Effectiveness of Common Extraction Solvents in Obtaining Antioxidant Compounds from African Medicinal Plants

The efficacy of phytoextracts is equally affected by the extraction solvent and the extraction method. Details of the solvent type, concentration, density, and other characteristics are associated with the quality of the resultant extract. Some solvents have been found to be effective only on specific parts of plants. Industry has shown a growing interest in eco-friendly plant extracts for the formulation of medication, food additives, cosmetics, and agricultural products. This interest is aligned with the proven necessity of sustainability, marketability, and regulation of manufactured products in value chains. In this review, the literature on antioxidant compounds and activity of extracts from African medicinal plants is reviewed. Findings indicate that the use of ethanol, methanol, water, and to a lesser extent, acetone as solvents for the extraction of antioxidant compounds is common. The use of these solvents is supported by decisive selection of procedure, ideal temperature, duration, solvent pH, and the extracted plant parts. Fermentation enhances the antioxidant activity of aqueous extracts but reduces that of alcohol extracts. This is particularly essential in continents such as Africa, where water is available but alcohol is scarce. "Green" extraction technologies are not as successful as solvent extractions for use with African medicinal plants. There is a financial hurdle that results in a mismatch between academic research innovations and societal transmission to new technologies, as most communities are dominated by small-to-medium enterprises. Further studies on the extraction of antioxidants from African medicinal plants are recommended to guide the research and link it to ordinary African societies.