UP researchers stumbled upon the blood-thinning potential of South Africa’s indigenous lavender tree “by accident” while trying to establish the safety of an oral rinse, and they say a local sweet-smelling herb could fight inflammation in the lungs. 

The findings were recently published in the South African Journal of Botany (SAJB), in two separate basic research studies led by Prof Namrita Lall. 

Prof Lall has made a name for herself studying the potential medical uses of South Africa’s rich diversity of indigenous plants, hand-in-hand with traditional knowledge holders. She is based at UP’s Department of Plant and Soil Sciences and serves as South Africa’s Research Chair for Indigenous Knowledge Systems.

Blood thinning potential

“The wild lavender tree has been proven for periodontal diseases,” explained Prof Lall. “But if we want to produce an oral rinse we have to do a full toxicology study to ensure that if a small amount is swallowed by accident, it should not be toxic.”

She says that although the rinse was found to be non-toxic and safe when used correctly (spitting out after rinsing), they noticed during the toxicology study in mice that a few of the animals bled a little bit when they ingested large amounts.

“That’s when we thought of checking, ‘does some part of this plant have any anticoagulant effect?’,” said Prof Lall.

Prof Lall and her postgraduate students. Lilitha Lwando Denga, Bianca Diedericks and Anna-Mari Kok revealed in the February edition of the SAJB that, indeed, plant extracts from the wild lavender tree have the potential to prevent blood clots.

The wild lavender tree is native to KwaZulu Natal, as per its scientific name Heteropyxis natalensis, but it also grows in Gauteng, Mpumalanga, Swaziland and Zimbabwe. Parts of the plant are traditionally used in tea and potpourri, according to the South African National Biodiversity Institute (SANBI).

Lall’s all-woman team investigated its blood-thinning properties alongside several other indigenous plants, but they determined that H. natalensis was the best candidate for further studies.

Over the years, Prof Lall has taken many such preliminary studies on indigenous plants all the way to clinical studies and commercial products, including an oral rinse to prevent periodontal disease, as well as a sunscreen and a cream to combat skin hyperpigmentation.

Indigenous knowledge and scientific evidence

She says the first clue for a scientific study of a plant’s potential medicinal or cosmeceutical value often comes from indigenous knowledge, where communities and traditional healers are already using herbs in similar ways.

“But those medicines are not registered, so only a handful of people benefit,” said Prof Lall. “If we can generate scientific data, we feel a lot more people will benefit, and there will be a chance to export these things to other countries.”

This is important, she says because South Africans are currently using many clinically proven treatments and cosmetics developed and sourced in other countries. “So why not develop our own local stuff? Local is lekker!”

She explained that the intellectual property behind commercial products would be shared if the knowledge comes directly from indigenous communities or traditional healers. 

“The plant diversity of South Africa is very impressive. So if anyone knows plant usage for a particular ailment, they can approach us,” said Prof Lall. Once scientific data confirms potential medicinal uses, she explains, the industry can refine the products, put them through clinical testing, and eventually get them onto shop shelves.

To ensure that indigenous knowledge holders are protected and also benefit, Prof Lall uses her government funding to establish greenhouse facilities in communities, and to develop their cultivation and harvesting skills.

“In this way, if industry is interested, they should buy the plants from the community,” she said. 

Sweet herbs for the lungs?

In the March edition of SAJB, Lall and an international team of researchers, including two of her other UP postgraduate students, Tenille Esmear and Danielle Twilley, also revealed that a sweet indigenous herb called Helichrysum odoratissimum might work against lung cancer and inflammation.

This herb is traditionally used to treat coughs and colds, and as a perfume and insect repellent, according to SANBI.

Prof Lall cautioned, however, that both of these SAJB publications describe basic research studies into the potential medicinal use of plants. 

“We are definitely not telling the public to take these herbs to treat blood clots or cancer yet,” she says, adding that much more research is needed before scientists, industry and medicine regulators can establish effectiveness, dosages, safety and recommended uses through clinical trials.

DOI

https://doi.org/10.1016/j.sajb.2024.01.056

https://doi.org/10.1016/j.sajb.2024.02.028