Anti-inflammatory effects of Dioscorea alata L. anthocyanins in a TNBS-induced colitis model

Abstract

The purple yam, Dioscorea alata L., is an important source of starch, vitamins and polyphenols. Five different pigments from the purple tubers of this plant were separated by high-performance liquid chromatography-mass spectrometry, and the anthocyanin fraction (DACN) was collected. The anti-inflammatory effects of DACNs were investigated at different concentrations and compared with the standard colitis treatment, 5-aminosalicylic acid, in a trinitrobenzenesulfonic acid (TNBS)-induced colitis mouse model. Macro- and microscopic parameters including body weight change, disease activity index (DAI) and intestinal histology were used for the determination of the anti-inflammatory effects of DACNs. The gene expression levels of tight junction-related proteins in the intestine, myeloperoxidase activity, inducible nitric oxide synthase activity in colonic tissues and pro-inflammatory cytokine production in serum were also measured to elucidate the mechanism of DACN action. Eighty micrograms of DACNs per kilogram of body weight produced potent anti-inflammatory effects in the mouse model of inflammatory bowel disease (IBD), as shown by the DAI (2.78 ± 0.38 vs. 0.44 ± 0.51). Therefore, DACNs may be applied as a potential food supplement in IBD therapy.

The Anti-inflammatory Effects of Dietary Anthocyanins against Ulcerative Colitis

“…In a recent study by Lei Zhao et al, mice supplemented with 100 mg/kg black rice extract via oral gavage showed a reduction in DSS-induced colonic IL-6, IL-1β, and TNF-α expression levels and MPO levels that are linearly related to the neutrophil infiltration [90]. Anthocyanin fraction from the tubers of purple yam down-regulated TNF-α, IFN-γ, and inflammation-associated ROS-producing enzyme myeloperoxidase (MPO) in mice treated with TNBS to induce colitis [135]. Similar observations are reported in a study using grapes, where anthocyanin-rich grape pomace extracts were found to prevent a DSS-induced increase of IL-6, MPO, and nitric oxide synthase (iNOS), whose production is triggered by bacterial products and pro-inflammatory cytokines [136].…”

Astragalin Attenuates Dextran Sulfate Sodium (DSS)-Induced Acute Experimental Colitis by Alleviating Gut Microbiota Dysbiosis and Inhibiting NF-κB Activation in Mice

“…Most flavonoids or polyphenols have low bioavailability and a low absorption rate, and up to 90% of these compounds remain in the colon (7). Polyphenols such as resveratrol, epigallocatechin-3-gallate, curcumin, quercetin, and anthocyanin have been verified to have therapeutic roles in IBD animal models (8)(9)(10)(11)(12). Their therapeutic functions in IBD usually include regulating the NF-κB pathway and gut barrier function, and a large number of studies have shown that the gut microbiota is also an important target (13).…”

Antinociceptive and Antibacterial Properties of Anthocyanins and Flavonols from Fruits of Black and Non-Black Mulberries

“…Anthocyanins have important roles in plants and animals, such as protecting plants from damage caused by UV light, attracting pollinators and serving as antioxidants [ 10 , 11 , 12 ]. They also have pharmacological activities, including anti-inflammatory, antitumor, and blood lipid-regulating activities [ 3 , 13 , 14 , 15 ]. Mulberry fruits also contain many other active substances, such as flavonols, polyphenols, alkaloids and polysaccharides [ 1 , 3 , 8 , 16 ].…”