Post-COVID-19 approach to teaching an undergraduate laboratory class focused on experimental design and data interpretation.

To best prepare students for the real-world research environment, key skills, including experimental design, data analysis, communication of results, and critical thinking, should be key components of undergraduate science courses. Furthermore, the impact of the COVID-19 pandemic on in-person teaching has resulted in a need to develop courses that enable flexible learning. This paper details the laboratory component of a senior-level toxicology class that was developed to emphasize all these skills and allow for flexible learning. The aim of the laboratory class was for students to determine how curcumin protected against acetaminophen-induced hepatoxicity. To stimulate critical thinking, students were required to choose a maximum of four experiments from the six on offer. Before conducting an experiment, students stated a hypothesis and selected the appropriate treatment groups. Once an experiment was completed, students were given access to a complete dataset, on which they performed statistical analysis and drew conclusions. Students who were unable to attend the laboratory session in person were able to complete the required pre-lab work and access the dataset. Following each experiment, students could write a lab summary, and receive thorough feedback. The final assessment was a written manuscript of their findings as well as a chance to respond to reviewer comments. This teaching approach prioritized the critical thinking, analysis, and experimental design aspects of scientific research. Overall, this structure was well received by students and it could easily be adapted for use on other life science courses.

Utility of the second-generation curcumin analogue RL71 in canine histiocytic sarcoma.

Canine histiocytic sarcoma is an aggressive cancer, with a high rate of metastasis. Thus, novel therapeutic approaches are needed. Synthetic analogues of curcumin have elicited potent anti-cancer activity in multiple in vitro and in vivo models of human cancer. Furthermore, the compound 3,5-bis(3,4,5-trimethoxybenzylidene)-1-methylpiperidine-4-one (RL71) has recently exhibited potent cell cycle arrest and apoptotic induction in a canine osteosarcoma cell line. To determine its potency in canine histiocytic sarcoma cells, cell viability of DH82 and Nike cells was measured using the sulforhodamine B assay. Flow cytometry was then used to analyse both cell cycle distribution and apoptosis. Of the five curcumin analogues examined, RL71, had the highest potency with EC50 values of 0.66 ± 0.057 µM and 0.79 ± 0.13 µM in the DH82 and Nike cell lines, respectively. Furthermore, RL71 at the 1x EC50 concentration increased G2/M cell cycle arrest 2-fold, and at the 2x EC50 concentration increased the number of apoptotic cells 4-fold. These findings are consistent with previous work using RL71 in both canine and human cancer cell lines. Future research should be directed on time-dependent changes, and mechanistic investigation in greater detail to elucidate RL71 mechanisms of action.

Short-Term Intravenous Administration of Carbon Nano-Onions is Non-Toxic in Female Mice.

Background: A nanoscale drug carrier could have a variety of therapeutic and diagnostic uses provided that the carrier is biocompatible in vivo. Carbon nano-onions (CNOs) have shown promising results as a nanocarrier for drug delivery. However, the systemic effect of CNOs in rodents is unknown. Therefore, we investigated the toxicity of CNOs following intravenous administration in female BALB/c mice. Results: Single or repeated administration of oxi-CNOs (125, 250 or 500 µg) did not affect mouse behavior or organ weight and there was also no evidence of hepatotoxicity or nephrotoxicity. Histological examination of organ slices revealed a significant dose-dependent accumulation of CNO aggregates in the spleen, liver and lungs (p<0.05, ANOVA), with a trace amount of aggregates appearing in the kidneys. However, CNO aggregates in the liver did not affect CYP450 enzymes, as total hepatic CYP450 as well as CYP3A catalytic activity, as meased by erythromycin N-demethylation, and protein levels showed no significant changes between the treatment groups compared to vehicle control. CNOs also failed to act as competitive inhibitors of CYP3A in vitro in both mouse and human liver microsomes. Furthermore, CNOs did not cause oxidative stress, as indicated by the unchanged malondialdehyde levels and superoxide dismutase activity in liver microsomes and organ homogenates. Conclusion: This study provides the first evidence that short-term intravenous administration of oxi-CNOs is non-toxic to female mice and thus could be a promising novel and safe drug carrier.

The second-generation curcumin analogue RL71 elicits G2/M cell cycle arrest and apoptosis in canine osteosarcoma cells.

