinnamic acid hybrids was rationally designed, synthesized and evaluated by the multi-target-directed ligands (MTDLs) strategy. Hybrid 4e was the most promising one among these hybrids with a reversible huBuChE inhibitor (IC50 = 2.5 µM) and good MAO-B inhibition activity (IC50 = 1.3 µM) and antioxidant potency (ORAC = 0.4 eq). Moreover, compound 4e significantly inhibited self-mediated Aß1-42 aggregation (65.2% inhibition rate). Compound 4e exhibited remarkable anti-inflammatory propery and neuroprotective effect. Furthermore, compound 4e displayed favourable blood-brain barrier penetration via parallel artificial membrane permeation assay (PAMPA). The obtained results also revealed that compound 4e significantly improved dyskinesia recovery rate and response efficiency on AD model zebrafish. Further, 4e did not show obvious acute toxicity at dose up to 1500 mg/kg in vivo and improved scopolamine-induced memory impairment. Importantly, compound 4e showed good stability in both artificial gastric fluid and artificial intestinal fluid. Therefore, compound 4e presented a promising multi-targeted active molecule for treating AD.

Design, synthesis and evaluation of novel dimethylamino chalcone-O-alkylamines derivatives as potential multifunctional agents against Alzheimer's disease.

A novel series of dimethylamino chalcone-O-alkylamines derivatives was designed and synthesized as multifunctional agents for the treatment of AD. All the target compounds exhibited significant abilities to inhibit and disaggregate Aß aggregation, and acted as potential selective AChE inhibitors, biometal chelators and selective MAO-B inhibitors. Among these compounds, compound TM-6 showed the greatest inhibitory activity against self-induced Aß aggregation (IC50 = 0.88 µM) and well disaggregation ability toward self-induced Aß aggregation (95.1%, 25 µM), the TEM images, molecular docking study and molecular dynamics simulations provided reasonable explanation for its high efficiency, and it was also found to be a remarkable antioxidant (ORAC-FL values of 2.1eq.), the best AChE inhibitor (IC50 = 0.13 µM) and MAO-B inhibitor (IC50 = 1.0 µM), as well as a good neuroprotectant. UV-visual spectrometry and ThT fluorescence assay revealed that compound TM-6 was not only a good biometal chelator by inhibiting Cu2+-induced Aß aggregation (95.3%, 25 µM) but also could disassemble the well-structured Aß fibrils (88.1%, 25 µM). Further, TM-6 could cross the blood-brain barrier (BBB) in vitro. More importantly, compound TM-6 did not show any acute toxicity in mice at doses of up to 1000 mg/kg and improved scopolamine-induced memory impairment. Taken together, these data indicated that TM-6, an excellent balanced multifunctional inhibitor, was a potential lead compound for the treatment of AD.

Novel 3-benzylidene/benzylphthalide Mannich base derivatives as potential multifunctional agents for the treatment of Alzheimer's disease.

To discover novel multifunctional agents for the treatment of Alzheimer's disease, a series of 3-benzylidene/benzylphthalide Mannich base derivatives were designed, synthesized and evaluated. The biological screening results indicated that most of these derivatives exhibited good multifunctional activities. Among them, compound (Z)-13c raised particular interest because of its excellent multifunctional bioactivities. It displayed excellent EeAChE and HuAChE inhibition (IC50 = 9.18 × 10-5 and 6.16 × 10-4 µM, respectively), good MAO-B inhibitory activity (IC50 = 5.88 µM) and high antioxidant activity (ORAC = 2.05 Trolox equivalents). Additionally, it also exhibited good antiplatelet aggregation activity, moderate self- and Cu2+-induced Aß1-42 aggregation inhibitory potency, disaggregation ability on Aß1-42 fibrils, biometal chelating ability, appropriate BBB permeability and significant neuroprotective effect. Furthermore, (Z)-13c can also ameliorate the learning and memory impairment induced by scopolamine in mice. These multifunctional properties highlight compound (Z)-13c as a promising candidate for further development of multifunctional drug against AD.

