Effects of dietary flaxseed oil on cholesterol metabolism of hamsters

High-fat/cholesterol diets (HFCD) formulated by addition of butter (BU), coconut oil (CO), or flaxseed oil (FX) enhanced (P < 0.05) serum lipids of hamsters compared to the low-fat/cholesterol diet (Control). However, FX groups showed a hypocholesterolaemic effect compared to CO and BU groups. Lower (P < 0.05) hepatic triacylglycerol and cholesterol contents were measured in FX groups than those of CO and BU groups; whereas, higher (P < 0.05) faecal triacylglycerol and cholesterol contents were observed in FX groups. HMG-CoA reductase mRNA expression was upregulated (P < 0.05) by HFCD, whilst FX groups showed no (P > 0.05) influence on LDL-receptor mRNA expression compared to that of Control groups; however, higher (P < 0.05) than those of CO and BU groups. Meanwhile, there was a tendency towards higher CYP7A1 expression in the CO or FX group than the BU group. Thus, the hypocholesterolaemic effect of FX might result from increases of LDL-receptor mRNA expression, and cholesterol catabolism/output.     

Protective effect of a litchi (Litchi chinensis Sonn.)-flower-water-extract on cardiovascular health in a high-fat/cholesterol-dietary hamsters

Cardiovascular disease (CVD) is the major cause of death in the developed countries. Litchi-flower-water-extract (LFWE) contains plenty of phytochemicals, i.e. phenols, flavonoids, tannins which may own cardio-protection. Ten male hamsters per group were assigned randomly to one of the following dietary groups: chow diet and normal distilled water (LFCD/NDW); high-fat/cholesterol diet and normal distilled water (HFCD/NDW); HFCD and 2.5% litchi-flower-water-extract (HFCD/2.5% LFWE); HFCD and 5% LFWE (HFCD/5% LFWE). Serum lipids, cardiac index, and hepatic lipids were lowered (p < 0.05) in high-fat/cholesterol-dietary hamsters by drinking 2.5% and 5% LFWE which may result from higher (p < 0.05) LDL receptor and peroxisome proliferator-activated receptor-alpha (PPAR-α) gene expressions and lower (p < 0.05) fatty acid synthase (FAS) gene expression, as well as increased (p < 0.05) faecal lipid and bile acid excretions. Drinking LFWE also lowered (p < 0.05) serum malondialdehyde (MDA) contents in high-fat/cholesterol-dietary hamsters, and even showed the same (p > 0.05) serum MDA contents as the LFCD/NDW group’s which could be due to increased (p < 0.05) serum trolox equivalent antioxidant capacity (TEAC). Therefore, this study indicated that LFWE indeed characterises a protective effect on cardiovascular health in vivo.     

Cardiovascular protection of deep-seawater drinking water in high-fat/cholesterol fed hamsters

Cardiovascular protection of deep-seawater (DSW) drinking water was assessed using high-fat/cholesterol-fed hamsters in this study. All hamsters were fed a high-fat/cholesterol diet (12% fat/0.2% cholesterol), and drinking solutions were normal distiled water (NDW, hardness: 2.48 ppm), DSW300 (hardness: 324.5 ppm), DSW900 (hardness: 858.5 ppm), and DSW1500 (hardness: 1569.0 ppm), respectively. After a 6-week feeding period, body weight, heart rates, and blood pressures of hamsters were not influenced by DSW drinking waters. Serum total cholesterol (TC), triacylglycerol (TAG), atherogenic index, and malondialdehyde (MDA) levels were decreased (p < 0.05) in the DSW-drinking-water groups, as compared to those in the NDW group. Additionally, increased (p < 0.05) serum Trolox equivalent antioxidant capacity (TEAC), and faecal TC, TAG, and bile acid outputs were measured in the DSW-drinking-water groups. Hepatic low-density-lipoprotein receptor (LDL receptor) and cholesterol-7α-hydroxylase (CYP7A1) gene expressions were upregulated (p < 0.05) by DSW drinking waters. These results demonstrate that DSW drinking water benefits the attenuation of high-fat/cholesterol-diet-induced cardiovascular disorders in hamsters.     

Comparative effects of safflower oil and perilla oil on serum and hepatic lipid levels, fatty acid compositions of serum and hepatic phospholipids, and hepatic mRNA expressions of 3-hydroxy-3-methylglutaryl CoA reductase, LDL receptor, and cholesterol 7alpha-hydroxylase in young and adult rats

Male Wistar rats, 4 and 33 weeks of age, were fed the diets containing safflower oil (SO-diet, 77.3% linoleic acid) or perilla oil (PO-diet, 58.4% -linolenic acid) for 7 days. Serum total cholesterol was lower on the PO-diet in both ages. On the other hand, hepatic cholesterol and phospholipids were significantly higher in the PO group than in the SO group of the adult rats. The PO group showed significantly lower 20:4 n-6 but higher 18:2 n-6 in hepatic phosphatidylcholine compared with the SO group in both ages. Hepatic 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase mRNA was significantly lower on the PO-diet than on the SO-diet irrespective of age. The present results show that -linolenic acid has a higher hypocholesterolemic ability than linoleic acid in rats irrespective of age and these fatty acids behaved differently in affecting hepatic mRNA expressions of HMG-CoA reductase, LDL receptor, and cholesterol 7-hydroxylase.     

