Identification of novel PD-1/PD-L1 small molecule inhibitors: virtual screening, synthesis and in vitro characterisation.

The PD-1/PD-L1 pathway is considered as one of the most promising immune checkpoints in tumour immunotherapy. However, researchers are faced with the inherent limitations of antibodies, driving them to pursue PD-L1 small molecule inhibitors. Virtual screening followed by experimental validation is a proven approach to discover active compounds. In this study, we employed multistage virtual screening methods to screen multiple compound databases to predict new PD-1/PD-L1 ligands. 35 compounds were proposed by combined analysis of fitness scores, interaction pattern and MM-GBSA binding affinities. Enzymatic assay confirmed that 10 out of 35 ligands were potential PD-L1 inhibitors, with inhibitory rate higher than 50% at the concentration of 30 µM. Among them, ZDS20 was identified as the most effective inhibitor with low micromolar activity (IC50 = 3.27 µM). Altogether, ZDS20 carrying novel scaffold was identified and could serve as a lead for the development of new classes of PD-L1 inhibitors.

Development of a hydroxypropyl methyl cellulose/polyacrylic acid interpolymer complex formulated buccal mucosa adhesive film to facilitate the delivery of insulin for diabetes treatment.

Buccal mucosa administration is a promising method for insulin (INS) delivery with good compliance. However, buccal mucosa delivery systems still face challenges of long-term mucosal adhesion, sustained drug release, and mucosal drug penetration. To address these issues, a double-layer film consisting of a hydroxypropyl methylcellulose/polyacrylic acid interpolymer complex (IPC)-formulated mucoadhesive layer and an ethylcellulose (EC)-formulated waterproof backing layer (IPC/EC film) was designed. Protamine (PTM) and INS were co-loaded in the mucoadhesive layer of the IPC/EC film (PTM-INS-IPC/EC film). In ex vivo studies with porcine buccal mucosa, this film exhibited robust adhesion, with an adhesion force of 120.2 ±â€¯20.3 N/m2 and an adhesion duration of 491 ±â€¯45 min. PTM has been shown to facilitate INS mucosal transfer. Pharmacokinetic studies indicated that the PTM-INS-IPC/EC film significantly improved the absorption of INS, exhibiting a 1.45 and 2.24-fold increase in the area under the concentration-time curve (AUC0-∞) compared to the INS-IPC/EC film and free INS, respectively. Moreover, the PTM-INS-IPC/EC film effectively stabilized the blood glucose levels of type 1 diabetes mellitus (T1DM) rats with post oral glucose administration, maintaining lower glucose levels for approximately 8 h. Hence, the PTM-INS-IPC/EC film provides a promising noninvasive INS delivery system for diabetes treatment.

Design and Synthesis of Novel Phthalide Derivatives containing 1,3,4-Oxadiazole/1,2,4-Triazole Units as Potential Antifungal Agents.

Four series of novel 1,3,4-oxadiazole/1,2,4-triazole hybrids of phthalide derivatives were designed and synthesized to search for novel potential antifungal agents. Preliminary antifungal activity assay results showed that compounds 4 a, 4 b, 4 m, 5 b, 5 f, 5 h, and 7 h exhibited moderate to excellent inhibitory activity against some phytopathogenic fungi. Among them, compound 5 b displayed the most outstanding antifungal effects against V. mali and S. sclerotiorum, with the EC50 mean of 3.96 µg/mL and 5.60 µg/mL, respectively, which was superior to those of commercial fungicides hymexazol and chlorothalonil. Furthermore, compound 5 b could completely suppress the spore germination of V. mali at a concentration of 10 µg/mL. Finally, molecular docking revealed that the potential target for the antifungal activity of compound 5 b was succinate dehydrogenase (SDH). This research provides novel candidate compounds for the prevention of phytopathogenic fungi.

Integrated investigation and experimental validation of PPARG as an oncogenic driver: implications for prognostic assessment and therapeutic targeting in hepatocellular carcinoma.