Development of genistein-O-alkylamines derivatives as multifunctional agents for the treatment of Alzheimer's disease.

The multi-target-directed ligands have been regarded as the promising multifunctional agents for the treatment of Alzheimer's disease (AD). Based on our previous work, a series of genistein-O-alkylamines derivatives was developed to further explore the structure-activity-relationship. The results showed that compound 7d indicated reversible and highly selective hAChE inhibitory activity with IC50 value of 0.53 µM. Compound 7d also displayed good antioxidant activity (ORAC = 1.1 eq.), promising neuroprotective effect and selective metal chelation property. Moreover, compound 7d significantly inhibited self-induced, hAChE-induced and Cu2+-induced Aß aggregation with 39.8%, 42.1% and 74.1%, respectively, and disaggregated Cu2+-induced Aß1-42 aggregation (67.3%). In addition, compound 7d was a potential autophagy inducer and improved the levels of GPX4 protein. Furthermore, compound 7d presented good blood-brain-barrier permeability in vitro. More importantly, compound 7d did not show any acute toxicity at doses of up to 1000 mg/kg and presented good precognitive effect on scopolamine-induced memory impairment. Therefore, compound 7d was a promising multifunctional agent for the development of anti-AD drugs.

[Pharmacokinetics of eight active ingredients of Salviae Miltiorrhizae Radix et Rhizoma-Puerariae Lobatae Radix combination in rats].

To reveal the rationality of compatibility of Salviae Miltiorrhizae Radix et Rhizoma(SMRR) and Puerariae Lobatae Radix(PLR) from the perspective of pharmacokinetics, this study established a UPLC-MS/MS method for quantitative determination of PLR flavonoids(3'-hydroxy puerarin, puerarin, puerarin 6″-O-xyloside, 3'-methoxy puerarin, puerarin apioside) and salvianolic acids and tanshinones(salvianolic acid B, cryptotanshinone, and tanshinone Ⅱ_A) in plasma of rats. Rats were given SMRR extract, PLR extract, and SMRR-PLR extract by gavage and then plasma was collected at different time. UPLC separation was performed under the following conditions: Eclipse C_(18) column(2.1 mm×50 mm, 1.8 µm), 0.1% formic acid in water(A)-0.1% formic acid in acetonitrile(B) as mobile phase for gradient elution. Conditions for MS are as below: multiple reaction monitoring(MRM), ESI~(+/-). Comprehensive validation of the UPLC-MS/MS method(specifically, from the aspects of calibration curve, precision, accuracy, repeatability, stability, matrix effect, extract recovery) was performed and the result demonstrated that it complied with quantitative analysis requirements for biological samples. Compared with SMRR extract alone or PLR extract alone, SMRR-PLR extract significantly increased the AUC and C_(max) of PLR flavonoids and tanshinones in rat plasma, suggesting that the combination of SMRR and PLR promoted the absorption of the above components. The underlying mechanism needs to be further studied.

Pyrazinamide alleviates rifampin-induced steatohepatitis in mice by regulating the activities of cholesterol-activated 7α-hydroxylase and lipoprotein lipase.

