A Comprehensive Analysis of Chemical Composition and Anti-Inflammatory Effects of Cassava Leaf Extracts in Two Varieties in Manihot esculenta Crantz

Cassava is a tropical tuberous root crop, feeding over a billion people globally. However, research on the chemical composition and bioactive effects of cassava leaves remains scarce. Two specific varieties of South China No. 9 (green leaves (G.L.)) and South China No. 20 (purple leaves (P.L.)) were investigated in this study. The components of G.L. and P.L. were analyzed under different extraction methods using ultra-performance liquid chromatography time-of-flight mass spectrometry (UPLC-Q-TOF/MS). Results showed that cassava leaf extracts are rich in bioactive metabolites such as D-(+)-mannose, trigonelline, rutin, kaempferol-3-<i>O</i>-rutinoside, and oleamide. To assess the anti-inflammatory efficacy of bioactive compounds, animal models were established. Compared to the histamine group (NA), the group treated with the extracts had reduced epidermal thickness in hematoxylin and eosin (HE) staining. Further analysis revealed a drastic reduction in the number of mast cells in toluidine blue (TB) staining and expression levels of inflammatory cytokines (IL-17 and TNF-α) in immunohistochemistry (IHC) staining. The ethanolic extracts from the leaves demonstrated potent anti-inflammatory activities, with the extract from G.L. surpassing that from P.L. Transcriptomic analyses propose that the anti-inflammatory effects of cassava leaves may be related to the modulation of genes involved in mast cell activation, such as <i>Cma1</i>, <i>Cpa3</i>, and <i>Fn1</i>, among others. Network pharmacology unveiled that the extract of cassava leaves modulates pathways associated with apoptosis, inflammation, and metabolism. Molecular docking revealed strong binding interactions between 1-stearoylglycerol and oleamide from cassava leaves extracts and the proteins of AKT1, TNF, and BRAF. Overall, cassava leaf extracts seem to be a promising natural anti-inflammatory agent.