Cornelia Locher’s research while affiliated with The University of Western Australia and other places

Introduction Tonsillectomy, a common childhood surgery, is associated with difficult postoperative recovery. Previous reviews provided low‐grade evidence that honey may improve recovery. The BEE PAIN FREE study investigated whether honey alongside multimodal analgesia improved the recovery trajectory in children following tonsillectomy. Methods A prospective randomised controlled trial was conducted across three centres in Western Australia. Children undergoing extracapsular tonsillectomy by coblation were allocated randomly to one of four postoperative treatment groups: standard treatment alone; Marri honey (from Western Australia); Manuka honey (from Western Australia); or placebo. The intervention groups took 5 ml of honey or placebo, six times a day, for at least 7 days, in addition to usual discharge analgesia (standard treatment). Data for daily pain scores, Parents' Postoperative Pain Measure scores, medications and unplanned re‐presentations were collected. Results A total of 400 children were recruited; 20% were lost to follow‐up or withdrew. The mean number of honey doses taken varied between 2 and 3 doses per day over 7 days. Treatment with honey at this frequency did not impact postoperative pain scores significantly, with all groups showing similar trajectories. These findings did not alter with as‐treated analysis or using imputed models for missing data. Most children experienced significant pain until around postoperative day 8. Children allocated to the honey and placebo groups showed some improved oral tolerance around day 6 but had increased vomiting during earlier days. There were no clinically significant differences in medical re‐presentations, simple analgesia or oxycodone usage between groups. Discussion Two to three doses daily of oral honey/placebo in children post‐extracapsular tonsillectomy for 7 days, in addition to regular paracetamol, ibuprofen and as required oxycodone did not result in a clinical improvement in pain or recovery over a 14‐day follow‐up period.

This study investigates the physiochemical properties, chemical composition, and antioxidant activity of Australian stingless bee honey blends from two bee species, Tetragonula carbonaria and Tetragonula hockingsi, harvested in Burpengary East, Queensland at different times of the year. The moisture content of the honey samples ranged from 26.5% to 30.0%, total soluble solids from 70.0 to 73.5° Brix, and pH from 3.57 to 4.19. The main sugars identified were trehalulose (13.9 to 30.3 g/100 g), fructose (12.9 to 32.3 g/100 g), and glucose (4.80 to 23.7 g/100 g). The total phenolic content (TPC), measured using the Folin–Ciocalteu assay, ranged from 26.1 to 58.6 mg of gallic acid equivalents/100 g. The antioxidant activity was investigated with the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, with values ranging from 1.39 to 6.08 mmol of Trolox equivalents/kg. Antioxidant constituents were determined using a High-Performance Thin-Layer Chromatography (HPTLC)-DPPH assay. The HPTLC-DPPH analysis revealed that honey samples collected in May 2022 contained the highest number of antioxidant compounds. Some constituents were identified using an HPTLC-derived database and also quantified utilising HPTLC analysis. Lumichrome was present in all honey samples, while luteolin and kaempferide were detected only in some. Kaempferol or isorhamnetin was also found to be present, although a definitive distinction between these two chemically closely related compounds could not be made by HPTLC analysis. The results showed that honey produced by Tetragonula hockingsi and Tetragonula carbonaria shares similar properties and composition when harvested at the same time, with only minor differences in moisture, fructose, and glucose content.

The complex chemical composition of honey presents significant challenges for its analysis with variations influenced by factors such as botanical source, geographical location, bee species, harvest time, and storage conditions. This study aimed to employ high-performance thin-layer chromatography (HPTLC) fingerprinting, coupled with multivariate data analysis, to characterise the chemical profiles of Australian stingless bee honey samples from two distinct bee species, Tetragonula carbonaria and Tetragonula hockingsi. Using a mobile phase composed of toluene:ethyl acetate:formic acid (6:5:1) and two derivatisation reagents, vanillin–sulfuric acid and natural product reagent/PEG, HPTLC fingerprints were developed to reveal characteristic patterns within the samples. Multivariate data analysis was employed to explore the similarities in the fingerprints and identify underlying patterns. The results demonstrated that the chemical profiles were more closely related to harvest time rather than bee species, as samples collected within the same month clustered together. The quality of the clustering results was assessed using silhouette scores. The study highlights the value of combining HPTLC fingerprinting with multivariate data analysis to produce valuable data that can aid in blending strategies and the creation of reference standards for future quality control analyses.

Background The behavior of bees results in important natural products such as honey, propolis, wax, beeswax, bee pollen, royal jelly and bee venom. Sometimes, the terms propolis, geopropolis and cerumen are used interchangably despite some diferences. Objective. To discuss the commonalities and differences between substances referred to as propolis, cerumen and geopropolis respectively and to provide an overview of their bioactvities, medicinal uses and also their chemical composition to assist with a more consistent use of these terms into the future. Methodology. Scientific articles related to these three bee substances, published between 2019 and 2024, were reviewed. Results and Discussion. The main differences related to the use of the three terms relate to the bee species involved in their production and also their chemical characteristics. Propolis is produced by Apis mellifera bees, whereas native bees produce cerumen, that sometimes is also referred to as geopropolis, depending on the presence of soil components. All three bee products, propolis, geopropolis and cerumen, have medicinal applications and are also used in the food and cosmetic industry. Conclusion: Based on a review of their typical charactristics, this study creates the foundation for a more consistent use in the future of the terms propolis, geopropolis and cerumen, which are important bee derived natural products. Based on the findings of this study it is also suggested that future research should aim to further improve knowledge of the nutrient content and presence of bioactive compounds in these popular bee products.