The combination of rifampin and pyrazinamide is commonly used in the clinical treatment of tuberculosis, but its safety needs to be further clarified. Mice were intragastric administration of rifampin 300 mg/kg, pyrazinamide 625 mg/kg, rifampin 300 mg/kg plus pyrazinamide 625 mg/kg. The results showed that rifampin significantly increased transaminases, TBIL and TBA levels in serum, increased TG, TC content, HMGCR and CYP7A1 protein, CYP7A1, FGFR4, PXR, FAS and FXR mRNA expression, but decreased the level of SREBP-1c mRNA and induced severe steatohepatitis and hepatocyte necrosis in liver in mice. While pyrazinamide can improve many abnormal indexes when it used with RFP, including liver histopathology, liver TG, TC level and serum biochemistry, GPHBP1, FAS and CYP7A1 mRNA, LPL protein expression and activity induced by rifampin. However, pyrazinamide alone significantly decreased liver TG levels and caused only slight inflammatory pathological changes in liver histopathology in mice. These data suggested that rifampin increases TG and TC levels in the liver may be related to activate HMGCR, CYP7A1, PXR and FXR, theses toxic actions of rifampin were alleviated by pyrazinamide may be due to inhibite the activity of CYP7A1, PXR and FAS, and increasing the LPL protein expression and activity.

Design, synthesis and biological evaluation of novel O-carbamoyl ferulamide derivatives as multi-target-directed ligands for the treatment of Alzheimer's disease.

A novel series of O-carbamoyl ferulamide derivatives were designed by multitarget-directed ligands (MTDLs) strategy, the derivatives were synthesized and evaluated to treat Alzheimer's disease (AD). In vitro biological evaluation demonstrated that compound 4f was the best pseudo-irreversible hBChE (human butyrylcholinesterase) inhibitor with an IC50 value of 0.97 µM 4f was a potent selective MAO-B (monoamine oxidase-B) inhibitor (IC50 = 5.3 µM), and could inhibit (58.2%) and disaggregate (43.3%) self-mediated Aß aggregation. 4f also could reduce the levels of pathological tau and APP clearance, and displayed a wide safe range hepatotoxicity on LO2 cells. The in vivo studies revealed that 4f exhibited fascinating dyskinesia recovery rate and response efficiency on AlCl3-mediated zebrafish, and demonstrated significant protective effect on vascular injury caused by Aß1-40. PET-CT imaging demonstrated that [11C]4f exhibited high BBB penetration (especially could reach to hippocampus and striatum of brain) and had a fast brain uptake after intravenous bolus injection. Furthermore, compound 4f could improve scopolamine-induced cognitive impairment. Further, the metabolism in vitro of 4f was also investigated, and presented 3 metabolites in rat liver microsome metabolism, 4 metabolites in human liver microsome, and 4 metabolites in rat intestinal flora, providing previous data for the preclinical study. Therefore, these results implied that compound 4f was an advanced multi-function agent and deserved further preclinical study against mild-to-serve Alzheimer's disease.

The development of advanced structural framework as multi-target-directed ligands for the treatment of Alzheimer's disease.

In this work, we have developed a novel series of multi-target-directed ligands to address low levels of acetylcholine (ACh), oxidative stress, metal ion dysregulation, and the misfolded proteins. Novel apigenin-donepezil derivatives, naringenin-donepezil derivatives, genistein-donepezil derivatives and chalcone-donepezil derivatives have been synthesized, in vitro results showed that TM-4 was a reversible and potent huAChE (IC50 = 0.36 µM) and huBChE (IC50 = 15.3 µM) inhibitor, and showed potent antioxidant activity (ORAC = 1.2 eq). TM-4 could significantly inhibit self-induced Aß1-42 aggregation (IC50 = 3.7 µM). TM-4 was also an ideal neuroprotectant, potential metal chelation agent, and it could inhibit and disaggregate huAChE-induced and Cu2+-induced Aß aggregation. Moreover, TM-4 could activate UPS degradation pathway in HT22 cells and induce autophagy on U87 cells to clear abnormal proteins associated with AD. More importantly, TM-4 could cross BBB in vitro assay. In addition, in vivo assay revealed that TM-4 exhibited remarkable dyskinesia recovery rate and response efficiency on AlCl3-induced zebrafish AD model, and TM-4 indicated surprising protective effect on Aß1-40-induced vascular injury. TM-4 presented precognitive effect on scopolamine-induced memory impairment. And the regulation of multi-targets for TM-4 were further conformed through transcriptome sequencing. More interesting, the blood, urine and feces metabolism in rat and rat/human liver microsome metabolism towards TM-4 were also investigated. Overall, TM-4 is a promising multi-function candidate for the development of drugs to Alzheimer's disease.