Canine osteosarcoma is an aggressive cancer, comprising 85% of canine bone neoplasms. Current treatment practices of surgery and chemotherapy increase 1-year survival by only 45%. The curcumin analogue RL71, has demonstrated potent in vitro and in vivo efficacy in several models of human breast cancer through increased apoptosis and cell cycle arrest. Thus, the present study aimed to investigate efficacy of curcumin analogues in two canine osteosarcoma cell lines. Osteosarcoma cell viability was assessed using the sulforhodamine B assay and mechanisms of action were determined by analysing the levels of cell cycle and apoptotic regulatory proteins via Western blotting. Further evidence was obtained using flow cytometry to detect cell cycle distribution and the number of apoptotic cells. RL71 was the most potent curcumin analogue with EC50 values of 0.64 ± 0.04 and 0.38 ± 0.009 µM (n = 3) in D-17 (commercial) and Gracie canine osteosarcoma cells, respectively. RL71 significantly increased the ratio of cleaved-caspase 3 to pro-caspase 3 and the level of apoptotic cells at the 2× and 5× EC50 concentration (p < 0.001, n = 3). Furthermore, at the same concentration, RL71 significantly increased the number of cells in the G2/M phase. In conclusion, RL71 has potent cytotoxic activity in canine osteosarcoma cells triggering G2/M arrest and apoptosis at concentrations achievable in vivo. Future research should further investigate molecular mechanisms for these changes in other canine osteosarcoma cell lines prior to in vivo investigation.

Investigating the Contribution of Major Drug-Metabolising Enzymes to Possum-Specific Fertility Control.

The potential to improve the effectiveness and efficiency of potential oestrogen-based oral contraceptives (fertility control) for possums was investigated by comparing the inhibitory potential of hepatic CYP3A and UGT2B catalytic activity using a selected compound library (CYP450 inhibitor-based compounds) in possums to that of three other species (mouse, avian, and human). The results showed higher CYP3A protein levels in possum liver microsomes compared to other test species (up to a 4-fold difference). Moreover, possum liver microsomes had significantly higher basal p-nitrophenol glucuronidation activity than other test species (up to an 8-fold difference). However, no CYP450 inhibitor-based compounds significantly decreased the catalytic activity of possum CYP3A and UGT2B below the estimated IC50 and 2-fold IC50 values and were therefore not considered to be potent inhibitors of these enzymes. However, compounds such as isosilybin (65%), ketoconazole (72%), and fluconazole (74%) showed reduced UGT2B glucuronidation activity in possums, mainly at 2-fold IC50 values compared to the control (p < 0.05). Given the structural features of these compounds, these results could provide opportunities for future compound screening. More importantly, however, this study provided preliminary evidence that the basal activity and protein content of two major drug-metabolising enzymes differ in possums compared to other test species, suggesting that this could be further exploited to reach the ultimate goal: a potential target-specific fertility control for possums in New Zealand.

The piperazine analogue para-fluorophenylpiperazine alters timing of the physiological effects of the synthetic cannabinoid receptor agonist AMB-FUBINACA, without changing its discriminative stimulus, signalling effects, or metabolism.

AMB-FUBINACA is a synthetic cannabinoid receptor agonist (SCRA), which has been associated with substantial abuse and health harm since 2016 in many countries including New Zealand. A characteristic of AMB-FUBINACA use in New Zealand has included the observation that forensic samples (from autopsies) and drugs seized by police have often been found to contain para-fluorophenylpiperazine (pFPP), a relatively little-characterised piperazine analogue that has been suggested to act through 5HT1a serotonin receptors. In the current study, we aimed to characterise the interactions of these two agents in rat physiological endpoints using plethysmography and telemetry, and to examine whether pFPP altered the subjective effects of AMB-FUBINACA in mice trained to differentiate a cannabinoid (THC) from vehicle. Though pFPP did not alter the ability of AMB-FUBINACA to substitute for THC, it did appear to abate some of the physiological effects of AMB-FUBINACA in rats by delaying the onset of AMB-FUBINACA-mediated hypothermia and shortening duration of bradycardia. In HEK cells stably expressing the CB1 cannabinoid receptor, 5HT1a, or both CB1 and 5HT1a, cAMP signalling was recorded using a BRET biosensor (CAMYEL) to assess possible direct receptor interactions. Although low potency pFPP agonism at 5HT1a was confirmed, little evidence for signalling interactions was detected in these assays: additive or synergistic effects on potency or efficacy were not detected between pFPP and AMB-FUBINACA-mediated cAMP inhibition. Experiments utilising higher potency, classical 5HT1a ligands (agonist 8OH-DPAT and antagonist WAY100635) also failed to reveal evidence for mutual CB1/5HT1a interactions or cross-antagonism. Finally, the ability of pFPP to alter the metabolism of AMB-FUBINACA in rat and human liver microsomes into its primary carboxylic acid metabolite via carboxylesterase-1 was assessed by HPLC; no inhibition was detected. Overall, the effects we have observed do not suggest that increased harm/toxicity would result from the combination of pFPP and AMB-FUBINACA.

