Nutritional composition, health-promoting effects, bioavailability, and encapsulation of tree peony seed oil: a review.

Tree peony is cultivated worldwide in large quantities due to its exceptional ornamental and medicinal value. In recent years, the edible value of tree peony seed oil (TPSO) has garnered significant attention for its high content of alpha-linolenic acid (ALA, >40%) and other beneficial minor components, including phytosterols, tocopherols, squalene, and phenolics. This review provides a systematic summary of the nutritional composition and health-promoting effects of TPSO, with a specific focus on its digestion, absorption, bioavailability, and encapsulation status. Additionally, information on techniques for extracting and identifying adulteration of TPSO, as well as its commercial applications and regulated policies, is included. Thanks to its unique nutrients, TPSO offers a wide range of health benefits, such as hypolipidemic, anti-obesity, cholesterol-lowering, antioxidant and hypoglycemic activities, and regulation of the intestinal microbiota. Consequently, TPSO shows promising potential in the food and cosmetic industries and should be cultivated in more countries. However, the application of TPSO is hindered by its low bioavailability, poor stability, and limited water dispersibility. Therefore, it is crucial to develop effective delivery strategies, such as microencapsulation and emulsion, to overcome these limitations. In conclusion, this review provides a comprehensive understanding of the nutritional value of TPSO and emphasizes the need for further research on its nutrition and product development.

Cholesterol-lowering activity of protocatechuic acid is mediated by increasing the excretion of bile acids and modulating gut microbiota and producing short-chain fatty acids.

The present study aimed to investigate the effects of protocatechuic acid (PCA) on plasma lipid profiles and associated mechanisms with a focus on reshaping gut microbiota. Twenty-four male hamsters were randomly divided into three groups receiving a high-cholesterol diet (HCD) and two HCD diets containing 0.5% (PL) and 1% (PH) PCA, respectively. Feeding PL and PH diets for six weeks significantly reduced plasma total cholesterol by 18% and 24%, respectively. PL and PH diets also significantly lowered plasma non-HDL cholesterol by 37% and 44%, respectively. This was accompanied by an increase in fecal short-chain fatty acids (SCFAs) and fecal bile acids with up-regulation on gene of cholesterol 7α-hydroxylase and down-regulation of 3-hydroxy-3-methylglutaryl-CoA reductase in the liver. Dietary PCA supplementation decreased hepatic lipid accumulation, whereas it increased fecal excretion of lipids. The 16S rRNA analysis found that dietary PCA significantly reduced the ratio of Firmicutes to Bacteroidetes and increased the relative abundance of Bacteroidales S24-7, whereas it reduced the abundance of Lactobacillaceae. It was concluded that dietary PCA favorably modulated plasma lipid profiles and prevented the accumulation of hepatic cholesterol and lipid disposition. Such effect was mediated at least partially by increasing gut production of SCFAs and fecal excretion of bile acids via modulating the gut microbiome.

Ursolic acid alleviates hypercholesterolemia and modulates the gut microbiota in hamsters.

Ursolic acid (UA) is a triterpenoid acid widely abundant in fruits and vegetables such as apple, blueberry and cranberry. The present study was carried out to investigate the effect of UA supplementation in diet on blood cholesterol, intestinal cholesterol absorption and gut microbiota in hypercholesterolemic hamsters. A total of thirty-two hamsters were randomly assigned to four groups and given a non-cholesterol diet (NCD), a high-cholesterol diet containing 0.1% cholesterol (HCD), an HCD diet containing 0.2% UA (UAL), or an HCD diet containing 0.4% UA (UAH) for 6 weeks. Results showed that UA supplementation reduced plasma cholesterol by 15-16% and inhibited intestinal cholesterol absorption by 2.6-9.2%. The in vitro micellar cholesterol solubility experiment clearly demonstrated that UA could displace 40% cholesterol from micelles. In addition, UA decreased the ratio of Firmicutes to Bacteroidetes, whereas it enhanced the growth of short chain fatty acid (SCFA)-producing bacteria in the intestine. In conclusion, UA possessed a cholesterol-lowering activity and could favorably modulate the gut microbiota.

Tomato seed oil attenuates hyperlipidemia and modulates gut microbiota in C57BL/6J mice.

