F1: Schematic representations of three types of membrane lipid.(a) Phosphatidylcholine, a glycerophospholipid. (b) Glycolipid. (c) A sterol.
Three types of lipid are found in biological membranes, namely phospholipids, glycolipids and sterols. Phospholipids consist of two fatty acid chains linked to glycerol and a phosphate group. Phospholipids containing glycerol are referred to as glycerophospholipids. An example of a glycerophospholipid that is commonly found in biological membranes is phosphatidylcholine (PC) (Figure 1a), which has a choline molecule attached to the phosphate group. Serine and ethanolamine can replace the choline in this position, and these lipids are called phosphatidylserine (PS) and phosphatidylethanolamine (PE), respectively. Phospholipids can also be sphingophospholipids (based on sphingosine), such as sphingomyelin. Glycolipids can contain either glycerol or sphingosine, and always have a sugar such as glucose in place of the phosphate head found in phospholipids (Figure 1b). Sterols are absent from most bacterial membranes, but are an important component of animal (typically cholesterol) and plant (mainly stigmasterol) membranes. Cholesterol has a quite different structure to that of the phospholipids and glycolipids. It consists of a hydroxyl group (which is the hydrophilic ‘head’ region), a four-ring steroid structure and a short hydrocarbon side chain (Figure 1c).
生物膜中存在三种脂质，即磷脂、糖脂质和甾醇。磷脂由两个与甘油相连的脂肪酸链和一个磷酸基组成。含有甘油的磷脂被称为甘油磷脂。生物膜中常见的甘油磷脂的一个例子是磷脂酰胆碱(PC)(图1a)，它有一个胆碱分子附着在磷酸基上。丝氨酸和乙醇胺可以取代胆碱在这个位置，这些脂质分别被称为磷脂酰丝氨酸(PS)和磷脂酰乙醇胺(PE)。磷脂也可以是鞘磷脂(以鞘磷脂为基础)，如鞘磷脂。糖脂既可以含有甘油，也可以含有鞘氨醇，并且总是含有一种糖，如葡萄糖，来代替磷脂中的磷酸头(图1b)。大多数细菌的细胞膜上都没有甾醇，但甾醇是动物(特别是胆固醇)和植物(主要是甾醇)细胞膜的重要组成部分。胆固醇与磷脂和糖脂有着完全不同的结构。它由一个羟基(即亲水“头”区)、一个四环甾体结构和一个短的烃侧链组成(图1c)。
https://openi.nlm.nih.gov/detailedresult.php?img=PMC4626904_bse0590043i001&req=4
The influence of saponins on cell membrane cholesterol.
saponin-induced cholesterol liberation as well as the saponin-induced inhibition of cholesterol uptake with the membrane toxicity
The results suggested that the general cytotoxicity of saponins is mainly dependent on their membrane toxicity and that the membrane toxicity might be caused by the loss of cholesterol from the cell membrane.
The experiments revealed a correlation between the membrane toxicity and the reduction in surface tension.
The influence of saponins on cell membrane cholesterol. - PubMed - NCBI
https://www.ncbi.nlm.nih.gov/pubmed/24084294Saponins can perturb biologic membranes and reduce the surface tension of aqueous solutions: a correlation? - PubMed - NCBI
https://www.ncbi.nlm.nih.gov/pubmed/22503361
Benefits of Phosphatidylcholine
By Kalli Harrison
Bildpoet/iStock/Getty Images
Phosphatidylcholine is a ubiquitous, naturally occurring phospholipid molecule. It is the major lipid, or fat, of cell membranes and blood proteins. Also known as PC, phosphatidylcholine serves as the body’s main source of choline, an essential nutrient and precursor to the neurotransmitter, acetylcholine. PC is also necessary for the production of surfactants, which are critical for lung function and gastrointestinal health. The terms "phosphatidylcholine" and "lecithin" are sometimes used interchangeably; however, lecithin is actually a mixture of several lipids and phospholipids.
Liver Health
PC is necessary for the composition and repair of cell membranes and is vital for normal liver function. Research indicates PC's most beneficial role is in the prevention and treatment of various forms of liver disease and toxicity. PC protects liver cells from viral damage, reduces fibrosis, and prevents cell death from drugs, alcohol and other chemical toxins.
