An upscaled extraction protocol for Tasmannia lanceolata (Poir.) A.C. Sm.: Anti-bacterial, anti-Giardial and anticancer activity

Background: Tasmannia lanceolata is an endemic Australian plant with a high anti-oxidant capacity. Liquid solvent extractions of T. lanceolata inhibit bacterial growth and block proliferation of several carcinomas and the gastrointestinal parasite Giardia duodenalis. Despite these promising therapeutic properties, methods for the rapid extraction of large quanti- ties of T. lanceolata are lacking. This study aimed to develop a rapid su- percritical extraction method to produce extracts which retain therapeutic propertyes and phytochemistry characteristics. Materials and Methods: T. lanceolata fruit and leaf were extracted by both solvent maceration extraction and supercritical fluid extraction (SFE). The extracts were tested for the ability to inhibit bacterial and G. duodenalis growth. Inhibition of CaCo2 and HeLa cancer cells was evaluated using MTS-based colorimetric cell proliferation assays. Toxicity was evaluated using an Artemia franciscana nauplii bioassay and GC-MS headspace analysis was used to evaluate phytochemical similarity between the extracts. Results: T. lanceolata berry and leaf SFEs displayed strong bacterial growth inhibitory activity against bacterial triggers of autoimmune inflammatory diseases, with efficacies similar to the smaller scale liquid solvent extractions. The growth inhibition of the berry SFE was particularly noteworthy against P. mirabilis and K. pneumoniae, with MIC values of approximately 160 and 190 µg/mL, respectively. The berry and leaf SFE extracts also had similar antiprolifera- tive potencies against G. duodenalis (492 and 375 µg/mL, respectively), CaCo2 (4133 and 3347 µg/mL, respectively) and HeLa carcinomas (2652 and 3497 µg/mL, respectively) to those determined for the corresponding liquid solvent extractions. GC-MS analysis of the berry SFE revealed similar terpenoid components and similar abundances to those in liquid solvent berry extraction. Furthermore, all SFEs were either non-toxic or of only low toxicity in the Artemia franciscana toxicity assay. Conclusion: The T. lanceolata SFE retained the tested therapeutic properties, were non- toxic and had similar phytochemical profiles as smaller scale liquid solvent extractions. Thus, SFE is a viable method of rapidly extracting large masses of T. lanceolata plant material to produce quality extracts which retain ther- apeutic properties.