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

Abstract

Aspilia africana (Pers.) C. D. Adams (Family Asteraceae) and Warburgia ugandensis Sprague (Family Canellacea) are widely used in African traditional medicine to treat diabetes mellitus (DM), inflammatory diseases, and prostate and breast cancers. However, their inhibitory effects on α-glucosidase and 15-soybean lipoxygenase (15-sLOX), and prostate and breast anticancer activities remain unexplored, except for a single 15-sLOX report on W. ugandensis . Therefore, this study aimed to evaluate extracts of in vitro derived- A. africana tissues, namely in vitro leaf (IL) and in vitro root (IR), in comparison with traditionally used wild A. africana leaf (WL) and W. ugandensis stembark (WAB), for α-glucosidase and 15-sLOX inhibition, as well as anti-proliferative activity against prostate (DU145) and breast (4T1) cancer cell lines. Ethanolic extracts (80%) were prepared from all tissues and assessed for enzyme inhibition and anticancer activity using standard assays. Volatile metabolite profiling was performed using headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME/GC/MS) combined with multivariate analysis. At 500 µg/mL, WAB showed the highest α-glucosidase inhibitory activity (100%), which was comparable to that of the positive control (acarbose). IR exhibited the highest 15-sLOX inhibition (6.32 ± 0.75 µmol NDGAE/mg DE), similar to WAB. Only WAB and WL demonstrated anticancer activity, with WAB showing the lowest IC₅₀ values against DU145 and 4T1 cells (28.76 ± 2.28 and 15.29 ± 1.02 µg/mL, respectively), and greater selectivity toward breast cancer cells. A total of 126 volatile compounds were identified, and the major bioactive compounds included linalool, terpinen-4-ol, p-cymene, and humulene. The findings could support research focused on developing treatments for DM, inflammatory diseases, and prostate and breast cancers. Moreover, effective in vitro-derived tissues offer a sustainable, scalable source of standardized medicinal material, reducing pressure on wild populations.