Several studies have shown PC's protective and healing effect on patients with hepatitis A, B and C. In a double blind trial published in the journal Liver, PC administration for chronic, active hepatitis resulted in significant reduction of disease activity. Another study in Hepatology, revealed that choline-deficient patients had a reversal of hepatic steatosis, or fatty liver disease, upon choline supplementation. Additionally, a study from the journal Alcoholism: Clinical and Experimental Research, resulted in PC protection of rat liver cells from alcohol-induced toxicity. The authors propose that phosphatidylcholine reduces cell death through a reduction in oxidative stress.
Intestinal Health
Phosphatidylcholine is a major lipid in the protective mucus layer of the gastrointestinal tract. It can mitigate GI injury by exerting an anti-inflammatory effect. A recent study in BMC Gastroenterology, shows that PC inhibits pro-inflammatory substances and is beneficial for those suffering from ulcerative colitis.
Emerging evidence also indicates that PC can protect the stomach and intestinal lining from the damaging effects of non-steroidal anti-inflammatory drugs, also called NSAIDs. Using a combined product of the NSAID, naproxen and PC, a study in Inflammopharmacology states that " Naproxen-PC appears to induce significantly less GI injury and bleeding in two rodent model systems while maintaining anti-inflammatory and COX-inhibitory activity."
Neuropsychiatric Disorders
Phosphatidylcholine's importance in cell membrane integrity and intracellular communication has led to research in the area of neurology. Although studies are limited, data suggests PC supplementation can reduce symptoms of illnesses associated with low levels of acetylcholine including, schizophrenia, bipolar disorder, Huntington's chorea, Tourette's syndrome and Alzheimer's disease. Results from a study in the Journal Proteome Research, revealed that lipid abnormalities within the brain and blood may be factors in the disease processes of both schizophrenia and bipolar disorder.Benefits of Phosphatidylcholine | LEAFtv
https://www.leaf.tv/3428663/benefits-of-phosphatidylcholine/
THE SURRPISING BENEFITS OF PHOSPHATIDYL CHOLINE
WHAT IS PHOSPHATIDYL CHOLINE?
Phosphatidyl choline (PC) is an important type of phospholipid and a major structural component of cell membranes, where it provides integrity and structure to the all-important membranes and regulates their fluidity. PC also provides structure to circulating lipoproteins and is essential for lipid transport and metabolism.[1] As an essential component of bile, PC facilitates fat emulsification, absorption and transport.[2] Additionally, PC is a constituent of surfactants in the body, including those of the lungs and gastrointestinal tract, where it protects these important epithelial-luminal interfaces.[2]
The clinical applications of PC centre on its role in hepatic detoxification and protection, and through its role in providing choline in the body for lipid metabolism, liver function, homocysteine metabolism, cell signalling, neurotransmitter synthesis and methylation reactions.
Structurally, PC is made up of a choline ‘head’, a glycerol ‘body’, and two fatty acid ‘tails’. Over 95% of the body’s tissue stores of the essential nutrient choline are found in PC.[1,2]
The clinical applications of PC centre on its role in hepatic detoxification and protection, and through its role in providing choline in the body for lipid metabolism, liver function, homocysteine metabolism, cell signalling, neurotransmitter synthesis and methylation reactions.[1,3]
PHOSPHATIDYL CHOLINE, LIVER HEALTH AND DETOXIFICATION
Undoubtedly, PC’s most researched and well known role is in supporting liver health, where it has shown to be beneficial in the treatment of liver diseases, including alcoholic hepatic steatosis, drug-induced liver damage, and hepatitis.[4] Both human and animal studies confirm that PC provides a hepatoprotective effect.
In the liver, PC is essential for the distribution of fat and cholesterol into extrahepatic tissues. It does this by packaging fat and cholesterol into very low density lipoprotein (VLDL) particles and secreting them from the liver. Inadequate PC and choline results in impaired VLDL secretion leading to an accumulation of fat and cholesterol in the liver. This accumulation of lipids triggers a cascade of reactions, including mitochondrial dysfunction, generation of reactive oxygen species (ROS), lipid peroxidation, DNA damage, inflammation, apoptosis and finally liver damage and disease.[1] Ensuring adequate PC levels is therefore essential in promoting optimal liver health.
