About
Biography
Dr Steven Ogbourne is an experienced research scientist with a background in drug discovery and drug development with a focus in areas including plant science, molecular biology and natural product drug discovery. Biodiscovery is his key focus area following his move into the field of drug discovery as a post-doctoral researcher at the Queensland Institute of Medical Research and drug development with the pharmaceutical companies, Peplin and LEO Pharma and more recently with EcoBiotics and QBiotics.
Dr Ogbourne’s research at QIMR helped result in the identification of the natural product ingenol mebutate, which showed significant anti-cancer activity. He worked for the Australian biotechnology company, Peplin (who owned the rights to the compound) and later the international dermatology company LEO Pharma (who acquired Peplin in 2009), where he was intimately involved in the drugs development. Ingenol mebutate has now been approved for use as a topical treatment for actinic keratosis around the world.
Since joining USC, Dr Ogbourne’s research focusses on biodiscovery in collaboration with other members of the University’s GeneCology Research Centre and the Australian companies EcoBiotics and QBiotics. Dr Ogbourne's biodiscovery research spans a range of therapeutic areas including cancer, anti-bacterials and wound-healing.
Dr Ogbourne’s most significant current research projects are in collaboration with EcoBiotics and QBiotics, focusing on the anti-cancer drug EBC-46 and domestication of Fontainea picrosperma (the native tropical rainforest tree from which EBC-46 is isolated), as well as the discovery of natural product anti-bacterial drug candidates. Dr Ogbourne also has a passion for conservation and his team is actively involved in several projects relating to the conservation of threatened species of plants and animals. Current and previous projects have focussed on Fontainea australis, F. venosa, F. rostrata, Alectryon ramiflorus, Calyptorhynchus lathami and Delma impar in collaboration with several groups including the Burnett Mary Regional Group, Royal Botanic Gardens Sydney and the Gympie Regional Council. This research will provide substantial conservation outcomes as well as adding to our scientific understanding of the biology and ecology of these important species and the ecosystems in which they live.
Research areas
- biodiscovery
- drug development
- natural products chemistry
- population genetics
- conservation genetics
Expert Media Commentary
Steven's area of knowledge include plant biotechnology, biodiscovery, drug development, population genetics and conservation genetics.
Organisational Affiliations
Past Affiliations
Highlights - Outputs
Journal article
Lessons from Exploring Chemical Space and Chemical Diversity of Propolis Components
Published 2020
International Journal of Molecular Sciences, 21, 14, 1 - 35
Propolis is a natural resinous material produced by bees and has been used in folk medicines since ancient times. Due to it possessing a broad spectrum of biological activities, it has gained significant scientific and commercial interest over the last two decades. As a result of searching 122 publications reported up to the end of 2019, we assembled a unique compound database consisting of 578 components isolated from both honey bee propolis and stingless bee propolis, and analyzed the chemical space and chemical diversity of these compounds. The results demonstrated that both honey bee propolis and stingless bee propolis are valuable sources for pharmaceutical and nutraceutical development.
Journal article
Published 2020
Plants, 9, 2, 228
Tree nuts play an important role in healthy diets, but their economic value and nutritional quality may be affected by their size and paternity. We assessed relationships between nut size and kernel recovery, the incidence of whole kernels, fatty acid composition and mineral nutrient concentrations in three macadamia cultivars, "Daddow", "816" and "A4". We determined to what extent differences in nut size and quality were the result of different levels of cross- or self-paternity. Small nuts of all cultivars had lower kernel recovery than large nuts, and small nuts provided lower incidence of whole kernels in "Daddow" and "A4". Small kernels had a lower relative abundance of the saturated fatty acid, palmitic acid, in all cultivars and higher relative abundance of the unsaturated fatty acid, oleic acid, in "Daddow" and "A4". Small kernels had higher concentrations of many essential nutrients such as nitrogen and calcium, although potassium concentrations were lower in small kernels. Most nuts arose from cross-pollination. Therefore, nut size and kernel quality were not related to different levels of cross- and self-paternity. Identified cross-paternity was 88%, 78% and 90%, and identified self-paternity was 3%, 2% and 0%, for "Daddow", "816" and "A4", respectively. Small macadamia kernels are at least as nutritious as large macadamia kernels. High levels of cross-paternity confirmed that many macadamia cultivars are predominantly outcrossing. Macadamia growers may need to closely inter-plant cultivars and manage beehives to maximise cross-pollination.