Characterisation of AMB-FUBINACA metabolism and CB1-mediated activity of its acid metabolite.

PURPOSE: AMB-FUBINACA is a synthetic cannabinoid receptor agonist (SCRA) which is primarily metabolised by hepatic enzymes producing AMB-FUBINACA carboxylic acid. The metabolising enzymes associated with this biotransformation remain unknown. This study aimed to determine if AMB-FUBINACA metabolism could be reduced in the presence of carboxylesterase (CES) inhibitors and recreational drugs commonly consumed with it. The affinity and activity of the AMB-FUBINACA acid metabolite at the cannabinoid type-1 receptor (CB1) was investigated to determine the activity of the metabolite. METHODS: The effect of CES1 and CES2 inhibitors, and delta-9-tetrahydrocannabinol (Δ9-THC) on AMB-FUBINACA metabolism were determined using both human liver microsomes (HLM) and recombinant carboxylesterases. Radioligand binding and cAMP assays comparing AMB-FUBINACA and AMB-FUBINACA acid were carried out in HEK293 cells expressing human CB1. RESULTS: AMB-FUBINACA was rapidly metabolised by HLM in the presence and absence of NADPH. Additionally, CES1 and CES2 inhibitors both significantly reduced AMB-FUBINACA metabolism. Furthermore, digitonin (100 µM) significantly inhibited CES1-mediated metabolism of AMB-FUBINACA by ~ 56%, while the effects elicited by Δ9-THC were not statistically significant. AMB-FUBINACA acid produced only 26% radioligand displacement consistent with low affinity binding. In cAMP assays, the potency of AMB-FUBINACA was ~ 3000-fold greater at CB1 as compared to the acid metabolite. CONCLUSIONS: CES1A1 was identified as the main hepatic enzyme responsible for the metabolism of AMB-FUBINACA to its less potent carboxylic acid metabolite. This biotransformation was significantly inhibited by digitonin. Since other xenobiotics may also inhibit similar SCRA metabolic pathways, understanding these interactions may elucidate why some users experience high levels of harm following SCRA use.

Raloxifene potentiates the effect of gefitinib in triple-negative breast cancer cell lines.

Triple-negative breast cancers (TNBCs) are characterized by a lack of approved targeted therapies and remain a challenge in the clinic. Several overexpressed proteins, including epidermal growth factor receptor (EGFR), have been associated with TNBCs and are considered potential therapeutic targets. However, EGFR inhibitors alone failed to demonstrate a cutting-edge advantage for treating TNBCs over conventional chemotherapies. Studies have shown that selective estrogen receptor modulators (SERMs) tamoxifen and raloxifene also affect TNBC cell viability. The combination of gefitinib and raloxifene was assessed against TNBC cell lines in vitro. Two TNBC cell lines, MDA-MB-231 and MDA-MB-468, were used to investigate the combination of gefitinib and raloxifene on cell viability, DNA synthesis, and apoptosis. The combination was assessed on intracellular signaling pathways, colony formation, migration, and angiogenesis. In the present study, raloxifene, in combination with gefitinib, decreased cell viability. The combination potentiates apoptosis and affects the expression and phosphorylation pattern of proteins involved in cell proliferation, such as NFκB, ß-catenin, and EGFR. Furthermore, evidence of apoptosis activation was also observed, along with a decreased cell migration and tumorigenicity of TNBC cells. Moreover, the combined treatment decreased the ability of neovascularization as assessed by tube formation of endothelial cells. These results suggested the potential of the combination of raloxifene and gefitinib for the prevention of TNBC growth and the appearance of metastatic events. Our findings provide the basis for future studies on the mechanism involved in raloxifene-gefitinib inhibition of ER-negative tumor growth.