PC can provide liver and detoxification support in a number of ways with human and animal research showing PC to have the following beneficial effects on liver health:
reduces hepatic inflammation
reduces liver enzymes associated with liver damage
protects against chemical toxins and pharmaceutical adverse effects
reduces fat accumulation in the liver
reduces reactive oxygen species
improves hepatic injury and fibrosis
improves the structure and function of liver tissue
improves parameters of hepatitis B and C.[2,5]
Researchers have also combined PC with silybin, an active constituent of Silybum marianum (milk thistle) finding the combination to improve liver enzymes, liver histology, and insulin resistance, while also protecting gastric and liver cells from oxidative stress.[6,7]
With over six million Australians affected by liver disease, including the increasingly common NAFLD (non-alcoholic fatty liver disease),[8] PC can provide practitioners with an effective addition to complement their current liver and detoxification protocols.
CELL MEMBRANE HEALTH
The importance of PC for cellular health cannot be underestimated, as it provides the main structural component of the all-important cell membrane. In addition to providing structural support and regulating membrane fluidity, PC also acts as a precursor for intracellular messenger molecules that are central to cell signalling and thereby influence cell function.[1]
The beneficial effects of PC on damaged liver tissue are probably due largely to the replacement of cell membrane mass, which occurs when adequate levels of PC are available for incorporation into the cell membranes.[2]
CARDIOVASCULAR DISEASE
An interesting application for PC supplementation may be for the maintenance of cardiovascular health due to its effect on lipid transport and metabolism, and by providing a source of methyl groups for the remethylation of homocysteine to methionine.
PC provides a source of choline which can be oxidised into betaine, an important metabolite used as a methyl donor in the conversion of homocysteine to methionine.[2] Researchers have found that PC supplementation lowers plasma homocysteine concentrations, potentially reducing cardiovascular disease risk, although further research is needed in this area.[9]
PC may reduce other cardiovascular risk factors according to a recent animal study. In this study, PC administration was found to alleviate obesity-related complications of a high fat diet such as body weight gain, lipid accumulation and hyperlipidaemia – all risk factors for cardiovascular disease – results that can hopefully be replicated in human clinical trials.[10]
NERVOUS SYSTEM
Another important area where PC may prove of value is the nervous system and its effect on cognitive function. Choline, provided through PC, is essential for the synthesis of the neurotransmitter acetylcholine,[1] which is involved in muscle control, circadian rhythm, memory, and many other neuronal functions.
Accumulating evidence has found a link between PC levels and cognitive function, with low plasma PC levels highly predictive of cognitive decline and age-related membrane degeneration.[11] PC may deliver a neuroprotective role by providing a significant supply of choline and being an essential component of neuronal membranes.[11]
SOURCES OF PHOSPHATIDYL CHOLINE
PC may be endogenously produced or obtained through the diet. Supplemental PC is most commonly derived from soy or sunflower lecithin. PC is synthesised in the body from dietary choline via the CDP-choline pathway or through the methylation of phosphatidylethanolamine, another phospholipid.[1]
The best dietary sources of PC include animal products such as eggs, liver, fish, beef, chicken, and pork, while wheat germ, soy beans, peanuts, peas, broccoli and spinach also provide vegetarian sources.[12] Interestingly, krill oil also provides a good source of PC.
INCLUDING PHOSPHATIDYL CHOLINE IN A DETOX
With its ability to repair and protect liver cells, PC is a smart choice for incorporating into a detoxification program. Its main benefit in detoxification stems from its critical role as a building block of liver cell membranes, which are highly vulnerable to damage from alcohol, pharmaceutical medications, pollutants, viruses and other toxic influences.[13] By providing PC – the main building block of these cell membranes – detoxification and liver function can be optimised.
