Vallikannan Baskaran

Enhanced lutein bioavailability by lyso-phosphatidylcholine in rats.

The bioavailability of lutein solubilized in mixed micelles containing either phosphatidylcholine (PC) or lysophosphatidylcholine (lysoPC) was evaluated in male rats. Mixed micelles contained 2.5 mM monooleoylglycerol, 7.5 mM oleic acid, 12 mM sodium taurocholate and 200 μM lutein either with 3 mM PC or lysoPC. To study lutein bioavailability, single and repeated dose experiments were conducted. For single dose study, group of rats (n = 30/group) were fed single dose of lutein solubilized in lysoPC (LPC group), PC (PC group) and no phospholipids (NoPL group) in micellar form. Each group was further divided in to five sub-groups (n = 6/sub group) to measure lutein bioavailability over time up to 9 h. For repeated dose study, group of rats (n = 6/group) were fed daily for 10 days a dose of lutein in mixed micelles with NoPL, PC and LPC. A separate group (n = 6) not fed mixed micelles was considered as zero-time control. In both the experiments, mixed micelles (0.2 ml/rat) were fed to the rat by direct intubation to the stomach. Results of single dose studies showed that the mean lutein levels in the plasma and liver of the PC group was significantly lower (p < 0.05) than those of the other two groups. Moreover, the average lutein level in the plasma and liver was significantly (p < 0.05) different among the groups in the order LPC > NoPL > PC. But, repeated dose experiment followed the order LPC > PC > NoPL. The level of lutein excreted through urine and feces of PC group was significantly higher (p < 0.05) than those of the other two groups. Thus, the results indicate that the PC in the mixed micelles suppressed the intestinal uptake of lutein after single dose but not after repeated dose and that lysoPC enhanced the absorption. In both the experiments, plasma and liver level of lutein was higher in LPC compared with PC group. Results also suggest that the luminal hydrolysis of PC to lysoPC is necessary for intestinal uptake of lutein solubilized in mixed micelles.

Effect of micellar lipids, dietary fiber and β-carotene on lutein bioavailability in aged rats with lutein deficiency

OBJECTIVE To determine the effect of various dietary components on the intestinal uptake of lutein in aged rats. METHODS This study determined the time-course (2, 4, 6, 8 h) plasma and tissue responses of a pharmacologic dose of lutein (200 μM) solubilized in mixed micelles with fat (3%, soybean oil), phosphatidylcholine (PC; 3 mM), lysophosphatidylcholine (lysoPC; 3 mM), dietary fiber (pectin, 1.25%), β-carotene (200 μM), or micelles with no dietary components (control) in aged rats with lutein deficiency. RESULTS No lutein was detected in the plasma of rats at 0 h indicating the deficiency. After gavages of lutein, the mean percent area under the curve (picomoles per milliliter per 8 h) of plasma lutein in the fat (91.4), PC (218.0), and lysoPC (94.1) groups were higher (P > 0.05), whereas its level in the dietary fiber and β-carotene groups was lower than the control group. The liver and eye lutein levels of the PC (95.4, 38.67%) and fat (18.2, 143%) groups were significantly higher, whereas the lysoPC (9.6, 27.2%), β-carotene (19.2, 35.4%), and dietary fiber (3.1, 88.4%) groups were lower than the control group. CONCLUSION Results indicate that soybean oil and soy phospholipids greatly sway lutein absorption in aged rats with lutein deficiency. The results also suggest that ingestion of lutein with pectin and β-carotene suppresses lutein absorption. Hence, to improve the absorption of lutein in older adults with macular pigment deficiency, foods with sufficient fat with low dietary fiber and β-carotene may be suggested.

Spray-dried milk supplemented with α-linolenic acid or eicosapentaenoic acid and docosahexaenoic acid decreases HMG Co A reductase activity and increases biliary secretion of lipids in rats

In our earlier study, we have shown that rats fed spray-dried milk containing alpha-linolenic acid (LNA 18:3 n-3) or eicosapentaenoic acid (EPA 20:5 n-3) and docosahexaenoic acid (DHA 22:6 n-3) had significantly lower amounts of serum and liver cholesterol. To evaluate the mechanism for hypocholesterolemic effect of n-3 fatty acids containing milk formulation, we fed male Wistar rats with spray-dried milk containing linseed oil (LSO) (source of LNA) or fish oil (FO) (source of EPA+DHA) for 8 weeks. Feeding n-3 fatty acid containing milk formulation lowered the hepatic 3-hydroxy-methylglutaryl coenzyme A (HMG Co A) activity by 17-22% compared to rats given control diet devoid of n-3 fatty acids. The cholesterol level in liver microsomes was found to be decreased by 16% and 20%, respectively, in LSO and FO containing formulation fed rats. The bile flow was enhanced to an extent of 19-23% in experimental groups compared to control animals. The biliary cholesterol and phospholipid secretion was increased to an extent of 49-55% and 140-146%, respectively, in rats fed n-3 fatty acid containing formulation. The increase in the total bile acids secretion in bile was mainly reflected on an increase in the levels of taurine conjugated bile acids. These results indicated that n-3 fatty acid containing spray-dried milk formulation would bring about the hypocholesterolemic effect by lowering HMG Co A reductase activity in liver and by increasing the secretion of bile constituents.

