Acute Oral Toxicity and Genotoxicity Test and Evaluation of Cinnamomum camphora Seed Kernel Oil.

Cinnamomum camphora seed kernel oil (CCSKO) is one of the important natural medium chain triglycerides (MCT) resources, with more than 95.00% of medium chain fatty acids found in the world, and has various physiological effects. However, CCSKO has not been generally recognized as a safe oil or new food resource yet. The acute oral toxicity test and a standard battery of genotoxicity tests (mammalian erythrocyte micronucleus test, Ames test, and in vitro mammalian cell TK gene mutation test) of CCSKO as a new edible plant oil were used in the study. The results of the acute oral toxicity test showed that CCSKO was preliminary non-toxic, with an LD50 value higher than 21.5 g/kg body weight. In the mammalian erythrocyte micronucleus test, there was no concentration-response relationship between the dose of CCSKO and micronucleus value in polychromatic erythrocytes compared to the negative control group. No genotoxicity was observed in the Ames test in the presence or absence of S9 at 5000 µg/mL. In vitro mammalian cell TK gene mutation test showed that CCSKO did not induce in vitro mammalian cell TK gene mutation in the presence or absence of S9 at 5000 µg/mL. These results indicated that CCSKO is a non-toxic natural medium-chain oil.

Effects of medium chain triglycerides on lipid metabolism in high-fat diet induced obese rats.

This study aimed to compare the effects of three different medium chain triglycerides (MCTs) on lipid metabolism in obese rats. A high fat diet was fed to Sprague-Dawley rats to induce obesity, and then caprylic triglyceride (CYT), capric triglyceride (CT) and lauric triglyceride (LT) were synthesized and used to treat the obese rats for 12 weeks. The obesity phenotype and molecular changes related to lipid metabolism were determined. The results showed that all the three MCTs reduced the body weight (BW) and fat coefficient in obese rats, and the levels of plasma and liver lipids were also improved. Among the MCT groups, the LT group showed the lowest BW with the lowest food intake. Furthermore, three MCTs had different effects on the expression levels of lipid metabolism-related proteins (PPARs and SREBPs). The LT group performed the best among the three MCT groups in the protein expression levels. Interestingly, high-dose LT decreased the expression of the low density lipoprotein receptor (LDLR) in the liver, which impaired the transport of the very low density lipoprotein (VLDL)/low density lipoprotein (LDL) to the liver, resulting in high levels of total plasma cholesterol (TC) and LDL-c in the rats. We have for the first time found that different MCTs had different effects on the expression levels of triacylglycerol and cholesterol metabolism-related proteins in obese rats. These findings would help better understand the relationship between the health benefit and the type of MCT.

Effects of preheat treatment and polyphenol grafting on the structural, emulsifying and rheological properties of protein isolate from Cinnamomum camphora seed kernel.

In this study, protein isolate (PI) and purified polyphenol extract (PPE) were prepared from Cinnamomum camphora seed kernel (CCSK). The effects of preheat treatment (50-90 °C) combined with polyphenol grafting (5 % PPE, w/w) on the structural, emulsifying and rheological properties of PI were investigated. Results demonstrated the preheat treatments at 80 and 90 °C significantly increased the extent of protein aggregation of PI. Fluorescence spectra and thermal behavior analysis revealed that preheat-treated PI exhibited more compact structure and higher thermal stability. Moreover, the emulsifying stability and apparent viscosity of PI were enhanced after preheat treatments at 50, 60 and 70 °C. After modification by PPE, the secondary structural changes of preheat-treated PI were confirmed by FTIR. PPE modification improved the thermal stability and antioxidant activities of preheat-treated PI. These results provide a novel way to combine the advantages of preheat treatment and polyphenol grafting in developing a novel protein ingredient.

Assessment of the effect of ethanol extracts from Cinnamomum camphora seed kernel on intestinal inflammation using simulated gastrointestinal digestion and a Caco-2/RAW264.7 co-culture system.

Cinnamomum camphora seeds have multiple bioactivities. There were few studies on the effect of C. camphora seeds on intestinal inflammation in vitro and in vivo. The study aimed to investigate the effects of ethanol extracts from C. camphora seed kernel on intestinal inflammation using simulated gastrointestinal digestion and a Caco-2/RAW264.7 co-culture system. Results showed that the digested ethanol extracts (dEE) were rich in polyphenols, and a total of 17 compounds were tentatively identified using UPLC-LTQ-Orbitrap-MS/MS. dEE increased cell viability, while decreasing the production of reactive oxygen species, and the secretion and gene expression of inflammatory markers (NO, PGE2, TNF-α, IL-1ß and IL-6). dEE also down-regulated NF-κB/MAPK pathway activities by suppressing the phosphorylation of relevant signaling molecules (p65, IκBα, ERK and p38), as well as the expression of TLR4 receptor protein. Furthermore, dEE may improve intestinal barrier function by increasing the TEER value, and the expression of tight junction proteins (ZO-1, claudin-1 and occludin). The results suggest the ethanol extracts from C. camphora seed kernel may have strong anti-inflammatory activities, and a potential application in the prevention or treatment of intestinal inflammation and enhancement of intestinal barrier function in organisms.

High Dietary Intervention of Lauric Triglyceride Might be Harmful to Its Improvement of Cholesterol Metabolism in Obese Rats.

Hypercholesterolemia is often considered to be a major risk factor for atherosclerosis, and medium-chain fatty acids have been found to reduce the total cholesterol (TC) level and maintain low-density lipoprotein cholesterol (LDL-c) stability. However, we unexpectedly found that the levels of TC and LDL-c were increased in obese rats treated with high-dose lauric triglycerides (LT). The study aimed to investigate the effect and mechanism of LT on cholesterol metabolism in obese rats. Our results showed that LT intervention could reduce cholesterol biosynthesis by downregulating the expression of HMG-CoA reductase in obese rats. LT increased the expression levels of PPARγ1, LXRα, ABCA1, and ABCG8 in the liver. These results indicated that LT could improve the lipid transfer and bile acid efflux. However, LT significantly increased the expression of PCSK 9, resulting in accelerated degradation of LDLR, thus reducing the transport of very LDL (VLDL) and LDL to the liver. Together with the increased expression of NPC1L1 protein, LT impaired the uptake of VLDL/LDL by the liver and increased the reabsorption of sterols, leading to an increase in the levels of TC and LDL-c in obese rats.