Total lipids were extracted from 22 species of Malaysian fish and the constituent fatty acids were analysed by gas chromatography. Malaysian fish generally contained high levels of saturated fatty acids (range 36-55% total fatty acids) and contained variable amounts of monounsaturates, chiefly palmitic and stearic acids, but only trace levels of 20:1 and 22:1. Unlike fish caught in colder northern hemisphere waters, Malaysian fish were found to contain arachidonic acid (20:4 omega 6, range 2-12%) in addition to the expected eicosapentaenoic acid (20:5 omega 3, range 1-13%) and docosahexaenoic acid (22:6 omega 3, range 6.6-40.4%).
The fatty acid composition of samples of breast milk obtained from 51 mothers (26 Malay, 15 Chinese, 10 Indian) residing in Penang, Malaysia was determined by gas chromatography. Despite living in close physical proximity the mothers from the three racial groups showed distinct cultural differences in dietary intake. These differences were reflected in differences in the fatty acid composition of breast milk samples. The milk of Chinese mothers was generally less saturated (41%) than that of Malay and Indian mothers (52 and 50% respectively). The milk of Chinese mothers was also richer in linoleic acid (17%) than that of Malay and Indian mothers (9% and 11% respectively). Overall the level of individual fatty acids fell within the range of values reported for Western mothers on well nourished diets and pointed to breast milk of high standard despite large variations in the diet of Malaysian mothers.
Female Sprague-Dawley rats, 50 days of age, were treated with a single dose of 5 mg of 7,12-dimethylbenz(a)anthracene intragastrically. 3 days after carcinogen treatment, the rats were put on semisynthetic diets containing 20% by weight of corn oil (CO), soybean oil (SBO), crude palm oil (CPO), refined, bleached, deodorized palm oil (RBD PO) and metabisulfite-treated palm oil (MCPO) for 5 months. During the course of experiments, rats fed on different dietary fats had similar rate of growth. Rats fed 20% CO or SBO diet have higher tumor incidence than rats fed on palm oil (PO) diets; however differences of mean tumor latency periods among the groups were not statistically significant. At autopsy, rats fed on high CO or SBO diets had significantly more tumors than rats fed on the three PO diets. Our results showed that high PO diets did not promote chemically induced mammary tumorigenesis in female rats when compared to high CO or SBO diets. CO and SBO differ greatly from the palm oils in their contents of tocopherols, tocotrienols, and carotenes. But further experiments would be required to determine whether the observed differences in tumor incidence and tumor numbers were due to the differences in these minor components or due to the unique triglyceride structure of the palm oils. Analysis of the fatty acid profiles of plasma total lipids of tumor-bearing rats and of the tumor total lipids showed that, with the exception of arachidonic acid, the fatty acid profiles reflect the nature of the dietary fats. At autopsy, there were no differences in the plasma total cholesterol contents among rats fed on different dietary fats, but rats fed on palm oil diets had a significantly higher plasma triglyceride level than that of rats fed CO or SBO diets. As for the tumor lipids, there were no significant differences in the triglyceride, diglyceride, and phospholipid levels when the CO or SBO groups were compared to the palm oil groups.
Male Sprague Dawley rats were fed semipurified diets containing 20% fat for 15 weeks. The dietary fats were corn oil, soybean oil, palm oil, palm olein and palm stearin. No differences in the body and organ weights of rats fed the various diets were evident. Plasma cholesterol levels of rats fed soybean oil were significantly lower than those of rats fed corn oil, palm oil, palm olein or palm stearin. Significant differences between the plasma cholesterol content of rats fed corn oil and rats fed the three palm oils were not evident. HDL cholesterol was raised in rats fed the three palm oil diets compared to the rats fed either corn oil or soybean oil. The cholesterol-phospholipid molar ratio of rat platelets was not influenced by the dietary fat type. The formation of 6-keto-PGF1 alpha was significantly enhanced in palm oil-fed rats compared to all other dietary treatments. Fatty acid compositional changes in the plasma cholesterol esters and plasma triglycerides were diet regulated with significant differences between rats fed the polyunsaturated corn and soybean oil compared to the three palm oils.
