Bioactive Root Extracts of Cannabis sativa Cultivars: Antioxidant and Anti-AChE Properties

Abstract

Cannabis sativa roots represent a historically significant yet scientifically understudied plant part, despite their traditional medicinal use and potential as a source of bioactive compounds. This study investigates the antioxidant and acetylcholinesterase (AChE) inhibitory activities of root extracts from three C. sativa cultivars— ‘Early Remedy’ (ER) is a high-CBD, low-THC medical cultivar. ‘Siskiyou Gold’ (SG) contains high levels of CBD and has a herbal, woody aroma, making it ideal for extraction, whereas ‘Kroeng Krawia’ (KK) is a tall, slender Thai landrace valued for research and economic potential. Sequential extraction was performed using solvents of increasing polarity (n-hexane, ethyl acetate, and methanol). Total phenolic content (TPC), total flavonoid content (TFC), and chemical profiles were assessed using standard assays and GC–MS analysis, with Trolox and galantamine serving as positive controls. The methanolic extract of KK-M showed the highest TPC (65.43 ± 0.73 mg GAE/g) and antioxidant activity (IC₅₀ = 200.46 ± 6.87 µg/mL), while SG-M exhibited the strongest AChE inhibition (IC₅₀ = 0.010 ± 0.002 mg/mL). GC–MS profiling of KK-M and KK-H revealed a rich array of sterols, triterpenoids, and fatty acid esters. These findings underscore the influence of solvent polarity and cultivar on extract composition and bioactivity. Importantly, they highlight the untapped therapeutic potential of C. sativa roots and the need to conserve phytochemical and genetic diversity for sustainable bioprospecting.