Selective inhibition of interleukin-1 receptor-associated kinase 1 ameliorates lipopolysaccharide-induced sepsis in mice

Interleukin-1 receptor-associated kinases (IRAKs), particularly IRAK1 and IRAK4, are important in transducing signal from Toll-like receptor 4. We interrogated if a selective inhibition of IRAK1 could alleviate lipopolysaccharide (LPS)-induced sepsis. In this study, we tested the impact of a novel selective IRAK1 inhibitor Jh-X-119-01 on LPS-induced sepsis in mice. Survival at day 5 was 13.3% in control group where septic mice were treated by vehicle, while the values were 37.5% (p = 0.046, vs. control) and 56.3% (p = 0.003, vs. control) for 5 mg/kg and 10 mg/kg Jh-X-119-01-treated mice. Jh-X-119-01 alleviated lung injury and reduced production of TNFα and IFNγ in peritoneal macrophages. Jh-X-119-01 decreased phosphorylation of NF-κB and mRNA levels of IL-6 and TNFα in LPS-treated macrophages in vitro. Jh-X-119-01 selectively inhibited IRAK1 phosphorylation comparing with a non-selective IRAK1/4 inhibitor which simultaneously inhibited phosphorylation of IRAK1 and IRAK4. Both Jh-X-119-01 and IRAK1/4 inhibitor increased survival of septic mice, but Jh-X-119-01-treated mice had higher blood CD11b⁺ cell counts than IRAK1/4 inhibitor-treated ones [24 h: (1.18 ± 0.26) × 10⁶/ml vs. (0.79 ± 0.20) × 10⁶/ml, p = 0.001; 48 h: (1.00 ± 0.30) × 10⁶/ml vs. (0.67 ± 0.23) × 10⁶/ml, p = 0.042]. IRAK1/4 inhibitor induced more apoptosis of macrophages than Jh-X-119-01 did in vitro. IRAK1/4 inhibitor decreased protein levels of anti-apoptotic BCL-2 and MCL-1 in RAW 264.7 and THP-1 cells, an effect not seen in Jh-X-119-01-treated cells. In conclusion, Jh-X-119-01 selectively inhibited activation of IRAK1 and protected mice from LPS-induced sepsis. Jh-X-119-01 showed less toxicity on macrophages comparing with a non-selective IRAK1/4 inhibitor.     

Phyllanthus emblica (Amla) methanolic extract regulates multiple checkpoints in 15-lipoxygenase mediated inflammopathies: Computational simulation and in vitro evidence

Amla (Phyllanthus emblica) has long been used in traditional folk medicine to prevent and cure a variety of inflammatory diseases. In this study, the antioxidant activity (DPPH scavenging and reducing power), anti-inflammatory activity (RBC Membrane Stabilization and 15-LOX inhibition), and anticoagulation activity (Serin protease inhibition and Prothrombin Time assays) of the methanolic extract of amla were conducted. Amla exhibited a substantial amount of phenolic content (TPC: 663.53 mg GAE/g) and flavonoid content (TFC: 418.89 mg GAE/g). A strong DPPH scavenging effect was observed with an IC₅₀ of 311.31 µg/ml as compared to standard ascorbic acid with an IC₅₀ of 130.53 µg/ml. In reducing power assay, the EC₅₀ value of the extract was found to be 196.20 µg/ml compared to standard ascorbic acid (EC₅₀ = 33.83 µg/ml). The IC₅₀ value of the RBC membrane stabilization and 15-LOX assays was observed as 101.08 µg/ml (IC₅₀ of 58.62 µg/ml for standard aspirin) and 195.98 µg/ml (IC₅₀ of 19.62 µg/ml for standard quercetin), respectively. The extract also strongly inhibited serine protease (trypsin) activity with an IC₅₀ of 505.81 µg/ml (IC₅₀ of 295.44 µg/ml for standard quercetin). The blood coagulation time (PTT) was found to be 11.91 min for amla extract and 24.11 min for standard Warfarin. Thus, the findings of an in vitro study revealed that the methanolic extract of amla contains significant antioxidant, anti-inflammatory, and anticoagulation activity. Furthermore, in silico docking and simulation of reported phytochemicals of amla with human 15-LOXA and 15-LOXB were carried out to validate the anti-inflammatory activity of amla. In this analysis, epicatechin and catechin showed greater molecular interaction and were considerably stable throughout the 100 ns simulation with 15-lipoxygenase A (15-LOXA) and 15-lipoxygenase B (15-LOXB) respectively.     

