Heteroglycan of Annona muricata leaves: Extraction, characterization, modulation of the inflammatory response in raw 264.7 macrophages and peripheral Blood mononuclear cells

• Published in: Carbohydrate polymer technologies and applications 2024-06, Vol.7, p.100501, Article 100501
• Main Authors: Kanemoto, Judith Emery Ngomoyogoli, Ella, Fils Armand, Woguia, Alice Louise, Kanemoto, Stanley Olivier, Boudjeko, Thaddée, Ngondi, Judith Laure, Njintang, Nicolas Yanou
• Format: Article
• Language: English
• Subjects: Annona muricata; Anti-inflammatory properties; Antioxidant activity; Heteroglycan; Immunodulatory activity; Reduce Fe2
• ISSN: 2666-8939; 2666-8939
• DOI: 10.1016/j.carpta.2024.100501

•The Water-soluble polysaccharides are made by neutral sugars and uronic acid.•The polysaccharides displayed strong metal chelating and scavenging abilities.•The polysaccharides protected against DNA damage and inhibited hemolytic activity.•The polysaccharides inhibited the production of nitric acid.•The polysaccharides down-regulated the expression of TNF-α, IL-1β, IL-6, COX-2. The natural products contained in Annona muricata leaves are characterized by their ability to effectively enhance the immune response without exhibiting toxicity. The immunomodulatory effect of natural polysaccharides is considered one of the most important bioactive functions. In this study, we investigated the antioxidant activities and immunological properties of heteroglycans extracted from A. muricata leaves using hot water followed by ethanol precipitation. The polysaccharide was characterized for its physicochemical properties (UV spectroscopy, FTIR, gas chromatography), antioxidant potential (scavenging properties, chelating ability, reducing capability, and protection against DNA damage), immunomodulatory activities, and production of pro-inflammatory cytokines using peripheral blood mononuclear cells (PBMCs) and RAW 264.7 cells. The results indicated that the heteroglycans consisted of Glu-Man-GalA-GluA-Xyl and GluA-Man-Glu, respectively, for low and high molecular weight water-soluble polysaccharides coded as LWPC and HWPC. They exhibited strong metal chelating and scavenging activities. Additionally, each sample provided protection against DNA damage induction, with LWPC exhibiting up to 73.1 % protection. LWPC and HWPC significantly down-regulated the expression of pro-inflammatory cytokines TNF-α, IL-1β, IL-6, and COX-2, as well as NO production. At 200 µg/mL, only LWPC increased the production of IL-1β and IL-6 in PBMCs. Therefore, LWPC and HWPC hold promise for inhibiting radical-induced and inflammatory disorders. [Display omitted]