Peroxisome proliferator-activated receptor gamma (PPARG), a key transcription factor involved in lipid metabolism and glucose homeostasis, has been implicated in various types of cancer. However, its precise role in cancer remains unclear. In this study, we conducted a comprehensive pan-cancer analysis of PPARG expression using various types of cancer obtained from public databases. We observed significant heterogeneity in PPARG expression across different types of cancer. The association between PPARG expression and patient prognosis was investigated using Cox proportional hazards regression models and survival analysis. Clinical features and protein expression levels in the cohort showed that PPARG expression was strongly associated, suggesting its potential as a therapeutic target. We also evaluated the prognostic potential of PPARG by analyzing immune infiltration and genomic stability. We experimentally validated the potential of PPARG as a therapeutic target by analyzing drug sensitivity profiles, molecular docking simulations, and in vitro cell proliferation assays associated with PPARG expression. We identified common expression patterns of PPARG with other genes involved in key carcinogenic pathways. This provides deeper insights into the molecular mechanisms underlying its carcinogenic role. Additionally, functional enrichment analysis revealed significant enrichment of genes related to drug metabolism, cell proliferation, and immune response pathways associated with PPARG. Our findings highlight the importance of PPARG in the broader biology of cancer and suggest its potential as a diagnostic and therapeutic target for specific types of cancer. The results of our study provide strong support for the potential role of PPARG as a promising prognostic biomarker and immunotherapeutic target across various types of cancer.

Aerobic Dehydrogenative Aromatization in the Preparation of 4-Aminoquinoline Derivatives by Synergistic Pd/Cu Catalysis.

The 4-aminoquinoline moiety is widely present in various bioactive compounds and marketed drugs, while the preparation of this target structure relies heavily on the amination of 4-chloroquinolines. Herein, an atom and step economic procedure was developed based on an aerobic dehydrogenative aromatization strategy. Unlike the well-known palladium-catalyzed dehydrogenative aromatization of cyclohexanones with amines, synergistic Pd/Cu catalysis is crucial for 2,3-dihydroquinolin-4(1H)-one type of substrates. Under the optimized conditions, a range of aromatic/aliphatic amines and 2,3-dihydroquinolin-4(1H)-ones were coupled to give the corresponding 4-aminoquinoline products in moderate to high yields, and the application of the current methodology for the preparation and late-stage diversification of marketed drugs was also demonstrated.

Design, synthesis and bioevaluation of PI3Kα-selective inhibitors as potential colorectal cancer drugs.

The dysregulation of the phosphoinositide 3-kinase (PI3K)/mammalian target of rapamycin signaling pathway has been implicated in various human cancers, and isoform-selective inhibitors targeting PI3Kα have received significant interest in recent years. In this study, we have designed and synthesized three series of substituted benzoxazole derivatives based on the clinical candidate TAK-117 (8a). A detailed structure-activity relationship (SAR) study has identified the optimal compound 18a bearing a quinoxaline scaffold. Compared to the control 8a, 18a exhibited 4.4-fold more potent inhibitory activity against PI3Kα (IC50: 2.5 vs 11 nM) and better isoform-selective profiles over other PI3Ks. In addition, 18a showed a 1.5-fold more potent antiproliferative effect against HCT-116 cell lines (IC50: 3.79 vs 5.80 µM) and a better selectivity over the normal tissue cells. The potential antitumor mechanism and in vitro metabolic stability of 18a were also investigated. Notably, pharmacokinetic assays indicated that 18a had a higher plasma exposure, a higher maximum concentration and shorter elimination time compared to 8a.

Design, synthesis and evaluation of 2, 6, 8-substituted Imidazopyridine derivatives as potent PI3Kα inhibitors.

Inhibition of PI3K pathway has become a desirable strategy for cancer treatment. In this work, a series of 2, 6, 8-substituted Imidazo[1,2-a]pyridine derivatives were designed and screened for their activities against PI3Kα and a panel of PI3Kα-addicted cancer cells. Among them, compound 35 was identified as a PI3Kα inhibitor with nanomolar potency as well as acceptable antiproliferative activity. Flow cytometry analysis confirmed 35 induced cell cycle arrest and apoptosis in T47D cells. In addition, it also showed desirable in vitro ADME properties. The design, synthesis, and SAR exploration of 35 are described within.