Bioactivity and molecular docking of lactones isolated from Centaurea pseudosinaica Czerep

Two cytotoxic sesquiterpene lactones, 17-epichlorohyssopifolin A (1) and chlorjanerin (2), and a monoterpene lactone, loliolide (3) were isolated from Centaurea pseudosinaica. The cytotoxicity of the total extract and terpenoids 1–3 were evaluated against three human cancer cells (HepG2, PC-3, and HT-29), along with the human normal primary epidermal keratinocytes (HEKa) cells. With IC₅₀ values ranging between 0.6 ± 0.04 and 5.0 ± 0.61 μg/mL against HepG2; 0.2 ± 0.01 and 11.9 ± 1.31 μg/mL against PC-3, and 0.04 ± 0.013 and 8.9 ± 0.97 μg/mL against HT-29, the total extract, and lactones 1–3 demonstrated cytotoxic effects. Compound 1 displayed the strongest impact on all cancer cells and a slightly safe effect on the normal cells HEKa. Compound 1 caused accumulation of HepG2 and HT-29 cells in G1 phase as displayed cell cycle analysis. On the other hand, the cell distributions were increased in the S phase in PC-3 cells. Furthermore, 1 caused apoptosis in PC-3 and HePG2 cells with 91.50%, and 79.72 %, respectively. A higher fraction of necrotic cells was observed in HT-29 cells amounting to 23.60%. These results suggested that the promising cytotoxicity exhibited by 1 is brought by the apoptosis induction in the cancer cells, which were evaluated. As the compounds showed antiproliferative effect against the HT-29 cells, the docking simulation was performed aiming at determining how they would interact with the EGFR enzyme, whose PDB: 4I23 is considered one of the two distinct wild types of EGFR enzymes. The antibacterial activity results revealed that 3 showed the most remarkable antibacterial effects, especially against the examined Gram-positive bacteria. The total extract exhibited potent activity against all examined bacteria. The total extract showed a potent antifungal effect against two Candida and two Aspergillus pathogens. The antioxidant activity revealed the potency of the total extract and 3 as antioxidant candidates. The obtained results refer to the importance of Centaurea pseudosinaica as a source of potent antiproliferative agents and the whole plant as an antipathogenic and antioxidant agent.     

UM171 promotes expansion of autologous peripheral blood hematopoietic stem cells from poorly mobilizing lymphoma patients

BackgroundAutologous hematopoietic stem cell transplantation is an effective therapeutic strategy for lymphoma patients. However, some patients have to give up receiving transplantation because of failing to obtain sufficient CD34⁺ cells yields. Therefore, we ex vivo expanded HSCs of lymphoma patients using UM171 to solve the problem of HSCs deficiency.MethodsMobilized peripheral blood-derived CD34⁺ cells from lymphoma patients were cultured for 10 days with or without UM171. The fold of cell expansion and the immunophenotype of expanded cells were assessed by flow cytometry. RNA-seq experiment was performed to identify the mechanism by which UM171 promoted HSCs expansion.ResultsUM171 treatment increased the proportion of CD34⁺ (68.97 ± 6.91%), CD34⁺ CD38⁻ cells (44.10 ± 9.20%) and CD34⁺CD38⁻CD45RA⁻CD90⁺ LT-HSCs (3.05 ± 2.08%) compared to vehicle treatment (36.08 ± 11.14%, 18.30 ± 9.49% and 0.56 ± 0.45%, respectively). UM171 treatment led to an 85.08-fold increase in LT-HSC numbers relative to initial cells. Importantly, UM171 promoted expansion of LT-HSCs achieved 138.57-fold in patients with poor mobilization. RNA-seq data showed that UM171 upregulated expression of HSC-, mast cell-specific genes and non-canonical Wnt signaling related genes, and inhibited genes expression of erythroid, megakaryocyte and inflammatory mediated chemokine.ConclusionsOur study shows that UM171 can efficiently promote ex vivo expansion of HSCs from lymphoma patients, especially for poorly mobilizing patients. In terms of mechanism, UM171 upregulate HSC-specific genes expression and suppress erythroid and megakaryocytic differentiation, as well as activate non-classical Wnt signaling.     