Journal article
Published 2020
Fitoterapia, 146, 1 - 9
Euphorbiaceae is a large and diverse family of herbs, shrubs and trees that includes a number of species of considerable economic importance as sources of food, medicines and raw materials. One member of this family, Fontainea picrosperma, is the source plant for the diterpene ester tigilanol tiglate, a natural product recently approved as a treatment for canine mast cell tumours. Here we report the development of reference transcriptomes from root and leaf tissues of F. picrosperma, which include core diterpene biosynthesis genes. A total of ~12 Gb of combined clean reads were generated for assembly into 167,566 contigs with a GC (guanine-cytosine) content of ~41%. Gene ontology showed that 2286 and 2504 transcripts were enriched in the cellular process and 2369 and 2529 transcripts were enriched in the metabolic process categories in leaf and root tissue, respectively. The reference transcriptome contains genes coding for core enzymes involved in common secondary metabolite biosynthetic pathways, including the diterpene biosynthesis pathway within the mevalonate (MVA) and 2-C-methyl-D-erythritol 4- phosphate (MEP) pathways. A phylogenetic analysis using these genes found that F. picrosperma clustered most closely to Jatropha curcas. We found a significantly higher concentration of tigilanol tiglate in F. picrosperma root tissue, which correlated with higher levels of gene expression for enzymes associated with the MVA (6 genes) and MEP (7 genes) pathways, and we hypothesise that the initial stages of tigilanol tiglate biosynthesis occur primarily in the roots of F. picrosperma. This study provides a resource for future gene-related biodiscovery investigations in F. picrosperma and diterpene biosynthesis, in particular for tigilanol tiglate and related macrocyclic diterpenes. [Display omitted]
Journal article
Published 2019
PLoS One, 14, 1, e0210560
Assisted migration can aid in the conservation of narrowly endemic species affected by habitat loss, fragmentation and climate change. Here, we employ a multidisciplinary approach by examining the population genetic structure of a threatened, dioecious rainforest tree of the subtropical notophyll vine forests of eastern Australia, Fontainea rostrata, and its potential requirements for population enhancement and translocation to withstand the effects of anthropogenic fragmentation and climate change. We used microsatellite markers to gain an understanding of the way genetic diversity is partitioned within and among the nine extant populations of F. rostrata identified in this study. We combined the results with species distribution modelling to identify populations vulnerable to possible future range shifts based on climate change projections. We found regional differences between the species' main distribution in the south and a disjunct northern population cluster (FRT = 0.074, FSR = 0.088, FST = 0.155), in mean allelic richness (AR = 2.77 vs 2.33, p & 0.05), expected heterozygosity (HE = 0.376 vs 0.328), and inbreeding (F = 0.116 vs 0.219). Species distribution models predicted that while southern populations of F. rostrata are likely to persist for the next 50 years under the RCP6.0 climate change scenario, with potential for a small-scale expansion to the south-east, the more highly inbred and less genetically diverse northern populations will come under increasing pressure to expand southwards as habitat suitability declines. Given the species' genetic structure and with the aim to enhance genetic diversity and maximise the likelihood of reproductive success, we recommend that plant reintroductions to supplement existing populations should be prioritised over translocation of the species to new sites. However, future conservation efforts should be directed at translocation to establish new sites to increase population connectivity, focussing particularly on habitat areas identified as persisting under conditions of climate change.
Journal article
The impact of human activities on Australian wildlife
Published 2019
PLoS One, 14, 1, e0206958
Increasing human population size and the concomitant expansion of urbanisation significantly impact natural ecosystems and native fauna globally. Successful conservation management relies on precise information on the factors associated with wildlife population decline, which are challenging to acquire from natural populations. Wildlife Rehabilitation Centres (WRC) provide a rich source of this information. However, few researchers have conducted large-scale longitudinal studies, with most focussing on narrow taxonomic ranges, suggesting that WRC-associated data remains an underutilised resource, and may provide a fuller understanding of the anthropogenic threats facing native fauna. We analysed admissions and outcomes data from a WRC in Queensland, Australia Zoo Wildlife Hospital, to determine the major factors driving admissions and morbidity of native animals in a region experiencing rapid and prolonged urban expansion. We studied 31,626 admissions of 83 different species of native birds, reptiles, amphibians, marsupials and eutherian mammals from 2006 to 2017. While marsupial admissions were highest (41.3%), admissions increased over time for all species and exhibited seasonal variation (highest in Spring to Summer), consistent with known breeding seasons. Causes for admission typically associated with human influenced activities were dominant and exhibited the highest mortality rates. Car strikes were the most common reason for admission (34.7%), with dog attacks (9.2%), entanglements (7.2%), and cat attacks (5.3%) also high. Admissions of orphaned young and overt signs of disease were significant at 24.6% and 9.7%, respectively. Mortality rates were highest following dog attacks (72.7%) and car strikes (69.1%) and lowest in orphaned animals (22.1%). Our results show that WRC databases offer rich opportunities for wildlife monitoring and provide quantification of the negative impacts of human activities on ecosystem stability and wildlife health. The imminent need for urgent, proactive conservation management to ameliorate the negative impacts of human activities on wildlife is clearly evident from our results.