Micellar oleic and eicosapentaenoic acid but not linoleic acid influences the β-carotene uptake and its cleavage into retinol in rats

Improving the bioavailability of β-carotene is vital to manage vitamin A deficiency. The influence of micellar oleic (OA), linoleic (LA) and eicosapentaenoic (EPA) acids on plasma β-carotene response and its conversion to retinol has been studied in rats employing single (9 h time course) and repeated (10 days) dose administrations. After a single dose, the levels (area under the curve) of plasma β-carotene and retinyl palmitate in OA and EPA groups were higher (p < 0.05) by 13, 7 and 11, 6 folds than LA group. The liver β-carotene level in OA and EPA groups were higher (p < 0.05) by 3 and 1.2 folds than LA group. After repeated dose, the plasma β-carotene and retinyl palmitate levels in OA (6.2%, 51.7%) and EPA (25.4%, 17.23%) groups were higher (p < 0.05) than LA group. The liver β-carotene level in OA (21.2%) and EPA (17.6%) groups were higher (p < 0.05) than LA group. In both the experiments, the activity of β-carotene 15,15′-dioxygenase in the intestinal mucosa and plasma triglyceride levels were also higher in OA and EPA groups than LA group. β-Carotene excreted through urine and feces of OA and EPA groups was lower than the LA group. These results demonstrate an improved absorption and metabolism of β-carotene when fed mixed micelles with OA or EPA compared with LA. Although the mechanism involved in selective absorption of fatty acids needs further studies, intestinal β-carotene uptake and its conversion to vitamin A can be modulated using specific fatty acids.

Modulation of antioxidant enzyme activities, platelet aggregation and serum prostaglandins in rats fed spray-dried milk containing n-3 fatty acid.

Spray-dried milk enriched with n-3 fatty acids from linseed oil or fish oil were fed to rats to study its influence on liver lipid peroxides, hepatic antioxidant enzyme activities, serum prostaglandins and platelet aggregation. Significant level of α linolenic acid, eicosapentaenoic acid and docosahexaenoic acid were accumulated at the expense of arachidonic acid in the liver of rats fed n-3 fatty acid enriched formulation. The linseed oil and fish oil enriched formulation fed group had 44 and 112% higher level of lipid peroxides in liver homogenate compared to control rats fed groundnut oil enriched formulation. Catalase activity in liver homogenate was increased by 37 and 183% respectively in linseed oil and fish oil formulation fed rats. The glutathione peroxidase activity decreased to an extent of 25–36% and glutathione transferase activity increased to an extent of 34–39% in rats fed n-3 fatty acids enriched formulation. Feeding n-3 fatty acid enriched formulation significantly elevated the n-3 fatty acids in platelets and increased the lipid peroxide level to an extent of 4.2–4.5 fold compared to control. The serum thromboxane B2 level was decreased by 35 and 42% respectively in linseed oil and fish oil enriched formulation fed rats, whereas, 6-keto- prostaglandin F1α level was decreased by 17 and 23% respectively in linseed oil and fish oil enriched formulation fed rats. The extent and rate of platelet aggregation was decreased significantly in n-3 fatty acids enriched formulation fed rats. This indicated that n-3 fatty acids enriched formulation beneficially reduces platelet aggregation and also enhances the activities of hepatic antioxidant enzymes such as catalase and glutathione transferase. (Mol Cell Biochem xxx: 9–16, 2005)

Biodegradable Poly (Lactic‐co‐Glycolic Acid)–Polyethylene Glycol Nanocapsules: An Efficient Carrier for Improved Solubility, Bioavailability, and Anticancer Property of Lutein

Lutein bioavailability is limited because of its poor aqueous solubility. In this study, lutein-poly (lactic-co-glycolic acid) (PLGA)-polyethylene glycol (PEG) nanocapsules were prepared to improve the solubility, bioavailability, and anticancer property of lutein. The scanning electron microscopy and dynamic light scattering examination revealed that the nanocapsules are smooth and spherical with size ranging from 80 to 500 nm (mean = 200 nm). In vitro lutein release profile from nanocapsules showed controlled sustainable release (66%) up to 72 h. Aqueous solubility of lutein nanocapsules was much higher by 735-fold than the lutein. Fourier transform infrared spectroscopy analyses showed no chemical interaction among PLGA, PEG, and lutein, indicating possible weak intermolecular forces like hydrogen bonds. X-ray diffraction revealed lutein is distributed in a disordered amorphous state in nanocapsules. Postprandial plasma kinetics (area under the curve) of an oral dose of lutein from nanocapsules was higher by 5.4-fold compared with that of micellar lutein (control). The antiproliferative effect of lutein from nanocapsules (IC50 value, 10.9 μM) was higher (43.6%) than the lutein (IC50 value, 25 μM). Results suggest that PLGA-PEG nanocapsule is an efficient carrier for enhancing hydrophilicity, bioavailability, and anticancer property of lipophilic molecules such as lutein.

Supplementation and delivery of n-3 fatty acids through spray-dried milk reduce serum and liver lipids in rats.