The effectiveness and safety of direct-acting antivirals for hepatitis C virus treatment: A single-center experience in Saudi Arabia

BackgroundThe introduction of direct-acting antivirals (DAA) to treat the hepatitis C virus (HCV) overcame many drawbacks of interferon-based therapy. DAA achieved sustained viral response (SVR) rates above 90% and overcame many drawbacks of pegylated interferon regimens.The HCV genotype (GT) distribution varies by geographical area, with GT-4 being most prevalent in the Middle East region, including Saudi Arabia. Yet, the real-world evidence about using DAAs in the Saudi population is limited.Thus, the aim of this study to investigate the effectiveness and safety of DAAs in Saudi patients with HCV infection.MethodsA retrospective cohort study included patients treated with DAAs from 2015 to 2017 at a tertiary care hospital in Riyadh, Saudi Arabia. All patients with HCV treated with either ledipasvir plus sofosbuvir (LDS/SOF) ± ribavarin (RBV) or ombitasvir-paritaprevir-ritonavir (OBV/PTV/r) ± dasabuvir (DSV) ± RBV were included. Using a per-protocol analysis, the effectiveness outcome was the end-of-treatment response (EOTr) and Sustained virologic reponce12 weeks after competing the regimen (SVR12). The secondary safety outcome was the adverse event related to the therapy reported by the patients.ResultsA total of 97 patients were included; with the majority infected with GT-4 (64 %), followed by GT-1 (18 %), in addition to 8 % having a mixed GT (1 + 4). The EOTr and SVR12 rates were 98 % and 96 %, respectively. SVR12 was 94.4 % within the LDS/SOF ± RBV group and 97.7 % within the OBV/PTV/r ± DSV ± RBV group. Only 4 % had a response failure due to relapse or breakthrough, and all were infected with mixed GT1 + 4. Medications were well tolerated with minimal side effects, including vomiting, nausea, and weakness.ConclusionDAAs regimens are associated with high rates of SVR12 and are well tolerated with a good safety profile in Saudi HCV-infected patients.     

Preparation and Evaluation of Quinapyramine Sulphate-Docusate Sodium Ionic Complex Loaded Lipidic Nanoparticles and Its Scale Up Using Geometric Similarity Principle

The objective of the present work is to prepare and evaluate ionically complexed Quinapyramine sulphate (QS) loaded lipid nanoparticles and its scale up using geometric similarity principle. Docusate sodium (DS), at a molar ratio of 1:2 of QS to DS, was used to prepare hydrophobic Quinapyramine sulphate-Docusate sodium (QS-DS) ionic complex. Based on the difference in total solubility parameter and polarity of QS-DS complex and different lipids, precirol was selected as a lipid for the preparation of lipidic nanoparticles. The particle size, zeta potential, and % entrapment efficiency (%EE) of QS-DS ionic complex loaded solid lipid nanoparticles (QS-DS-SLN) was found to be 250.10 ± 26.04 nm, ?27.41 ± 4.18 mV and 81.26 ± 4.67% respectively. FTIR studies confirmed the formation of QS-DS ionic complex. DSC and XRD studies revealed the amorphous nature of QS in QS-DS-SLN. The spherical shape of nanoparticles was confirmed by scanning electron microscopy. QS-DS-SLN showed sustained release of QS for up to 60 h. No significant difference was observed in particle size, zeta potential, and % entrapment efficiency of pilot-scale batch prepared by using rotational speed of 700 rpm. In conclusion, ionic complexation approach can be used to increase % EE of charged drugs into lipid nanoparticles.     

