Organic extract of an edible blue‐green algae Spirluina platensis exerts anti‐inflammatory effects in C57BL/6J mice fed a high fat/high sucrose diet

We previously demonstrated that organic extract of Spirulina platensis , an edible blue‐green algae, (SPE) possess potent anti‐inflammatory properties in macrophages in vitro. To investigate whether SPE exhibits anti‐inflammatory effects in vivo, 10 weeks old male C57BL/6J mice were fed a high fat/high sucrose diet (HF/HS; 30.5% fat and 35.0% sucrose by weight) for 4 weeks and then assigned to one of two diet groups: one continuing on the HF/HS diet and the other on a HF/HS diet supplemented with 0.25% (w/w) SPE. Sixteen weeks after the mice were on the experimental diets, splenocytes and resident peritoneal macrophages were harvested and cultured ex vivo. The mRNA expression of interleukin (IL)‐1b and IL‐6 in the splenocytes from control and SPE‐fed mice did not differ significantly at basal levels. In contrast, when splenocytes were stimulated with lipopolysaccharide (LPS) for 20 h ex vivo, IL‐1b and IL‐6 mRNA levels were significantly increased in control splenocytes, while the gene expression in the splenocytes from SPE‐fed mice remained at a similar level as unstimulated splenocytes. Additionally, the mRNA expression of IL‐1b was significantly lowered in the peritoneal macrophages of SPE‐fed mice compared to control macrophages. When peritoneal macrophages were stimulated with LPS ex vivo, the expression of IL‐1b was lower in the SPE‐fed group than the control. Taken together, the data suggest that SPE may prime splenocytes and macrophages to be less inflammatory in vivo. Therefore, SPE supplementation may prevent obesity‐associated chronic inflammation. (Funded by USDA Hatch)