Design, synthesis and biological evaluation of cajanonic acid A analogues as potent PPAR γ antagonists.

Peroxisome proliferator-activated receptor γ (PPAR γ) antagonists are a key instrument of insulin sensitizers since they have the ability to sensitize insulin and can avoid adverse reactions caused by receptor agonist. In this paper, two series of 28 novel Cajanonic acid A (CAA) derivatives were designed and synthesized. The biological activity showed that a novel CAA derivative 9f was identified as a potential PPAR γ antagonist by medicinal chemistry efforts. The results in vitro displayed that compound 9f could improve the PPAR γ antagonist activity (96.2 % / 50.2 % decrease in PPAR γ transactivation at 10 µM / 1 µM, respectively). It also could improve the glucose consumption activity of insulin-resistant HepG2/3T3-L1 cell line (33.27 % / 72.61 % increase in glucose consumption). And in 3 T3-L1 adipocytes, it showed anti-adipogenesis activity (7.04 % increase in oil red staining). Further, in vivo study suggested that compound 9f could improve the oral glucose tolerance in db/db mice. Taken together, derivative 9f served as a promising candidate for anti-diabetic drug discovery and deserve further study.

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.

Synthesis and biological evaluation of cajanonic acid A derivatives as potential PPARγ antagonists.

Four series of cajanonic acid A (CAA) derivatives have been designed and synthesized. The newly prepared compounds have been screened for glucose consumption activity in HepG2 cell lines and PPARγ antagonistic activity in HEK293 cell lines. Compound 26g bearing a tetrahydroisoquinolinone scaffold showed the most potent PPARγ antagonistic and hypoglycemic activities. An oral glucose tolerance test (OGTT) was performed and the results further confirmed that 26g was a potent hypoglycemic agent. In addition, the possible binding modes for compound 26g in the PPARγ protein have been investigated in this study.

Design, synthesis and evaluation of tetrahydrocarbazole derivatives as potential hypoglycemic agents.

Two series of tetrahydrocarbazole derivatives have been designed and synthesized based on ZG02, a promising candidate developed in our previous studies. The newly prepared compounds were screened for glucose consumption activity in HepG2 cell lines. Aza-tetrahydrocarbazole compound 12b showed the most potent hypoglycemic activity with a 45% increase in glucose consumption when compared to the solvent control, which had approximately 1.2-fold higher activity than the positive control compounds (metformin and ZG02). An investigation of the potential mechanism indicated that 12b may exhibit hypoglycemic activity via activation of the AMPK pathway. Metabolic stability assays revealed that 12b showed good stability profiles in both artificial gastrointestinal fluids and blood plasma from SD rats. An oral glucose tolerance test (OGTT) was performed and the results further confirmed that 12b was a potent hypoglycemic agent.

Design, synthesis and bioevaluation of novel substituted triazines as potential dual PI3K/mTOR inhibitors.

A series of novel substituted triazines bearing a benzimidazole scaffold were designed and synthesized based on the structures of known anti-cancer agents, namely gedatolisib and alpelisib. All the target compounds were screened for inhibitory activity against PI3Kα and mTOR kinases. Notably, most analogs exhibited IC50 in the nanomolar range. Investigation of the isozyme selectivity indicated that the compounds exhibited remarkable inhibitory activity against PI3Kδ, especially compound 19f showed an IC50 value of 2.3 nM for PI3Kδ and moderate δ-isozyme selectivity over other class I PI3K isoforms and mTOR (with IC50 values of 14.6, 34.0, 849.0 and 15.4 nM for PI3Kα, ß, γ and mTOR, respectively). An in vitro MTT assay was conducted to assess the antiproliferative and cytotoxic effects of the prepared analogs. It was revealed that the compounds displayed significant inhibitory activities against the HCT116 human colon cancer cell line. Compound 19i showed 4.7-fold higher potency than the positive control gedatolisib (0.3 vs. 1.4 µM, IC50 values). Phosphoblot studies demonstrated that 19c and 19i could significantly suppress the PI3K/Akt/mTOR signaling pathway at 10 µM. Moreover, analogs 19b, 19c and 19i displayed better stability in artificial gastric fluids than gedatolisib, while 19i was indicated not very stable in rat liver microsomes, and may occur phase I metabolic transformations.

