Biology subjects

Crayn, D.

Publications and source records attributed to Crayn, D..

8 recordsLinked to original sources

bioRxiv2026

The Anti-Cancer Effects of Selected Indigenous Medicinal Plants of the Arid Bioregion

Ethnopharmacological relevance: Australian Indigenous medicinal plants represent a valuable yet underexplored source of bioactive compounds with potential therapeutic relevance. The Iningai community of Central Queensland has traditionally used native plants to manage conditions associated with inflammation, pain, infection, and general illness. Scientific evaluation of these plants may provide evidence for their customary applications and identify bioactivities relevant to anticancer biodiscovery. Aim of the study: This study evaluated leaf and stem extracts of seven medicinal plants-Pittosporum angustifolium, Alphitonia excelsa, Calytrix microcoma, Geijera parviflora, Melaleuca uncinata, Gossypium australe, and Eucalyptus similis-traditionally used by the Iningai community, focusing on three biological processes relevant to cancer: oxidative stress, inflammation, and cellular proliferation. Materials and methods: Antioxidant activity was assessed using DPPH radical-scavenging and ferric reducing antioxidant power (FRAP) assays. Anti-inflammatory activity was evaluated in lipopolysaccharide (LPS)-stimulated THP-1 macrophage-like cells by profiling IFN-, TNF-, IL-6, IL-12, IL-18, and IL-23. Antiproliferative activity was assessed using MTT-based viability assays in human and murine liver cancer cell lines (Huh7, Hep3B, Hep-55.1c, and A52). Results: The extracts exhibited distinct biological activity profiles. G. parviflora stem and C. microcoma leaf extracts showed the strongest antioxidant activities, whereas P. angustifolium stem exhibited the weakest radical-scavenging capacity. Cytokine responses were extract-specific, with E. similis leaf extract demonstrating broad and pronounced suppression of multiple LPS-induced pro-inflammatory cytokines. Several extracts produced concentration-dependent reductions in liver cancer cell viability, with P. angustifolium stem exhibiting the most consistent and potent antiproliferative activity across the cell lines tested. Notably, strong antioxidant or anti-inflammatory activity did not necessarily correspond with antiproliferative activity. Conclusion: Australian Indigenous medicinal plant extracts demonstrated distinct antioxidant, immunomodulatory, and antiproliferative activities rather than uniform bioactivity across experimental systems. The divergent activities of G. parviflora, C. microcoma, E. similis, and P. angustifolium highlight the importance of integrated biological screening and support the value of Indigenous knowledge-guided biodiscovery. These plants represent promising sources for further investigation of selective bioactive compounds with potential relevance to anticancer drug discovery.

cancer biology↗

bioRxiv2026

Plant Molecules Protect Against Inflammatory Bowel Disease by Restoring Gut Microbiota-Immune Homeostasis and Suppressing Pro-inflammatory Markers

Inflammatory bowel disease (IBD) is associated with chronic intestinal inflammation and gut microbial dysbiosis, yet effective microbiome-targeted therapeutics remain limited. Here, we investigated the anti-inflammatory and microbiome-modulating activities of metabolites isolated from Garcinia brassii, an endemic species of the Australian Wet Tropics. Five compounds, including a new natural product named garcitine, were isolated and structurally characterised. In human immune cells, garcinol and garcinia biflavonoid 1 significantly suppressed lipopolysaccharide-induced production of IL-1{beta}, IL-6, and TNF without detectable cytotoxicity, while parvifoliol F selectively inhibited IL-1{beta} release. Therapeutic efficacy was further evaluated in a TNBS-induced murine colitis model, where garcinia biflavonoid 1 and parvifoliol F significantly reduced colonic inflammation and improved histopathological outcomes. 16S rRNA sequencing demonstrated that both compounds restored gut microbial homeostasis by reversing colitis-associated dysbiosis and reducing inflammation-associated microbial signatures. Functional pathway prediction further suggested suppression of pro-inflammatory microbial metabolic pathways following treatment. Together, these findings demonstrate that Garcinia-derived metabolites alleviate experimental colitis through coordinated immunomodulatory and microbiome-reprogramming mechanisms and identify garcinia biflavonoid 1 and parvifoliol F as promising candidates for microbiome-targeted IBD therapeutics.

immunology↗

bioRxiv2026

From mountaintops to metacollections: using genomics to evaluate ex situ conservation collections. A case study from tropical montane cloud forest plants

A core aim of ex situ conservation is to represent wild genetic diversity in managed living collections. For the climate-threatened tropical montane cloud forest (TMCF) flora of northeast Australia, an ex situ metacollection of plants and seeds has been established by the Tropical Mountain Plant Science (TroMPS) project. In this study we used reduced-representation sequencing (DArTseq) of wild, herbarium, and ex situ material alongside provenance information for ten species, to pursue two central aims: to characterise landscape-scale genetic structure across species ranges, and to evaluate how well the assembled metacollections represent that wild diversity. Analyses revealed consistent patterns of genetic differentiation among mountain top populations across multiple species, reflecting the isolating influence of lowland gaps between upland habitats, with the degree of differentiation varying among species. These results provide the first genetic baseline for Australian TMCF flora and reinforce the importance of treating individual mountain top populations as distinct units for conservation management. Additionally, the project provided valuable insights into the logistical challenges of coordinated multi-institutional collecting, informing strategies for metacollection design more broadly. Evaluation of the metacollection revealed both strengths and gaps in representation across species, providing an evidence base to refine the current holdings and guide future targeted collecting to strengthen their long-term conservation value.

genomics↗

bioRxiv2026

Phylogenomics of the mega genus Bulbophyllum (Orchidaceae) and implications for its infrageneric classification

