Castor Bean (Ricinus communis L.) Polyphenolic Extracts Exhibited Anti-inflammatory Effects on LPS-Stimulated RAW 264.7 Macrophages

• Published in: Current developments in nutrition 2022-06, Vol.6 (Supplement_1), p.309-309
• Main Authors: Luzardo-Ocampo, Ivan, Vasco-Leal, Jose, Cuellar-Nuñez, M. Liceth, Quintero-Castaño, Victor, Pérez-Serrano, Rosa
• Format: Article
• Language: English
• ISSN: 2475-2991; 2475-2991
• DOI: 10.1093/cdn/nzac053.050

This research aimed to explore the anti-inflammatory properties of two different aqueous extracts from Mexican Castor bean leaves accessions (R1 and R2) in lipopolysaccharide (LPS)-challenged murine RAW 264.7 cells. Two leaves accessions (S1 and S2) grown in Amazcala (Mexico) were washed, sun-dried (35–60 °C), ground, and screened (250 mm particle size). Aqueous extracts were prepared by dissolving 100 mg of the powders in 10 mL distilled water and maintained in a water bath (40 °C) under stirring for 1 h. Samples were then centrifuged (3500 g, 15 min, 4 °C). Total phenolics (TP), total flavonoids (TF), condensed tannins (CT), and antioxidant capacity measurements (ABTS and DPPH) were quantified spectrophotometrically. Individual phenolics were quantified by HPLC-DAD, and metabolomic analysis from gas chromatography (GC)-MS was conducted using MetaboAnalyst. The extracts were assayed against LPS-induced RAW 264.7 cells, whereas cell viability (MTT) and nitric oxide (Griess reaction) measurements were carried out. The total polyphenolic composition of the extracts showed no differences (P < 0.05) on their TF and CT composition, but S2 displayed a higher TF content than S1. Identifying individual phenolic compounds by HPLC-DAD highlighted ellagic and gallic acids (17.13–28.77 mg/g dry weight) as the primary phenolic acids, whereas S2 showed the highest abundance of (+)-catechin. S1 was the extract with the highest DPPH antioxidant capacity (P < 0.05) (80.17%). None of the extracts was cytotoxic at the evaluated concentrations (10–50% v/v), but S2 was more effective in inhibiting nitric oxide production (44.94%). The extracts showed anti-inflammatory potential by inhibiting NO production and could be used to manufacture bioactive compounds-rich food-grade-based ingredients. However, as ricinine, a toxic protein, has been reported in the leaves, methods eliminating ricinine from the extracts are required for safely using the extracts. The authors acknowledge “Fondos para el Desarrollo del Conocimiento (FONDEC) from Universidad Autónoma de Querétaro (UAQ) 8289, Registry SVSU-DV-2021–09) for the provided resources.