African Medicinal Plants Show Potent Antidiabetic and Anticancer Activity in Lab Tests

Two plants long revered in African traditional medicine are now giving scientists concrete biochemical reasons to take them seriously. A new study published in BMC Complementary Medicine and Therapies reports that extracts of Aspilia africana and Warburgia ugandensis, two species used for generations across East Africa to treat diabetes, inflammation, and cancers, display measurable inhibitory activity against key disease-related enzymes and can slow the growth of prostate and breast cancer cells in laboratory assays. The work, led by Roggers Gang of the Korea Institute of Oriental Medicine and the University of Science and Technology in South Korea, together with collaborators at the Kenya Medical Research Institute and the National Agricultural Research Organization in Uganda, also maps the volatile chemical signatures of the plants in unprecedented detail, identifying 126 volatile compounds and highlighting several well-known bioactive molecules as likely contributors to the observed effects.

The research team set out to fill a conspicuous gap in the scientific literature. Although A. africana, a flowering member of the daisy family, and W. ugandensis, an aromatic tree in the Canellaceae family, are staples of traditional healing systems, their ability to inhibit α-glucosidase and 15-soybean lipoxygenase, two enzymes central to diabetes and inflammation respectively, had gone almost entirely untested in controlled laboratory settings. Only a single prior report had examined 15-lipoxygenase inhibition in W. ugandensis. The researchers compared four tissue types: leaves and roots grown from in vitro cultures of A. africana, wild-harvested A. africana leaves, and stem bark of W. ugandensis, the latter being the form most commonly used by traditional practitioners.

All plant materials were extracted with 80 percent ethanol, a standard solvent system that captures a broad spectrum of polar and semi-polar phytochemicals. The extracts were then run through a battery of standardized in vitro assays. α-Glucosidase inhibition matters because the enzyme breaks down complex carbohydrates into glucose in the intestine; blocking it blunts post-meal blood sugar spikes, which is exactly the mechanism exploited by acarbose, a widely prescribed antidiabetic drug. Lipoxygenase inhibition, meanwhile, is a proxy for anti-inflammatory potential, since lipoxygenases produce leukotrienes and other lipid mediators that drive inflammatory cascades.

The results for α-glucosidase were striking. At a concentration of 500 micrograms per milliliter, the W. ugandensis stem bark extract achieved complete inhibition of the enzyme, reaching 100 percent activity blockade that was statistically comparable to acarbose, the positive control used in the assay. This finding lends quantitative support to the plant’s traditional use as a diabetes remedy and suggests that its bark chemistry contains compounds capable of engaging the enzyme’s active site with drug-like potency, at least in a cell-free system. The A. africana extracts showed weaker but still detectable glucosidase inhibition, indicating that the two plants operate through partially different chemical arsenics.

On the inflammation front, the in vitro-derived A. africana root extract emerged as the standout performer, delivering the highest 15-lipoxygenase inhibition of any sample, measured at 6.32 plus or minus 0.75 micromoles of NDGA equivalents per milligram of dry extract. Nordihydroguaiaretic acid, the reference compound against which activity was normalized, is a classic lipoxygenase inhibitor, so expressing activity in these equivalents allows direct comparison across samples. Notably, the root extract performed on par with the W. ugandensis bark, meaning that tissue grown entirely under sterile laboratory conditions could match the pharmacological output of a wild-harvested tree bark, a result with significant conservation implications.

The anticancer arm of the study produced perhaps its most clinically intriguing data. Only the two wild A. africana leaf extract and the W. ugandensis bark extract showed anti-proliferative activity against the cancer cell lines tested: DU145, a human prostate cancer line, and 4T1, a highly metastatic mouse breast cancer line. W. ugandensis bark was the clear leader, with half-maximal inhibitory concentrations of 28.76 plus or minus 2.28 micrograms per milliliter against DU145 cells and 15.29 plus or minus 1.02 micrograms per milliliter against 4T1 cells. The lower IC50 value against breast cancer cells, combined with a greater selectivity index toward that line, suggests the extract preferentially targets breast cancer cells over healthy tissue, a property that any future therapeutic candidate would need to possess.