Brachiaria decumbens toxicity resulted in an altered reticulorumen environment in the sheep. This adversely affected the growth and activity of microorganisms in the rumen as reflected by greatly decreased concentrations of the volatile fatty acids (acetic, propionic and butyric) in B decumbens-intoxicated sheep.
The utilisation of palm oil and its fractions by Penicillium chrysogenum for growth and penicillin production is strain-dependent. Strain H1107 could utilise crude palm oil, its liquid (palm olein) and solid (palm stearin) fractions and its component fatty acids (oleic, palmitic, stearic and myristic) as the main carbon source; strain M223 could not. Cell-bound lipase activity was higher in H1107 than in M223.
Zooplankton samples were collected from the indigenous tropical brackish water lagoon during the wet monsoon (January and February 1990) and the dry monsoon (April and May 1990). The dominant copepod species in the zooplankton community comprising of Oithona sp (especially O. nana and O. robusta) accounted for more than 70% of the zooplankton in January and was gradually replaced by other zooplanktonic species later in the dry season. The lipid contents in zooplankton varied from 0.18 to 1.04% wet weight or 1.14 to 5.92% dry weight respectively. The major fatty acid contents of the zooplankton showed high concentration of 14:0, 16:0, 18:1, 20:5 omega 3 and 22:6 omega 3 especially in the wet season. It also contained high omega-3 highly unsaturated fatty acid series necessary for the growth of commercial fish larvae. It has a better food value than the normally use food organism, brine shrimp; thus reflecting its potential use as food organism for fish larval rearing.
In a double-blind crossover study, 17 normocholesterolemic male volunteers were fed carefully designed whole-food diets in which 5% of energy was exchanged between palmitic (16:0) and lauric + myristic acids (12:0 + 14:0) whereas all other fatty acids were held constant. Resident males received each diet during separate 4-wk periods. The test diets supplied approximately 30% of energy as fat and 200 mg cholesterol/d. Compared with the 12:0 + 14:0-rich diet, the 16:0-rich diet produced a 9% lower serum cholesterol concentration, reflected primarily by a lower (11%) low-density-lipoprotein-cholesterol concentration and, to a lesser extent, high-density-lipoprotein cholesterol. No diet-induced changes were noted in the cholesterol content of other lipoproteins, nor did exchange of saturated fatty acids affect the triglyceride concentration in serum or lipoprotein fractions. These data indicate that a dietary 12:0 + 14:0 combination produces a higher serum cholesterol concentration than does 16:0 in healthy normocholesterolemic young men fed a low-cholesterol diet.
1. Two species of snakehead fish are available in Sabah, i.e. Channa striatus and Channa melanosoma, and are commonly known as haruan. Haruan is consumed by many Malaysians to induce healing after a clinical operations. However, there is no scientific evidence as yet to substantiate the claim, and so it was decided to analyse the biochemical composition in haruan to determine which compounds may have a possible role or potential in wound healing. 2. Samples (midline fillet) of both species were extracted separately in hexane for the qualitative analysis of fatty acids by a gas chromatography, Hewlett-Packard 5890A, using a 10 meter superox 11 column (Alltech) at temperature between 190 and 245 degrees C. Peak areas were calculated automatically using Hewlett-Packard 3393A computing integrator. Subsequently, the amino acid composition was analysed using a precolumn derivatization reverse phase HPLC waters PICO-TAG system. 3. Haruan is found to contain unusually high arachidonic acid (AA) but almost no eicosapentaenoic acid (EPA). AA which is a precursor of prostaglandin may initiate blood clotting and be responsible for growth. Haruan also contains all the essential amino acids for wound healing, particularly glycine which is the most important component of human skin collagen. Therefore, haruan contained all the basic biochemical requirements for wound healing.
