Antioxidant and Anti-inflammatory Effects of Yam (Dioscorea batatas Decne.) on Azoxymethane-induced Colonic Aberrant Crypt Foci in F344 Rats

Abstract

Yam (Dioscorea batatas Decne.) has long been used as a health food and oriental folk medicine because of its nutritional fortification, tonic, anti-diarrheal, anti-inflammatory, antitussive, and expectorant effects. Reactive oxygen species (ROS), which are known to be implicated in a range of diseases, may be important progenitors of carcinogenesis. The aim of this study was to investigate the modulatory effect of yam on antioxidant status and inflammatory conditions during azoxymethane (AOM)-induced colon carcinogenesis in male F344 rats. We measured the formation of aberrant crypt foci (ACF), hemolysate antioxidant enzyme activities, colonic mucosal antioxidant enzyme gene expression, and colonic mucosal inflammatory mediator gene expression. The feeding of yam prior to carcinogenesis significantly inhibited AOM-induced colonic ACF formation. In yam-administered rats, erythrocyte levels of glutathione, glutathione peroxidase (GPx), and catalase were increased and colonic mucosal gene expression of Cu/Zn-superoxide dismutase (SOD), Mn-SOD, and GPx were up-regulated compared to the AOM group. Colonic mucosal gene expression of inflammatory mediators (i.e., nuclear factor kappaB, inducible nitric oxide synthase, cyclooxygenase-2, tumor necrosis factor alpha, and interleukin-1beta) was suppressed by the yam-supplemented diet. These results suggest that yam could be very useful for the prevention of colon cancer, as they enhance the antioxidant defense system and modulate inflammatory mediators.

Protective Effects of Dioscorea batatas Flesh and Peel Extracts against Ethanol-Induced Gastric Ulcer in Mice

“…Although recent studies have highlighted the anti-inflammatory effect of Dioscorea spp., the mechanism underlying the protective effect against ethanol-induced damage is incompletely understood [ 26 , 27 , 28 ]. We examined the anti-inflammatory activity of DBD extracts in acute gastric ulcer in mice by evaluating the plasma levels of NO, IL-6, and TNFα ( Figure 5 ).…”

“…Dioscorea species, belonging to the family Dioscoreaceae, are mostly grown for their starchy tubers or medicinal properties [ 26 , 28 , 30 ]. DBD is known to have biologically beneficial effects including antioxidative, antidiabetic, anti-atherosclerotic, and anti-inflammatory activities [ 14 , 16 , 17 , 27 , 31 , 32 ]. In particular, the ethanol extract of DBD peel is known to inhibit the production of NO and PGE 2 in lipopolysaccharide-induced Raw 264.7 cells [ 16 ].…”

“…In particular, the ethanol extract of DBD peel is known to inhibit the production of NO and PGE 2 in lipopolysaccharide-induced Raw 264.7 cells [ 16 ]. Supplementation of DBD flesh powder in diet enhanced antioxidant enzyme activities and reduced colonic mucosal inflammatory mediator gene expression in azoxymethane-treated F344 rats [ 27 ]. Despite the evidences demonstrating the diverse health-promoting benefits of DBD, little is known about the positive effect of its flesh and peel on gastric injury.…”

Enhanced Therapeutic Treatment of Colorectal Cancer Using Surface-Modified Nanoporous Acupuncture Needles

“…To induce CRC in rats, azoxymethane (AOM) 20 , 21 is administered according to the experimental scheme provided in Table 1 . The progress of CRC by AOM to initiation (I) and maturation (M) stages are presented in Supplementary Figure S2 .…”

“…The number of Aberrant crypt foci (ACF) in the entire distal tubule was determined for animals in groups I1 to I6, as previously described 20 . Briefly, colons opened longitudinally were rinsed with PBS, and the rest of colon tissue excised by approximately 1 cm in width was positioned flat between two pieces of filter paper and fixed in 10% formalin for 24 h. Colons were then stained with 0.2% methylene blue in PBS for 10 min, placed on a microscope slide with the mucosal side up, and visualized using a light microscope (Olympus, Tokyo, Japan) at ×200 magnification.…”