Kānuka extract shows promise in reducing organ transplant medication’s side effects

Researchers have identified a compound in an extract from native kānuka that may have the potential to limit the adverse effects of rapamycin, a drug primarily used as an immune suppressant in kidney transplants.

“Our lab studies suggest that when this compound, called nerolidol, is used in combination with rapamycin, it could make it easier for the body to absorb the drug, lowering the dosage required,” said Dr. Andrew Munkacsi, a senior lecturer in Biological Sciences at Te Herenga Waka—Victoria University of Wellington.

For patients, this would reduce the risk of adverse side effects from rapamycin. These side effects include anemia, hyperglycemia, and kidney problems.

“We know rapamycin can have toxic effects when administered at high but clinically relevant doses. While further research and clinical trials would be needed to support the use of this kānuka extract, results so far indicate it has good potential to reduce rapamycin’s toxicity,” said Dr. Munkacsi.

The kānuka plant, which is endemic to Aotearoa New Zealand, has a long history of use by Māori, said Dr. Storm Blockley-Powell, who worked on the project as part of her Ph.D. at Victoria University and is now a postdoctoral research scientist at New York’s Columbia University.

“In recent years, kānuka has been investigated for its potential anti-microbial and anti-inflammatory properties. What’s distinctive about our research is that it’s the first to look at the nerolidol compound and identify its potential use in combination with rapamycin,” she said.

The project was done as part of a partnership established in 2016 between the University and Ruatōria-based Hikurangi Bioactives, which develops products derived from kānuka oil. The company works with Māori landowners to source raw materials and plans to share intellectual property and a majority of any profits with the community.

“Providing research support to Hikurangi Bioactives with the involvement of Indigenous landowners has made this an exciting and fulfilling collaboration. We hope the results from this project lead to development opportunities for the Indigenous peoples of Tairāwhiti and future opportunities to collaborate,” said Dr. Munkacsi.

He contrasted the process with that used in the discovery of rapamycin: “Rapamycin was developed in the 1970s from a compound found in soil on Rapa Nui (Easter Island). However, the people of Rapa Nui were unfortunately not involved in the drug’s development.”

Bella Paenga (Ngāti Porou, Ngāti Kahungunu), a Tairāwhiti landowner who worked with Hikurangi Bioactives, had the role of liaising with other landowners to arrange access to the kānuka samples used by the researchers. “It was great for our whenua and whānau to be involved, learning and working alongside the project team, other landowners, and organizations as we look to understand our taonga and how we might together develop sustainable industries that benefit all,” she said.

Identifying a potential new use for kānuka made it an “exciting project” to be involved with, said Hikurangi Bioactives director Manu Caddie (Ngāti Pūkenga, Ngāi Te Rangi).

“We’re grateful for the commitment and expertise of the researchers as well as for the funding support from the Health Research Council and Callaghan Innovation. Aotearoa New Zealand needs to direct more investment into this kind of research to investigate the possible uses of kānuka and other native plants,” he said.