A partnership between The Wistar Institute and the University of Buea in Cameroon has revealed how a medicinal plant, Croton oligandrus Pierre & Hutch, may help combat HIV. This African tree has a long history in traditional medicine in Cameroon, where it has been utilized to treat various ailments, including cancers and diabetes.
The research team consists of Fidele Ntie-Kang, Ph.D., an Associate Professor of Pharmaceutical Sciences at the University of Buea and the head of the University of Buea Centre for Drug Discovery, alongside Ian Tietjen, Ph.D., an Assistant Professor and Education Director of Global Studies & Partnerships at The Wistar Institute’s Hubert J.P. Schoemaker Education and Training Center. They detailed their findings in the Journal of Experimental Pharmacology in a paper titled “Croton oligandrus Pierre & Hutch (Euphorbiaceae) extracts and isolated compounds reverse HIV-1 latency.”
This study is part of ongoing research that has explored the properties of various African chemical compounds, stemming from the collaboration between Wistar and the University of Buea Centre for Drug Discovery, which started in 2021. Besides pushing forward HIV cure research in Cameroon, this partnership allowed lead author Chantal Emade Nkwelle to travel to Wistar for five months, where she learned various laboratory techniques related to HIV research to bring back to the University of Buea.
“This research highlights the importance of global collaborations in the quest for an HIV cure,” stated Luis Montaner, D.V.M., D.Phil., Wistar’s Executive Vice President and director of the HIV Cure and Viral Diseases Center. He emphasized that a successful cure must be accessible worldwide, and by utilizing traditional African medicine, significant strides are being made toward this goal.
Although effective antiretroviral therapy (ART) allows for the management of HIV globally, there still isn’t a widely available cure. Even with ongoing ART, the virus remains dormant in various body reservoirs that can reactivate, potentially leading to chronic inflammation and accompanying health issues over time.
To address the critical need for strategies to cure HIV in Sub-Saharan Africa, Wistar researchers collaborated with the University of Buea to study the effects of C. oligandrus chemical extracts on HIV latency.
“This Croton species was selected for research due to its long-established history of use in ethnomedicine alongside other similar African plants. For centuries, communities in Cameroon and surrounding regions have turned to traditional, plant-based medicine from healers to treat numerous health concerns, extending to HIV in modern times. Our collaboration with the Wistar Institute has not only led to scientific discoveries but has also contributed to building our human development capacity,” noted Dr. Ntie-Kang.
Building on research from related plants used in African ethnomedicine, the team explored whether the beneficial compounds found in C. oligandrus could act as latency-reversing agents (LRAs), substances that reactivate dormant HIV. LRAs play a vital role in HIV cure research through the concept known as “kick and kill,” where HIV is reactivated and then targeted for elimination from the body.
By extracting compounds from the dried bark of the plant, Drs. Tietjen, Ntie-Kang, and their teams conducted tests to see if these compounds could reverse HIV latency in vitro. Their hypothesis was confirmed for four out of the six isolated compounds. Remarkably, some compounds exhibited a synergistic effect when combined with existing LRA compounds, leading to enhanced latency reversal.
“Our findings provide hope regarding the role of C. oligandrus in HIV cure efforts,” remarked Dr. Tietjen, the lead author from Wistar. “Encouraging HIV to come out of hiding so that we can target and eliminate it is a complex challenge. Identifying an LRA that works in synergy with others to boost their effectiveness is a significant achievement—especially given its origin from a region where HIV cure research can drastically influence outcomes. We also acknowledge and appreciate the traditional knowledge that local healers have cultivated over generations, which is essential to respect and uphold. We anticipate further insights into how compounds from this plant can aid HIV cure research in Cameroon and globally.”
Chantal Emade Nkwelle expressed that her experience at the Wistar Institute was a rare chance to conduct research in advanced laboratories and produce publishable results that would contribute to her PhD, with funding for living expenses provided by the Calestous Juma Science Leadership Fellowship, a grant from the Bill & Melinda Gates Foundation awarded to Dr. Ntie-Kang and thirteen other African scientists.
The study also included contributions from participants in the Biomedical Technician Training (BTT) Program and students from the Research Experience for Undergraduates (REU), who engaged in cytokine ELISA experiments, demonstrating Wistar’s commitment to providing research-driven scientific experience to trainees.