Pharmacokinetics, Tissue Distribution, and Excretion Study of Cajanonic Acid A in Rats by UPLC-MS/MS.

Cajanonic acid A (CAA), a prenylated stilbene derivative extracted from the leaves of pigeon pea (Cajanus cajan), has been reported to possess inhibitory activity on the peroxisome proliferator-activated receptor gamma (PPARγ) and protein tyrosine phosphatase 1B (PTP1B). Its hypoglycemic activity in rats is comparable to that of the approved antidiabetic agent rosiglitazone. Therefore, CAA is a potential candidate for the treatment of type 2 diabetes and a lead compound for the discovery of novel hypoglycemic drugs. To achieve a thorough understanding of the biological behavior of CAA in vivo, our current study was designed to investigate the pharmacokinetics, bioavailability, distribution, and excretion of CAA in rats by UPLC-MS/MS. Chromatographic separation was performed on BEHC18 column (2.1 mm × 50 mm, 1.7 µm). Quantification was performed under the negative ion mode by using single reaction monitoring (SRM) of the transitions of m/z 353.14 → 309.11 for CAA and m/z 269.86 → 224.11 for genistein, respectively. Standard calibration curve showed excellent linearity (r2 > 0.99) within the range of 2 - 800 ng/mL. The accuracies and precisions were within the acceptance limits (all < 20%). CAA was quickly absorbed into bloodstream and distributed rapidly and widely to various tissues. The excretion ratio of CAA in the 3 main pathways via bile, feces, and urine was only 5.17%. These results indicate that CAA was quickly and thoroughly metabolized in vivo and excreted mainly as metabolites.

Novel berberine-based derivatives with potent hypoglycemic activity.

Four series of berberine derivatives were designed and synthesized. All the synthetic compounds were screened for in vitro glucose consumption activity in HepG2 cell lines. The results showed that most of the tested compounds exhibited potent hypoglycemic activity, and the most potent compound 20b exhibited its potency by 3.23-fold of berberine, 1.39-fold of metformin and 1.20-fold of rosiglitazone, respectively. Western blot assay indicated these novel berberine-based derivatives executed their glucose-decreasing activity via the activation of AMPK pathway.

Munronin O, a potential activator for plant resistance.

A series of limonoids (1-8) were isolated from the whole plant of Munronia henryi and antiviral activities of the compounds were evaluated. The bioassay results demonstrated that Munronin O (1) showed remarkable protective activity and compounds 7 and 8 showed significant inactivating, protective, and curative activities against tobacco mosaic virus (TMV). With a 50% effective concentration (EC50) value of 91.5 µg/mL, compound 1 exhibited the best protective activity compared with ningnanmycin (192.3 µg/mL). The potential for these compound of inducing systemic acquired resistance (SAR) was also evaluated, and compound 1 showed excellent induction activities. Furthermore, it was found that potentiation of defense-related enzyme activity and the contents of SA was increased. Compound 1 could also inhibit the expression of TMV CP and up-regulate the expression of defense-related genes. This work revealed that compound 1 can induce resistance and enhance plant tolerance to TMV infection. Hence, compound 1 can be considered as a potential activator for inducing plant resistance.

Oleanolic acid derivative DKS26 exerts antidiabetic and hepatoprotective effects in diabetic mice and promotes glucagon-like peptide-1 secretion and expression in intestinal cells.