Characterization of marine-derived halogenated indoles as ligands of the aryl hydrocarbon receptor.

The aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor thought to mediate a number of physiological roles in the body, is becoming a target of interest for the development of new therapeutics. However, previous research has demonstrated that the downstream effects of AhR ligands cannot be predicted based simply on whether a ligand acts as an agonist or antagonist and the persistence of AhR signaling is thought to be a key determining feature. The current study investigated the AhR activity of four halogenated indoles isolated from the New Zealand red alga, Rhodophyllis membranacea: 4,7-dibromo-2,3-dichloroindole (4DBDCI), 7-bromo-2,3-dichloro-6-iodoindole (BDCII), 6,7-dibromo-2,3-dichloroindole (6DBDCI) and 2,6,7-tribromo-3-chloroindole (TBCI). Their ability to activate AhR signaling, measured as CYP1A1 activity via the ethoxyresorufin O-deethylase (EROD) assay, was determined in human HepG2, mouse Hepa1c1c7 and rat H4IIE liver cancer cells. All four compounds induced CYP1A1 activity in HepG2 cells, suggesting they all acted as AhR agonizts. 4DBDCI was particularly efficacious, inducing an 11-fold increase. Hepa1c1c7 and H4IIE cells, however, were generally less responsive to the halogenated indoles. All four compounds were persistent AhR agonizts, inducing peak CYP1A1 activity after 72 h. Moreover, the 2,3,6,7-substituted BDCII, 6DBDCI and TBCI, but not 4DBDCI, competed with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) for AhR binding as observed by the inhibition of TCDD-induced CYP1A1 activity. Overall, the current study has characterized four previously untested AhR ligands, highlighting differences in species sensitivity and persistence of signaling to provide a framework for their potential future use.

Exploring the Mechanism and Suggesting Combination Therapies for HDAC Inhibitors in Androgen Receptor-Null Prostate Cancer Using Multivariate Statistical Analysis and Data Mining Techniques.

Previously, we showed that novel histone deacetylase (HDAC) inhibitors, N1-hydroxy-N 8-(4-(pyridine-2-carbothioamido)phenyl)octanediamide (Jazz90) and [chlorido(η5-pentamethylcyclopentadienyl)(N1-hydroxy-N8-(4-(pyridine-2-carbothioamido-κ2 N, S)phenyl)octanediamide)rhodium(III)] chloride (Jazz167), have cytostatic and anti-angiogenic effects in androgen receptor-negative prostate cancer cells and are also non-toxic in BALB/c mice. However, only univariate statistical analysis was carried out to determine the role of individual proteins. In this study, multivariate statistical analyses (MVAs) and data mining procedures were carried out with the objective of determining the molecular networks that explain the growth inhibitory potential of Jazz90 and Jazz167 in PC3 cells and to determine potential inhibitors that can be used in combination with these HDAC inhibitors. Lasso regression revealed that angiogenic factors, vascular endothelial growth factor-A (VEGF-A), and vascular endothelial growth factor receptor-2 (VEGFR-2), alongside HDAC inhibition, predicted the reduction in cell number with an adjusted R 2 value of 0.99 following Jazz90 treatment, whereas VEGFR-2, acetylation of histone-3, and HDAC inhibition predicted cell number with an adjusted R 2 value of 0.84 following Jazz167 treatment. These results were further followed up with ridge regression, hierarchical cluster analysis, random forest classification (RFC), and support vector machines. RFC and support vector machines also predicted the treatment groups with a 100% accuracy. MVAs also revealed that Jazz90 should be examined in combination with epithelial to mesenchymal transitioning inhibitors, such as simvastatin and olaparib, whereas Jazz167 should be examined with venetoclax or navitoclax. Future studies should also address the roles of VEGF-A and VEGFR-2 in cellular proliferation, whereas p27 function should be examined for its role in PC3 cell migration.

Raloxifene Suppresses Tumor Growth and Metastasis in an Orthotopic Model of Castration-Resistant Prostate Cancer.