Phytochemical analysis and comprehensive evaluation of pharmacological potential of Artemisia brevifolia Wall. ex DC

Multitude of diseases and side effects from conventional drugs have surged the use of herbal remedies. Thus, the current study aimed to appraise various pharmacological attributes of Artemisia brevifolia Wall. ex DC. Extracts prepared by successive solvent extraction were subjected to phytochemical and multimode antioxidant assays. Various polyphenolics and artemisinin derivatives were detected and quantified using RP-HPLC analysis. Compounds present in methanol (M) and distilled water (DW) extracts were identified using high resolution mass spectrometry (HRMS). Extracts were pharmacologically evaluated for their antibacterial, antifungal, antimalarial, antileishmanial and antidiabetic potentials. Moreover, cytotoxicity against Artemiasalina, human cancer cell lines and isolated lymphocytes was assessed. Genotoxicity was evaluated using comet, micronucleus and chromosomal aberration assays. Lastly, anti-inflammatory potential was determined through a series of in vitro and in vivo assays using BALB/c mice.Maximum extract recovery (5.95% w/w) was obtained by DW extract. Highest phenolics and flavonoids content, total antioxidant capacity, total reduction potential, percentfree radical scavenging, β-carotene scavenging and iron chelating activities were exhibited by M extract. RP-HPLC analysis revealed significant amounts of various polyphenolic compounds (vanillic acid, syringic acid, emodin and luteolin), artemisinin, dihydro artemisinin, artesunate and artemether in ethyl acetate (EA) extract. Total 40 compounds were detected through HRMS. A noteworthy antimicrobial activity (MIC 22.22 µg/ml) was exhibited by EA extract against A. fumigatus and several bacterial strains. Maximum antimalarial, antileishmanial, brine shrimp lethality and cytotoxic potential against cancer cells was manifested by EA extract. None of the extracts exhibited genotoxicity and toxicity against isolated lymphocytes. Highest α-amylase and α-glucosidase inhibition capacities were demonstrated by DW extract. Various in-vivo anti-inflammatory models revealed significant (p < 0.05) anti-inflammatory potential of M and DW extracts. In conclusion, present findings divulged theremarkable pharmacological potential of A. brevifolia and endorse its richness in artemisinin.     

Design of a Novel Nucleus-Targeted NLS-KALA-SA Nanocarrier to Delivery Poorly Water-Soluble Anti-Tumor Drug for Lung Cancer Treatment

In this study, we designed a novel nucleus-targeted nanocarrier (NLS-KALA-SA, NKSN) consisting of Kala peptide (KALA), nuclear localization signal (NLS) and stearic acid (SA) using Fmoc solid phase synthesis method. We chose Curcumin (CUR), Paclitaxel (PTX), Ginsenoside compound K(CK) as models of poorly water-soluble antitumor drugs, The drugs loaded NLS-KALA-SA nanoparticles (CUR/NKSN, PTX/NKSN, CK/NKSN) were obained by the dialysis method, their physicochemical properties were determined and antitumor activity were evaluated. The NLS-KALA-SA nanoparticles were spherical shaped with an average size of 76.4 ± 7.6 mm and a zeta potential of 43.7 ± 5.8 mV. The drug-loaded NLS-KALA-SA nanoparticles were above 86.1% and 17.1% in entrapment efficiency and drug loading capacity, and had sustained drug release behavior. Biodistribution and cellular uptake study exhibited that PTX/NKSN mainly distributed in tumor site of A549-bearing mice, and coumarin-6(C6) loaded NLS-KALA-SA nanoparticle (C6/NKSN) was predominantly accumulated in the nucleus of A549 cells. Western blot analysis indicated that PTX/NKSN could more remarkably inhibit Bcl-2 expression and enhance the expression of Bax and Caspase-3 as compared to the controls in A549 cells. Cell apoptosis and antitumor activity study showed that PXT/NKSN could more obviously induce apoptosis of A549 cells compared with free PXT, the PTX/NKSN administration was more effective than free PTX for lung cancer treatment and displayed mild toxicity in A549-bearing mice. The results demonstrates that the NLS-KALA-SA nanoparticles system could enhance the antitumor effects of the encapsulated drug and reduce tissue toxicity due to its long circulating properties and tumor targeting, which might provide a promising strategy for lung cancer treatment.     