In this study we aimed to investigate the role of tomato seed oil (TSO) in the alleviation of hyperlipidemia and the regulation of gut microbiota in C57BL/6J mice. Mice were divided into the following four diet-based groups: low-fat diet (LF, n = 8), high-fat diet (HF, n = 6), HF diet with TSO replacing one-third of lard (TL, n = 8), and HF diet with TSO replacing two-thirds of lard (TH, n = 8). The results showed that TH significantly reduced weight gain, relative adipose tissue weights, plasma cholesterol, triacylglycerol, low-density lipoprotein cholesterol (LDL-C), ratio of LDL-C to high-density lipoprotein cholesterol (HDL-C), hepatic cholesterol, and total fatty acids, and markedly increased plasma HDL-C. TSO supplementation also dose-dependently increased fecal cholesterol excretion and reduced fecal total fatty acids. This was accompanied by upregulation of the gene expression of hepatic PPARα, ACADL, CYP7A1, LXRα, ABCA1, and SR-B1. Metagenomic analyses demonstrated that TSO tended to reduce the Firmicutes/Bacteroidetes ratio, significantly increased the relative abundance of the genus Lactobacillus, and reduced the relative abundance of the genera Rikenella, Enterorhabdus, unclassified_o_Clostridiales and Ruminococcaceae_UCG-009. These results proved that TSO was effective in attenuating hyperlipidemia in C57BL/6J mice by enhancing fatty acid ß-oxidation, reducing cholesterol absorption, promoting cholesterol efflux, and favorably modulating the gut microbiota.

Fish Oil Is More Potent than Flaxseed Oil in Modulating Gut Microbiota and Reducing Trimethylamine-N-oxide-Exacerbated Atherogenesis.

Trimethylamine-N-oxide (TMAO) is a risk factor for atherosclerosis. We compared the potency of fish oil with flaxseed oil in reducing TMAO-exacerbated atherogenesis. Five groups of ApoE-/- mice were given one of five diets, namely, a low-fat diet, a Western high fat diet (WD), a WD plus 0.2% TMAO, and two WDs containing 0.2% TMAO with 50% lard being replaced by flaxseed oil or fish oil. TMAO accelerated atherosclerosis and disturbed cholesterol homeostasis. Compared with flaxseed oil, fish oil was more effective in inhibiting TMAO-induced atherogenesis by lowering plasma cholesterol and inflammatory cytokines. Both oils could reverse TMAO-induced decrease in fecal acidic sterols. Fish oil promoted fecal output of neutral sterols and downregulated hepatic cholesterol biosynthesis. Fish oil was more effective than flaxseed oil in promoting the growth of short-chain fatty acid-producing bacteria and lowering microbial generation of lipopolysaccharide. In conclusion, fish oil is more potent than flaxseed oil to ameliorate TMAO-exacerbated atherogenesis.

Sea buckthorn seed oil reduces blood cholesterol and modulates gut microbiota.

Sea buckthorn seed oil (SBSO) has been used as a functional food in the prevention of heart diseases. The present study investigates the effects of SBSO on blood cholesterol and the gut microbiota in hypercholesterolemia hamsters. Four groups of hamsters (n = 8 each) were given one of four diets, namely a non-cholesterol control diet (NCD), a high-cholesterol control diet (HCD) containing 0.1% cholesterol, and an HCD diet with sea buckthorn seed oil replacing 50% lard (SL) or replacing 100% lard (SH). Feeding SL and SH diets could reduce blood total cholesterol by 20-22%. This was accompanied by the down-regulation of the gene expression of acyl-CoA:cholesterol acyltransferase 2 (ACAT2), microsomal triacylglycerol transport protein (MTP), and ATP-binding cassette transporter8 (ABCG8). SBSO supplementation also increased the production of intestinal short-chain fatty acids and fecal outputs of neutral sterols. Metagenomic analysis demonstrated that feeding SL and SH diets could favorably modulate the relative abundance of Bacteroidales_S24-7_group, Ruminococcaceae, and Eubacteriaceae. It was therefore concluded that SBSO was effective in reducing blood cholesterol in hypercholesterolemic hamsters via increasing intestinal cholesterol excretion and promoting the growth of SCFA-producing bacteria.

Beneficial effects of tea water extracts on the body weight and gut microbiota in C57BL/6J mice fed with a high-fat diet.

