Non‐alcoholic steatohepatitis (NASH) is an extreme form of NAFLD.
It may progress to cirrhosis and liver cancer without hepatitis virus infection or chronic alcohol consumption.
On the other hand, Euglena gracilis (Euglena) is a unicellular microalga which stores paramylon, a unique β‐1, 3‐glucan particle that stimulates the immune system.
This study was supported by euglena Co, a Japanese dietary supplement firm which specialises in the use of Euglena.
In the study, 36 mice which were induced with NASH and high-fat diets were used for study.
They were later divided into 1) a control group that ate only ordinary food, 2) group that ate food supplemented with the Euglena powder, 3) group that ate food supplemented with the paramylon powder, and 4) group that ate pharmaceutical drug telmisartan.
After 27 days, the researchers examined the degree of liver inflammation in the mice.
One of the methods was conducting immunostaining of F4/80. The larger the positive area ratio of F4/80, the higher the degree of inflammation.
Both groups which ate Euglena and paramylon powder exhibited a decrease in the positive area ratio of F4/80 by approximately 40% as compared to the control group.
For instance, the average of F4/80-positive area in the control group was 2.57%, while that of Euglena and paramylon were 1.56% and 1.46% respectively.
The greatest improvement, however, came from the telmisartan drug. The average of F4/80-positive area in mice fed with the drug was 0.92%.
Another test conducted, the Sirius red staining, also showed that oral administration of Euglena and paramylon inhibits the process of liver fibrosis.
“The progression of fibrosis is mainly attributed to inflammation and/or abnormal collagen accumulation,” the researchers said.
“The Sirius red positively stained area decreased in both Euglena‐ and paramylon‐treated groups, suggesting that collagen overproduction was suppressed by both test substances.”
Limitations of Euglena
The researchers did a further liver tissue examination to confirm the ability of Euglena and paramylon in inhibiting NASH progression.
They did so by calculating the NAFLD activity scores (NAS).
It was found that Euglena did not lead to an improvement in NAS.
The NAS was lowest in the liver of mice which took the telmisartan drug.
The paramylon group also showed a decreasing trend of NAS.
This suggests that Euglena is not involved in the inhibition of inflammation, but may be effective in activating hepatic stellate cells, hence preventing collagen overproduction.
On the other hand, Euglena and paramylon did not lead to body and liver weight loss, although they were able to ameliorate liver fibrosis.
Only the group that took telmisartan showed body and liver weight loss after 27 days, indicating the effectiveness of telmisartan as a pharmaceutical drug.
Source: Food Science and Nutrition
“Anti‐fibrotic activity of Euglena gracilis and paramylon in a mouse model of non‐alcoholic steatohepatitis”
Authors: Ayaka Nakashima et al