Hepatotoxicity reports in the FDA adverse event reporting system database: A comparison of drugs that cause injury via mitochondrial or other mechanisms

Drug-induced liver injury (DILI) is a leading reason for preclinical safety attrition and post-market drug withdrawals. Drug-induced mitochondrial toxicity has been shown to play an essential role in various forms of DILI, especially in idiosyncratic liver injury. This study examined liver injury reports submitted to the Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) for drugs associated with hepatotoxicity via mitochondrial mechanisms compared with non-mitochondrial mechanisms of toxicity. The frequency of hepatotoxicity was determined at a group level and individual drug level. A reporting odds ratio (ROR) was calculated as the measure of effect. Between the two DILI groups, reports for DILI involving mitochondrial mechanisms of toxicity had a 1.43 (95% CI 1.42–1.45; P < 0.0001) times higher odds compared to drugs associated with non-mitochondrial mechanisms of toxicity. Antineoplastic, antiviral, analgesic, antibiotic, and antimycobacterial drugs were the top five drug classes with the highest ROR values. Although the top 20 drugs with the highest ROR values included drugs with both mitochondrial and non-mitochondrial injury mechanisms, the top four drugs (ROR values > 18: benzbromarone, troglitazone, isoniazid, rifampin) were associated with mitochondrial mechanisms of toxicity. The major demographic influence for DILI risk was also examined. There was a higher mean patient age among reports for drugs that were associated with mitochondrial mechanisms of toxicity [56.1 ± 18.33 (SD)] compared to non-mitochondrial mechanisms [48 ± 19.53 (SD)] (P < 0.0001), suggesting that age may play a role in susceptibility to DILI via mitochondrial mechanisms of toxicity. Univariate logistic regression analysis showed that reports of liver injury were 2.2 (odds ratio: 2.2, 95% CI 2.12–2.26) times more likely to be associated with older patient age, as compared with reports involving patients less than 65 years of age. Compared to males, female patients were 37% less likely (odds ratio: 0.63, 95% CI 0.61–0.64) to be subjects of liver injury reports for drugs associated with mitochondrial toxicity mechanisms. Given the higher proportion of severe liver injury reports among drugs associated with mitochondrial mechanisms of toxicity, it is essential to understand if a drug causes mitochondrial toxicity during preclinical drug development when drug design alternatives, more clinically relevant animal models, and better clinical biomarkers may provide a better translation of drug-induced mitochondrial toxicity risk assessment from animals to humans. Our findings from this study align with mitochondrial mechanisms of toxicity being an important cause of DILI, and this should be further investigated in real-world studies with robust designs.     