Androgen receptor (AR)-castrate-resistant prostate cancer (CRPC) is an aggressive form of prostate cancer that does not have clinically approved targeted treatment options. To this end, the cytotoxic potential of raloxifene and the synthetic curcumin derivative 2,6-bis (pyridin-4-ylmethylene)-cyclohexanone (RL91) was examined in AR-(PC3 and DU145) cells and AR+ (LnCaP) CRPC cells. The results showed that both raloxifene and RL91 elicited significant cytotoxicity across three cell lines with the lowest EC50 values in PC3 cells. Additionally, the two drugs were synergistically cytotoxic toward the PC3, DU-145 and LNCaP cell lines. To determine the effect of the drug combination in vivo, an orthotopic model of CRPC was used. Male mice were injected with PC3 prostate cancer cells and then treated with vehicle (5 mL/kg), raloxifene (8.5 mg/kg, po), RL91 (8.5 mg/kg, po) or a combination of raloxifene and RL91 for six weeks. Sham animals were subjected to the surgical procedure but were not implanted with PC3 cells. The results showed that raloxifene decreased tumor size and weight as well as metastasis to renal lymph nodes. However, combination treatment reversed the efficacy of raloxifene as tumor volume and metastasis returned to control levels. The results suggest that raloxifene has tumor suppressive and anti-metastatic effects and has potential for further clinical use in AR-CRPC.

Six fruit and vegetable peel beads for the simultaneous removal of heavy metals by biosorption.

In this study, a comparison between the biosorption performance of six fruit and vegetable peels, namely kiwifruit (KP), apple, banana, cucumber, orange and potato immobilized on sodium alginate beads has been made. Inductively coupled plasma coupled with mass spectroscopy was used for measuring the concentration of metal ions in solution before and after biosorption. A range of kinetic models were also applied to the biosorption batch data. The results showed that biosorption percentage of the ions were different on the various beads. For example, the decreasing order of biosorption by one KP bead at equilibrium was Cd > Cu > Hg > Ni > Pb > Cr > As, with approximately 92%, 84%, 80%, 75%, 67%, 34%, and 17% simultaneous removal of ions, respectively. The fastest biosorption was seen with Cd and Pb, as both reached equilibrium by 24 h. Equilibrium time of all other ions occurred by 48 h. While all beads in their unmodified form were suitable for the removal of divalent cations, KP bead showed significantly higher removal of the anion hexavalent Cr. Biosorption of Cd, Hg and Ni was limited by both pseudo-first order and pseudo-second order reaction rates. For Cr and Cu, the reaction was controlled by film diffusion and pseudo-first order rates. At a higher solution concentration, the preference of ions biosorbed as well as their percentage removed changed. Overall, the results indicated that KP beads show promise as a cost-effective method for removing toxic ions by biosorption, especially hexavalent chromium from drinking water.

Key considerations when using the sulforhodamine B assay for screening novel anticancer agents.

Anticancer drug discovery programmes use a large number of in-vitro assays to screen the potency of compound libraries. The accuracy and reliability of these in-vitro assays are vital in selecting potent lead candidates for further (pre)clinical studies. Among the commonly used cell viability assays, the sulforhodamine B (SRB) assay has been a popular choice due to its simplicity, accuracy, reliability and reproducibility. SRB dye interacts with protein's basic amino acids and viable cell number is determined based on the cellular protein content. In this study, the cytotoxic potency of the novel hydroxythiopyridone derivatives towards A549 and H522 cells was determined using the SRB assay. The known drugs oxaliplatin and vorinostat were also examined. The resulting EC50 values were accurate, reliable and reproducible. However, all EC50 values calculated in 6-well plates were higher compared to those determined from 96-well plates. Furthermore, results from 6-well plates were also more variable compared to 96-well plates. Our results confirm that SRB assay is a reliable technique in screening the potency of anticancer drug candidates but plating conditions need to be carefully considered.

In Vitro Hepatic Assessment of Cineole and Its Derivatives in Common Brushtail Possums (Trichosurus vulpecula) and Rodents.

