From waste to value: evaluation of chemical composition and anti-inflammatory activity of Cannabis sativa stem extracts

Cannabis sativa L. is a chemically diverse plant historically valued for its nutritional, textile, and medicinal properties. While the pharmacological relevance of inflorescences and seeds is well-established, the stems are commonly considered waste. In this study, we investigated the chemical composition and anti-inflammatory activity of stem extracts from fiber hemp (C. sativa, Felina 32), cultivated under saline irrigation at different electrical conductivities (0, 2.0, 4.0, and 6.0 dS m^-1). LC-HRMS analysis revealed the presence of diverse secondary metabolites, predominantly flavonoid glycosides and alkaloids, with minimal phytocannabinoid content. Extracts exhibited differential metabolomic profiles influenced by salinity, with higher phenolic content under high salinity, suggesting stress-induced biosynthetic responses. Functional assays in J774A.1 macrophages demonstrated that all stem extracts significantly suppressed inflammatory responses, reducing IL-6 expression, calcium flux, iNOS and COX2 expression, and secretion of NO and PGE2. These findings highlight the potential of C. sativa stem by-products as sustainable sources of bioactive compounds with anti-inflammatory properties, promoting their revaluation within circular economy models.