Journal article
Published 2019
Heredity, 123, 4, 503 - 516
Gene flow via pollen movement affects genetic variation in plant populations and is an important consideration in plant domestication. Fontainea picrosperma is a subcanopy rainforest tree that is of commercial interest because it is the source of tigilanol tiglate, a natural product used for the treatment of solid tumors. We identify patterns of pollen-mediated gene flow within natural populations of F. picrosperma and estimate genetic parameters and genetic structure between adult and juvenile groups using microsatellite markers. Our results show pollination events occur over much shorter distances than reported for tropical canopy species. At least 63% of seeds are sired by male trees located within 30 m of the mother. On average, 27% of the local male population contributed to successful reproduction of F. picrosperma with most fathers siring a single seed, however, the contributions to reproduction were uneven. Larger male trees with more flowers had greater reproductive success than those with less flowers (P < 0.05). There were comparatively low levels of genetic variation across the species (HE = 0.405 for adult trees and 0.379 for juveniles) and we found no loss of genetic diversity between adult and juvenile trees. Short distance pollen flow and low genetic diversity is theoretically a prelude to genetic impoverishment, however F. picrosperma has persisted through multiple significant climatic oscillations. Nevertheless, the remaining low genetic diversity is of concern for domestication programs which require maximal genetic diversity to facilitate efficient selective breeding and genetic improvement of this commercially significant species.
Journal article
Tattoo removal with ingenol mebutate
Published 2017
Clinical, Cosmetic and Investigational Dermatology, 2017, 10, 205 - 210
An increasing number of people are getting tattoos; however, many regret the decision and seek their removal. Lasers are currently the most commonly used method for tattoo removal; however, treatment can be lengthy, costly, and sometimes ineffective, especially for certain colors. Ingenol mebutate is a licensed topical treatment for actinic keratoses. Here, we demonstrate that two applications of 0.1% ingenol mebutate can efficiently and consistently remove 2-week-old tattoos from SKH/hr hairless mice. Treatment was associated with relocation of tattoo microspheres from the dermis into the posttreatment eschar. The skin lesion resolved about 20 days after treatment initiation, with some cicatrix formation evident. The implications for using ingenol mebutate for tattoo removal in humans are discussed.
Journal article
Published 2016
Environmental Science and Pollution Research, 23, 19, 18988 - 19001
Glyphosate has been the most widely used herbicide during the past three decades. The U.S. Environmental Protection Agency (EPA) classifies glyphosate as 'practically non-toxic and not an irritant' under the acute toxicity classification system. This classification is based primarily on toxicity data and due to its unique mode of action via a biochemical pathway that only exists in a small number of organisms that utilise the shikimic acid pathway to produce amino acids, most of which are green plants. This classification is supported by the majority of scientific literature on the toxic effects of glyphosate. However, in 2005, the Food and Agriculture Organisation (FAO) reported that glyphosate and its major metabolite, aminomethylphosphonic acid (AMPA), are of potential toxicological concern, mainly as a result of accumulation of residues in the food chain. The FAO further states that the dietary risk of glyphosate and AMPA is unlikely if the maximum daily intake of 1 mg.kg-1 body weight (bw) is not exceeded. Research has now established that glyphosate can persist in the environment and therefore, assessments of the health risks associated with glyphosate are more complicated than suggested by acute toxicity data that relate primarily to accidental high rate exposure. We have used recent literature to assess the possible risks associated with the presence of glyphosate residues in food and the environment.