Featured Application The developed HPTLC method was able to detect and quantify four targeted fat-soluble vitamins in commercial pharmaceutical preparations. Abstract A simple, cost-effective, and efficient novel high-performance thin-layer chromatography (HPTLC) tool was developed and validated in accordance with International Conference on Harmonisation (ICH) guidelines for the detection and quantification of four fat-soluble vitamins, D2, D3, E, and K1, using chloroform: cyclohexane (55:45, v/v) as mobile phase. The detection and quantification limits were found to be 30.86 and 93.52 ng/band for vitamin D2, 19.44 and 58.92 ng/band for vitamin D3, 14.17 and 42.95 ng/band for vitamin E, and 0.86 and 2.61 ng/band for vitamin K1, which were similar or lower than those reported in previous methods. The advantage of the developed method is that it uses a simple mobile phase in a single development step and has low detection and quantification limits. The application of the developed HPTLC method was successfully demonstrated with the quantitative analysis of these vitamins in some commercially available pharmaceutical preparations.

This study critically investigates the aluminium chloride–based colorimetric determination of the total flavonoid content (TFC) of honey. Following a comprehensive review of the recent literature reporting the use of the assay in the determination of TFC in honey, 10 honeys of different botanical origins were investigated using the colorimetric method alongside an artificial honey that was used as a control. Using spiking experiments, this study demonstrates that the flavonoid concentrations commonly found in honey are too low for a direct measurement and thus some of the TFC data reported in the literature might more likely be a reflection of the honey’s inherent colour rather than a product of the coordination complex formed specifically between flavonoids and Al³⁺ ions. This paper highlights the importance of correct blanking and suggests alternative approaches to the traditional TFC assay for honey to ensure analysis results that are truly reflective of honey’s TFC.

This is the first study to report on high performance thin layer chromatography (HPTLC) generated spectrophotometric data to systematically capture flavonoid compounds using optimized derivatization with either AlCl3 or NaNO2-AlCl3-NaOH as visualisation reagents. While the traditional AlCl3 colorimetric method using UV–Vis analysis provides valuable insights into the presence of flavonoids and allows derivation of the total flavonoid content (TFC) of a sample, HPTLC fingerprints obtained after spraying with AlCl3 or NaNO2-AlCl3-NaOH enable the visualization of the various flavonoids present in a sample based on their respective absorption shifts, thus complementing the traditional TFC assay. In this study, 40 different flavonoids representing different classes (flavonols, flavanolols, flavan-3-ol, flavones, flavanones, and isoflavonoids) were analysed. Upon derivatization with AlCl3 most of the investigated flavonoids recorded bathochromic shifts, yielding characteristic λmax values between 370 and 420 nm, while spraying with NaNO2-AlCl3-NaOH triggered hyperchromic shifts, and thus an increase in absorbance intensity in flavonoids with particular substitution patterns. A few non-flavonoid components with structural similarities to flavonoids (e.g., rosmarinic acid, gallic acid, aspirin, salicylic acid) served as the negative control in this study to determine whether the derivatization reagents allowed exclusive detection of flavonoids. The method was then applied to the analysis of flavonoid containing supplements as well as red clover honey to demonstrate the method’s application in the analysis of natural products.

Oral liquid prednisolone medications have poor acceptance among paediatric patients due to ineffective masking of the bitterness taste of prednisolone. This study aimed to develop a child-friendly prednisolone tablet using a patented chewable chocolate-based delivery system (CDS) previously applied successfully to mask the bitterness tastes of midazolam and tramadol. Prednisolone sodium phosphate (PSP) and prednisolone base (PB) CDS tablets were prepared, and the manufacturing process was optimised using a design of experiments (DoE) approach. Stability was assessed by quantifying residual drug content via a validated HPLC assay. A pilot randomised crossover taste study involving 25 young adult volunteers evaluated taste-masking effectiveness against Redipred™, a commercial oral PSP liquid medicine. The results showed that the PSP CDS tablet was chemically stable following storage for three months at ambient temperature, while the PB CDS tablet was unstable. The optimised PSP CDS tablet, manufactured at 50 °C with a stirring time of 26 h, was found to release over 80% of its drug load within 20 min in 0.1 M HCl and had a significantly better mean taste score compared to Redipred™ (7.08 ± 2.40 vs. 5.60 ± 2.33, p = 0.03). Fifty six percent of the participants preferred the PSP CDS tablet. In conclusion, compared to Redipred™, the CDS technology provided a more effective taste masking of PSP, potentially offering a child-friendly prednisolone formulation with improved compliance, dosing accuracy, and storage stability.

This study reports on the physicochemical and antioxidant properties of propolis samples from various regions across Western Australia and identifies some phenolic constituents using high-performance thin-layer chromatography (HPTLC). Total phenolic content (TPC) was determined using a modified Folin–Ciocalteu assay, and antioxidant activity was investigated with the Ferric Reducing Antioxidant Power (FRAP) assay and also visualised and semi-quantified by HPTLC-DPPH analysis. TPC values ranged from 9.26 to 59.3 mg gallic acid equivalent/g of raw propolis and FRAP assay data from 4.34 to 53.8 mmol Fe²⁺ mmol/kg of raw propolis, although some of these variations might be related to differences in extraction yields obtained with 70% ethanol. The presence of luteolin, taxifolin, naringenin, and 4-hydroxyphenylacetic acid was confirmed based on a comprehensive, validated matching approach against an HPTLC-derived database. The findings of the study highlight the importance of future research on the chemical composition and bioactivity of Western Australian propolis.

In the original publication [...]