Design, synthesis and evaluation of phthalide alkyl tertiary amine derivatives as promising acetylcholinesterase inhibitors with high potency and selectivity against Alzheimer's disease.

A series of phthalide alkyl tertiary amine derivatives were designed, synthesized and evaluated as potential multi-target agents against Alzheimer's disease (AD). The results indicated that almost all the compounds displayed significant AChE inhibitory and selective activities. Besides, most of the derivatives exhibited increased self-induced Aß1-42 aggregation inhibitory activity compared to the lead compound dl-NBP, and some compounds also exerted good antioxidant activity. Specifically, compound I-8 showed the highest inhibitory potency toward AChE (IC50 = 2.66 nM), which was significantly better than Donepezil (IC50 = 26.4 nM). Moreover, molecular docking studies revealed that compound I-8 could bind to both the catalytic active site and peripheral anionic site of AChE. Furthermore, compound I-8 displayed excellent BBB permeability in vitro. Importantly, the step-down passive avoidance test indicated that I-8 significantly reversed scopolamine-induced memory deficit in mice. Collectively, these results suggested that I-8 might be a potent and selective AChE inhibitor for further anti-AD drug development.

Design, synthesis and evaluation of flurbiprofen-clioquinol hybrids as multitarget-directed ligands against Alzheimer's disease.

A series of novel flurbiprofen-clioquinol hybrids were designed and synthesized as multifunctional agents for Alzheimer's disease therapy, and their potential was evaluated through various biological experiments. In vitro studies showed that most target compounds exhibited significant ability to inhibit self- and Cu2+-induced ß-amyloid aggregation. Furthermore, some target compounds, especially 7i and 7r, also showed biometal chelating abilities, antioxidant activity, anti-neuroinflammatory activity and appropriate BBB permeability. These biological activities indicated that the representative compound 7i and 7r might be promising multifunctional agents for AD treatment.

Apigenin-rivastigmine hybrids as multi-target-directed liagnds for the treatment of Alzheimer's disease.

Here we reported novel apigenin-rivastigmine hybrids were rationally designed and synthesized by the multi-target-directed ligands (MTDLs) strategy, their activity in vitro results revealed that compound 3d showed significant antioxidant potency (ORAC = 1.3 eq), and it was a reversible huAChE (IC50 = 6.8 µM) and huBChE (IC50 = 16.1 µM) inhibitor. 3d also served as a selective metal chelator, and it significantly inhibited and disaggregated self-mediated and Cu2+-mediated Aß1-42 aggregation, and also inhibited hAChE-mediated induced Aß1-40 aggregation. Compound 3d exhibited remarkable neuroprotective effect and hepatoprotective activity. In addition, compound 3d presented favourable blood-brain barrier penetration in vitro and drug-like property. Further, the in vivo assay displayed that 3d indicated remarkable dyskinesia recovery rate and response efficiency on AD zebrafish, and exhibited surprising protective effect on Aß1-40-mediated zebrafish vascular injury. More importantly, 3d did not indicate obvious acute toxicity at dose up to 2000 mg/kg, and could improve scopolamine-induced memory impairment. Subsequently, the regulation of multi-targets for 3d were further confirmed through transcriptome sequencing of brain hippocampi, which also offered novel potential targets and opened a new way to treat Alzheimer's disease. More interestingly, the metabolism of 3din vitro indicated that 4 metabolites in rat liver microsome metabolism, 2 metabolites in human liver microsome metabolism, and 4 metabolites in intestinal flora metabolism, which offered supports for the preclinical study of 3d. Overall, this study exhibited that compound 3d was a promising advanced compound targeted multiple factors associated with AD.