Food & Function Blog

Scientists in Germany have investigated the effects of encapsulating polyphenolic grape seed extract in liposomes. Grape seed extract contains polyphenols which can reduce the extent of oxidative processes in organisms, and hence may be a beneficial food for chronic diseases such as cancer, diabetes mellitus and cardiovascular disease.

Phenolic compounds are, however, difficult to incorporate into food systems because they can strongly interact with other compounds and cause aggregation. By encapsulating the polyphenols they are protected and this may prevent them from being degraded during digestion, thereby enhancing their bioactivity and bioavailability.

In this work, coated liposomes containing grape seed extract were prepared by using chitosan and citrus pectin polymers.  The amount of polyphenols that reacted in the antioxidant test was decreased, suggesting that the polyphenols were no longer exposed to the aqueous phase. This indicates that polymer coated liposomes are highly capable carrier systems for polyphenol compounds.

This work was presented at the Delivery of Functionality in Complex Food Systems Symposium held in Guelph in August 2011, and is part of our themed issue on the Delivery of Functionality coming soon in 2012. To read the full article for free, please follow the link below:

Encapsulation of polyphenolic grape seed extract in polymer-coated liposomes, Monika Gibis, Effie Vogt and Jochen Weiss, Food Funct., 2012, DOI: 10.1039/c1fo10181a

Other articles from this conference have recently been published as Advance Articles in Food & Function. Click the following links to read Potential biological fate of ingested nanoemulsions: influence of particle characteristics and Fibrillar structures in food

Scientists in Taiwan and the US have investigated the effects of garcinol and pterostilbene on cell proliferation and adipogenesis in 3T3-L1 cells. Antiadipogenic compounds are important compounds for the control of obesity as they inhibit the formation of fatty tissues. By controlling obesity this can also mediate other health problems associated with the condition, such as type 2 diabetes, cardiovascular disease and cancer.

In this study, 3T3-L1 preadipocytes, 3T3-L1 differentiation- phase adipocytes, and mature 3T3-L1 adipocytes were used to investigate antiproliferation and adipogenesis in vitro. It was found that garcinol, a benzophenone found in mangosteen, and pterostilbene commonly found in grapes, wines and berries, both inhibit cell proliferation and adipogenesis in 3T3-L1 cells. Garcinol also significantly up-regulated the gene expression of adiponectin as well as down-regulated the gene expressions of leptin and fatty acid synthase. This suggests that garcinol and pterostilbene have anti-adipogenic effects on fat cells.

To read the free article in full, click the link below:

Inhibitory effects of garcinol and pterostilbene on cell proliferation and adipogenesis in 3T3-L1 cells, Chin-Lin Hsu, Yu-Jyun Lin, Chi-Tang Ho and Gow-Chin Yen, Food Funct., 2011, DOI: 10.1039/c1fo10209e

Scientists from the US have investigated the relationship between the Taq1 A1 allele and percentage of body fat in overweight and obese subjects. Although there are many environmental factors which can reduce body fat, such as long-duration exercise, aerobic exercise and diet, it has been proposed that genetics may play a significant role in compulsive eating disorders.

In this study 122 obese/overweight Caucasian subjects and 30 non-obese Caucasian controls were genotyped and split into two independent groups; those with the Taq1 A1 allele and those without the A1 allele. It was found that the DRD2 Taq1 A1 allele was present in 67% of the obese/overweight subjects compared to 3.3% of super control group. Therefore it is proposed that, while obesity is a polygenic disorder and there are other factors involved,  the DRD2 gene plays a significant role in obesity, as measured by percent body fat.

To read the article in full for free, click the link below.

Correlation of the Taq1 dopamine D2 receptor gene and percent body fat in obese and screened control subjects: A preliminary report, Amanda L. C. Chen, Kenneth Blum, Thomas J. H. Chen, John Giordano, B. William Downs, David Han, Debmalya Barh and Eric R. Braverman, Food Funct., 2011, DOI: 10.1039/c1fo10089k

Scientists from Ehime, Japan, have investigated the effects of (–)-secoisolariciresinol on obese rats. (–)-Secoisolariciresinol [(–)-SECO] is a pure stereoisomer of a lignan primarily found in flaxseed. It has previously been found to suppress triglyceride accumulation and therefore could be useful to decrease obesity by reducing fat accumulation.

In this study, male mice were fed a high fat diet for 28 days and different groups were administered with (–)-SECO at different concentrations. It was shown that oral administration of (–)-SECO stimulates adiponectin production in the mice and significantly suppressed weight gain in a dose dependant manner. When (–)-SECO is metabolised, it is converted into other compounds which were also tested by subcutaneous injections, however (–)-SECO still showed the highest activity amongst them.

Follow the link below to read the article for free:

(–)-Secoisolariciresinol attenuates high-fat diet-induced obesity in C57BL/6 mice, Shiori Tominaga, Kosuke Nishi, Sogo Nishimoto, Koichi Akiyama, Satoshi Yamauchiad and Takuya Sugahara, Food Funct., 2011, DOI: 10.1039/c1fo10166h

There is increasing evidence to show that dietary fatty acids play an important role in modulating hypertriglyceridemia in the postprandial state, which contributes to the pathogenesis of type 2 diabetes, atherosclerosis, coronary heart disease and stroke. In this review, by Francisco Muriana and colleagues, the potential of dietary monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), and saturated fatty acids (SFA) to postprandially affect metabolic abnormalities related to chronic diseases is discussed.

