Sefako Makgatho Health Sciences University (SMU) researcher and lecturer Dr Sithembiso Lethukuthula Ndwandwe has completed a PhD in Biochemistry, advancing research into the potential of selected medicinal plants traditionally used to treat respiratory viral infections.
His doctoral research, titled Efficacy of Formulated Herbal Concoction Comprising Selected Medicinal Plants Used for Treatment of Respiratory Viral Infections, investigated the antiviral, antioxidant and anti-inflammatory properties of plant extracts and formulated concoction, as well as their potential toxicity on selected cell lines.
The study focused on formulating an evidence-based concoction from four medicinal plants: Artemisia afra, Lippia javanica, Tetradenia riparia and Tulbaghia violacea. Researchers selected these plants because of their traditional use in treating respiratory illnesses and related inflammatory conditions.
Ndwandwe’s research assessed the plants’ phytochemical composition and their activity against viral neuraminidase; an enzyme associated with influenza virus replication. It also examined the effects of individual extracts on inflammatory responses against those of the formulated concoction.
The findings revealed that the plant extracts contained several classes of phytochemicals, with different plant parts showing varying secondary metabolites levels, antioxidant and neuraminidase-inhibitory activity.
Among the findings, the ethanolic stem extract of Artemisia afra showed the strongest activity in two antioxidant assays, while the aqueous root extract of Lippia javanica recorded the strongest inhibition of viral neuraminidase among the tested extracts. Higher anti-neuraminidase activity was seen with aqueous plant extracts, which suggest that the active components against neuraminidase activity could be of extremely high polar in nature.
The study also found that extracts from Tetradenia riparia leaves demonstrated notable anti-inflammatory activity in laboratory tests, including inhibition of nitrite production. This study further demonstrated a positive correlative association between phytochemical content and nitrite inhibition in medicinal plants tested.
Stability studies on the formulated concoction were done looking at different parameters. Over the 28-day study, the concoction stayed physically stable, with no changes in colour, thickness, smell, or UV-Vis results. However, the concoction’s pH decreased before becoming stable, and microbial growth was found on m-Endo and MacConkey agars, while no Enterococcus growth was detected throughout the study. The results provide scientific evidence supporting further investigation into these plants’ medicinal properties and the formulated concoction.
Ndwandwe’s work contributes to a growing body of research examining how traditional medicinal knowledge can be investigated using scientific methods, potentially informing future pharmaceutical and health-related applications.
His academic journey at SMU includes a BSc in Physical and Mineral Sciences (2016), a BSc Honours in Biochemistry (2017), and an MSc in Biochemistry, completed cum laude in 2020, before earning his doctorate in 2026.
Alongside his research, Ndwandwe has contributed to undergraduate teaching in Biochemistry and Biotechnology at SMU since 2021. His responsibilities include preparing and presenting lectures and developing and marking assessments.
He has also supervised nine postgraduate students to completion and is currently supervising five Honours and master’s students. In addition, he serves as deputy chair of the Departmental Research and Postgraduate Committee and participates in the university’s community engagement, marketing, and outreach committees.
He presented his PhD research at nine conferences, including the ISE-APSS International Conference, the Tshwane District Health Research Conference, and the South African Association of Botanists conference. He also published five papers in peer reviewed journals from his PhD work.
Through his combined research, teaching and postgraduate supervision, Ndwandwe continues to contribute to scientific inquiry and the development of emerging researchers at SMU.
“The most difficult step is often the first one. Our forefathers have already laid the foundation and provided generations of empirical evidence showing that these traditional systems work. Our task is comparatively simpler: to use modern technology to explain the molecular mechanisms behind what has long been observed in practice. We are, because they were. They were, so that we can become.”
By Tumelo Moila
