Rhonda Joy Rosengren

Background/Objectives: Metabolic (dysfunction)-associated steatotic liver disease (MASLD), the hepatic consequence of metabolic syndrome, affects 30% of the global population. Studies in animals and humans investigating the effect of fructose on MASLD present conflicting findings, while in vitro methods often fail to add meaningful evidence due to acute exposures (SREBPF1, NR1H3, FASN, and ACACA) was determined using qPCR. Results: Neither fructose nor glucose, with or without fatty acids, changed the TG levels in cells at 48 h and the media glucose concentration had no effect on this result. Similarly, fructose did not increase TG levels after 28 days. While fructose and glucose did not affect key DNL genes at 6 h, the fatty acid mixture reduced FASN by 41%. Conclusions: This study shows that fructose did not significantly impact TG synthesis or DNL gene expression in the HepG2 cell model. Future studies should consider using primary human hepatocytes or more complex in vitro models.

Synthetic cannabinoids are a rapidly evolving, diverse class of new psychoactive substances. Synthetic cannabinoid use results in a higher likelihood of adverse events and hospitalization when compared to cannabis use. The mechanisms behind synthetic cannabinoid toxicity remain elusive. Furthermore, poly-substance use may be a significant contributing factor in many cases. This scoping review aimed to identify the key characteristics of synthetic cannabinoid co-exposure cases and discuss the potential implications of poly-substance use in humans. There were 278 human cases involving 64 different synthetic cannabinoids extracted from the databases. Cases involved a total of 840 individual co-exposures, with an average of four substances involved in each case. The most common co-exposures were alcohol (11.4%), opioids (11.2%), and cannabis (11.1%). When analyzed by case outcome, co-exposure to either antipsychotics/antidepressants, alcohol, or tobacco were significantly associated with mortality as an outcome (p < 0.05). Drug-use history (63.4%), mental illness (23.7%), and hypertensive and atherosclerotic cardiovascular disease (20.1%) were prevalent patient histories in the case cohort. There are several potential pharmacodynamic and pharmacokinetic interactions between co-exposure drugs and synthetic cannabinoids that could worsen clinical presentation and toxicity in synthetic cannabinoid users. Individuals with substance-use disorders or psychiatric illness would be especially vulnerable to these multi-drug interactions. Further research into these complex exposures is needed for the successful prevention and treatment of synthetic cannabinoid-related harms.

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.

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.

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.

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 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 presence of heavy metals in drinking water is a serious global issue. Sustainable methods for treating drinking water such as biosorption are gaining popularity. The maximum permissible limits of most metal ions in drinking water are in the range from 0.003 to 2 mgL−1, however, the elevated concentrations in the range 0.01–2.5 mgL−1 are reported in contaminated waters in various regions of the world. Therefore, selecting the initial metal ion concentration range, and an optimum pH suitable for treating drinking water (pH 6.5–8.5) for laboratory experiments is a challenge for multi-ion biosorption studies. For the quantification of metal ions, ICP-MS is often used owing to its many advantages, however, the high operational costs of this instrument limits its use in research laboratories. Surface characterisation techniques such as TEM, NMR, ESR and related techniques are often ignored in biosorption studies although, these give valuable information pertaining to the mechanism of biosorption. Many theoretical models for explaining the biosorption mechanism have been proposed in the literature, one often contradicting the other. One of the major drawbacks of published biosorption studies is that too much emphasis has been laid on the theoretical explanation of biosorption mechanism and too little has been done to address the lack of practical application in terms of translatability of the methodology for commercial use. The present review highlights such issues while giving an insight on the processes, parameters and models used in biosorption reactions. GRAPHICAL ABSTRACT