The oxidative susceptibilities of low density lipoproteins (LDL) isolated from rabbits fed high-fat atherogenic diets containing coconut, palm, or soybean oil were investigated. New Zealand white rabbits were fed atherogenic semisynthetic diets containing 0.5% cholesterol and either (i) 13% coconut oil and 2% corn oil (CNO), (ii) 15% refined, bleached, and deodorized palm olein (RBDPO), (iii) 15% crude palm olein (CPO), (iv) 15% soybean oil (SO), or (v) 15% refined, bleached, and deodorized palm olein without cholesterol supplementation [RBDPO(wc)], for a period of twelve weeks. Total fatty acid compositions of the plasma and LDL were found to be modulated (but not too drastically) by the nature of the dietary fats. Cholesterol supplementation significantly increased the plasma level of vitamin E and effectively altered the plasma composition of long-chain fatty acids in favor of increasing oleic acid. Oxidative susceptibilities of LDL samples were determined by Cu2(+)-catalyzed oxidation which provide the lag times and lag-phase slopes. The plasma LDL from all palm oil diets [RBDPO, CPO, and RBDPO(wc)] were shown to be equally resistant to the oxidation, and the LDL from SO-fed rabbits were most susceptible, followed by the LDL from the CNO-fed rabbits. These results reflect a relationship between the oxidative susceptibility of LDL due to a combination of the levels of polyunsaturated fatty acids and vitamin E.
The heat-shock responses of barley (Hordeum vulgare L. cv Hi- malaya) aleurone layers incubated with or without gibberellic acid (GA3) were compared. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that heat shock blocked the synthesis and secretion of secretory proteins from GA3-treated layers but not untreated layers. This suppression of secretory protein synthesis has been correlated with changes in endoplasmic reticulum (ER) membranes (F.C. Belanger, M. R. Brodl, T.-h.D. Ho [1986] Proc Natl Acad Sci USA 83: 1354-1358; L. Sticher, A.K. Biswas, D.S. Bush, R.L. Jones [1990] Plant Physiol 92: 506-513). Our secretion data suggested that the ER membranes of aleurone layers incubated without GA3 may be more heat shock tolerant. To investigate this, the lipid profiles of membrane extracts in aleurone layers labeled with [14C]glycerol were examined. Heat shock markedly increased [14C]glycerol incorporation into phosphatidylcholine (PC), and gas chromatography revealed an increase in the amount of saturated fatty acids associated with thin layer chromatography-purified PC in GA3-treated layers. In contrast, aleurone layers incubated without GA3 at normal temperature contained PC-associated fatty acids with a greater degree of saturation than GA3-treated layers. Heat shock modestly increased the degree of fatty acid saturation in untreated aleurone layers. This same trend was noted in fatty acids isolated from ER membranes purified by continuous sucrose density centrifugation. We propose that increased fatty acid saturation may help sustain ER membrane function in heat-shocked aleurone layers incubated in the absence of GA3.
We determined the relative atherogenicity of two saturated fats by studying their effects on lipid peroxidation (LP), by way of malonaldehyde (MDA) and conjugated dienes (CD) and glutathione peroxidase (GSHPx) activity in serum, liver and heart; and on serum lipid profile after 4 months and 9 months of feeding. Male Rattus norwegicus rats were fed a basal diet (control) or basal diet fortified with 20% weight/weight butterfat (ghee) (BF) or coconut oil (CO). Serum high-density-lipoprotein-cholesterol (HDL-chol) and HDL-chol:LDL-chol ratio was lower in the BF group compared to CO after both feeding periods. Conjugated dienes (CDs) were higher in the serum and liver after 4 months, and heart after 9 months, of the rats fed BF compared to CO. Serum low-density-lipoprotein-cholesterol (LDL-chol) was higher, but CD were lower at 9 months than at 4 months feeding for all three groups. Liver and heart MDA and CD were higher in both groups after 9 months compared to 4 months. Liver GSHPx activity was higher after 9 months compared to 4 months in the BF group. Heart GSHPx activity was lower after 9 months compared to 4 months for both BF and CO groups. In conclusion, BF is potentially more atherogenic than CO in terms of serum lipids and LP. The unfavourable responses in serum lipids, with the exception of triglycerides, and LP were exaggerated with the longer duration of feeding with both oils.