Galactosylated Chitosan Coated Liposomes of Ledipasvir for Liver Targeting: Chemical Synthesis,Statistical Optimization,In-vitro and In-vivo evaluation

Ledipasvir is a novel antiviral agent used in the treatment of hepatitis C. We aim in our study to increase its delivery to hepatocytes and prolong its retention within liver. Several formulae of ledipasvir loaded liposomes were prepared and the best formula regarding particle size, zeta potential, polydispersity index and entrapment efficiency was selected. On the other hand, galactosylated chitosan was synthesized in a chemical reaction. Then the best liposomes formula was coated with the galactosylated chitosan. Having galactose residues on their surface, the coated liposomes can bind to the asialoglycoprotein receptors on the targeted hepatocytes enhancing ledipasvir uptake into them. The galactosylated chitosan coated liposomes had particle size of 218.2 nm ± 7.21, zeta potential of 27.15 mV ± 1.76, polydispersity index of 0.278 ± 0.055 and entrapment efficiency % of 54.63% ± 0.05 respectively. The pharmacokinetic study revealed a significant increase in the liver peak concentration (C_max) and the area under liver concentration versus time curve AUC_(0–72 h) and significant prolongation in the liver terminal half life (t½) and mean residence time (MRT) in comparison to the oral dispersion of ledipasvir with values of 11,400 ng/g, 88,855 ng1h/g, 32.00 h and 18.11 h respectively.     

Evodiamine-inspired dual inhibitors of histone deacetylase 1 (HDAC1) and topoisomerase 2 (TOP2) with potent antitumor activity

A great challenge in multi-targeting drug discovery is to identify drug-like lead compounds with therapeutic advantages over single target inhibitors and drug combinations. Inspired by our previous efforts in designing antitumor evodiamine derivatives, herein selective histone deacetylase 1 (HDAC1) and topoisomerase 2 (TOP2) dual inhibitors were successfully identified, which showed potent in vitro and in vivo antitumor potency. Particularly, compound 30a was orally active and possessed excellent in vivo antitumor activity in the HCT116 xenograft model (TGI = 75.2%, 150 mg/kg, p.o.) without significant toxicity, which was more potent than HDAC inhibitor vorinostat, TOP inhibitor evodiamine and their combination. Taken together, this study highlights the therapeutic advantages of evodiamine-based HDAC1/TOP2 dual inhibitors and provides valuable leads for the development of novel multi-targeting antitumor agents.     

Discovery of [1,2,3]triazolo[4,5-d]pyrimidine derivatives as highly potent,selective, and cellularly active USP28 inhibitors

Ubiquitin specific peptidase 28 (USP28) is closely associated to the occurrence and development of various malignancies, and thus has been validated as a promising therapeutic target for cancer therapy. To date, only few USP28 inhibitors with moderate inhibitory activity have been reported, highly potent and selective USP28 inhibitors with new chemotypes remain to be discovered for pathologically investigating the roles of deubiquitinase. In this current study, we reported the synthesis and biological evaluation of new [1,2,3]triazolo[4,5-d]pyrimidine derivatives as potent USP28 inhibitors. Especially, compound 19 potently inhibited USP28 (IC₅₀ = 1.10 ± 0.02 μmol/L, K_d = 40 nmol/L), showing selectivity over USP7 and LSD1 (IC₅₀ > 100 μmol/L). Compound 19 was cellularly engaged to USP28 in gastric cancer cells. Compound 19 reversibly bound to USP28 and directly affected its protein levels, thus inhibiting the proliferation, cell cycle at S phase, and epithelial-mesenchymal transition (EMT) progression in gastric cancer cell lines. Docking studies were performed to rationalize the potency of compound 19. Collectively, compound 19 could serve as a new tool compound for the development of new USP28 inhibitors for exploring the roles of deubiquitinase in cancers.     

Investigation of non-linear Mate1-mediated efflux of trimethoprim in the mouse kidney as the mechanism underlying drug-drug interactions between trimethoprim and organic cations in the kidney