PC is highly bioavailable, and through its action as an emulsifier, may enhance the bioavailability of other nutrients that are supplemented alongside it.[13] As previously detailed, PC has been combined with silybin from milk thistle to improve markers of liver function, with the results achieved greater than that with silybin alone. PC also appears to be a safe supplement, with very few adverse effects reported in clinical trials, which is particularly important for patients who require safe and effective detoxification and liver support.[14]
A minimum daily dose of 800mg of PC, easily achieved via supplementation, has been recommended in the literature to improve liver function and enhance its recovery.[2,13]Surprising Benefits of Phosphatidyl Choline | FX Medicine
https://www.fxmedicine.com.au/blog-post/surprising-benefits-phosphatidyl-choline
Cell Membranes, Fatty Acids & Inflammation
Every cell has a cell membrane — it’s the outer layer that holds the cell together and does so much more!
Cell Membranes Can Affect Your Health and Wellness
The fatty acid composition of your cell membranes is a reflection of the foods you eat and dietary supplements you take.
The fatty acid composition of your cell membranes is also related to your inflammatory response.
What Do Cell Membranes “Do”?
Cell membranes let nutrients into the cells and waste products pass out of the cells.
Cell membranes provide a protective barrier for cells — they don’t let everything in, especially large particles.
Cell membranes are important in the communication between cells.
Cell membranes are reservoirs for fatty acids.
Cell membranes release fatty acids when the body needs it, such as for growth or dealing with an injury.
Dietary Fats, Flexibility of Cell Membranes, and Inflammation
“You are what you eat” applies on the cellular level — to cell membranes.
If you eat a diet with a lot of red meat, high fat dairy products (high in Omega-6’s), processed foods (high in Omega-6’s and possibly trans fats), and not much fish, fruit, vegetables and whole grains, nuts, seeds (high in Omega-3’s), your cell membranes will be largely composed of unhealthy fatty acids (arachidonic fatty acids, a non-essential Omega-6 from animal products, as well as trans fatty acids found in many processed foods) from those foods.
This will lead to less flexible and less permeable cell membranes that have reduced ability to transport nutrients into your cells and to rid the cells of wastes. The cells will also have impaired ability to communicate with one another.
In contrast, if you eat a lot of vegetables, fruit, nuts, seeds, whole grains, low fat dairy, fish (and/or take supplements with fatty acids from fish containing Omega-3’s) and not much processed foods, meat or high fat dairy, your cell membranes will be largely composed of healthy fatty acids from these foods.
This will lead to more flexible and more permeable cell membranes that have increased ability to transport nutrients into your cells and to rid the cells of wastes. The cells will also have improved ability to communicate with one another.
How is This Related to Inflammation?
When your body experiences an insult, (physical, stress, allergy, infection, etc.), your cells release the fatty acids stored in your cell membranes.
Cell membranes containing a large proportion of fatty acids from a high meat, high fat dairy and processed foods diet will release pro-inflammatory fatty acids.
However, cell membranes containing a large proportion of fatty acids from a diet high in fish, fruit, vegetables, whole grains, nuts, and seeds will act in an anti-inflammatory manner when released from cell membranes.
Many medical doctors and scientists believe that inflammation is the root of many degenerative diseases such as arthritis, diabetes type 2, heart disease, obesity, Alzheimers, and certain pulmonary diseases, digestive disorders and cancers.
You Can Modify the Composition of Your Cell Membranes!
The good news is that you can change the composition of your cell membranes. Through the foods you eat and nutrition supplements you take, over time, you can improve the composition of your cell membranes so they contain more Omega-3’s and fewer Omega-6’s.
According to scientific research, a positive change in the composition of the fatty acids in your cell membranes will also promote healthier inflammatory responses.
Here are some suggestions:
Eat more fish, vegetables, fruit, nuts, seeds, whole grains, and low fat dairy. (High in Omega-3’s)
Eat less red meat, pork, chicken, eggs, and high fat dairy. (High in Omega-6’s)
Look for meat or dairy products that are pasture-raised or grass-fed. (Grass is high is Omega-3’s; Corn or Soy feed is high in Omega-6’s)
Eat wild fish vs. farm raised fish whenever possible. (It’s related to the diet of the fish.)
Lower the amount of vegetable oils in your diet. If you need oil, use olive oil and limit corn, soy, safflower, or sunflower oils, or most vegetable oil blends.