Indian diets comprising staples such as cereals, millets, and pulses provide 4.8 energy % from linoleic acid (18∶2n−6) but fail to deliver adequate amounts of n−3 FA. Consumption of long-chain n−3 PUFA such as EPA (20∶5n−3) and DHA (22∶6n−3) is restricted to those who consume fish. The majority of the Indian population, however, are vegetarians needing additional dietary sources of n−3 PUFA. The present work was designed to use n−3 FA-enriched spray-dired milk powder to provide n−3 FA. Whole milk was supplemented with linseed oil to provide α-linolenic acid (LNA, 18∶3n−3), with fish oil to provide EPA and DHA, or with groundnut oil (GNO), which is devoid of n−3 PUFA, and then spray-dired. Male Wistar rats were fed the spray-dired milk formulations for 60 d. The rats given formulations containing n−3 FA showed significant increases (P<0.001) in the levels of LNA or EPA/DHA in the serum and in tissue as compared with those fed the GNO control formulation. Rats fed formulations containing n−3 FA had 30–35% lower levels of serum total cholesterol and 25–30% lower levels of serum TAG than control animals. Total cholesterol and TAG in the livers of rats fed the formulations containing n−3 FA were lower by 18–30% and 11–18%, respectively, compared with control animals. This study showed that spray-dried milk formulations supplemented with n−3 FA are an effective means of improving dietary n−3 FA intake, which may decrease the risk factors associated with cardiovascular disease.

Bioefficacy of EPA–DHA from lipids recovered from fish processing wastes through biotechnological approaches

The effect of fish oil recovered from fish visceral waste (FVW-FO) on serum and liver lipids, activity of HMG-CoA reductase in liver microsomes and EPA+DHA incorporation in liver, heart and brain were evaluated. Rats were fed different concentrations of FVW-FO providing 1.25%, 2.50%, 5.0% EPA+DHA recovered by either fermentation or enzymatic hydrolysis for 8weeks. Feeding FVW-FO reduce triacylglycerols (5.96-20.3%), total cholesterol (7.9-21.5%) and LDL (7.39-21.7%) cholesterol levels in serum compared to group fed on a control diet (groundnut oil). The activity of HMG-CoA reductase was reduced (p<0.05) in the FVW-FO fed groups compared to the control. EPA+DHA level in serum, liver, brain and heart increased with increments in dietary EPA+DHA. Results show the hypolipidemic property of FVW-FO and reduced HMG-CoA reductase activity which is proportional to the incorporation of EPA+DHA. Recovery of FVW-FO will address the increasing demand for fish oil and reduce pollution problems.

Enhanced cytotoxic and apoptosis inducing activity of lycopene oxidation products in different cancer cell lines.

Currently, upon understanding the metabolomics of carotenoids, it is important to address the key role of carotenoid derived products. In this regard, aim of the study was to elucidate and explore the role of lycopene (LYC) oxidative products generated through autoxidation (AOL) or chemical (KMnO4) oxidation (COL) against proliferation of selected cancer cells. Preliminary, we investigated the effect of LYC on cell viability of various cancer cell lines (PC-3, MCF-7, A431, HepG2, HeLa and A549). Based on the results of LYC treatment on cell cytotoxicity levels, MCF-7, PC-3 and HeLa cell lines were further tested with AOL and COL products. The decreased cell viability with depleted GSH and increased MDA levels were observed when treated with COL products than control, LYC and AOL. In addition, COL products increased ROS levels and percent apoptosis. The typical morphological changes and nuclear condensations showed that COL products have anti-proliferation and apoptosis inducing activity. Based on results, we hypothesized that ROS generation by LYC oxidation products may be one of intermediate step involved in apoptosis. The redox status and therapeutic approach of COL products in modulating ROS and induction of apoptosis in cancer cells were reported for the first time, to our knowledge. To conclude, COL products involves in cancer growth inhibition efficiently than intact LYC and AOL. Hence, there is a great potential for synthesizing or producing such carotenoid oxidation products to augment cancer complication.

Acute and Subacute Toxicity Assessment of Lutein in Lutein-Deficient Mice

Dietary lutein consumption is lower than the actual recommended allowances to prevent macular degeneration; thus dietary lutein supplements have been recommended. This study aimed to investigate potential adverse effect of lutein from Tagetes erecta in lutein-deficient (LD) male mice. Preliminary acute toxicity study revealed that the LD50 exceeded the highest dose of 10000 mg/kg BW. In a subacute study, male mice were gavaged with 0, 100, 1000 mg/kg BW/day for a period of 4 wk. Plasma lutein levels increased dose dependently (P < 0.01) after acute and subacute feeding of lutein in LD mice. Compared to the control (peanut oil without lutein) group, no treatment-related toxicologically significant effects of lutein were prominent in clinical observation, ophthalmic examinations, body, and organ weights. Further, no toxicologically significant findings were eminent in hematological, histopathological, and other clinical chemistry parameters. In the oral subacute toxicity study, the no-observed-adverse-effect level (NOAEL) for lutein in LD mice was determined as 1000 mg/kg/day, the highest dose tested.