The purpose of this study was to elucidate the involvement of Mate1 in the tubular secretion of trimethoprim and saturation of Mate1-mediated efflux to address the mechanisms underlying the pharmacokinetic drug interactions with trimethoprim. Trimethoprim is a more potent inhibitor of MATE2-K than MATE1 with K_i values (μM) of 0.030–0.28 and 2.4–5.9, respectively. Trimethoprim is a substrate of human MATE1 and MATE2-K with K_m values of 2.3 ± 0.9 and 0.018 ± 0.004 μM, and mouse Mate1, but not human OCT2, mouse Oct1 and Oct2. Pyrimethamine significantly reduced the renal clearance (CL_R) of trimethoprim (mL/min/kg) from 40.0 ± 5.1 to 20.1 ± 3.7 (p < 0.05). Trimethoprim was given to mice at three infusion rates (150, 500, and 1500 nmol/min/kg). Together with an increase in the plasma concentrations of trimethoprim, the CL_R (mL/min/kg) of trimethoprim decreased to 25.9 ± 3.2, 13.5 ± 5.7, and 8.92 ± 1.50 at the respective rates. Trimethoprim decreased the CL_R of rhodamine 123 in an infusion rate-dependent manner: 11.5 ± 1.3 (control), 5.17 ± 1.55, 1.31 ± 0.50, and 0.532 ± 0.180. These results suggest that Mate1 mediates the tubular secretion of trimethoprim, and at therapeutic doses, MATEs-mediated efflux can be saturated, and thereby, cause drug interactions with other MATE substrates.     

Blood-Brain Barrier Permeability of Asiaticoside,Madecassoside and Asiatic Acid in Porcine Brain Endothelial Cell Model

Neurotherapeutic potentials of Centella asiatica and its reputation to boost memory, prevent cognitive deficits and improve brain functions are widely acknowledged. The plant's bioactive compounds, i.e. asiaticoside, madecassoside and asiatic acid were reported to have central nervous system (CNS) actions, particularly in protecting the brain against neurodegenerative disorders. Hence, it is important for these compounds to cross the blood-brain barrier (BBB) to be clinically effective therapeutics. This study aimed to explore the capability of asiaticoside, madecassoside and asiatic acid to cross the BBB using in vitro BBB model from primary porcine brain endothelial cells (PBECs). Our findings showed that asiaticoside, madecassoside and asiatic acid are highly BBB permeable with apparent permeability (P_app) of 70.61 ± 6.60, 53.31 ± 12.55 and 50.94 ± 10.91 × 10^?6 cm/s respectively. No evidence of cytotoxicity and tight junction disruption of the PBECs were observed in the presence of these compounds. Asiatic acid showed cytoprotective effect towards the PBECs against oxidative stress. This study reported for the first time that Centella asiatica compounds demonstrated high capability to cross the BBB, comparable to central nervous system drugs, and therefore warrant further development as therapeutics for the treatment of neurodegenerative diseases.     

Design of semisynthetic derivatives of the Amaryllidaceae alkaloid ambelline and exploration of their in vitro cytotoxic activities

Ambelline, an alkaloid from the Amaryllidaceae family with a crinane-type skeleton, has not yet demonstrated any outstanding biological activity. However, its analogues prepared by derivatization of the C-11 hydroxyl group show different interesting effects. Continuing our earlier work, twelve novel aromatic esters were developed (10, 14, 16, 17, 22–25, 30–33) and studied, together with previously synthesized derivatives (2–9, 11–13, 15, 18–21, 26–29) in terms of their cytotoxic activity. The cytotoxic potential was determined on a panel of nine human cancer cell lines and one noncancerous cell line to characterize their biological activity spectrum. To describe and foresee the structure–activity relationship for further research, substances synthesized and described in our previous work were also included in this cytotoxicity study. The most significant activity was associated with analogues having methyl (10), methoxy (14–17), or ethoxy (18) substitution on the phenyl condensed to ambelline. However, the 4-chloro-3-nitrobenzoyl derivative (32) showed the most promising IC₅₀ values, ranging from 0.6 ± 0.1 µM to 9.9 ± 0.2 µM. In vitro cytotoxicity studies indicated the most potent antiproliferative activity of 32 in a dose-dependent and time-dependent manner. Besides, 32 was found to be effective in decreasing viability and triggering apoptosis of MOLT-4 T-lymphoblastic leukemia cells.