Accumulative evidence has suggested that tea consumption has benefits in reducing body fat and alleviating metabolic syndrome. We hypothesize that benefits of tea consumption can be partially mediated by modulating intestinal microbiota via inhibiting the formation of lipopolysaccharides (LPS) and promoting the production of short chain fatty acids (SCFAs). C57BL/6J mice were fed a high fat diet with the addition of 1% water extracts of green tea, oolong tea and black tea. Results showed that the dietary supplementation of three tea water extracts equally improved the glucose tolerance and reduced a high fat diet-induced gain in weight, hepatic lipids, and white adipose tissue weights. This was accompanied by a significant reduction in plasma LPS and a significant increase in the production of SCFAs. The metagenomic analyses showed that the tea extracts changed the overall composition of gut microbiota and decreased the relative abundance of family Rikenellaceae and Desulfovibrionaceae. In addition, tea water extracts could also change the abundance of key operational taxonomic units (OTUs) including OTU473 (Alistipes), OTU229 (Rikenella), OTU179 (Ruminiclostridium) and OTU264 (Acetatifactor). In conclusion, three tea extracts could improve the glucose tolerance, induce the production of SCFAs and inhibit the production of endotoxin LPS, most likely mediated by modulating gut microbiota.

Soybean germ oil reduces blood cholesterol by inhibiting cholesterol absorption and enhancing bile acid excretion.

Health benefits of soybean germ oil have not yet been fully explored. The present study examined the blood cholesterol-lowering activity of soybean germ oil and the underlying mechanisms in hypercholesterolemic hamsters. Forty hamsters were randomly assigned into five groups and fed a non-cholesterol diet, a high cholesterol diet and one of three high cholesterol diets containing 0.50% cholestyramine, 4.75% soybean germ oil, and 9.50% soybean germ oil, respectively, for 6 weeks. The result showed that soybean germ oil significantly decreased plasma cholesterol by 18.5-31.5%, which was accompanied by 28.3-62.7% increase in excretion of fecal neutral sterols and bile acids. The effect was mediated by down-regulation of intestinal Niemann-Pick C1-like 1 protein (NPC1L1) and up-regulation of liver cholesterol-7α-hydroxylase (CYP7A1). We concluded that soybean germ oil favorably modulated the blood cholesterol concentration by inhibiting cholesterol absorption through inhibiting gene expression of NPC1L1 and by enhancing bile acid excretion via promoting gene expression of CYP7A1.

Role of plant stanol derivatives in the modulation of cholesterol metabolism and liver gene expression in mice.

The present study was to evaluate the cholesterol-lowering effect of two novel plant stanol derivatives and its potential molecular mechanism in hyper-cholesterol mice induced by a high-cholesterol diet. Results showed that oral administration of plant stanyl hemisuccinate (2×, 5×) and plant stanyl sorbitol succinate (2×, 5×) effectively attenuated the serum total cholesterol and low density lipoprotein cholesterol levels, while had no effect on the serum triacylglycerol and high density lipoprotein cholesterol. And plant stanol derivatives decreased liver cholesterol concentration and increased faecal cholesterol output. Meanwhile, both plant stanyl hemisuccinate and plant stanyl sorbitol succinate could remarkably promote liver X receptor alpha (LXRα) expression, and increased cholesterol 7α-hydroxylase (CYP7A1) expression and faecal total bile acid output to varying degrees. These results suggested two novel plant stanol derivatives possessed hypocholesterolemic effect, and the cholesterol-lowering action of plant stanol derivatives may be through activating the potential LXRα-CYP7A1-bile acid excretion pathway.

Efficient solvent-free synthesis of phytostanyl esters in the presence of acid-surfactant-combined catalyst.

An efficient approach based on the synthesis of phytostanyl esters with an acid-surfactant-combined catalyst in a solvent-free system was developed. The effect of catalyst dose, substrate molar ratio, reaction temperature, and acyl donor was considered. The reaction conditions were further optimized by response surface methodology, and a high yield of phytostanyl laurate (>92%) was obtained under optimum conditions: 3.17:1 molar ratio of lauric acid to plant stanols, 4.01% catalyst dose (w/w), 119 °C, and 4.1 h. FT-IR, MS, and NMR were adopted to confirm the chemical structure of phytostanyl laurate. Meanwhile, the physiochemical properties of different phytostanyl esters were investigated. Compared with phytostanols, the prepared phytostanyl esters had much lower melting temperature and higher oil solubility. There was no obvious difference in melting and solidification properties between sunflower oil with phytostanyl laurate (<5%) or oleate (<10%) and the original sunflower oil, suggesting that the esterification of phytostanols greatly facilitated their corporation into oil-based foods.