Abstract / Summary
Background: Bitter kola (Garcinia kola) and kola nuts (Cola acuminata and Cola nitida) are native African plant products that hold significant cultural, medicinal, and economic relevance throughout West Africa. Although these plants are frequently consumed as stimulants and utilized in traditional medicine, there is a notable lack of general information concerning their caffeine content, particularly in the context of Nigeria. Methods: This study determined and compared the caffeine levels in Cola acuminata, Cola nitida, and Garcinia kola sourced from Ozoro, Delta State, Nigeria, using ultraviolet-visible (UV-Vis) spectrophotometry after solvent extraction and purification. Results: The analytical approach confirmed strong linearity, with a coefficient of determination (R²) of 0.9803, suggesting its suitability for the quantitative analysis of caffeine in the selected plant samples. The findings revealed a considerable species-dependent variation in caffeine accumulation, with Cola acuminata exhibiting the highest concentration (11.23–11.49 mg/L; 21.78%–22.29%). This was followed by Cola nitida, which recorded a concentration of 8.39–8.49 mg/L (16.28%–16.47%), while Garcinia kola showed the lowest levels at 5.91–5.99 mg/L (11.47%–11.63%). Conclusion: These results identify Cola acuminata as the most abundant natural caffeine source among the species analyzed, thereby affirming its traditional use as an effective stimulant. The findings provide essential baseline data to inform dietary choices, public health education, pharmaceutical applications, and quality control of local stimulant products. This research enhances the growing understanding of the phytochemical composition of African medicinal plants and emphasizes the inevitability of species-specific caffeine profiling for food safety, nutraceutical improvement, and industrial use.