Dietary calcium decreases plasma cholesterol by down‐regulation of intestinal Niemann–Pick C1 like 1 and microsomal triacylglycerol transport protein and up‐regulation of CYP7A1 and ABCG 5/8 in hamsters

Scope: It has been shown that calcium supplementation favorably modifies plasma lipoprotein profile in postmenopausal women. The present study investigated the interaction of dietary calcium with genes of transporters, receptors and enzymes involved in cholesterol metabolism. Methods and results: Forty‐eight ovariectomized hamsters were fed one of the four diets containing 0, 2, 6 and 8 g calcium per kg. Plasma total cholesterol (TC), triacylglycerols (TG), and non‐high density lipoprotein cholesterol were dose‐dependently decreased, whereas high‐density lipoprotein cholesterol (HDL‐C) was dose‐dependently increased with the increasing dietary calcium levels. Dietary calcium had no effect on protein mass of hepatic sterol regulatory element binding protein‐2 (SREBP), liver X receptor‐alpha (LXR), 3‐hydroxy‐3‐methylglutaryl‐CoA reductase (HMGR), LDL receptor (LDLR) and cholesterol‐7α‐hydroxylase (CYP7A1). However, dietary calcium up‐regulated the mRNA levels of hepatic CYP7A1 and intestinal ATP binding cassette transporters (ABCG5/8) whereas it down‐regulated the intestinal Niemann‐Pick C1 like 1 (NPC1L1) and microsomal triacylglycerol transport protein (MTP). In addition, dietary calcium increased the activity of intestinal acyl coenzyme A: cholesterol acyltransferase 2, while it decreased plasma cholesteryl ester transport protein (CETP). Conclusion: Beneficial modification of lipoprotein profile by dietary calcium was mediated by sequestering bile acid absorption and enhancing excretion of fecal cholesterol, via up‐regulation of mRNA CYP7A1 and intestinal ABCG 5/8 with down‐regulation of mRNA NPC1L1 and MTP.     

Phytochemistry, traditional uses and pharmacology of Eugenia jambolana Lam. (black plum): A review

Eugenia jambolana Lam. (syn. Syzigium cumini (L.) SKEELS; S. jambolana DC; Family: Myrtaceae), commonly known as black plum or Jamun is a plant native to India. Annually the trees produce oblong or ellipsoid fruits (berries). They are green when raw and purplish black when fully ripe. The ripe fruits are sweetish sour to taste and are used to prepare health drinks, squashes, juices, jellies and wine. Studies have shown that the berries contain carbohydrates, minerals and the pharmacologically active phytochemicals like flavonoids, terpenes, and anthocyanins. Jamun is a plant with known ethnomedicinal uses. Before the discovery of insulin, Jamun was useful in the treatment of diabetes and is an integral part in the various alternative systems of medicine. Scientific studies have shown that the various extracts of Jamun possess a range of pharmacological properties such as antibacterial, antifungal, antiviral, anti-genotoxic, anti-inflammatory, anti-ulcerogenic, cardioprotective, anti-allergic, anticancer, chemopreventive, radioprotective, free radical scavenging, antioxidant, hepatoprotective, anti-diarrheal, hypoglycemic and antidiabetic effects. The present paper reviews these aspects and also addresses the lacunas in the existing knowledge.     

The chemistry and medicinal uses of the underutilized Indian fruit tree Garcinia indica Choisy (kokum): A review

Garcinia indica Choisy Syn Brindonia indica, commonly known as kokum and belonging to Guttiferae family, is a plant native to certain regions of India. The trees yield fruits annually in the summer season during the months of March to May. The fruits are green when raw and red to dark purple when fully ripe. They are used to prepare juice, pickles and as acidulant in curries. In the traditional Indian system of medicine the Ayurveda and in various folk systems of medicine, the fruit rinds and leaves are used to treat various inflammatory ailments, rheumatic pain and bowel complaints. The kokum butter prepared from the seed is of both commercial and medicinal use. Chemical studies have shown that the rind contains protein, tannin, pectin, sugars, fat, organic acids like (−)-hydroxycitric acid, hydroxycitric acid lactone and citric acid; the anthocyanins, cyanidin-3-glucoside and cyanidin-3-sambubioside; and the polyisoprenylated phenolics garcinol and isogarcinol. Preclinical studies have shown that kokum or and some of its phytochemicals possess antibacterial, antifungal, anti-ulcerogenic, cardioprotective, anticancer, chemopreventive, free radical scavenging, antioxidant and anti-obesity effects. The present paper reviews the nutritional value, the phytochemical compounds, traditional uses and validated pharmacological properties of kokum.     

A review of botanical characteristics, phytochemistry, clinical relevance in efficacy and safety of Lycium barbarum fruit (Goji)

Lycium barbarum has been used as a traditional Chinese medicine (TCM) to nourish liver and kidney, and brighten the eye. The fruits are dried or freshly squeezed for their juice and concentrated for beverages. Among various constituents, a group of polysaccharides (LBP) with a Glycan-O-Ser glycopeptide structure has been most researched and considered to be important for the efficacy of L. barbarum. Studies indicate effects of L. barbarum on aging, neuroprotection, general well-being, fatigue/endurance, metabolism/energy expenditure, glucose control in diabetics, glaucoma, anti-oxidant properties, immunomodulation, anti-tumor activity and cytoprotection. In addition to TCM, L. barbarum can be sold as a dietary supplement or classified as a food based upon the long and safe traditional usage. This review is to provide background and updated information of chemical constituents and efficacies with safety including a new direction for research and current regulatory situation of L. barbarum.