Folivore marsupials, such as brushtail possum (Trichosurus Vulpecula) and koala (Phascolarctos cinereus), can metabolise higher levels of dietary terpenes, such as cineole, that are toxic to eutherian mammals. While the highly efficient drug metabolising enzymes, cytochrome P450 3A (CYP3A) and phase II conjugating enzymes (UDP-glucuronosyltransferase, UGT), are involved in the metabolism of high levels of dietary terpenes, evidence for inhibitory actions on these enzymes by these terpenes is scant. Thus, this study investigated the effect of cineole and its derivatives on catalytic activities of hepatic CYP3A and UGT in mice, rats, and possums. Results showed that cineole (up to 50 µM) and its derivatives (up to 25 µM) did not significantly inhibit CYP3A and UGT activities in mice, rats, and possums (both in silico and in vitro). Interestingly, basal hepatic CYP3A catalytic activity in the possums was ~20% lower than that in rats and mice. In contrast, possums had ~2-fold higher UGT catalytic activity when compared to mice and rats. Thus, these basal enzymatic differences may be further exploited in future pest management strategies.

Anti-Proliferative, Anti-Angiogenic and Safety Profiles of Novel HDAC Inhibitors for the Treatment of Metastatic Castration-Resistant Prostate Cancer.

Metastatic castration-resistant prostate cancer (CRPC) has a five-year survival rate of 28%. As histone deacetylases (HDACs) are overexpressed in CRPC, the HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) was trialled in CRPC patients but found to be toxic and inefficacious. Previously, we showed that novel HDAC inhibitors (Jazz90 (N1-hydroxy-N8-(4-(pyridine-2-carbothioamido)phenyl)octanediamide) and Jazz167 ([chlorido(η5-pentamethylcyclopentadieny[1-4](N1-hydroxy-N8-(4-(pyridine-2-carbothioamido-κ2N,S)phenyl)octanediamide)rhodium(III)] chloride) had a higher cancer-to-normal-cell selectivity and superior anti-angiogenic effects in CRPC (PC3) cells than SAHA. Thus, this study aimed to further investigate the efficacy and toxicity of these compounds. HUVEC tube formation assays revealed that Jazz90 and Jazz167 significantly reduced meshes and segment lengths in the range of 55-88 and 43-64%, respectively. However, Jazz90 and Jazz167 did not affect the expression of epithelial-to-mesenchymal transitioning markers E-cadherin and vimentin. Jazz90 and Jazz167 significantly inhibited the growth of PC3 and DU145 spheroids and reduced PC3 spheroid branching. Jazz90 and Jazz167 (25, 50 and 75 mg/kg/day orally for 21 days) were non-toxic in male BALB/c mice. The efficacy and safety of these compounds demonstrate their potential for further in vivo studies in CRPC models.

Using Natural Compounds to Target KRAS Mutated Non-Small Cell Lung Cancer.

Approximately 85% of all lungs cancer cases are classified as non-small cell lung cancer (NSCLC). Kirsten rat sarcoma (KRAS) viral oncogene homolog mutations frequently occur in NSCLC patients resulting in a decreased overall survival. Additionally, currently used chemotherapeutic drugs lack selectivity,and patients experience side effects. Therefore, potent therapeutic agents are urgently needed for these patients. Plant- based compounds could be a potential option to treat KRAS-mutated NSCLC. These compounds are reported to be effective against the KRAS-linked up-stream and downstream signaling pathways that are directly or indirectly linked with cell proliferation, division, and apoptosis. Additionally, plant phytochemicals also suppressed different cell cycle phases of KRAS-mutant NSCLC cells. Furthermore, phytochemicals have a wider therapeutic index compared to chemotherapeutic drugs. Therefore, phytochemicals could benefit NSCLC patients as sole agents or as a combination therapy with approved chemotherapies. The current review aims to summarize the potential benefit of natural compounds in KRAS-mutant NSCLC.

Cytostatic Action of Novel Histone Deacetylase Inhibitors in Androgen Receptor-Null Prostate Cancer Cells.

