Female scientists have been at the forefront of researching Rooibos – one of the country’s most treasured natural resources.

The first documented scientific research on the healing properties of Rooibos in the early 1990’s started a chain reaction, which hasn’t let up. Today, largely due to the vast amount of research that underpins its health claims, Rooibos has become a sought-after superfood both locally and abroad, and is exported to more than 30 countries.

In the wake of International Day of Women and Girls in Science (11 February), the SA Rooibos Council (SARC) is paying tribute to specifically the female researchers for their invaluable contribution to the industry, and in doing so, also hopes to inspire young girls to pursue a career in science.

Adele du Toit, spokesperson for the SA Rooibos Council says since the industry actively started to pursue research into Rooibos, it has involved more than 40 women scientists from South Africa, France, the Netherlands, Germany, Japan and Taiwan.

“These incredible women are all attempting to answer some of the most pertinent questions of our time and provide solutions to life-inhibiting and life-threatening illnesses. We salute them for their dedication and commitment to science, while many of them juggle motherhood and other demands.

“It’s unfortunate that women still account for less than 30% of the world’s researchers, as they have such a major role to play. The contribution that these women are making in the generation of knowledge is fuelling the exciting innovation within the sector and is giving a proudly South African product a significant competitive edge”, remarks du Toit.

Here are some of the women scientists who are putting Rooibos on the map:

Jeanine Marnewick

Prof Jeanine Marnewick, Research Chair in Biotechnology & Director of the Applied Microbial and Health Biotechnology Institute at Cape Peninsula University of Technology (CPUT) has made a major contribution to the field of disease prevention with the use of Rooibos as a complementary strategy to ensure increased intake of plant flavonoids as a “health boosting” or disease preventing option. The studies Prof Marnewick have conducted in the past 20 years on Rooibos resulted not only in the first scientific evidence on the cancer prevention properties of the herbal tea, but also in the first clinical evidence of Rooibos’ redox status (balance between oxidants and antioxidants) and lipid profile (cholesterol and triglycerides) improvement properties and how this can reduce one’s risk of heart disease.

Prof Elizabeth Joubert, a Principal Researcher at the Plant Bioactives Group of the Agricultural Research Council of South Africa and Extraordinary Professor in Food Science at Stellenbosch University, has been doing Rooibos product research for 37 years, focussing on improving the consumer’s enjoyment of the product and unlocking value for the Rooibos producer. Her past research on Rooibos antioxidants and continued interest in its phenolic composition underpins current efforts to enhance the “healthy” image of Rooibos tea. The phenolic constituents of Rooibos are key to its beneficial properties, as well as key drivers for the development of new products.

Rabia Johnson

Dr Rabia Johnson, Principal Investigator and Senior Specialist Scientist at the SA Medical Research Council (SAMRC) proved that Rooibos helps the heart to function better by decreasing oxidative stress, triglycerides (fatty acids) and LDL (bad cholesterol), while increasing HDL (good cholesterol). Her studies have further shown that the antioxidant potential of Rooibos can reduce cell death, which occurs more rapidly when chronic disease, such as cardiovascular disease or diabetes is present, while keeping vital organs healthy.

Amanda Swart

Prof Amanda Swart, head of the P450 Steroid Research Group, Department of Biochemistry at Stellenbosch University, has been investigating Rooibos as a complementary functional food for the last decade. Her focus has been on steroid hormones which influence the endocrine system. Steroid hormones produced by the adrenal gland are crucial to the normal day-to-day functioning of the body. Imbalances are associated with many chronic diseases and conditions which are also linked to diet and lifestyle. She has shown that Rooibos impacts favourably on the production of cortisol, the stress hormone. Her investigations have highlighted a role for Rooibos in the maintenance of normal cortisol levels, suggesting applications in a natural approach aiding in the management of stress and metabolic diseases. In addition, her work has shown that Rooibos impacts the immune system, facilitating the anti-inflammatory state by promoting anti-inflammatory responses and toning down pro-inflammatory responses. Rooibos has been touted as a preventative and complementary functional food in the context of cardiovascular disease and as such she is currently investigating the effect of Rooibos consumption on blood pressure.

