Chapter 4: Extraction Technologies for Plant-derived Nutraceuticals and Natural Health Products

Extraction of plants for drug discovery, ethnopharmacology or application as nutraceuticals and natural health products (NHPs; also known as dietary supplements, phytomedicines and complementary and alternative medicines) is described for scientists new to the field. Primary identification and handling of plant material for extraction is a key first step. Simple solvent extractions are described with routine procedures in the lab to produce crude extracts for bioassay screening or industrial use. Specialized methods targeting specific groups of compounds but rarely producing pure compounds can also be used. These methods include soxhlet, accelerated solvent, subcritical water, supercritical CO₂, ultrasound, microwave, countercurrent, steam distillation and other technologies. Ultimately, researchers must identify the active principles and/or unique marker compounds in their extracts and this is accomplished by bioassay guided isolation or newer metabolomics methods. Once bioactive compounds are identified, standardized products can be produced that are reproducible and can be compared to clinically tested materials.