Eat other foods high in Omega-3’s such as flaxseed, chia seeds, and walnuts.
If needed, take a high quality dietary supplement with Omega-3’s every day.
细胞膜，脂肪酸和炎症
每个细胞都有一层细胞膜——这是将细胞连接在一起的外层，它的功能远不止这些!
细胞膜会影响你的健康
细胞膜的脂肪酸组成反映了你吃的食物和吃的营养补充剂。
细胞膜的脂肪酸组成也与炎症反应有关。
细胞膜的作用是什么?
细胞膜让营养物质进入细胞，废物排出细胞。
细胞膜为细胞提供了一个保护屏障——它们不会让任何东西进入，尤其是大颗粒。
细胞膜在细胞间的通讯中很重要。
细胞膜是脂肪酸的储藏库。
当身体需要脂肪酸时，如生长或处理损伤时，细胞膜就会释放脂肪酸。
饮食脂肪，细胞膜的柔韧性和炎症
“吃什么就是什么”适用于细胞层面——细胞膜。如果你吃大量红肉,高脂肪乳制品(富含ω- 6的),加工食品(富含ω- 6的和可能的反式脂肪),而不是鱼,水果,蔬菜和全谷物、坚果、种子(富含ω- 3的),你的细胞膜主要由不健康的脂肪酸(花生四烯酸脂肪酸,动物产品的不必要的ω- 6,以及反式脂肪酸中发现许多加工食品)的食物。
这将导致细胞膜的柔韧性和渗透性降低，从而降低了将营养物质输送到细胞和清除细胞废物的能力。细胞之间的交流能力也会受损。
相比之下,如果你吃很多蔬菜、水果、坚果、种子、谷物、低脂乳制品、鱼类(和/或采取补充剂与鱼含有ω- 3脂肪酸),而不是加工食品,肉类或高脂肪奶制品,细胞膜将在很大程度上从这些食物健康的脂肪酸组成。
这将导致更灵活和更渗透的细胞膜，增加了运输营养物质到你的细胞和清除细胞废物的能力。细胞之间的交流能力也将得到提高。
这和炎症有什么关系?
当你的身体受到伤害时(身体、压力、过敏、感染等)，你的细胞就会释放储存在细胞膜中的脂肪酸。
含有大量脂肪酸的细胞膜从高脂肪的肉类、高脂肪的奶制品和加工食品中会释放出促炎性脂肪酸。
然而，含有大量脂肪酸的细胞膜富含鱼类、水果、蔬菜、全谷物、坚果和种子，当它们从细胞膜中释放出来时，会产生抗炎作用。
许多医生和科学家认为，炎症是许多退行性疾病的根源，如关节炎、2型糖尿病、心脏病、肥胖、阿尔茨海默病，以及某些肺部疾病、消化系统疾病和癌症。
你可以改变细胞膜的成分!
好消息是你可以改变细胞膜的组成。通过你所吃的食物和服用的营养补充品，随着时间的推移，你可以改善你细胞膜的成分，因此它们含有更多的-3脂肪酸，而较少的-6脂肪酸。
根据科学研究，细胞膜中脂肪酸组成的积极变化也会促进更健康的炎症反应。
以下是一些建议:
多吃鱼、蔬菜、水果、坚果、种子、全谷物和低脂奶制品。(富含ω- 3的)
少吃红肉、猪肉、鸡肉、鸡蛋和高脂肪奶制品。(富含ω- 6的)
寻找那些放牧或食草的肉类或奶制品。(草多就是欧米伽-3;玉米或大豆饲料富含-6)
只要有可能，就吃野生鱼和农场养殖的鱼。(这与鱼的饮食有关。)
减少饮食中植物油的摄入。如果你需要油，用橄榄油，少用玉米，大豆，红花，或葵花籽油，或大多数混合植物油。
吃其他富含Omega-3的食物，如亚麻籽、奇亚籽和核桃。
如果需要，每天服用高质量的膳食补充剂和-3脂肪酸。Cell Membranes, Fatty Acids & Inflammation - The Nutrition Supplement Dietitian
https://mysupplementrd.com/fish-oils-omega-3-fatty-acids/cell-membranes-fatty-acids-inflammation/