Prof Dalene de Beer is a Specialist Researcher at the Plant Bioactives Group of the Agricultural Research Council of South Africa and an Extraordinary Associate Professor in Food Science at Stellenbosch University. Her interest in plant phenolics and appropriate advanced analytical methodologies to unravel Rooibos’ phenolic composition and quantifying plant constituents has contributed greatly to the body of bioactivity research on Rooibos over the last 13 years and has helped the industry to unlock its value.

Hanél Sadie-Van Gijsen and Liske Kotzé-Hörstmann

Dr Hanél Sadie-Van Gijsen (left), Principal Investigator and Senior Researcher in the Division of Medical Physiology at Stellenbosch University, together with post-doctoral research fellow Dr Liske Kotzé-Hörstmann (right), studies the stem cells within fat to better understand obesity, with a view of one day helping society to better address and manage this major public health issue. Obesity is characterized by inflammation and oxidative stress in fat, as well as on a whole-body level. It is therefore possible that the anti-inflammatory and antioxidant actions of Rooibos may relieve some of the negative effects of obesity. Her work examining the metabolic effects of Rooibos on fat tissue stem cells is the first study of its kind.

Tandeka Magwebeba

Dr Tandeka Magwebeba, a researcher based at the Institute of Biomedical and Microbial Biotechnology at CPUT is currently involved in a Rooibos study led by Dr Mariska Lily. The other female scientists on the team are Dr S Samodien, Dr CH Abrahams and Prof E Joubert. The project focuses on how Rooibos could protect against UVB-induced skin damage – a major problem in SA where skin cancer rates are high.

Sarah Pedretti

Dr Sarah Pedretti, Senior Research Scientist at the University of Cape Town’s Lung Institute focuses on allergic diseases, which are on the increase worldwide. She studies “basophils”, which are white blood cells involved in many kinds of inflammatory reactions, particularly those that cause allergic symptoms. In one of her studies, she proved that Rooibos suppressed basophil activation, which means that Rooibos could to a certain degree control or inhibit the allergic response. Her preliminary study will be followed up by clinical trials in the coming months.

Pamela Sithole

Pamela Sithole, master’s student at Stellenbosch University is currently busy with a study which aims to demonstrate that Rooibos can protect the heart when it is undergoing cell death or when it has an abnormal size – a common sign of chronic high blood pressure or coronary artery disease. She hails from the small town of Mqanduli in the Eastern Cape.

Sylvia Riedel-van Heerden

Dr Sylvia Riedel-van Heerden, a scientist at the Biomedical Research and Innovation Platform at the SAMRC is investigating the role that Rooibos can play in reducing inflammation in type 2 diabetes. The aim of her research is to characterise additional health benefits for rooibos that have not yet been investigated.

Barbara Huisamen

Prof Barbara Huisamen who is based at the Medical Physiology Faculty of Health Sciences at Stellenbosch University has been studying Rooibos’ effect on cardiometabolic diseases over the past five years. Her research has shown that green Rooibos extract has an anti-obesogenic, anti-hypertensive and anti-hyperglycaemic effect on Wister rats. Ingestion of the extract reduced weight-gain, blood pressure and blood sugar levels, whilst improving heart function – providing further evidence of how Rooibos can protect against heart disease and diabetes. In addition, the reproductive function of the male animals involved in the trial improved and Rooibos was also found to alleviate fatty liver disease.

Uljana Hesse

Dr Uljana Hesse, a Senior Lecturer at the Department of Biotechnology at the University of the Western Cape (UWC), is the Principal Investigator of the Rooibos Genomics Programme. Genome data represents an invaluable resource for a wide range of industries. It provides insight into the genes and biosynthetic pathways associated with important plant traits, such as medicinal compound production, drought and heat stress tolerance, pest and pathogen resistance, and plant growth form, to name but a few. This information can be used for targeted selection of plants to improve agricultural production and is also relevant for downstream industries interested in specific Rooibos compounds, including the medicinal and cosmetics industries. To date, her team has sequenced and computationally characterized eight Rooibos transcriptomes (sets of molecules), which are now available for data mining. Current work focuses on the computational assembly of the Rooibos genome.

Nearly all mainstream universities and research institutions now have departments that focus specifically on biotechnology and alternative sources of raw materials, instead of laboratory manufactured chemicals, hence the increased interest in Rooibos and other natural ingredients.