The regulation of vitamin D₃ actions in humans occurs mainly through the Cytochrome P450 24-hydroxylase (CYP24A1) enzyme activity. CYP24A1 hydroxylates both 25-hydroxycholecalciferol (25(OH)D₃) and 1,25-dihydroxycholecalciferol (1,25(OH)₂D₃), which is the first step of vitamin D catabolism. An abnormal status of the upregulation of CYP24A1 occurs in many diseases, including chronic kidney disease (CKD). CYP24A1 upregulation in CKD and diminished activation of vitamin D₃ contribute to secondary hyperparathyroidism (SHPT), progressive bone deterioration, and soft tissue and cardiovascular calcification. Previous studies have indicated that CYP24A1 inhibition may be an effective strategy to increase endogenous vitamin D activity and decrease SHPT. This study has designed and synthesized a novel C-24 O-methyloxime analogue of vitamin D₃ (VD1-6) to have specific CYP24A1 inhibitory properties. VD1-6 did not bind to the vitamin D receptor (VDR) in concentrations up to 10⁻⁷ M, assessed by a VDR binding assay. The absence of VDR binding by VD1-6 was confirmed in human embryonic kidney HEK293T cultures through the lack of CYP24A1 induction. However, in silico docking experiments demonstrated that VD1-6 was predicted to have superior binding to CYP24A1, when compared to that of 1,25(OH)₂D₃. The inhibition of CYP24A1 by VD1-6 was also evident by the synergistic potentiation of 1,25(OH)₂D₃-mediated transcription and reduced 1,25(OH)₂D₃ catabolism over 24 h. A further indication of CYP24A1 inhibition by VD1-6 was the reduced accumulation of the 24,25(OH)D₃, the first metabolite of 25(OH)D catabolism by CYP24A1. Our findings suggest the potent CYP24A1 inhibitory properties of VD1-6 and its potential for testing as an alternative therapeutic candidate for treating SHPT.

Pharmacology is essential for safe medication use in healthcare, yet its role in allied health education, particularly medical radiation science programs, is underexplored. As medical radiation practitioners increasingly administer contrast agents and radiopharmaceuticals, foundational pharmacology knowledge is critical. This study investigates Australian medical radiation science students' perceptions of pharmacology education and assessment. A cross-sectional survey was conducted among second-year medical radiation science students (n = 129) at the University of South Australia before and after completing a foundational pharmacology course. Two anonymous surveys assessed students' attitudes, confidence, and preferences regarding pharmacology and its academic assessment via assignment versus examination. Survey 1 (n = 77) indicated low initial confidence in pharmaceutical knowledge (72 % not confident), and 50 % viewed pharmacology education as beneficial to practice. Survey 2 (n = 71) demonstrated strong support for assignment-based assessment: 86 % found the assignment effective, 82 % preferred the assignment over exams, and 79 % agreed that the assignment improved their application of pharmacology knowledge. Students also reported gains in research skills (73 %), critical thinking (64 %), and written communication skills (81 %) through undertaking the assignment. Despite initial uncertainty, students recognised the relevance of pharmacology to their future roles. Assignment-based assessment was perceived as more authentic and beneficial than exams, fostering deeper learning and transferable skills. These findings align with broader educational trends favouring contextualised, practice-oriented learning. Medical radiation science students value pharmacology education when it is clinically relevant and assessed through authentic formats. Assignment-based assessments enhance engagement, confidence, and professional preparedness. Curriculum designers should integrate pharmacology with real-world applications. Embedding clinically relevant pharmacology and authentic assessment into medical radiation science curricula may improve student confidence, engagement, and readiness for safe clinical practice.