Effect of dietary laminaria angustata (brown seaweed) on azoxymethane‐induced intestinal carcinogenesis in male F344 rats

Abstract

The effect of dietary Laminaria angustata (brown seaweed) on azoxymethane (AOM)-induced intestinal carcinogenesis was studied in male F344 rats. Five-week old rats were fed semipurified diets containing 0 and 10% seaweed. When the rats were 7 weeks old, all except the vehicle-treated groups received weekly subcutaneous injections of AOM in normal saline for two weeks (20 mg/kg body wt/week). All animals were fed the experimental diets until the termination of the experiment, which was 28 weeks after the last AOM injection. The incidence (percent of animals with tumors) and multiplicity (tumors/animal) of small intestinal tumors did not differ significantly between the control and seaweed groups. The incidence and multiplicity of colon adenomas along with the size of colon tumors were increased in rats fed the seaweed diet compared with those fed the control diet. Dietary seaweed had no major effect on the concentration of fecal bile acids; however, the concentration of fecal cholesterol and total neutral sterols was decreased in the seaweed group. These results suggest that dietary seaweed increases the risk for colon tumors.

Pattern of dietary fiber intake among the Japanese general population

“…Furthermore, there are several reports regarding the preventive effect of seaweed consumption against breast cancer (Teas, 1983;Kang et al, 2004). However, it is important to recognize that to increase seaweed intake beyond current levels in Japan does not necessarily mean enhanced health benefits; indeed some researchers have shown disadvantages, for example, stimulatory effects upon cancers (Ashi et al, 1978;Watanabe et al, 1978;Reddy et al, 1985;Funahashi et al, 2001). Fiber intake pattern S Fukuda et al…”

Fucoxanthin and Colorectal Cancer Prevention

“…These findings suggested that S. japonica extract exerted an inhibitory effect on the onset of colorectal ACF with the same potency as Fx alone [ 103 ]. Further complicating matters, Reddy et al showed that the dietary intake of Laminaria angustata (Mitsuishikombu) (diet containing 10% algae) for 28 weeks significantly increased the incidence and multiplicity of colorectal tumors in an AOM-induced F344 rat CRC model [ 104 ].…”

Sulfated Fucogalactan From Laminaria Japonica Ameliorates β-Cell Failure by Attenuating Mitochondrial Dysfunction via SIRT1–PGC1-α Signaling Pathway Activation

“…The brown seaweed Laminaria japonica is the most important economic seaweed cultured in China and is consumed as a health food. L. japonica exhibits numerous biological activities, including anti-tumor, anti-microbial, antioxidative, antiviral, anti-aging, anti-fatigue, and antiinflammatory effects (10)(11)(12)(13)(14)(15). Recent studies have demonstrated that polysaccharides are the main bioactive components of L. japonica, and consist of alginate, laminarin, fucoidan, and different proportions of xylose, galactose, and glucuronic acid (16).…”