Dietary Lipids Essay

4691 Words 19 Pages
General Introduction
Dietary lipids:
Dietary lipids consist of a broad group of compounds that are soluble in organic solvents and insoluble in water. Their density is lower than water and consistency varies from liquids to solids at normal room temperature, depending on their structure and function. They are also referred as ‘Oils’ which are liquid and ‘fats’ which are solid at room temperature. Lipids are the important constituents of diet due to their higher energy value. One gram of lipid yields 9.3 KCal of energy, while the same amount of carbohydrate or protein yields 4.5 Kcal. Triacylglycerols are major components of oils and fats: they are composed of three fatty acids esterified to a glycerol molecule. They are the predominant components
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Monoblasts and phagocytes are the earliest recognizable cells of this family which after two or three cell divisions give rise to monocytes. Monocytes then enter blood circulation and migrate into the tissues where they mature into macrophages (Mosser, 2003). Tissue macrophages are spread throughout the body and designated by specific name depending on the site of tissue occupation. These macrophages are called by different names like kupffer cells, alveolar cells, microglia, peritoneal macrophages, osteoblasts, langerhans cells when they are in liver, lungs, central nervous system, peritoneal cavity, bone and skin/mucosa, respectively. They act as scavenger cells collecting the damaged cells and cell debris. They also serve as first line of defense against a variety of infections by interacting with lymphocytes (Bianchia & Manfredi, 2014). Macrophages play an important role in immune and inflammatory responses. The macrophage functions are influenced by dietary lipids (De Lima et al, …show more content…
This is attributed to the unsaponifiable matter com¬prising γ-Oryzanol, campesterol and β-sitosterols (Raghuram et al, 1989). RBO is shown to inhibit HMG (hydroxyl-methylglutaryl)-CoA reductase and up-regulated the expression of sterol regulatory element binding protein (SREBP)-2, which can modulates the cholesterol levels in plasma and tissues (Reena et al, 2011). The role of phytonutrients in correcting by abnormal pro-inflammatory signal transmissions mediated by NF-κB is documented. ROS activate NF-κB, which leads to the generation of pro-inflammatory cytokines and inducible enzymes, such as COX-2 and iNOS in macrophages. The pro-inflammatory cytokines cause oxidative stress by promoting the release of ROS by macrophages. The inflammation and oxidative stress are involved in the spiraling vicious inflammatory cycle. The presence of antioxidant and anti inflammatory properties of γ-Oryzanol from rice bran oil is due to its ability to inhibit eicosanoids production, reduce oxidative stress, matrix metallo proteinases and C-reactive protein in inside the environment of macrophages (Rukkumani et al, 2012). Rice bran could reduce the levels of nitric oxides, Il-1β, Il-6, TNF-α, COX-2 and 5-LOX expressions in mice (Choi et al, 2013). Recently, it has been shown that up-regulation of adeponectin levels via indirect activation of PPARγ through inhibition of NF-κB (Islam et

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