BACKGROUND AND PURPOSE: Glucagon-like peptide-1 (GLP-1) is an important target for diabetes therapy based on its key role in maintaining glucose and lipid homeostasis. This study was designed to investigate antidiabetic and hepatoprotective effects of a novel oleanolic acid derivative DKS26 in diabetic mice and elucidate its underlying GLP-1 related antidiabetic mechanisms in vitro and in vivo. EXPERIMENTAL APPROACH: The therapeutic effects of DKS26 were investigated in streptozotocin (STZ)-induced and db/db diabetic mouse models. Levels of plasma glucose, glycosylated serum protein (GSP), lipid profiles, insulin, alanine aminotransferase (ALT) and aspartate aminotransferase (AST), oral glucose tolerance (OGT), pancreatic islets and hepatic histopathological morphology, liver lipid levels and expression of pro-inflammatory cytokines were assessed. Intestinal NCI-H716 cells and diabetic models were used to further validate its potential GLP-1-related antidiabetic mechanisms. KEY RESULTS: DKS26 treatment (100 mg·kg-1 ·day-1 ) decreased plasma levels of glucose, GSP, ALT and AST; ameliorated OGT and plasma lipid profiles; augmented plasma insulin levels; alleviated islets and hepatic pathological morphology; and reduced liver lipid accumulation, inflammation and necrosis in vivo. Furthermore, DKS26 enhanced GLP-1 release and expression, accompanied by elevated levels of cAMP and phosphorylated PKA in vitro and in vivo. CONCLUSION AND IMPLICATIONS: DKS26 exerted hypoglycaemic, hypolipidaemic and islets protective effects, which were associated with an enhanced release and expression of GLP-1 mediated by the activation of the cAMP/PKA signalling pathway, and alleviated hepatic damage by reducing liver lipid levels and inflammation. These findings firmly identified DKS26 as a new viable therapeutic option for diabetes control.

Protective effects of Semiaquilegia adoxoides n-butanol extract against hydrogen peroxide-induced oxidative stress in human lens epithelial cells.

Context Hydrogen peroxide (H2O2)-induced damage in the lens epithelium leads to cell death and cataract. Semiaquilegia adoxoides (DC.) Makino (Ranunculaceae), a folk medicine of Hmong (an ethnic group of China), has been traditionally used to treat cataract; however, the underlying molecular mechanism is yet to be uncovered. Objective This study aimed to investigate whether the n-butanol extract of S. adoxoides (nSA) is effective against the H2O2-induced oxidative stress in human lens epithelial (HLE) cells. Materials and methods Human lens epithelial (SRA 01/04) cells were stimulated by H2O2 (250 µM) in the presence or absence of nSA. The antioxidant effects of nSA were determined in terms of cell viability (MTT assay), apoptosis (AnnexinV/PI staining), radical scavenging capability (various enzymatic assays), loss of mitochondrial membrane potential (Rhodamine 123 staining), expression of apoptotic markers including caspase-3 and caspase-9 and the change of Bcl-2/Bax ratio (western blot) in the HLE cells. Results The results showed that pretreatment of nSA (250, 500 and 1000 µg/mL) markedly reduced H2O2-induced cellular apoptosis and malondialdehyde accumulation, but elevated the activities of total superoxide dismutase, catalase, glutathione peroxidase. Thus, the total antioxidative capability was enhanced upon the nSA treatment meanwhile the loss of mitochondrial membrane potential was prevented. Moreover, nSA at concentrations of 250, 500 and 1000 µg/mL also significantly suppressed the activation of caspase-3 and -9, and increased the Bcl-2/Bax ratio in the HLE cells. Discussion and conclusion Our findings suggested that nSA is a potential prophylactic agent in the prevention of cataractogeneis.

Design, synthesis and biological evaluation of GY3-based derivatives for anti-type 2 diabetes activity.

A series of indole carboxylic acid derivatives were designed and synthesized. Their anti-type 2 diabetes activity was evaluated in HepG2 cell and db/db mice. The results showed that compounds 8c, 17a, 17b, 15a and 15b could significantly increase glucose consumption in HepG2 cell. Furthermore, compound 8c was able to lower the blood glucose level and induce less weight gain in db/db mice.

Design, synthesis and insulin-sensitizing activity of indomethacin and diclofenac derivatives.

A series of aromatic acetic acid compounds were designed and synthesized on the basis of Non-steroidal anti-inflammatory drugs indomethacin and diclofenac. Compounds 5a, 7a, 5h, 7h and 17 could strongly promote insulin-regulated differentiation of 3T3-L1 cells in vitro. They acted as full or partial PPARgamma agonist, or improved insulin resistance through non-PPARgamma pathway.