Equally important was what the extracts did not do. The in vitro-cultured A. africana leaf and root extracts failed to show meaningful anticancer activity in these assays, a divergence from their wild-grown counterpart that the authors attribute to differences in chemical composition between tissue culture conditions and the natural environment. Plant secondary metabolites, the defensive compounds that often carry pharmacological activity, are notoriously sensitive to growing conditions, light, nutrients, and stress. The result is a cautionary note for anyone hoping that laboratory propagation will automatically reproduce the full phytochemical profile of wild plants, even as it underscores the value of screening multiple tissue sources before drawing conclusions.

To understand what might be driving these activities, the team turned to headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry, a technique that captures and identifies the volatile organic compounds emanating from plant tissue without destructive solvent extraction. Combined with multivariate statistical tools including principal component analysis and partial least squares discriminant analysis, the profiling revealed 126 distinct volatile compounds across the four tissue types and allowed the researchers to distinguish the samples by their chemical fingerprints. Among the dominant bioactive compounds identified were linalool, a fragrant terpene alcohol with documented anti-inflammatory and cytotoxic properties; terpinen-4-ol, the principal active component of tea tree oil; p-cymene, an aromatic monoterpene with reported enzyme-inhibitory effects; and humulene, a sesquiterpene also found in hops that has attracted attention for its anti-inflammatory activity.

The volatile profiles also differed meaningfully between the in vitro and wild tissues, providing a chemical explanation for the divergent biological results. Such metabolomic comparisons are increasingly recognized as essential quality-control tools in medicinal plant research, where batch-to-batch variability can doom otherwise promising candidates. By establishing which compounds dominate each tissue type and correlating those profiles with enzyme inhibition and cancer cell data, the study lays groundwork for future efforts to standardize extracts, whether by selecting elite chemotypes, optimizing culture conditions, or developing marker-based quality specifications for herbal preparations.

Beyond the laboratory findings, the study carries a broader message about sustainability and the future of African medicinal plant research. Wild populations of W. ugandensis in particular face harvesting pressure because its bark, the most pharmacologically active tissue, can only be obtained by stripping the tree. The demonstration that in vitro-derived tissues can match wild bark in lipoxygenase inhibition points toward a scalable, standardized supply chain that does not depend on felling or wounding trees. The authors, funded by the Korea Institute of Oriental Medicine through Korea’s Ministry of Science and ICT, argue that their findings could support the development of treatments for diabetes mellitus, inflammatory diseases, and prostate and breast cancers. As with all in vitro work, the usual caveats apply: enzyme assays and cancer cell lines are early-stage models, and activity in a dish does not guarantee efficacy or safety in the human body. But for two plants whose reputations were built over centuries of traditional use, the convergence of folklore and hard biochemical data is a compelling starting point for the drug discovery pipeline that follows.

Subject of Research: In vitro evaluation of enzyme inhibitory, anticancer, and volatile metabolite properties of Aspilia africana and Warburgia ugandensis plant tissues

Article Title: In vitro α-glucosidase and 15-lipoxygenase inhibitory, anticancer, and volatile metabolite properties of Aspilia africana and Warburgia ugandensis tissues

Article References: Gang, R., Choi, K.-O., Ban, Y., Gathirwa, J., Wanjiru, J. N., Mugo, J., Happy, K., Mudondo, J., Haniffadli, A., Nor, I., & Kang, Y. (2026). In vitro α-glucosidase and 15-lipoxygenase inhibitory, anticancer, and volatile metabolite properties of Aspilia africana and Warburgia ugandensis tissues. BMC Complementary Medicine and Therapies. https://doi.org/10.1186/s12906-026-05512-1

Image Credits: AI Generated

DOI: 10.1186/s12906-026-05512-1

Keywords: Aspilia africana, Warburgia ugandensis, alpha-glucosidase inhibition, 15-lipoxygenase, anticancer activity, diabetes mellitus, volatile organic compounds, HS-SPME/GC-MS, traditional medicine, plant tissue culture, linalool, breast cancer