Androgen receptor (AR)-null prostate tumors have been observed in 11-24% of patients. Histone deacetylases (HDACs) are overexpressed in prostate tumors. Therefore, HDAC inhibitors (Jazz90 and Jazz167) were examined in AR-null prostate cancer cell lines (PC3 and DU145). Both Jazz90 and Jazz167 inhibited the growth of PC3 and DU145 cells. Jazz90 and Jazz167 were more active in PC3 cells and DU145 cells in comparison to normal prostate cells (PNT1A) and showed a 2.45- and 1.30-fold selectivity and higher cytotoxicity toward DU145 cells, respectively. Jazz90 and Jazz167 reduced HDAC activity by ~60% at 50 nM in PC3 lysates. At 4 µM, Jazz90 and Jazz167 increased acetylation in PC3 cells by 6- to 8-fold. Flow cytometry studies on the cell phase distribution demonstrated that Jazz90 causes a G0/G1 arrest in AR-null cells, whereas Jazz167 leads to a G0/G1 arrest in DU145 cells. However, apoptosis only occurred at a maximum of 7% of the total cell population following compound treatments in PC3 and DU145 cells. There was a reduction in cyclin D1 and no significant changes in bcl-2 in DU145 and PC3 cells. Overall, the results showed that Jazz90 and Jazz167 function as cytostatic HDAC inhibitors in AR-null prostate cancer cells.

High Antiproliferative Activity of Hydroxythiopyridones over Hydroxypyridones and Their Organoruthenium Complexes.

Hydroxypyr(id)ones are a pharmaceutically important class of compounds that have shown potential in diverse areas of drug discovery. We investigated the 3-hydroxy-4-pyridones 1a-1c and 3-hydroxy-4-thiopyridones 1d-1f as well as their Ru(η6-p-cymene)Cl complexes 2a-2f, and report here the molecular structures of 1b and 1d as determined by X-ray diffraction analysis. Detailed cell biological investigations revealed potent cytotoxic activity, in particular of the 3-hydroxy-4-thiopyridones 1d-1f, while the Ru complexes of both compound types were less potent, despite still showing antiproliferative activity in the low µM range. The compounds did not modulate the cell cycle distribution of cancer cells but were cytostatic in A549 and cytotoxic in NCI-H522 non-small lung cancer cells, among other effects on cancer cells.

Synthesis and Biological Evaluation of (-) and (+)-Spiroleucettadine and Analogues.

A second-generation enantiospecific synthesis of spiroleucettadine is described. The original reported antibacterial activity was not observed when the experiment was repeated on the synthetic samples; however, significant anti-proliferative activity was uncovered for both enantiomers of spiroleucettadine. Comparison of the optical rotational data and ORD-CD spectra of both enantiomers and the reported spectrum from the natural source have not provided a definitive answer regarding the absolute stereochemistry of naturally occurring spiroleucettadine. Efforts then focussed on alteration at the C-4 and C-5 positions of the slightly more active (-)-spiroleucettadine. Ten analogues were synthesised, with three analogues found to possess similar anti-proliferative profiles to spiroleucettadine against the H522 lung cancer cell line.

Cucumber peel bead biosorbent for multi-ion decontamination of drinking water collected from a mine region in New Zealand.

Cucumber peel as a bead was examined for its ability to remove heavy metals from drinking water. Deionised laboratory water was spiked with seven toxic ions namely, arsenic, cadmium, chromium, copper, mercury, lead and nickel at 0.1 mg L-1 and kinetic studies were performed over 72 h. Kinetic data were modelled using film diffusion, pore diffusion, Weber-Morris, pseudo-first-order, pseudo-second-order and Elovich equation. The bead surface was imaged before and after biosorption using scanning electron microscopy coupled with energy dispersive spectroscopy (EDS). Results indicated that different ions contained in a multi-ion solution were biosorbed by different mechanisms and at different rates. Equilibrium biosorption for Cd, Hg and Ni was ∼91, 90 and 67%, respectively, at 24 h. These ions diffused through the pores of the bead, as they were not identified by EDS, and their biosorption increased with an increase in temperature. The least biosorbed ions were As and Cr with ∼21 and 17% equilibrium biosorption, respectively. The removal of only Cu, Hg, Pb and Ni was pH-dependent. Cucumber peel beads removed all spiked ions from real drinking water collected near the Macraes gold mine in New Zealand, but the biosorption percentage was lower for Cd, Cu, Pb and Ni compared to spiked deionised laboratory water. The results of this study suggest that cucumber peel when immobilised on a sodium alginate bead can be used as a potential biosorbent for the removal of multiple toxic ions from drinking water and their use warrants further examination in contaminated drinking water.