Microplanktonic red tide blooms (dominated by dinoflagellates) were observed in brackish water fish ponds of Terengganu between March 1992 to January 1993. The first short-lived bloom (2-3 days) occurred in October 1992 while the second long-lived bloom (6-7 days) occurred in January 1993. The dominant dinoflagellate species comprised of Peridinium quinquecorne (> 90% total cell count) with considerable proportion of Protoperidinium excentricum. Ciliophora consisting of Tintinopsis sp. and Favella sp. were also present during the bloom period. The total ash, chlorophyll, phaeopigment, lipid and fatty acid content of the microplankton were studied. Considerable amounts (6-11% of the total fatty acid) of the polyunsaturated fatty acid 18:3w3 (linolenic acid) were present in the microplankton. However, high amounts of 20:5w3 (eicosapentanoic acid) and 22:6w3 (docosahexaenoic acid) were present with variable but usually high amounts of 22:4w6 and 22:5w6 acids. The latter microplankton bloom contained higher amounts of 20:5w3 and 22:6w3 acids than the earlier bloom. Lipid content were three to five times higher than chlorophyll a. There was an increase with successive day after bloom outbreak in the relative proportion of total C18, C20, and C22 fatty acid components. The algae microplankton contained the w3-polyunsaturated fatty acids (PUFAs) probably needed for the growth and survival rate of grazing pond animals.
Thirty six-male New Zealand White rabbits subdivided into four dietary groups (9 animals per group) were fed high fat (36% en), cholesterol-free diets for nine months. The dietary oil blends were formulated to contain high levels of the target fatty acids namely trans-rich (partially hydrogenated soybean oil; TRANS), cis monounsaturated-rich (rapeseed, sunflower seed oil and palm olein; MONO), palmitic-rich (palm olein; POL) and lauric-myristic rich (coconut, palm kernel and corn oils; LM). Ad libitum feeding of the rabbits resulted in normal growth throughout the nine months and no differences in the final body weights of the animals were evident at autopsy. Plasma total cholesterol was significantly elevated only by the LM enriched diet compared with all other treatments; values were comparable between the other three treatment groups. Changes in the total cholesterol were not reflected in the VLDL and LDL lipoproteins. However, HDL-cholesterol was significantly lowered by the TRANS diet compared with all other dietary groups. HDL-cholesterol was also significantly increased by the LM diet in comparison to the POL-diet. Both adipose and liver triglyceride fatty acid compositions tended to reflect the type of fatty acids fed the animals. Trans fatty acids were evident only in animals fed the trans diet and it was apparent that the trans fatty acids competed with linoleic acid for incorporation into these tissues. Increased concentrations of lauric and myristic fatty acids in the LM-fed animals were also evident. In the POL and high MONO fed rabbits, palmitic and oleic fatty acids (respectively) were concentrated in the adipose and liver. The diets, however, failed to induce severe atherosclerosis in this study. This can be explained, in part, by the lack of dietary cholesterol and the use of plant (rather than animal) proteins in our dietary formulations. The effect of these important atherosclerosis modulators in association with these fatty acids requires further evaluation.
Matched MeSH terms: Fatty Acids; Trans Fatty Acids
Several human clinical trials have now evaluated palm oil's effects on blood lipids and lipoproteins. These studies suggest that palm oil and palm olein diets do not raise plasma TC and LDL-cholesterol levels to the extent expected from its fatty acid composition. With maximum substitution of palm oil in a Western type diet some coronary heart disease risk factors were beneficially modulated: HDL2-cholesterol was significantly increased while the apolipoprotein B/A1 ratio was beneficially lowered by palm oil. Comparison of palm olein with a variety of monounsaturated edible oils including rapeseed, canola, and olive oils has shown that plasma and LDL-cholesterol were not elevated by palm olein. To focus these findings, specific fatty acid effects have been evaluated. Myristic acid may be the most potent cholesterol raising saturated fatty acid. Palmitic acid effects were largely comparable to the monounsaturated oleic acid in normolipidaemic subjects while trans fatty acids detrimentally increased plasma cholesterol, LDL-cholesterol, lipoprotein Lp(a) and lowered the beneficial HDL-cholesterol. Apart from these fatty acids there is evidence that the tocotrienols in palm oil products may have a hypocholesterolaemic effect. This is mediated by the ability of the tocotrienols to suppress HMG-CoA reductase. These new findings on palm oil merit a scientific reexamination of the classical saturated fat-lipid hypothesis and its role in lipoprotein regulation.
Matched MeSH terms: Fatty Acids; Trans Fatty Acids