AbstractHoney is a super-saturated sugar solution comprising of over 200 compounds, derived from a combination of nectar and bee salivary secretions, resulting in unique honey varieties. In Australia, most honey retail occurs in supermarkets and other commercial outlets. These honeys are subjected to treatments (heating and filtering) to maintain product quality and adhere to consumer expectations. The effect of these treatments on commercial honeys is conflicting, highlighting a need for further research investigating their specific properties. Honey has been used historically for a variety of medicinal purposes, with health-related properties of honey attributed to its composition. Honey displays effective antioxidant and antibacterial activities, with both properties contributing to honey’s well-established wound-healing effects. Therefore, a key focus of this thesis was to establish the potential of commercially available honey to be used in clinical settings, specifically in the management of oral mucositis (OM) in oncology patients.
Oral mucositis occurs as a side effect of common oncology treatments, causing erythema, oedema, and ulcerations, and is described as a significant burden to patients. While all patients receiving the causative treatments can develop OM, patients with head and neck cancer (HNC) receiving radiotherapy (RT) are at a high risk. The presence of mucositis is also associated with an increased risk of treatment interruption, hospitalisation, malnutrition, and decreased quality of life. Honey is a potential treatment option in the management of OM, with preliminary studies identifying reductions in the severity and duration of mucositis outcomes following honey application. However, previous OM research has not investigated the properties of the specific honeys used. Rather, the scientific rationale for the use of honey for OM management was based on published research reporting the in vitro wound-healing properties of honey. Therefore, this doctoral thesis had two aims. Firstly, to obtain a deeper understanding of specific properties of the previously unexplored commercially available Australian honeys, including sensory, and those associated with honey’s wound-healing abilities (including antioxidant and antibacterial). Secondly, based on these properties, explore the potential use of commercially available honey as a viable treatment option for OM in patients with HNC. The utilisation of this honey type for patients with OM would provide a convenient treatment option, due to its accessibility and affordability. To address the two aims, the thesis is presented as a ‘Thesis containing published works’, with each of the chapters presented as peer-reviewed publications, or unpublished manuscripts. The chapters include; a narrative review (Chapter 2; published), systematic review (Chapter 3; published), three food science-based original research articles (Chapters 4-6; published), and a protocol manuscript designed utilising the findings from the previous chapters (Chapter 7). The research objectives, which guided the development and completion of the individual research projects, contributed to achieving the thesis aims. Findings from the narrative literature review (Chapter 2) identify the impact of treatment-related side effects, particularly OM, for patients receiving oncological treatments for HNC, recognising the importance of investigating approaches to minimise their impacts. The systematic review (Chapter 3) supports the use of honey for OM management through providing evidence of the safety and efficacy of honey used in a variety of oral health conditions, recognising the potentially harmful application of Manuka honey. A sensory analysis (Chapter 4) was completed for a range of commercially available Australian honeys, and informed on the perceived likeability of the honeys, with factors influencing likeability, such as sweetness, also identified. This analysis has the potential to inform of the honeys most accepted by the Australian population, encouraging further commercial honey investigation. This included an analysis (Chapter 5) of the bioactive composition, antioxidant characteristics, antibacterial abilities, and physicochemical properties of the honeys. The results were comparable to other non-commercial honey varieties within international literature and propose a variation in properties commonly attributed to honey’s wound-healing abilities for the commercial Australian honeys. The determination of some of these honey properties (antioxidant characteristics and physicochemical properties) when the samples interact with saliva were also investigated (Chapter 6), with results suggesting a supportive effect of the saliva on these properties. This identifies how the honey may interact when applied to the mouth, encouraging the use of commercial honeys for investigations of the management of RT-induced OM. The doctoral research concludes with a protocol (Chapter 7) describing how some of the investigated commercially available Australian honeys may be used in future investigations for OM management in patients with HNC. The analysis completed on a variety of honeys in this thesis has provided an understanding of some of the properties attributed with honey’s wound-healing abilities for the commercial samples. The determination of OM outcomes following the application of commercial honeys in future investigations has the potential to inform of the parameters of these properties required for successful OM management, which can possibly inform future clinical guidelines.
|Date of Award||2021|
|Supervisor||Kellie Toohey (Supervisor), Nenad Naumovski (Supervisor) & Andrew Mckune (Supervisor)|