It is highlighted that consuming a high fat diet rich in SFA could increase the risk of developing chronic diseases such as obesity, diabetes, hypertension and cardiovascular disease. Consuming MUFA, primarily found in olive oil, leads to improved lipid tolerance and insulin action, whereas PUFA offers no additional benefits over MUFA.

To read the article in full for free, click the link below:

Dietary fatty acids linking postprandial metabolic response and chronic diseases, Almudena Ortega, Lourdes M. Varela, Beatriz Bermudez, Sergio Lopez, Rocio Abia and Francisco J. G. Muriana, Food Funct., 2011, DOI: 10.1039/c1fo10085h

Scientists in Australia have investigated the intestinal passage of fish oil using radio labelling to track free or microencapsulated fish oil . Fish oil is of great interest due to its many beneficial health effects, which have been attributed to its high level of long chain n-3 polyunsaturated fatty acids.  The bioavailability of oils depends on many factors including their state of emulsification and whether they are delivered in the presence of food.

In this work, Mary Ann Augustin and co-workers compare the oral delivery of free (oil-water mixture) or microencapsulated (oil-in-water emulsion formulation) fish oil to rats, which were then either fed or were not fed after dosing. This was to establish whether access to food after dosing affects the release of the oil. It was observed that feeding after administration of oils increases the rate of progress of oil through the lumen and that microencapsulation delays the lumenal progression of oil in fed rats. Delivery via microencapsulated oil also resulted in increase in the level of radiolabel in the liver and blood which is consistent with an increased bioavailability of microencapsulated oil.

To read the article in full for free, click the link below:

Intestinal passage of microencapsulated fish oil in rats following oral administration, Mary Ann Augustin, Glen Patten, Anthony De Luca, Mahinda Abeywardena, Trevor Lockett, Richard Head and Luz Sanguansri, Food Funct., 2011, DOI: 10.1039/c1fo10149h

Scientists in Israel have evaluated the literature surrounding oral food delivery systems. These delivery systems are used to protect foods enriched with bioactive ingredients as they pass through the gastrointestinal tract (GIT) and provide controlled targeted release of active compounds to the appropriate site.

In their review piece, Uri Lesmes and co-workers discuss carbohydrate-, protein- and lipid-based delivery systems and evaluate their benefits and limitations. It is highlighted that food grade delivery systems need to address the variety of physical and chemical processes of the human GIT by adopting a cutting edge pharmacological approach. Establishing structure–function relationships of food delivery systems and coping with the complexity of the digestive process are key factors for utilising the full potential of food delivery systems.

To view the full review article for free, please click below:

Development of oral food-grade delivery systems: Current knowledge and future challenges
Revital Cohen Benshitrit, Carmit Shani Levi, Sharon Levi, Eyal Shimoni and Uri Lesmes
Food Funct., 2011, DOI: 10.1039/c1fo10068h

Scientists in the US have looked into the mechanisms behind the protective effects of lowbush blueberries on cardiovascular disease. Lowbush blueberries have already been shown to inhibit the growth of atherosclerotic lesions in the aorta of mice, however, the mechanism of this action is not fully understood.

In their paper, Xianli Wu and co-workers from Arkansas, US, found that when blueberries were incorporated into the diet at 1% they were capable of inhibiting expression of scavenger receptors CD36 and SR-A in peritoneal macrophages of apoE deficient mice. This was proposed to be due to the down-regulation of PPAR-gamma receptor and a reduction in its endogenous ligands. CD36 and SR-A scavenger receptors have been shown to play a significant role in the development of atherosclerosis.

To read the article in full for free, click the link below:

Lowbush blueberries inhibit scavenger receptors CD36 and SR-A expression and attenuate foam cell formation in ApoE-deficient mice, Chenghui Xie, Jie Kang, Jin-Ran Chen, Oxana P. Lazarenko, Matthew E. Ferguson, Thomas M. Badger, Shanmugam Nagarajanad and Xianli Wu, Food Funct., 2011, DOI: 10.1039/c1fo10136f

Cruciferous vegetables such as broccoli, cabbage and cauliflower have been associated with a decreased risk of gastrointestinal, lung and prostate cancers. In their recent review article, Johanna Lampe and colleagues from the US provide an update on the proposed mechanisms of action behind this observed cancer chemoprevention.

Vegetables from the Brassicaceae family (such as cabbage and Brussels sprouts) contain significant amounts of sulfur-containing glucosinolates which are converted to bioactive compounds such as indoles and isothiocyanates during digestion. It is these compounds which are thought to be responsible for the increased chemoprotective effects observed by cruciferous vegetable consumption compared to other fruits and vegetables.  It is concluded that a systems biology approach may help our understanding of these compounds because such a wide variety of isothiocyanates are produced from glucosinolates and there are many diverse pathways on which they act.

To read the full article for free, click the link below:

Mechanisms of action of isothiocyanates in cancer chemoprevention: an update, Sandi Navarro, Fei Li and Johanna Lampe, Food Funct., 2011, DOI: 10.1039/c1fo10114e