Transformation of plant waste into pharmaceutical resources: Opportunities for sustainable development

Abstract

Agricultural production and food processing generate enormous quantities of plant waste, leading to economic losses and considerable environmental burden. However, these discarded materials represent abundant and underutilized sources of bioactive compounds and technologically valuable constituents. Among the most extensively investigated plant by-products are grape pomace and seeds, citrus and pomegranate peels, berry pomaces, olive leaves and pomace, as well as cereal residues. These materials contain a wide range of valuable compounds, including polyphenols (phenolic acids, flavonoids, tannins, and anthocyanins), carotenoids, polysaccharides, proteins, phytosterols, and vitamins. They may also serve as sources of pharmaceutical excipients, particularly cellulose and pectin. Numerous studies have demonstrated that compounds recovered from plant by-products exert antioxidant, antimicrobial, anti-inflammatory, cardiometabolic, and antiproliferative effects, making them promising candidates for the development of herbal medicinal products and dietary supplements. Recent advances in extraction technologies, particularly ultrasound-assisted, microwave-assisted, and supercritical fluid extraction, have made the recovery of bioactive compounds more efficient and sustainable by providing higher extraction yields, shorter extraction times, lower solvent consumption, and improved preservation of thermolabile constituents. Nevertheless, major challenges remain, particularly the standardization of agro-industrial by-products for pharmaceutical applications and the control of agricultural contaminants. Plant waste should therefore no longer be regarded as a burden, but rather as a renewable and strategically important resource for the development of sustainable pharmaceutical products.