New observations on the effect of camellia oil on fatty liver disease in rats / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Camellia oil has become an important plant oil in China in recent years, but its effects on non-alcoholic fatty liver disease (NAFLD) have not been documented. In this study, the effects of camellia oil, soybean oil, and olive oil on NAFLD were evaluated by analyzing the fatty acid profiles of the plant oils, the serum lipids and lipoproteins of rats fed different oils, and by cytological and ultrastructural observation of the rats' hepatocytes. Analysis of fatty acid profiles showed that the polyunsaturated fatty acid (PUFA) n-6/n-3 ratio was 33.33 in camellia oil, 12.50 in olive oil, and 7.69 in soybean oil. Analyses of serum lipids and lipoproteins of rats showed that the levels of total cholesterol and low-density lipoprotein cholesterol in a camellia oil-fed group (COFG) were lower than those in an olive oil-fed group (OOFG) and higher than those in a soybean oil-fed group (SOFG). However, only the difference in total cholesterol between the COFG and SOFG was statistically significant. Cytological observation showed that the degree of lipid droplet (LD) accumulation in the hepatocytes in the COFG was lower than that in the OOFG, but higher than that in the SOFG. Ultrastructural analysis revealed that the size and number of the LDs in the hepatocytes of rats fed each of the three types of oil were related to the degree of damage to organelles, including the positions of nuclei and the integrity of mitochondria and endoplasmic reticulum. The results revealed that the effect of camellia oil on NAFLD in rats was greater than that of soybean oil, but less than that of olive oil. Although the overall trend was that among the three oil diets, those with a lower n-6/n-3 ratio were associated with a lower risk of NAFLD, and the effect of camellia oil on NAFLD was not entirely related to the n-6/n-3 ratio and may have involved other factors. This provides new insights into the effect of oil diets on NAFLD.

Culture of mouse peritoneal macrophages with mouse serum induces lipid bodies that associate with the parasitophorous vacuole and decrease their microbicidal capacity against Toxoplasma gondii

Lipid bodies [lipid droplets (LBs)] are lipid-rich organelles involved in lipid metabolism, signalling and inflammation. Recent findings suggest a role for LBs in host response to infection; however, the potential functions of this organelle in Toxoplasma gondii infection and how it alters macrophage microbicidal capacity during infection are not well understood. Here, we investigated the role of host LBs in T. gondii infection in mouse peritoneal macrophages in vitro. Macrophages cultured with mouse serum (MS) had higher numbers of LBs than those cultured in foetal bovine serum and can function as a model to study the role of LBs during intracellular pathogen infection. LBs were found in association with the parasitophorous vacuole, suggesting that T. gondii may benefit from this lipid source. Moreover, increased numbers of macrophage LBs correlated with high prostaglandin E2 (PGE2) production and decreased nitric oxide (NO) synthesis. Accordingly, LB-enriched macrophages cultured with MS were less efficient at controlling T. gondii growth. Treatment of macrophages cultured with MS with indomethacin, an inhibitor of PGE2 production, increased the microbicidal capacity against T. gondii. Collectively, these results suggest that culture with MS caused a decrease in microbicidal activity of macrophages against T. gondii by increasing PGE2 while lowering NO production.