Understanding evolutionary relationships in hyperdiverse plant groups remains a major challenge in systematics. The orchid genus Bulbophyllum, the second largest genus of flowering plants, represents an exceptional example of phylogenetic and morphological complexity. Relationships, particularly within the species-rich Asian clade, have remained poorly resolved due to extensive morphological variation and limited resolution in previous phylogenetic studies. Here, we reconstructed phylogenetic relationships using 63 plastid genes from 355 specimens representing 322 species and 65 of the 97 recognised sections of Bulbophyllum. Our analyses confirmed that the genus comprises five major evolutionary lineages comprised of species predominantly from Australasia, Madagascar, Continental Africa, Neotropics, and Asia. We provide the first robust phylogenetic evidence for a dichotomous split within the Asian clade into two well-supported lineages: the Asian-Malesian clade and the Malesian-Papuasian clade, with the latter containing a strongly supported Papuasian subclade. Additionally, this study supports the monophyly of several currently recognised sections while clarifying relationships in previously problematic groups. This study provides the most comprehensive plastid-based phylogenomic framework for Bulbophyllum to date and establishes a foundation for future taxonomic revision and integrative analyses of diversification and trait evolution within this hyperdiverse genus.

evolutionary biology↗

bioRxiv2024

A-Islands: A plant dataset for biodiversity research and species monitoring on Australian islands

Australias coastline is fringed by more than 8,000 continental islands. These islands feature a diverse array of landforms, rock and soil types and geological origins. Some of these islands are among the least invaded, most pristine habitats in Australia and support high plant diversity. Here, we present a new Australia-wide curated dataset for plant species occurrences on islands. Combining information from 1,349 species lists and floras, A-Islands includes data on >6,500 plant species from 844 islands ranging in size from 18 m2 to 4,400 km2, exhibiting different degrees of isolation from the mainland, and spanning all major Australian climate zones. Of these, 251 islands have been repeatedly sampled up to 11 times making it possible to investigate temporal compositional change. A-Islands is open access and will be continuously updated. Its simple data structure consisting of three comma separated files allows easy integration with other Australian and global plant-occurrence databases and can serve as a repository for island research in Australia. Knowing which species occur on Australia's islands will provide opportunities for future research, including studying changes in biodiversity and species-turnover within and among archipelagos, tests of classical island biogeography theory and as a baseline for ecological monitoring and conservation.

ecology↗

bioRxiv2021

Hybphaser identifies hybrid evolution in Australian Thelypterid ferns

Hybridisation can lead to reproductive isolation and consequently speciation. It has been proposed to play an important role in fern evolution, but has been difficult to investigate. This study explores the utility of target sequence capture and reference guided read phasing to investigate the role of evolutionary reticulation in ferns using Australian Thelypteridaceae as a model. The bioinformatics workflow HybPhaser was used to assess divergence between alleles, phase sequence reads to references to construct accessions resembling parental haplotpes, and include them in phylogenetic and network analyses to detect hybrids and parentage. This approach identified two novel hybrid lineages in Thelypteridaceae, one occurring between two different genera (Abacopteris and Christella), and provided evidence that reticulation is likely to have played an important role in the diversification of Australian thelypterids. In addition, hybrid phasing successfully reduced conflicting data and improved overall resolution in the Thelypteridaceae phylogeny, highlighting the power of this approach for reconstructing evolutionary history in reticulated lineages.

evolutionary biology↗

bioRxiv2020

HybPhaser: a workflow for the detection and phasing of hybrids in target capture datasets

Premise of the studyHybrids contain divergent alleles that can confound phylogenetic analyses but can provide insights into reticulated evolution when identified and phased. We developed a workflow to detect hybrids in target capture datasets and phase reads into parental lineages using a similarity and phylogenetic framework. MethodsWe used Angiosperms353 target capture data for Nepenthes including known hybrids to test the novel workflow. Reference mapping was used to assess heterozygous sites across the dataset, detect hybrid accessions and paralogous genes. Hybrid samples were phased by mapping reads to multiple references and sorting reads according to similarity. Phased accessions were included in the phylogenetic framework. ResultsAll known Nepenthes hybrids and nine more samples had high levels of heterozygous sites, reads associated with multiple divergent clades, and were phased into accessions resembling divergent haplotypes. Phylogenetic analysis including phased accessions increased clade support and confirmed parental lineages of hybrids. DiscussionHybPhaser provides a novel approach to detect and phase hybrids in target capture datasets, which can provide insights into reticulations by revealing origins of hybrids and reduce conflicting signal leading to more robust phylogenetic analyses.

evolutionary biology↗

bioRxiv2020

The genetic origin of evolidine, the first cyclopeptide discovered in plants, and related orbitides

Cyclic peptides are reported to have antibacterial, antifungal and other bioactivities. Several genera of the Rutaceae family are known to produce orbitides, which are small head-to-tail cyclic peptides composed of proteinogenic amino acids and lacking disulfide bonds. Melicope xanthoxyloides is an Australian rain forest tree of the Rutaceae family in which evolidine - the first plant cyclic peptide - was discovered. Evolidine (cyclo-SFLPVNL) has subsequently been all but forgotten in the academic literature, but here we use tandem mass spectrometry to rediscover evolidine and using de novo transcriptomics we show its biosynthetic origin to be from a short precursor just 48 residues in length. In all, seven M. xanthoxyloides orbitides were found and they had atypically diverse C-termini consisting of residues not recognized by either of the known proteases plants use to macrocyclize peptides. Two of the novel orbitides were studied by nuclear magnetic resonance spectroscopy and although one had definable structure, the other did not. By mining RNA-seq and whole genome sequencing data from other species, it was apparent that a large and diverse family of peptides is encoded by sequences like these across the Rutaceae.

biochemistry↗